Standard Operating Procedure Inhouse Solar Simulator By Sanchit Khatavkar and Guru Burkