Home

Electronic load combination using the NOVA

1. Figure 78 FRA2 10 V input range labels 77 Autolab LED Driver User Manual RUES 435 Route 206 P O Box 366 Newton NJ 07860 0366 L Metrohm Autolab s v Appendix 2 Calibrated Photodiode Ph 973 579 7227 FAX 973 300 3600 FDS100 Si Photodiode High Speed Large Active Area The FDS100 is a high speed silicon photodiode with a spectral response from 350nm to over 1100nm This photodiode has a PIN structure that provides fast rise and fall times with a bias of 20V Electrical Characteristics Spectral Response 350 1100nm Active Area 13 0mm Rise Time RL 50Q 1Ons 20V bias Fall Time RL 509 10ns 20V bias NEP 900nm 1 2 x 107 W VHz 20V bias Dark Current 20nA max 20V Package 105 0 30 can Maximum Ratings Damage Threshold CW 100 mW cm Damage 10ns Pulse 500mJ cm7 Max Bias Voltage 25V a m en 23 14 Pin Description 20 36 1 Detector anode 2 Detector case 3 Detector cathode re The Thorlabs FDS100 photodiode is ideal for measuring both pulsed and CW light sources by converting the optical power to an electrical current The Si detector is housed in a T05 can with an anode cathode and case connection The photodiode anode produces a current which is a function of the incident light power and the wavelength The responsivity R can be read from Figure 1 to estimate the amount of photocurrent to expect This can be converted to a voltage by placing a load resistor
2. The light intensity of the LED array is controlled by setting the driving current passing through the LED power plug on the right hand side This driving current is defined by setting the DAC164 1 output to a value between 0 and 10 V This voltage value is converted by the LED driver to a constant current using the following relationship lRange 1000 mA liep gt Vpac1es a Voacies 100 mA V Vpaci64 Vrange 10 V Where ij rp is the output driving current in MA irange iS the current range of the LED driver 1000 mA by default Vrange is the input range of the LED driver 10 V and Vpacie4 IS the output value of the DAC164 1 in V Using the factory default values setting the Vpjcig4 to 1 V will result in a driving current iep Of 100 mA Setting the Vpacie4 to O V switches the light off and setting the Vpac164 to 10 V will generate the maximum light intensity A Warning Do not use DAC164 2 to control the light intensity The channel is internally connected to the PGSTAT and is not suitable for this application A Warning Do not look directly into the light generated by the LED array 4 3 2 Connections for modulated illumination measurements To modulate the light intensity the gt FRA V input is now connected to the front panel output of the FRA module The sinewave generated by the FRA module is used to modulate the output of the LED Driver using a sinewave current superimposed on the DC drivin
3. 100 mA V WVpaciea Vrrav Where izzp is the output driving current in MA irange is the current range of the LED driver 1000 mA by default Vrange is the input range of the LED driver 10 V Voacies IS the output value of the DAC164 1 in V and Vera y is the output value of the FRA V in V A Warning The Vpac g4 Value must always be larger than Vrray so that the Vpacie4 Veray difference is always positive When this difference is negative the net output driving current iep is O mA regardless of the values of Vpyjcig4 and Vrra v Autolab LED Driver User Manual L Metrohm The output driving current iep is given by the difference between the constant current ipc and the modulated current ic Using the factory default values setting the Vpac164 to 1 V and the Vep y to 0 1 V will result in a DC driving current ipc of 100 mA modulated by an AC current igc of 10 mA Setting the Vpacig4 Vergy to O V switches the light off and setting the Vpaciea Vergy to 10 V will generate the maximum light intensity A Warning Do not use DAC164 2 to control the light intensity The channel is internally connected to the PGSTAT and is not suitable for this application A Warning Do not look directly into the light generated by the LED array 4 3 3 Optional connections Additionally a number of connections are available on the left and right hand side of the driver These connections are not mandatory but
4. Measurements at modulated light illumination these measurements are performed with the LED driver set to a fixed user defined light intensity with an additional low amplitude intensity modulation For these measurements the DAC 1 and FRA V inputs are both connected to the Autolab while the Eou lou and DIO inputs can be connected to the Autolab if necessary see Section 4 3 2 for more information 17 Page Autolab LED Driver User Manual L Metrohm Autolab s v 4 3 1 Connections for constant illumination measurements Figure 12 shows the overview of the connections to the LED driver required to set the light intensity to a constant non modulated value maje ED hold gt pac DyN v gt neten gt DIO FRAY gt E el gt Eout FRA X gt Ci 5 gt iout LED DRIVER Figure 12 Overview of the connections for constant illumination experiments The FRA V input must be shorted when not in use with the provided 50 Ohm termination plug see Figure 13 Figure 13 A 50 ohm terminator plug must be used to short the gt FRA V input when this input is not used Make sure that the 50 Ohm plug is connected to the gt FRA V input at all times 18 Page Metrohm Autolab LED Driver User Manual If a FRA2 or FRA32M module is present it is possible to replace the 50 Ohm terminator plug by a BNC or SMB cable from the V connector on the front panel of the FRA module and the gt FRA V input
5. dm 0 125 1 10 1 0 100000 0 01 es W single sine External 0 125 10 0 1 Options High stability lt array gt Hz array gt arro arrow lt aray gt lt array gt s aray gt Cv aray Cv L Metrohm Autolab s v Links Figure 54 The FRA measurement external command is used during the IMVS frequency scan Before the measurement can be performed properly the parameters for the transfer function must be set in the FRA Sampler Click the L button located next to the FRA sampler parameter of the FRA signal frequency command see Figure 54 The parameters for the transfer function are defined in the Channel X and Channel Y of the FRA sampler window see Figure 55 58 Page L Metrohm Autolab LED Driver User Manual FRA Sampler Input amplitude Channel W Multiplier Sample time domain Channel C Sample frequency domain C Multiplier Transfer function Re jm C Retjlm xy Yx Channel Phase Sample time domain Channel Peal Sample frequency domain LC Multiplier Imaginary sample DC Figure 55 The transfer function parameters are specified in the FRA sampler Channel X and Channel Y Note Pin 1 located on DIO port A is used to control the switch In Figure 54 the parameters for the Input amplitude have already been set according to the instructions indicated in
6. 0 V using the Auto ab control command e Low 00000000 0 when pin 1 is set to low status 0 V the gt E out input is active This is also the default status when nothing is connected to the gt DIO input of the LED Driver e High 00000001 1 when pin 1 is set to high 5 V the gt i out input is active The switch will be kept in this position as long as pin 1 is set to high The status of pin 1 of the initialized port can be changed at any time using the Autolab control window The status can be set as a decimal value O or 1 or as a binary string 00000000 or 00000001 The status defined is permanent until changed see Figure 37 Autolab control DICHT F A Direction Unchanged set P1 A Write 1 F1 B Direction Unchanged FTD Write Unchanged Fl CLower Direction Unchanged Fi CLower Write Unchanged Flipper Direction Unchanged Fi CUpper Write Unchanged F2 4 Direction Unchanged Fetal Write Unchanged eiB Direction Unchanged i Fe B Write Unchanged eiCLower Direction Unchanged FeiCLower Write Unchanged FeiCipper Direction Unchanged FeiCipper Write Unchanged Figure 37 Setting the status of pin 1 For the PGSTAT101 or M101 module the same settings are used However in this case only a single port is available see Figure 38 Port A of the DIO connector of the PGSTAT101 or M101 does not have to be initialized since it is hardwired to o
7. Driving current to light intensity conversion curve measured at 590 nm Amber To use the photodiode connect the RE CE leads from the PGSTAT to the CE plug on the photodiode holder and connect the WE S to the WE plug on the photodiode holder Connect the green ground plug embedded in the cell cables of the Autolab to the matching GND banana connector of the photodiode holder The photodiode current must be measured at short circuit conditions 0 V applied and at known wavelength 7 Cell holder The calibrated photodiode holder is fitted with two sliding clamps that can be used to fix the cell onto the holder provided that the cell is small enough to fit in this space This holder is designed for a common form factor for experimental solar cells like the one shown in Figure 42 46 2 Metrohm Autolab LED Driver User Manual Autolab s v Figure 43 Typical experimental cell design suitable for the Autolab LED Driver kit The clamps can be repositioned if necessary by loosening the two screws that hold them in place see Figure 44 If the cell does not fit between the two clamps an external holder can be used to place the cell close to the photodiode Metrohm Autolab cannot anticipate all the possible cell configurations and it is left to the user to find a suitable solution if necessary 47 Page Autolab LED Driver User Manual L Metrohm Autolab s v Figure 44 The cell can be mounted onto the photodiode h
8. Only qualified personnel can perform this modification Please contact Metrohm Autolab B V info metrohm autolab com or your local distributor for more information This modification is not applicable for the uAutolablll FRA2 The FRA2 input range is directly specified in the Hardware setup Start NOVA and open the Hardware setup Tools Hardware setup Locate the FRA2 offset DAC range toggle at the bottom of the Hardware setup window see Figure 77 Hardware setup AUT 84148 File Tools Main Module Additional Maduleis PGSTATSO2N I FRA32M L PGSTAT302F M FRAZ PGSTAT302 PLgsDc10M C PGSTAT30 ADC 50 PGSTAT128N ADC 50r4 ET PGSTAT12 IScAN250 PGSTATIOON SCANGEN C PGSTAT100 m FIBA 4 01 L BIPFOT ARRAY TJECD vAutolab Il _ FI20 Filter tolab Il 5 C FI20 Integrator E FGSTAT1O L Booster204 L Boosteri DA Power Supply Frequency By C Program Data Metrohm Autolab 10 0 HarcdwareSetl Uv LS 18m Figure 77 The 10 V input range can be specified in the Hardware setup directly 76 Page L Metrohm Autolab LED Driver User Manual Set this toggle to 10 V as shown in Figure 77 Click OK to close the Hardware setup and save the modifications when prompted This modification is permanent If necessary new labels article codes CAB LABEL FRA2 V10 V and CAB LABEL FRA2 V10 XY can be ordered for the modified FRA2 module see Figure 78 gt X N lt an ire Y
9. 01 6 06E 01 6 13E 01 6 19E 01 6 25E 01 6 33E 01 6 36E 01 6 36E 01 6 31E 01 6 22E 01 6 04E 01 5 73E 01 5 28E 01 4 68E 01 3 99E 01 3 23E 01 2 59E 01 2 12E 01 1 42E 01 1 52E 01 1 62E 01 1 72E 01 1 82E 01 1 93E 01 2 03E 01 2 14E 01 2 25E 01 2 35E 01 2 46E 01 2 58E 01 2 68E 01 2 79E 01 2 91E 01 3 02E 01 3 13E 01 3 24E 01 3 35E 01 3 47E 01 3 57E 01 3 70E 01 3 81E 01 3 92E 01 4 03E 01 4 14E 01 Figure 41 Calibration data provided on the calibration certificate The calibration certificate provides a table of wavelengths A in nm and responsivity n in AW The responsivity values are reported in absolute values and should be normalized with respect to the active surface area of the photodiode 13 mm Using this strategy it is relatively easy to establish a driving current to light intensity correlation as shown in Figure 42 The data shown in this plot was obtained at a distance of 20 cm using a 590 nm LED cover Amber The light intensity P gp is calculated from the measured photodiode current Ls divided by the surface of the photodiode 0 13 cm and divided by the responsivity reported in the calibration certificate see Figure 41 p P p _ tsc tse LED A y 0 13 cm 0 279 A W 45 Page Autolab LED Driver User Manual 2 Metrohm 0 007 0 006 0 005 0 004 0 003 Wa Light intensity WAC 0 001 100 200 300 400 500 BOO FOO Driving current m Figure 42
10. OCP determination e set reference potential e Interrupt measurement e Interrupt measurement high speed Set BIPOT ARRAY potential e set pH measurement temperature Reset EOCM AFrequency Control Autolab RDE Switch Autolab RDE off Control external device DAC Timed procedure Control external device through the available DAC Z Create new drop e Determine integrator drift e Muli 4utolab software synchronization Muli 4utolab hardware synchronization Set ECD current offset Figure 24 The Control external device DAC command is used to set the DC light intensity The Control external device DAC command is a Timed command and as such must always be included in a 7imed procedure This command has the following parameters Parameter Description Set value The converted value required to control the external device the value corresponds to offset DAC voltage slope DAC channel The DAC channel used to control the external device DAC 3 corresponding to DAC 1 on the front panel should always be used Conversion offset Defines the offset for the value conversion Conversion slope Defines the slope for the value conversion For Autolab LED driver the conversion offset should be set to O and the conversion slope should be set to 10 V 1000 mA if the value should be defined in mA or to 10 V 1 A if the value should be defined in A see Figure 25 Autolab LED Driver User Manual El Timed
11. Section 5 1 2 For IMVS measurements the following settings are required see Figure 56 e Channel X this input is used to measure the AC cell potential during the frequency scan This input corresponds to the Eot coming from the Autolab which corresponds to the inverted cell potential Eour This input is therefore specified in V and requires a multiplier of 1 e Channel Y this input is used to the measure the AC LED Driver current during the frequency scan The FRA Y gt output of the LED Driver is connected to this input The values from this connection are expressed in V corresponding to the converted current The conversion factor is 1 V A This signal is therefore specified in A and requires a multiplier of 1 59 Autolab LED Driver User Manual L Metrohm FRA Sampler Input amplitude Channel V Multiplier L Sample time domain E DUT C Sample frequency domain Transfer function 7 Kdultiplier Rejim Retjlm Or O YX Channel r Phase L Sample time domain LED Current Real Sample frequency domain Imaginary W Multiplier sample DC Cancel Figure 56 Setting the parameters for the FRA sampler Using the FRA sampler window it is possible to specify if the time domain information corresponding to the raw sinewaves recorded by the FRA module have to be sampled during the measurement It is recommended to check both checkboxes for IMVS measurements in
12. V Vpaciea Where izzp is the output driving current in MA irange is the current range of the LED driver 1000 mA by default Vrange is the input range of the LED driver 10 V Vpac g4 Is the output value of the DAC164 1 in V and Verg y is the output value of the FRA V in V Using the factory default values setting the Vpac164 to 1 V and the Vera y to 0 1 V will result in a DC driving current inc of 100 mA modulated by an AC current isc of 10 mA Setting the Vpaciea4 Vergy to O V switches the light off and setting the Vpacig4 Vergy to 10 V will generate the maximum light intensity A Note When the input voltage is 90 mV or less the current output will be switched off and the output current will be O mA The minimum current is therefore limited to 9 mA 5 1 1 Settings for the DAC 1 input The DAC 1 input of the LED driver controls the DC light intensity This setting is defined in the software through the Control external device DAC command available from the Measurement general group of commands see Figure 24 The Control external device DAC command is an Advanced command Adjust the Profile in NOVA if necessary 30 L Metrohm Autolab LED Driver User Manual Commands Procedures m Favorite commands E Control H Metrohm devices Measurement general Timed procedure Autolab control Set potential Set current Set cell Wait time 3 Optimize current range
13. Wave type Integration time s Minimum number of cycles to integrate Number of frequencies Estimated duration El FRA single frequency Input frequency Hz Input amplitude Amplitude in RMS Amplitude unit Input wave type Input connection Integration time s Minimum number of cycles to integrate Number of cycles ta reach steady state Maximum time to reach steady state s with a minimum fraction of a cycle FRA sampler Options Lowest bandwidth Frequency H H H Phase Time Channel DC Y Channel DC lt gt Build signal Mhyauist 2 ys 2 H Bode modulus H Bode phase lt gt lt gt array gt Hz Meli Array gt Array arraw r arraty gt 3 array AA A A A A A 100000 0 01 Yes K single sine Oakes 1 AO Am ee A 100000 0 01 Yes K single sine External 0 125 10 1 0 Mo Options High stability lt array Hz Array Array Array gt aray gt I Array gt 3 array W aray gt ev Figure 30 The commands and parameters of the FRA measurement external command The settings for controlling the light source modulation are defined in the FRA sampler To edit these settings click the button located next to the FRA sampler in the FRA single frequency command see Figure 31 36 Page L Metrohm Autolab LED Driver User Manual Autolab s v El FRA single frequency ea Input frequency Hz 100000 Input am
14. measurements but is recommended because it facilitates the wiring schemes 4 4 Autolab connections to analog outputs The Autolab LED Driver provides two analog outputs labelled DYN V gt and FRA Y gt respectively on the right hand side of the driver These two outputs can be connected to the external inputs of the Autolab Depending on the output the following values are provided e DYN V gt this output provides the potential difference between the gt DAC 1 input and the gt FRA V input of the LED Driver in volts The output range is between O V and 10 V e FRA Y gt this output provides the value of the driving current passing through the LEDs converted to voltage by a current to voltage converter The current follower used in this circuit has a single current range of 1 A with a 1 V A conversion The output range is between O0 V and 1 V Figure 22 shows the values recorded on the DYN V gt plug in function of the specified driving current A linear relationship is observed between the two values and the measured slope corresponds to 0 01 V mA 27 Autolab LED Driver User Manual L Metrohm DYN WY gt output v4 100 200 300 400 S00 BOO FOO specified driving current mA Figure 22 Output value of the DYN V gt plug plotted against the specified driving current Figure 23 shows the values recorded on the FRA Y gt plug in function of the specified driving current A linear relationship is
15. procedure Control external device DAC L Metrohm Autolab s v zet value 100 linit m DAC channel J Conversion offset 0 Conversion slope 0 01 DAC voltage 4 1 0000 lt gt lt gt El Timed procedure Control external device DAC cet value nit A DAC channel J Lonversion offset 0 Conversion slope 10 DAL voltage t 1 0000 gt gt Figure 25 The settings required for the Control external device DAC command Top defined in mA Bottom defined in A For bookkeeping purposes it is convenient to rename the command and to indicate which units are used to set the light intensity In the rest of this document the V to mA conversion will be assumed see Figure 26 El Timed procedure Control LED Driver mA TC SSS Set value 100 Unit Mm DAC channel 3 Conversion offset 0 Conversion slope 0 01 DAC voltage 4 1 0000 lt gt Figure 26 Renaming the command note the units Furthermore it is recommended to save the modified command in the My commands database by right clicking the command and choosing the Save in My commands option see Figure 27 32 Page 2 Metrohm Autolab LED Driver User Manual Autolab s v El Timed procedure Control LED Driver mA Enabled zet value 100 Unit mA DAC channel 3 X Conversion offset 0 Conversion slope 0 01 DAC voltage w 1 0000 lt gt Name Control LED Drive
16. 01 10 HA 10 pA V 0 00001 1 HA 1 pA V 0 000001 100 nA 100 nA V 0 0000001 10 nA 10 nA V 0 00000001 Table 2 Multiplier factors per current range e Channel Y this input is used to the measure the AC LED Driver current during the frequency scan The FRA Y gt output of the LED Driver is connected to this input The values from this connection are expressed in V corresponding to the converted current The conversion factor is 1 V A This signal is therefore specified in A and requires a multiplier of 1 FRA Sampler Input amplitude W Multiplier Channel gt E sample time domain DT Sample frequency domain Transter function IM Multiolier 0 001 Re jlm A i Retjlm xr UE Channel Phase L Sample time domain Led Current Sey Sample frequency domain W Multiplier 1 Imaginary Sample DC w Cancel Figure 65 Setting the parameters for the FRA sampler Using the FRA sampler window it is possible to specify if the time domain information corresponding to the raw sinewaves recorded by the FRA module have to be sampled during the measurement It is recommended to check both checkboxes for IMPS measurements in order to verify the quality of the data during the experiments see Figure 65 68 L Metrohm Autolab s v FRA Sampler Input amplitude Multiolier Transter function Beim Retjm vx Phase Real Imaginary sample DC Autolab LED Driver User M
17. 25 mV O00 Nyquist plot E 1 35 MGM Nyquist plot E 1 505 mem N quist plot E 1 576 mem Todd Nyquist plot E 1 667 mW cme S000 GOOD S000 4000 S000 0 2000 1000 1000 2000 2000 4000 0 2000 4000 GOOD S000 10004 12000 Zi Figure 51 Typical Nyquist plots recorded at different light intensities 8 4 AC measurements at modulated illumination While it is possible to modulate the current or the potential in a classic electrochemical impedance spectroscopy measurement as explained in Section 8 3 1 it is also possible to modulate the light intensity directly Two measurement possibilities exist e Intensity modulated photovoltage spectroscopy IMVS e Intensity modulated photocurrent spectroscopy IMPS 8 4 1 Intensity modulated photovoltage spectroscopy IMVS The LED Driver can be used in combination with the PGSTAT FRA interface to record intensity modulated photovoltage spectroscopy measurements on the device under test DUT During an intensity modulated photovoltage spectroscopy IMVS measurement the DUT is exposed to a constant light intensity po modulated by a small 55 Autolab LED Driver User Manual N Metrohm A sakiai sla nu AITAIARN R V AUIOUIUU DV FAIViViVUl De Vo amplitude AC perturbation Ap The DUT settles at a constant voltage Vo modulated by a small amplitude AC response AV The IMVS impedance is the transfer function H between the AC volta
18. Figure 50 shows a possible procedure that can be used to perform EIS measurements on the DUT Commands Parameters Links FRA impedance potentiastatic Remarks ml End status Autolak ml oignal sampler Time WWE Current m Options 1 Options EEF Instrument Instrument description E Timed procedure Autolab contral Er Control LED Oriver mA Wait time s 5 OCF determination 0 000 fa set potential 0 000 Set cell Cn zl ait time 3 5 lt gt E FRA measurement potentiostatic Frequency Phase Time E 7 7 Index FRA frequency scan Build signal hhyquist 2 ws 2 Bode modulus Bode phase lt gt E Timed procedure Control LED Driver mA 0 Set cell Cit El lt gt lt gt ele H H array Hz aray gt 1 Array 8 array gt 02 arras gt 02 Array gt 01 Arraw gt hi e e e e e Figure 50 The FRA impedance potentiostatic procedure modified using the Control external device DAC command Note The Control external device DAC command is renamed to Control LED Driver mA in this example see Section 5 1 1 Typical electrochemical impedance spectroscopy measured at different light intensities are illustrated in Figure 51 As the illumination level increases the Nyquist plot indicates a lower total resistance 54 Page Metrohm Autolab LED Driver User Manual The data shown in Figure 51 has been recorded at 590 nm at open circuit potential using an amplitude of
19. LED Driver User manual Metrohm Autolab s v Please read this manual carefully before starting to use the Autolab LED Driver kit The next sections deal with appearance and use of the equipment and contain necessary information regarding operation and installation SAFETY PRACTICES General The following safety practices are intended to ensure safe operation of the equipment and must be observed during all phases of operation service and repair of the instrument Failure to follow these instructions may cause unsafe operation Metrohm Autolab is not liable for any damage caused by not complying with the safety requirements Failure to follow these instructions may void any warranty provided to this product Electrical hazards To avoid electric shock hazard always ground the equipment by using the provided power adaptor There are no user serviceable parts Equipment installation component replacement and internal adjustments must be done only by qualified personnel Opening the equipment poses a risk of exposure to potentially dangerous voltages Please also refer to the Electrical Hazards described separately for the Autolab instrument used General precautions Use only stable surfaces for setting up the system Do not look directly at the light coming out of the light source Allow the light source to cool down after prolonged used at high driving currents Autolab LED Driver User Manual L Me
20. LED Driver User Manual Metrohm The following basic connections are located on the right hand side LED power this connector is used to provide current to the LEDs through a dedicated cable This cable is used to interface the driver and the holder described in Section 4 2 Even output DYN V gt this output provides a voltage 0 10 V corresponding to the difference between the value provided to the DAC1 input and the value provided to the FRA V input on the left hand side of the driver liep Output FRA Y gt this output provides a voltage 0 1 V proportional to the LED current The output value in mV corresponds to the driving current in mA 1000 mV gt 1000 mA driving current For IMPS and IMVS measurements this output is fed into the FRA Y input 18 V input this input is used to supply power the LED driver The driver is powered when the power status LED located next to this input is lit 4 1 2 Optional connections Figure 6 shows an overview of the optional connections to and from the LED driver the basic connections are grayed out All the connectors located on the left hand side of the driver are input connections from the Autolab PGSTAT to the LED driver The BNC connectors located on the right hand side of the driver are the output connections to the Autolab PGSTAT lt r a gt FRA V AUTOLAB SA cD gt DAC1 DYNV gt DIO input gt DIO FRAY gt eon APH gt Eout FRAX gt l
21. Optimize current range 5 LE staircase O 000 1 000 0 0200000 set cell Of zel lt gt x x Figure 49 Using the Repeat for each value command in combination with the Control external device DAC command 8 3 AC measurements at constant illumination The LED Driver can be used in combination with the PGSTAT FRA to obtain the electrochemical impedance spectrum of the device under test DUT under constant illumination Electrochemical impedance measurements can be performed while illuminating the cell potentiostatically or galvanostatically Typically these measurements are performed at open circuit or at short circuit The measurement strategy is the same as for a DC measurement at constant illumination The light intensity is set to a fixed value using the Control external device DAC command 3 Warning When performing AC measurements at constant illumination the L of the LED Driver must be shorted using the supplied 50 Ohm terminator plug as explained in Section 4 3 1 53 Page Autolab LED Driver User Manual L Metrohm J i A arkal ea L A As ANTON ID R V MUVI D V 8 3 1 EIS measurements at constant illumination The standard Autolab procedure FRA impedance potentiostatic and FRA impedance galvanostatic procedures can be used to perform EIS measurements at constant illumination The Control external device DAC command can be added to the preconditioning stage in either one of the procedures
22. Roan from the photodiode anode to the circuit ground The output voltage is derived as Vo P R A Rr oap The bandwidth fgw and the rise time response tp are determined from the diode capacitance Cj and the load resistance Rioap as shown below Placing a bias voltage from the photo diode cathode to the circuit ground can lower the photo diode capacitance few 1 27 Rroap MC t 0 35 fpyw 0637 S01 Rev E 6 19 06 78 Page 2 Metrohm Autolab LED Driver User Manual Autolab s v Typical Circuit Diagram Noise Filter Typical Values FDS100 Typical Plots Figure 1 FDS100 Spectral Responsivity Curve 0 7 0 6 0 5 04 0 3 Responsivity A W 0 2 0 1 300 400 500 600 700 800 900 1000 1100 Wavelength nm Typical Responsivity Curve using Thorlabs calibration services 0637 S01 Rev E 6 19 06 79 Page Autolab LED Driver User Manual L Metrohm Appendix 3 Hardware specifications The specifications of the Autolab LED Driver kit are listed in Table 3 80 Power supply 18 V 1 2 A Maximum current 1000 mA Maximum LED current 700 mA Input voltage range 90 mV 10 V Output voltage range O mV 1000 mV Maximum modulation amplitude 5 V TOP Maximum modulation frequency 20 kHz Operating temperature 0 40 C Table 3 Specifications of the Autolab LED Driver 81 Page 07 2012 Kanaalweg 29 G 3526 KM Utrecht The Netherlands L Metrohm
23. To define the end conditions for the Autolab LED Driver kit and the cell the End status Autolab settings can be defined in the procedure editor The End status Autolab can be defined by clicking the button next to this parameter in the procedure editor see Figure 70 Commands Farameters Links hf curve Remarks ml End status Autolab es oignal sampler Time WEI Current ds Options Mo Options EEF Instrument Instrument description Figure 70 Editing the End status Autolab 71 Page Autolab LED Driver User Manual Metrohm The Autolab control editor will be displayed see Figure 71 Using the drop down boxes the required adjustments can be defined Autolab control Cell Unchanged Current range Unchanged Bandwidth Unchanged Mode Unchanged IR Compensation Unchanged IR Compensation value Unchanged FRA input Unchanged External input Unchanged Oscillation protection Unchanged Reference potential Unchanged Offset Value Unchanged Figure 71 The End status Autolab is defined using the Autolab control window The following settings can be relevant for this application Cell off to switch the cell off set the Cell drop down list on the WE 1 tab of the Autolab control window to Off see Figure 72 L Metrohm Autolab LED Driver User Manual Autolab s v C Cell Unchanged Cell On Mode Unchanged IR Compensation Unchanged IR Compensation value Unchanged FRA input Un
24. ange Integration time calculation First applied frequency 100000 Integration time maximum Last applied frequency 0 1 Integration cycles minimum Number of frequencies Frequency step Wave type Significant digits Linear Single sine Amplitude Logarithmic 5 sines Amplitude Square root 15 sines W RMS mm Frequency Hz Amplitude mA Wave type Integration time Minimum number of cycles to intearate to _____ Sngesme 0 125 VO es ho gngdesnelsjois bh alse lo fmen elos amna jo fsnaesinedalons hooo E A a ozs bh elza ho gngdesnelsjors hooo A a a ozs bh aliaaas lin a o O Figure 68 The FRA frequency scan editor window Once the frequency range is defined the measurement can be performed Figure 69 shows a typical IMPS measurement on a DSC The measurement is performed at 590 nm at a constant light intensity of 1 7 mW cm The AC amplitude is 10 of the DC light intensity 70 Page i Metrohm Autolab LED Driver User Manual O22 Oe 0 18 0 16 0 14 OL 0 4 0 08 T 0 06 0 04 002 U2 0 04 U 06 U 08 0 1 0 0 05 0 1 0 15 Oe 0 25 Oo Figure 69 A typical IMPS measurement on a DSC 8 5 Safety settings when measurement is aborted When measurements are manually interrupted by clicking the Stop button or when a cutoff condition is met that stops the complete procedure it may be necessary to completely switch off the light source and the cell
25. anual Channel 2 Sample time domain _ iDUT C Sample frequency domain Multiolier 0 001 Channel r Sample time domain Led Current C Sample frequency domain Multiolier 1 Cancel Figure 66 Sampling the time domain data for Channel X and Channel Y Close the FRA sampler with the button The frequency scan can now be defined in the procedure editor by clicking the l button next to the FRA frequency scan command see Figure 67 El FRA measurement external Frequency H H H Fhase Time Index FRA frequency scan Frequency Amplitude Amplitude in RMS Amplitude unit Wave type Integration time s Minimum number of cycles to integrate Number of frequencies Estimated duration FRA single frequency lt gt Build signal hhyquist 2 vs 2 Bode modulus Bode phase lt gt E E E lt array gt Hz array gt lt array gt lt array gt aray gt lt array gt s lt array gt o 100000 0 01 es m single sine kes BO Am OL eeN A Figure 67 Opening the FRA frequency scan editor The FRA frequency scan window will be displayed The highest frequency lowest frequency number of frequencies and frequency distribution can be defined in this editor see Figure 68 The amplitude can also be defined in mA or in A depending on the settings used in the FRA sampler 69 Page L Metrohm Autolab LED Driver User Manual Autolab s v Frequency r
26. applied frequency Integration cycles minimum Number of frequencies Frequency step Wave type Significant digits ica Bn Single sine Amplitude Logarithmic 5 sines Amplitude l mA Square root 15 sines Frequency Hz Amplitude mA Wave type Integration time Minimum number of cycles to integrate we 0 125 Se ek ek ek ok ok mk OO ml ian Ea IN T Figure 35 The FRA frequency scan editor window The units of the amplitude are indicated in the FRA frequency editor window In this example the conversion factor defined in Figure 33 specified that the units of the amplitude are mA The maximum amplitude i MAX that can be specified is 350 mA RMS or 500 mA TOP However for the default LED covers supplied by Metrohm Autolab the total driving current cannot exceed the maximum limit of 700 mA The applied amplitude must also be larger than the DC driving current at all time 0 mA lt leatai lnc iic TOP lt 700 mA 5 1 3 Settings for the DIO control The gt DIO BNC connector can be used to switch remotely between the gt E out or gt i out inputs on the LED Driver using the DIO port s provided by the Autolab as explained in Section 4 3 3 40 Page Metrohm Autolab LED Driver User Manual Autolab B To control the DIO of the Autolab the Auto ab control command must be used to initia
27. available see Figure 20 This cable can be connected to the DIO port of the instrument or module The female BNC connector can be connected to the gt DIO connector on the LED Driver using the supplied 2 m long BNC cable 25 Page L Metrohm Autolab LED Driver User Manual Autolab s v 00000000 O ecooese O Figure 20 DIO cable for the Autolab PGSTAT101 M101 By setting the DIO input to high or low the switch located in the driver can be toggled remotely The status LEDs located on the left hand side of the driver will indicate the selected input see Figure 21 DIO input down off E ut Input E gt Eout O lout input out INP Hj sio o out output LED DRIVER T DIO input up Et Input let nput Et OULDUL Figure 21 The iout Eout switch can be set remotely through the DIO input top DIO status UP or disconnected iout selected bottom DIO status DOWN E u selected 4 Please refer to the External devices tutorial available from the Help menu in NOVA for more information on the control of the DIO port s of the Autolab 26 Page LL Metrohm Autolab LED Driver User Manual By default when no connection to the DIO is present the tou is always selected indicated by the status LED on the left hand side The switch can also be toggled through an analog voltage Supplying more than 2 5 V on this DIO input triggers the switch Using the built in Eou iout switch is not mandatory for IMVS IMPS
28. can be used to facilitate the measurement of experimental values used in IMPS and IMVS measurement Figure 16 shows the overview of the optional connections between the Autolab and the LED driver The connections shown in Figure 16 are complementary to the connections shown in Figure 16 shown in grey in Figure 16 22 2 Metrohm Autolab LED Driver User Manual O000000000000 O eeeccoesseee OJ Dio Autolab s v iout Eout LED holder gt DAC 1 DYNV gt m B gt DIO FRA Y gt gt Eout FRAX gt mi gt iout LED DRIVER Figure 16 Overview of the optional black connections for modulated light intensity experiments The black connections shown in Figure 16 are optional and are provided for convenience sake These connections are required for signal readout during IMVS and IMPS measurements More information on these measurements can be found in Section 8 4 The FRA Y gt output located on the right hand side of the LED driver can be used to feed the converted current to the gt Y input of the FRA impedance analyzer The Eout and iot inputs located on the left hand side of the driver can be connected to the corresponding outputs located on the monitor cable provided with the Autolab PGSTAT see Figure 17 23 Page Autolab LED Driver User Manual 2 Metrohm TTY h Autolab s v Series 7 Series 8 Figure 17 Monitor cable for the series 7 PGSTAT above and the seri
29. changed External input Unchanged Oscillation protection Unchanged Reference potential Unchanged Offset alue Unchanged Figure 72 Switching the cell off e Light off to switch the light source off set the DAC voltage property to 0 V on the DAC 1 tab see Figure 73 WEI FRAM DIG Set Voltage 0l m B77 T i Set Voltage 0 Figure 73 Setting the DAC voltage to 0 V 73 Page Autolab LED Driver User Manual re Metrohm e Modulation off to switch off the modulation generated by the FRA module if applicable set the DSG property to off using the provided drop down list on the FRA 1 tab see Figure 74 Autolab control DIO DACH DSG Off DSG Unchanged Figure 74 Switching the output of the FRA module off 9 Thermal considerations Although the LED holder has been designed for optimal temperature management the behaviour of the LEDs located onto the PCB is affected by temperature variations Since the overall temperature of the LED PCB increases as the driving current increases the light output can be affected leading to a non linear relationship between driving current and light intensity Figure 75 and Figure 76 show how the relative light output of the LEDs is affected by the temperature The light intensity is normalized with respect to the light intensity measured at 25 C A Warning The LED light source can get hot
30. cp and the maximum power point Pax the fill factor FF of the cell can be calculated FF max war 100 100 Isc VocP Isc Vocp 82 558 uW FF my Erma LA 0 656 V 100 61 04 From the light intensity Pry the wavelength A and the short circuit current density jsc the incident photon to current conversion efficiency ICPE can be calculated Isc IPCE 1239 100 Pin 0 325 mA cm IPCE 1239 __ 100 41 2 1 655 E 590 nm cm 50 L Metrohm Autolab LED Driver User Manual Autolab s v 8 2 1 1 Software implementation DC measurements with the PGSTAT in combination with the LED Driver can be performed using a NOVA procedure The light intensity can be controlled using the Control external device DAC command as explained in Section 5 1 1 This command can be combined in a measurement with a LSV staircase or LSV staircase galvanostatic command depending on the experimental conditions Under potentiostatic condition it is common practice to start the scan a O V short circuit conditions and stop the scan when the current becomes zero open circuit conditions An example of a procedure for this type of measurement is Shown in Figure 47 Commands Parameters Links Linear sweep voltammetry potentiostatic Remarks Linear sweep voltammetry potentiostatic End status Autolak m oignal sampler Time WE 1 Potential WEI Current zel O
31. ction 4 2 for more information e Additional LED cover holders 6 L Metrohm Autolab LED Driver User Manual Autolab s v Figure 1 shows a complete overview of the LED Driver kit items Figure 1 The LED Driver kit including optical bench light source and photodiode holder The three SMB SMB shielded cables can be fitted with SMB to BNC adaptor plugs Depending on the type of FRA module used in combination with the LED Driver these cables can be modified accordingly e For the FRA2 module the cables must be fitted with SMB to BNC adaptors on both ends see Figure 2 F gt FRAY FRAY gt F gt FRAX FRAX gt el Figure 2 Configuration of the SMB cables used in combination with the FRA2 module e For the FRA32M module the cables must be fitted with SMB to BNC adaptors on a single end see Figure 3 7 Page Autolab LED Driver User Manual TTY 2 Metrohm gt FRAY FRAY gt gt FRAV FRAV gt FRAX FRAX gt Figure 3 Configuration of the SMB cables used in combination with the FRA32M module 2 Hardware requirements The experimental setups described in this manual require the following hardware Autolab PGSTAT uAutolab or Multi Autolab for DC measurements FRA2 or FRA32M module for AC measurements Autolab LED Driver Autolab LED cover with holder A Warning The LED Driver has a working range of 0 10 V which means that the FRA2 modules must be modified t
32. cy distribution can be defined in this editor see Figure 59 The amplitude can also be defined in mA or in A depending on the settings used in the FRA sampler 61 Page L Metrohm Autolab LED Driver User Manual Autolab s v Frequency range Integration time calculation First applied frequency 100000 Integration time maximum Last applied frequency 0 1 Integration cycles minimum Number of frequencies Frequency step Wave type Significant digits Linear Single sine Amplitude Logarithmic 5 sines Amplitude Square root 15 sines W RMS mm Frequency Hz Amplitude mA Wave type Integration time Minimum number of cycles to intearate to _____ Sngesme 0 125 VO es ho gngdesnelsjois bh alse lo fmen elos amna jo fsnaesinedalons hooo E A a ozs bh elza ho gngdesnelsjors hooo A a a ozs bh aliaaas lin a o O Figure 59 The FRA frequency scan editor window Once the frequency range is defined the measurement can be performed Figure 60 shows a typical IMVS measurement on a DSC The measurement is performed at 590 nm at a constant light intensity of 1 7 mW cm The AC amplitude is 10 of the DC light intensity 62 Page Metrohm Autolab LED Driver User Manual IMVS E 1 699 mem Figure 60 A typical IMVS measurement on a dye sensitized solar cell 8 4 2 Intensity modulated photocurrent spectroscopy IMPS The LED Driver can be used in combination with th
33. e potential V by the current i The following DC measurements are possible e Measurement of the i V curve of the cell e Charge extraction measurements 8 2 1 i V and power curves at constant illumination Characterization of solar cells usually requires the determination of i V curves As the potential of the cell is scanned from O V short circuit conditions to the open circuit potential the current changes from the maximum value short circuit current isc to OCP 0 A A typical example is shown in Figure 46 49 Autolab LED Driver User Manual Metrohm 250 00 u p 120 00 u 200 00 4 100 00 u short circuit current lSC 80 000 u _ 150 00 u 2 T 60 000 u z 5 100 00 u a Maximum power point MPP H 5 Li 50000 u 20 000 y 0 0000 0 0000 Open circuit potential OCP VE 20 000 p Fower plot 50 000 U 0 7 0 6 0 5 0 4 0 3 0 2 0 1 Potential applied W Figure 46 i V curve blue and power curve red obtained with the PGSTAT in combination with a 590 nm LED The light intensity is 1 655 mW cm the cell is a Dye Sensitized Solar Cell The i V curves and power curves can be recorded at different light intensities by varying the driving current If the conversion of driving current to light intensity in W cm is known then the light intensity to which the cell is exposed can be controlled directly see Section 6 From the short circuit current isc open circuit potential Vo
34. e LED cover and the holder are fitted with six radial cooling fins which allow evacuation of the heat generated by the light source The higher the light intensity or the driving current supplied to the LEDs by the LED driver the hotter the holder becomes see Figure 10 b i in Temperature J 100 200 300 400 S00 BOO FOO Driving current mA Figure 10 Surface temperature of the LED cover in function of the driving current in mA measured with a 590 nm Amber LED cover settling time 60 s 16 L Metrohm Autolab LED Driver User Manual A Warning When the light source is driven at high currents the cooling fins can get very hot up to 60 C Do not touch these fins and allow for enough cooling time to prevent injury Figure 11 shows the cover attached to the holder LED holder Figure 11 The complete LED cover holder 4 3 Autolab connections for light intensity control Depending on the experimental setup two connection schemes are possible between the LED driver and the Autolab Measurements at constant light illumination these measurements are performed with the LED driver set to a fixed user defined light intensity The light source intensity can be changed during the experiment but no additional modulation is used For this setup only the DAC 1 input of the driver is used The gt FRA V input must be shorted by a 50 Ohm terminator plug see Section 4 3 1 for more information
35. e PGSTAT FRA to record intensity modulated photocurrent spectroscopy measurements on the device under test DUT During an intensity modulated current spectroscopy IMPS measurement the DUT is exposed to a constant light intensity po modulated by a small amplitude AC perturbation Ag The DUT settles at a constant current ig modulated by a small amplitude AC response Ai The IMPS impedance is the transfer function H between the AC current Ai and the AC light modulation Ap Figure 61 shows a schematic overview of the experimental setup 63 Autolab LED Driver User Manual N Metrohm p Po LAP K exp jot DAC1 64 LED DRIVER A ao i ip Aiexp jat Figure 61 Overview of the IMPS measurement setup The fixed light intensity po is provided by the DAC voltage using the Control external device DAC command as described in the Sections 4 3 1 and 5 1 1 The AC modulation Ag is provided by the FRA V connector using the FRA measurement external command as described in Sections 4 3 2 and 5 1 2 The transfer function H w is monitored using the external inputs of the FRA module e The iou signal from the PGSTAT is fed into the FRA gt X input connector of the FRA module e The FRA Y gt output of the LED Driver is fed into the FRA gt Y input connector of the FRA module A Warning The automatic current ranging option cannot be used in an IMPS measure
36. e supplied voltage into driving current 10 V 1000 mA In the units field indicate the units used for this converted AC signal see Figure 33 37 Page Autolab LED Driver User Manual L Metrohm FRA Sampler Input amplitude Channel Multiplier E Sample time domain Channel Sample frequency domain LC Multiplier Transter function Rejim Retjlm xev O Yx Channel r Fhase C Sample time domain Y Channel Feal L Sample frequency domain Man C Multiplier sample DC Figure 33 The settings required for the input amplitude In the example shown in Figure 34 the conversion settings are defined in such way that the amplitude can be defined as AC driving current in mA If the AC unit is to be defined in A the conversion factor needs to be adjusted to 10 see page 30 for more information The settings for the transfer function defined in the Channel X and Channel Y sections of the FRA Sampler depend on the type of measurement More information is provided in Sections 8 4 1 1 and 8 4 2 1 Press the button to close the FRA sampler The applied light modulation can now be specified in the FRA frequency scan command Click the L button located next to the FRA frequency scan command to open the FRA frequency scan editor window see Figure 34 38 L Metrohm Autolab B v Commands El FRA measurement external Frequency H H H Fhase Time Index FRA frequency scan Frequency Amplit
37. e threshold A Warning The photodiode will be irreversibly damaged when exposed to a light intensity of 100 mW cm or more For very high intensity measurements a neutral density filter may be required Please contact your Metrohm Autolab distributor for more information The calibration procedure requires the calibrated photodiode to be placed at the required distance from the light source and to expose the photodiode to different light intensities controlled by the driving current supplied by the LED Driver The photodiode current can be converted to light intensity using the conversion values reported in the calibration certificate of the calibrated photodiode supplied with the LED Driver kit see Figure 41 To protect the photodiode a reflective neutral density filter can be used The size of the filter is 1 27 cm 1 2 inch 44 Page L Metrohm Autolab LED Driver User Manual Autolab s v Test Report Model FDS100 CAL Temperature 25 0 C Test Date 8 Jun 11 Serial No 11060821 Humidity 35 Tester Alexandra Ressel Scan CAL1 A nm n AW _Afnm n AW Afnm n AW Alnm n AW Alnm n AW Alnm i n AW 6 95E 02 4 24E 01 1 72E 01 6 59E 02 4 35E 01 1 37E 01 6 38E 02 4 45E 01 6 67E 02 4 56E 01 7 27E 02 4 66E 01 8 08E 02 4 76E 01 9 02E 02 4 86E 01 1 00E 01 4 96E 01 1 10E 01 5 06E 01 1 21E 01 5 16E 01 1 31E 01 5 26E 01 5 35E 01 5 43E 01 5 52E 01 5 60E 01 5 68E 01 5 75E 01 5 83E 01 5 91E 01 5 99E
38. ear sweep voltammetry H Measurement voltammetric analysis H Measurement chrono methods 5 Measurement impedance FRA measurement potentiastatic FRA measurement qalvanostatic FRA measurement external ne FRA frequency scan FRA single frequency ch Data handling E Analysis general G Analysis baseline correction 4 Analysis corrosion d Analysis impedance GH Flats general H Plots impedance E My commands Figure 29 The FRA measurement external command is used to modulate the light intensity When no modulation is required in the experiment the FRA V input of the LED driver must be shunted using a 50 Ohm terminator plug included see page 18 The FRA measurement external command is used to perform a FRA measurement using the external inputs and outputs of the FRA module The output of the FRA module is used to generate a sinewave which is fed into the LED Drive FRA V input This sinewave supplied as a voltage 0 5 V top amplitude range is converted into an AC driving current The FRA measurement external command is a composite command see Figure 30 The FRA measurement external command is an Advanced command Adjust the Profile in NOVA if necessary Autolab LED Driver User Manual Commands L Metrohm Autolab s v Farameters Links FRA measurement external Frequency H H H Phase Time Index E FRA frequency scan Frequency Amplitude Amplitude in AMS Amplitude unit
39. edicated LED array This array consists of a tri focal LED assembly collimated into a narrow beam with a lens The LED array and the lens are enclosed in an anodized aluminium cover see Figure 7 The light beam width is 18 A Warning The lens mounted on the light source provided a highly focused beam of light Do not look directly into the light source when it is operating even if the driving current is small The switch can also be toggled through an analog voltage Supplying more than 2 5 V on this DIO input triggers the switch 13 Autolab LED Driver User Manual L Metrohm Autolab s v Figure 7 Schematic top view of the LED array casing The factory default cover supplied with the kit is fitted with three 700 mA rated red LEDs wavelength 627 nm Other covers are available on request The following wavelengths are available see Table 1 Article code Color Wavelength nm Maximum output Lumen LDC655 Deep Red 655 n a LDC627 Red 627 306 LDC617 Red Orange 617 366 LDC590 Amber 590 396 LDC530 Green 530 390 LDC505 Cyan 505 360 LDC470 Blue 470 174 LDCCW White Cool n a 540 LDCWW White Warm n a 690 LDCNW White Neutral n a 330 Table 1 Overview of the available LED covers The back plane of the LED cover is fitted with two holes used to provide electrical contact to the LEDs enclosed in the cover see Figure 8 Three screws are embedded into the cover to fasten it to the holder 3 The
40. ency domain C Multiplier Transfer function Rejim Betim xy woe Channel Phase Sample time domain Channel Peal Sample frequency domain LC Multiplier Imaginary sample DC Figure 64 The transfer function parameters are specified in the FRA sampler Channel X and Channel Y Note In Figure 63 the parameters for the Input amplitude have already been set according to the instructions indicated in Section 5 1 2 For IMPS measurements the following settings are required see Figure 65 e Channel X this input is used to measure the AC cell current during the frequency scan This input corresponds to the iout coming from the Autolab which corresponds to the converted cell current which depends on the selected current range This input is therefore specified in A and requires a multiplier that depends on the current range used in the measurement The lou of the Autolab is given by the measured current in A divided by the current range in A V Table 2 shows the multiplier values depending on the selected current range Figure 65 shows the settings for a measurement in the 1 mA current range Please refer to the NOVA Getting Started manual for more information 67 Autolab LED Driver User Manual L Metrohm Current range Conversion factor Multiplier 1A 1 A V 1 100 mA 100 mA V 0 1 10 mA 10 mA V 0 01 1 mA 1 mA V 0 001 100 pA 100 HA V 0 00
41. ent a Options 0 Options ail Instrument Instrument description E Timed procedure Autolak control zal e Control LED Driver mA Set current O 000E 00 Vat time 3 z Set cell Cn EEN gt FRA measurement external E Timed procedure set cell Off zel Control LED Driver mA 0 lt gt lt gt Figure 53 An example of IMVS procedure The second stage of the procedure performs the IMVS measurement using the FRA measurement external command see Figure 54 57 Page Autolab LED Driver User Manual Commands El FRA measurement external Frequency H H H Phase Time Index El FRA frequency scan Frequency Amplitude Amplitude in RMS Amplitude unit Wave type Integration time s Minimum number of cycles to integrate Number of frequencies Estimated duration cl FRA single frequency Input frequency Hz Input amplitude Amplitude in RMS Amplitude unit Input wave tyoe Input connection Integration time s Minimum number of cycles to integrate Number of cycles to reach steady state Maximum time to reach steady state s with a minimum fraction of a cycle FRA sampler Options Lowest bandwidth Frequency Phase Time Channel DG Y Channel OC lt gt Build signal hhyquist 2 ws 2 Bode modulus Bode phase lt gt Parameters array Hz Arrow Array Arraw gt aray gt Array 5 Arrow ik ik ik ik ik ik ik 100000 0 01 es Me single sine ies BO
42. es 8 PGSTAT below The PGSTAT101 and M101 module are not supplied with a monitor cable This cable must be ordered separately article codes for PGSTAT101 CABLE MONITOR4 M101 CABLE MONITOR MAC Please contact Metrohm Autolab B V info metrohm autolab com or your local distributor for more information The Eou and iout outputs signals are used for the IMVS and IMPS respectively By feeding these two signals into the driver the user can pass either one of these Signals to the FRA X output located on the right hand side of the driver using the either one of the compatible DIO cables see Figure 18 24 Page 2 Metrohm Autolab LED Driver User Manual Autolab s v DIO input Et input lout input Fout loni output Figure 18 Overview of the feedthrough connections for Eout and iout Two different DIO cables are compatible with the LED Driver e For all the supported Autolab Potentiostat Galvanostat instruments except the PGSTAT101 and the M101 module a male DIN25 to female BNC cable is supplied with the LED Driver kit see Figure 19 This cable can be connected to either P1 or P2 of the instrument The female BNC connector can be connected to the gt DIO connector on the LED Driver using the supplied 2 m long BNC cable O OO0O00000000000 O elejelejelelelelelelele Figure 19 DIO cable for the Series 7 and Series 8 PGSTAT instruments e For the PGSTAT101 and the M101 module a male DIN15 to female BNC cable is
43. g current 19 Autolab LED Driver User Manual L Metrohm Autolab s v The maximum modulation frequency is 20 kHz For the FRA2 module the V BNC plug can be connected to the gt FRA V input of the LED driver as shown in Figure 14 using the provided SMB to BNC adaptor plugs A gt iout LED DRIVER Figure 14 Overview of the connections for modulated illumination experiments FRA2 The FRA32M module V SMB plug can be connected to the gt FRA V input of the LED driver as shown in Figure 15 using the provided SMB to BNC adaptor plug 20 Page N Metrohm Autolab LED Driver User Manual A Dn AUTOIOD gt FRAV l ED hold gt pact DyNv gt salaries gt odI0 FRAY gt gt Eout FRAX gt m gt iout LED DRIVER Figure 15 Overview of the connections for modulated illumination experiments FRA32M The light intensity of the LED array is controlled by setting the driving current passing through the LED power plug on the right hand side This driving current is defined by setting the DAC164 1 output to a value between 0 and 10 V and by setting the amplitude of the FRA V output to a value between 0 and 0 35 V RMS The difference between the DAC164 output and the FRA V output is converted by the LED driver to a modulated current using the following relationship LRange V Voaci64 g Vera Range liep Upc lac iep
44. ge AV and the AC light modulation Ap Figure 52 shows a schematic overview of the experimental setup pre Po 4 Ap K exp jat DAC164 LED DRIVER ak _ ot Il ZEN V V AVexp jot p Figure 52 Overview of the IMVS measurement setup The fixed light intensity po is provided by the DAC voltage using the Control external device DAC command as described in the Sections 4 3 1 and 5 1 1 The AC modulation Ag is provided by the FRA V connector using the FRA measurement external command as described in Section 4 3 2 and 5 1 2 The transfer function H w is monitored using the external inputs of the FRA module e The Esu signal from the PGSTAT is fed into the FRA gt X input connector of the FRA module e The FRA Y gt output of the LED Driver is fed into the FRA gt Y input connector of the FRA module 2 Metrohm Autolab LED Driver User Manual Autolab s v 8 4 1 1 IMVS measurements IMVS measurements are usually carried out at open circuit potential OCP Figure 53 shows an example of an IMVS procedure In the first step of the procedure the light intensity is set to a fixed DC level using the Control external device DAC command The cell is then set open circuit conditions by applying 0 A in Galvanostatic mode Commands Parameters Links A S Remarks FRA impedance potentiostatic require End status Autolab rr signal sampler Time WwE 1 Potential WEI Curr
45. ight profile depends on the experimental conditions Information This document provides basic information regarding the Autolab LED Driver and the associated products This kit is controlled through the NOVA software Additional resources are available online www metrohm autolab com support This manual describes the use of the Autolab LED Driver and LED light source in combination with the Autolab PGSTAT The LED Driver is compatible with all Autolab PGSTAT instruments except the Autolab PGSTAT302F In this manual the term Autolab is used to describe any type of compatible instrument The following measurement techniques are possible with the LED Driver in combination with the Autolab PGSTAT e Polarization curves and power density curves e Charge extraction measurements e Electrochemical impedance spectroscopy at constant illumination e Intensity modulated photovoltage spectroscopy IMVS e Intensity modulated photocurrent spectroscopy IMPS It is also possible to combine all the measurement techniques in a single experiment A Warning This device must be used carefully to prevent personal injury Metrohm Autolab is not responsible for physical injuries sustained while using this product It is advised to read this documentation very carefully before operating this equipment Please contact Metrohm Autolab info metrohm autolab com in case of problems 5 Autolab LED Driver User Manual L Metrohm Whenever a
46. lize the DIO port used in the experiment not required for the PGSTAT101 and the M101 module The DIO port used must be initialized at the beginning of the procedure Pin 1 located on DIO port A is used to control the switch To initialize the DIO port A located on either P1 or P2 the direction setting for this port must be set to Output using the drop down list provided in the Autolab control window see Figure 36 Autolab control WE ERA DIOC P1 A Direction Output P1 A Direction Unchanged P1 A Direction Input P1 A Direction Output B Write Unchanged Flt Fl CLower Direction Unchanged Fi CLower Write Unchanged Flipper Direction Unchanged Pi CUpper Write Unchanged Feta Direction Unchanged eLA Write Unchanged 2E Direction Unchanged B Wirte Unchanged e CLower Direction Unchanged Fe CLower Write Unchanged Fe CUpper Direction Unchanged FeiCipper Write Unchanged Figure 36 Setting the direction of Port A of connector P1 to Output gt More information on the settings of the DIO ports can be found in the External devices tutorial More information on the Autolab control command can be found in the Autolab control turorial Both tutorials can be found in the Help menu of NOVA Paaa 41 P ad T J Autolab LED Driver User Manual L Metrohm After the port is initialized the status of Pin 1 can be set at any time to high 5 V or low
47. ment 8 4 2 1 IMPS measurements IMPS measurements are usually carried out at short circuit conditions Figure 62 shows an example of an IMPS procedure In the first step of the procedure the light intensity is set to a fixed DC level using the Control external device DAC command The potential is set to O V short circuit conditions 64 Pa Q e 2 Metrohm Autolab LED Driver User Manual Autolab s v Commands Farameters Links IMPS Remarks End status Autolab signal sampler Time WE 1 Potential WEI Current Options 1 Options Instrument Instrument description E Timed procedure Autolak contral zl _ Control LED Driver mA Afait time 3 5 set potential 0 000 Set cell On zel lt gt FRA measurement external E Timed procedure K H H Control LED Driver mA 0 set cell Of m lt gt lt gt Figure 62 An example of IMPS procedure The second stage of the procedure performs the IMPS measurement using the FRA measurement external command see Figure 63 65 Page Autolab LED Driver User Manual Commands El FRA measurement external Frequency H H H Phase Time Index El FRA frequency scan Frequency Amplitude Amplitude in RMS Amplitude unit Wave type Integration time s Minimum number of cycles to integrate Number of frequencies Estimated duration cl FRA single frequency Input frequency Hz Input amplitude Amplitude in RMS Amplitude unit Input wave type Input co
48. nenn 48 el OU COMING COINS assar rasa E E E E EE E EEES 48 8 2 DC measurements at constant illumination unne 49 8 2 1 i V and power curves at constant illumination cece eee 49 8 2 1 1 Software implementation unne nennen 51 8 2 1 2 Possible refinements nonnen eneen eenenen eneen 52 8 3 AC measurements at constant illumination unne nnen 53 8 3 1 EIS measurements at constant illumination nnn 54 8 4 AC measurements at modulated illumination unne 55 8 4 1 Intensity modulated photovoltage spectroscopy IMVS 55 8 4 1 1 IMVS measurements annen vennen snenvenvensenneene 5 8 4 2 Intensity modulated photocurrent spectroscopy IMPS 63 8 4 2 1 IMPS measurements ccc cecccecc eee eeeeeee eee eeseeeeeeeeeneenees 64 8 5 Safety settings when measurement is aborted une 71 Oi Thermal considerations coteressesdswor airicoesaenswenseseaqeesetovaveatdudantoeieaseaesaonsose 74 4 Metrohm Autolab LED Driver User Manual Autolab PGSTAT in combination with LED Driver The characterization of optical energy conversion devices i e solar cells requires controlled illumination from a light source Depending on the experimental requirements the light source can be a solar simulator a simple LED or a laser This light source must be programmable in order to expose the device under test DUT to a user defined light intensity The type of l
49. nnection Integration time s Minimum number of cycles to integrate Number of cycles to reach steady state Maximum time to reach steady state s with a minimum fraction of a cycle FRA sampler Options Lowest bandwidth Frequency Phase Time Channel DG Y Channel OC lt gt Build signal hhyquist 2 ws 2 Bode modulus Bode phase lt gt Parameters array Hz Arrow Array Arraw gt aray gt Array 5 Arrow ik ik ik ik ik ik ik 100000 0 01 Yes W single sine ees i dm 0 125 1 10 17 0 100000 0 01 Yes W single sine External 0 125 10 0 0 Options High stability lt array gt Hz arrow arran arran lt aray lt array s lt aray gt Cv lt aray gt Cv L Metrohm Autolab s v Links Figure 63 The FRA measurement external command is used during the IMPS frequency scan Before the measurement can be performed properly the parameters for the transfer function must be set in the FRA Sampler Click the L button located next to the FRA sampler parameter of the FRA signal frequency command see Figure 63 The parameters for the transfer function are defined in the Channel X and Channel Y of the FRA sampler window see Figure 64 66 Page L Metrohm Autolab LED Driver User Manual FRA Sampler Input amplitude Channel W Multiplier Sample time domain Channel C Sample frequ
50. o the 0 10 V input range The hardware setup must be adjusted accordingly see Appendix 1 1 The pAutolab can only be used for DC measurements 8 L Metrohm Autolab LED Driver User Manual 3 Software requirements The experimental setups described in this manual require the following software e Latest version of NOVA This manual assumes that the reader is familiar with the operation of the Autolab Instrument in combination with the NOVA software More information on the software tools used in this manual can be found in the following document available from the Help Tutorials menu in NOVA e Autolab control tutorial e External devices tutorial e Impedance spectroscopy tutorial e NOVA Getting started e NOVA User manual e Command list 4 Installation This section describes the required connections between the Autolab PGSTAT and the Autolab LED driver The combination of the PGSTAT with a LED driver is a very useful hardware construction which allows measurements at controlled light intensity on solar cells In this setup the LED Driver is used to control the output of the light source while the Autolab PGSTAT is used to measure the potential and current on the device under test DUT The LED Driver can be operated in constant output mode or in modulated output which requires the FRA2 or FRA32M module The Autolab PGSTAT can be operated in potentiostatic mode or in galvanostatic mode 9 Autolab LED D
51. observed between the two values and the measured slope corresponds to 0 001 V mA 28 Metrohm Autolab LED Driver User Manual FRA Y gt output iW 100 200 200 400 S00 BOO FOO specified driving current mA Figure 23 Output value of the FRA Y gt plug plotted against the specified driving current 5 Software control The Autolab LED driver is intended to be controlled by the NOVA software The control of the driver is performed through the use of analog and or digital settings e Analog control of the light intensity and modulation if applicable e Digital control of the Eou iou through the DIO port This section provides details on the light intensity control 5 1 Analog control of the light intensity Regardless of the type of experiment the light intensity of the LED is controlled by supplying a voltage value between O V and 10 V to the DAC 1 input and the FRA V input of the driver At all times the value supplied to the FRA V input must be smaller than the value supplied to the DAC 1 input The supplied voltage difference between the inputs is converted into a driving current igp given by LRange lLED lpc lac Vpac164 Vera Vrange iep 100 mA V WVpaciea Vrrav 29 Autolab LED Driver User Manual L Metrohm Or when no voltage is supplied on the FRA V input 50 Ohm termination plug in place by 5 mn LRange lren gt Vpaci64 Vrange iep 100 MA
52. olarity 8 2 1 2 Possible refinements The sequence shown in Figure 47 is a very simple sequence which offers limited possibilities It is possible to combine this sequence with other NOVA commands in order to build a complete measurement sequence Since the description of such a sequence is left to the requirements of the users it falls outside of the scope of this document A few tips are provided below e A Repeat for each value command with the set current values defined in the values sequence of the repeat command can be used in combination with the Contro external device DAC command renamed to Contro LED Driver MA This will repeat the whole measurement sequence for each pre defined value see Figure 49 2 Metrohm Autolab LED Driver User Manual Autolab s v e The Calculate signal command can be added to the sequence in order to automatically calculate the Power signal using the values of the potential and the current Commands Parameters Links POWER Remarks al End status Autolak zl oignal sampler Time YWE 1 Potential WEI Current Options 1 Options zl Instrument Instrument description E Repeat for each value 100 200 300 al Number of repetitions 3 _ Parameter link E Timed procedure Autolak contral zl Control LED Driver mA _ Setvalue Unit rm DAC channel a Conversion offset 0 Conversion slope 0 01 DAC voltage v 1 0000 set potential 0 000 set cell On zel Afait time 3
53. older 8 Experiment description This section provides a description of different experiments that can be carried out with the LED Driver kit using the information provided in the previous sections 8 1 Cell connections Photovoltaic devices are usually characterized in the so called two electrode mode In this mode the Autolab PGSTAT is connected to both the anode and the cathode using the CE RE and WE S respectively see Figure 45 WE Figure 45 Overview of the connections to the cell 48 Page L Metrohm Autolab LED Driver User Manual In this configuration the potential difference across the cell is measured between the RE and the S using the differential amplifier electrometer of the Autolab PGSTAT The current is measured between the CE and the WE By convention the potential of the cell under operating conditions is always positive and the current under operating conditions is always negative 8 2 DC measurements at constant illumination DC measurements at constant illumination are the simplest measurements possible with the PGSTAT in combination with the LED Driver During these experiments the light source is set to a user defined driving current to provide constant illumination on the cell while the PGSTAT measures the i V curve of the cell The i V curve can be recorded either potentiostatically or galvanostatically The Power cannot be measured directly It can be calculated by multiplying th
54. order to verify the quality of the data during the experiments see Figure 56 FRA Sampler Input amplitude Channel Multiplier J Sample time domain E DUT Sample frequency domain Multiolier Transfer function Re jlm A had Channel r Phase Sample time domain LED Current Peal Sample frequency domain v Multiplier Imaginary sample DC Cancel Figure 57 Sampling the time domain data for Channel X and Channel Y Close the FRA sampler with the button The frequency scan can now be defined in the procedure editor by clicking the t button next to the FRA frequency scan command see Figure 58 60 2 Metrohm Autolab LED Driver User Manual Autolab s v FRA measurement external Frequency lt array Hz H arrow al arrow ame lt arrary gt Fhase lt aray Time lt array gt s Index arrayy gt FRA frequency scan Frequency 100000 Amplitude 0 01 Amplitude in RMS es Amplitude unit m Wave type single sine Integration time s Uis Minimum number of cycles to integrate 1 Number of frequencies sil Estimated duration dm FRA single frequency uaea We ME Te Ta lt 3 Build signal z Myguist lt ws zl Bode modulus z Bode phase z lt gt Figure 58 Opening the FRA frequency scan editor The FRA frequency scan window will be displayed The highest frequency lowest frequency number of frequencies and frequen
55. out input E en en Eout lout output LED DRIVER Z Ecut lout Status LED Figure 6 Overview of the optional connections provided on the LED Driver Basic connections are greyed out The following connections are located on the left hand side 12 P DIO input gt DIO this input can be used to connect to the DIO port s of the Autolab By setting the DIO to the down status default or the up L Metrohm Autolab LED Driver User Manual status the switch connected to the Eout and iout can be toggled The default position is set to iout Eout input gt E out this input can be used to connect to the Eou plug provided by the monitor cable of the Autolab see Section 8 4 1 for more information The Eou signal is required during IMVS measurements lout input gt i out this input can be used to connect to the iow plug provided by the monitor cable of the Autolab see Section 8 4 2 for more information The iou signal is required during IMPS measurements The following optional connections are located on the right hand side Eout lout output FRA X gt this connector provides a direct connection to either the Eou or the jou supplied on the left hand side of the driver through the Eou and iow connectors respectively The default is tou indicated by the status LED This output is connected to the FRA X for IMPS ius or IMVS Eou measurements 4 2 Autolab LED array The Autolab LED driver can be connected to a d
56. output in Lumen for the Deep Red source is not specified The maximum output power is 1740 mW at 700 mA driving current 14 Page L Metrohm Autolab LED Driver User Manual Autolab s v LDC590 Amber 590 nm 700 mA 396 Im Figure 8 Schematic bottom view of the LED array casing A label is located on the back of the cover indicating the type of LED included in the cover The cover can be mounted on a dedicated holder see Figure 9 The holder is fitted with two spring mounted pogo pins that are intended to provide the electrical contact to the LEDs through the matching holes located in the back plane of the cover LED holder Figure 9 The LED cover and the holder To attach the cover to the holder align the pogo pins with the matching holes in the back plane of the cover The three screws located in the cover can be used to tighten the cover onto the holder 15 Page Autolab LED Driver User Manual L Metrohm When tightening these screws do not tighten one screw at a time but alternate between both screws in order to distribute the traction on each screw evenly Do not over tighten the screws No soldering is required Connecting the LEDs through pogo pins allows for a quick change of the wavelength of the light source by simply replacing one cover by another A Warning Do not exchange the LED cover while the driver is in operation Always power off the LED Driver before exchanging the LED cover Th
57. outside of the scope of this manual When working in combination with the FRA2 or FRA32M module the maximum frequency that can be used in combination with the LED driver is 20 kHz The maximum frequency is limited by the voltage to current converter in the LED driver 4 1 1 Basic connections Figure 5 shows an overview of the basic connections to and from the LED driver All the connectors located on the left hand side of the driver are input connections from the Autolab PGSTAT to the LED driver The BNC connectors located on the right hand side of the driver are the output connections to the Autolab PGSTAT LED power FRA V input E ep output DAC164 1 input l gp output LED DRIVER 18 V input Power status LED Figure 5 Overview of the basic connections provided by the LED driver The following connections are located on the left hand side e FRA V input gt FRA V this input is used to supply the AC amplitude used to modulate the light intensity in volts 0 10 V input range See Section 4 3 2 for more information When no signal is supplied to this input this plug must be shorted using a 50 Ohm termination plug included e DAC164 1 input gt DAC 1 this input is used to supply the DC amplitude used to modulate the light intensity in volts 0 10 V input range See section 4 3 1 for more information This value must always be larger than the value supplied to the FRA V input 11 Autolab
58. plitude 0 01 Amplitude in RAS es Amplitude unit W Input wave type single sine Input connection External zl Integration time s 0 125 Minimum number of cycles to integrate Number of cycles to reach steady state 10 Maximum time to reach steady state s 1 with a minimum fraction of a cycle 0 FRA sampler Options Mo Options Lowest bandwidth High stability Frequency lt array gt Hz H Array gt sn arran H lt arrayy gt Phase Carrey lj Time lt array gt 5 Channel DC array v Y Channel DC lt array gt 4 Er Figure 31 The settings required for light source modulation are defined in the FRA sampler The FRA sampler window will be displayed see Figure 32 FRA Sampler Input amplitude Channel C Multiplier E Sample time domain Channel LC Sample frequency domain C Multiplier Transter function Re jim Retjlm xiv O Yx Channel r Fhase LC Sample time domain Y Channel Feal Sample frequency domain laaien C Multiplier sample DC Cancel Figure 32 The FRA sampler window The FRA sampler window is used to define the settings for the generation of the sinewave and the analysis of the transfer function To control the modulation of the LED directly in AC driving current the Input amplitude multiplier must be specified properly Click the W Mutipier Checkbox in the top left corner and specify the conversion factor required to convert th
59. pplicable a hot surface warning label or strong optical radiation warning label are used in this manual as reminder to the hazards that can be encountered when operating this equipment fh Warning This warning symbol is used in this document to indicate a hot surface hazard related to the heat dissipation in the light source Allow the system to cool down after prolonged use A Warning This warning symbol is used in this document to indicate an optical hazard related to highly focused beam of light generated by the LED light source Do not look directly into the light beam when the light source is on 1 Scope of delivery The LED Driver kit is supplied with the following items e Autolab LED Driver box e Power adaptor e 50 Q terminator plug e 6 BNC to SMB adaptor plugs e 3 SMB shielded cables 1 m e 1 BNC shielded cable 1 m e 1 BNC shielded cable 2 m e 2 BNC shielded cable 50 cm e DIO to BNC cable for Autolab N series PGSTAT instruments and uAutolab e DIO to BNC cable for Autolab PGSTAT101 and M101 module e Optical bench The LED Driver kit is intended to be used with the Autolab LED light source included with the LED Driver e 1 LED array cover 627 nm 700 mA maximum current e 1 LED cover holder e 1 LED cover holder connection cable 2 m e 1 calibrated photodiode holder with calibration certificate Additional accessories are available for the Autolab LED light source e Additional LED covers see Se
60. ptions 1 Options zl Instrument Instrument description El Timed procedure Autolak control zl Control LED Driver mA set value 100 Unit mA DAC channel 3 Conversion offset 0 Conversion slope 0 01 DAC voltage 47 1 0000 set potential 0 000 set cell On m Afait time s 5 Optimize current range 5 E LSY staircase 0 000 1 000 0 1000000 start potential v 0 000 stop potential 1 000 step potential v 0 00244 ocan rate v s 0 1000000 Estimated number of points ALE Interval time 5 0 024400 signal sampler Time WE 1 Potential WEI Current zel Options 1 Options zl Fotential applied array Cv Time lt array 5 WE Current lt array 4 WEN Fotential lt aray Cv Index arrow ws E ml set cell Of zel lt gt B Figure 47 An example of a procedure used to measure the i V curve of a cell 51 Page Autolab LED Driver User Manual N Metrohm A nkalaske nu AA J tol Mi ly B VV AVUIVIUD D V A cutoff condition can be used to detect the potential at which the current changes polarity see Figure 47 5 Automatic Current Ranging Cutoff Autolab control Automatic Integration Time Cutoff on vvE 1 Current Basic properties signal Ei Current Value I Action stop command Advanced properties Mr of detections 4 Additional cutoffs Mo Cutoff Figure 48 A cutoff condition can be used to detect the point where the current changes p
61. r mA Remarks Control the OC driving current of the LED Driver in mA Figure 27 Saving the command in the My commands database The command will appear in the My commands group of commands It can be used at any time in the procedure see Figure 28 33 Page Autolab LED Driver User Manual L Metrohm Autolab s v Commands Favorite commands HH Control Metrohm devices H Measurement general H Measurement cyclic and linear sweep voltammetry GH Measurement voltammetric analysis ois Measurement chrono methods be Measurement impedance H Data handling i Analysis general G Analysis baseline correction d Analysis corrosion Analysis Impedance H Plots general GH Flots impedance ji My commands 8 Control LED Driver mA Control the DC driving current of the LED Drier in mA Figure 28 The saved command is available in the My commands group F 5 1 2 Settings for the FRA V input The FRA V input of the LED driver controls the AC light intensity modulation This setting is defined in the software through the FRA measurement external command available from the Measurement impedance group of commands see Figure 29 34 Page Metrohm Autolab LED Driver User Manual REE Favorite commands H Control GE Metrohm devices H Measurement general H Measurement cyclic and lin
62. river User Manual L Metrohm Autolab s v 4 1 Autolab LED driver The Autolab LED driver is an analog and digitally programmable constant current source which can be used to supply a driving current to a LED or a LED array see Figure 4 The maximum driving current which can be generated by the LED driver is 1000 mA DC LED DRIVER Figure 4 Top view of the Autolab LED driver The LED driver provides the following functionality 1 A dual analog programmable input gt FRA V and gt DAC 1 for direct control of the LED current supplied by the driver 2 A current to voltage converter for direct analog readout of the driving current FRA Y gt 3 A dual input feedthrough for the Autolab Eot and lou signals to the FRA gt X output The input is controlled by a DIO triggered switch gt DIO input The LED Driver is designed to control a dedicated LED array of three 1000 mA rated LEDs provided by Metrohm Autolab see Section 4 2 for more information This light source is recommended for this application and will be assumed in the rest of the document 10 Page Metrohm Autolab LED Driver User Manual The light source is a critical component of this hardware setup and it should be chosen carefully Light sources like LEDs are economical and offer a narrow spectral distribution Laser diodes can also be used Both light sources have a low power output Alternative light sources can be used however their use fall
63. trohm Table of Contents EO OLO T E E E E E 6 2 Hardware requirements vanen er vennsereennerreennenr ennen vennen vennen vens 8 3 Software he OUP CR GIN Sots iesssessasdcmoearaetaacenantsaieaaicesesenatenaven steden 9 rad ISLAM IOM ee ee nee ee eee ee ee ee 9 de UO la LED GWIN GW osepcrcsssepausersghcncysvarteaeocensnacevetanearsehcsdostnsiecdsceesveceteas 10 deeld Basic CONNECTIONS nennen Eene 11 4 1 2 Optional connections naan sevenan erven ervenenen vennen vens 12 A OAD LED amay ee ctor nesters oie ee ese EE E EEE 13 4 3 Autolab connections for light intensity control nnen 17 4 3 1 Connections for constant illumination measurements 18 4 3 2 Connections for modulated illumination measurements 19 4 3 3 Optional CONNECTIONS uus srversnervenaner venen ervensnenre sne end 22 4 4 Autolab connections to analog outputs annnn orn nenn ereen 27 Bye SON WEES COMEN serene eene eenen E 29 5 1 Analog control of the light intensity nnn snennnenne neen 29 5 1 1 Settings for the DAC 1 IMPU seccmcsesecesnccutseand canuclaecwesisenununsimenmencsas 30 5 1 2 Settings for the FRA V input nanus oensenennan sene veevenn 34 5 1 3 Settings for the DIO control eaten eenen 40 C HINC OUr e Call OU O gn 43 TCE TAO nar E enden nennen ne 46 8 Experiment description oasa er vennnervensersennenreennenreennenveen
64. ude Amplitude in RMS Amplitude unit Wave type Integration time s Minimum number of cycles to integrate Number of frequencies Estimated duration cl FRA single frequency Input frequency Hz Input amplitude Amplitude in RMS Amplitude unit Input wave type Input connection Integration time s Minimum number of cycles to integrate Number of cycles to reach steady state Maximum time to reach steady state s with a minimum fraction of a cycle FRA sampler Options Lowest bandwidth Frequency H H H Phase Time Channel OC Y Channel OC lt gt Build signal hhyquist 2 ws 2 H Bode modulus H Bode phase lt gt lt gt Autolab LED Driver User Manual Parameters Links arran Hz arrayy gt arrayy gt arrayy gt arram arrary gt 5 array gt Ci dk a a T a 100000 0 01 Yes ma single sine Os AO am 0 125 1 10 1 0 100000 0 01 Yes ma Single sine External ml 0 125 10 0 Mo Options High stability lt array gt Hel Arraw gt Arraw gt Arraw gt arram arrary gt 3 arran gv arran fv Figure 34 Opening the frequency editor The FRA frequency scan editor window will be displayed see Figure 35 39 Page Autolab LED Driver User Manual L Metrohm Autolab s v Frequency range Integration time calculation First applied frequency L Integration time maximum Last
65. utput 42 2 Metrohm Autolab LED Driver User Manual Autolab s v Autolab control DACHI Inteqrator 1 Set P1 A Write 1 Figure 38 Setting the status of pin 1 for the PGSTAT101 or M101 module 6 Light source calibration Quantitative results can only be obtained after the calibration of the light source This can be done by using a calibrated photodiode exposed to the light source at a controlled distance on the optical bench The calibration can be performed with the Autolab or with external digital multimeters In this manual the procedure used in combination with the Autolab is described The LED Driver kit is supplied with a calibrated photodiode embedded into a cylindrical holder see Figure 39 The measurement range of the photodiode Is from 350 nm to 1100 nm Figure 39 The photodiode holder front view Autolab LED Driver User Manual L Metrohm The photodiode holder is fitted with three female 4 mm banana connectors labeled WE red CE black and GND green respectively These connectors are used to accommodate the cell connectors provided by the Autolab PGSTAT see Figure 40 Figure 40 The photodiode holder back view The photodiode holder is also supplied with an additional plastic cover which can be mounted on top of the calibrated photodiode This cover is designed to hold a filtere to protect the photodiode from exposure to light intensities beyond the damag
66. when operated at high driving currents Always allow the light source to cool down before touching it gen y LY f A 1 LA a L Metrohm Autolab LED Driver User Manual A skal oe L A ur Royal Blue B ue e Cyan mmm Green Relative Luminous Radiant Flux 20 0 20 40 60 80 100 120 140 Thermal Pad Temperature C Figure 75 Relative light output vs thermal pad temperature for green cyan blue and royal blue Red Red orange Amber Relative Luminous Flux Output 20 0 20 40 60 80 100 Thermal Pad Temperature C Figure 76 Relative light output vs thermal pad temperature for red red orange and amber 8 Adapted from LUXEON Rebel Direct Color Portfolio High power colored LEDs Technical Datasheet DS65 Adapted from LUXEON Rebel Direct Color Portfolio High power colored LEDs Technical Datasheet DS65 75 Page Autolab LED Driver User Manual L Metrohm Appendix 1 Modification of the input range of the FRA2 module By default the external inputs of the FRA2 modules shipped before July 2009 revision number 8 0 and lower can be used to record analog signals in the 5 V range For this application analog signals in the 10 V range are required In order to be able to record voltages between 5 and 10 V the FRA2 modules with revision numbers lower than 8 1 need to have the extended range offset DACs activated This requires a simple hardware modification

Electronic load combination using the NOVA

Contents

Download Pdf Manuals

Related Search

Related Contents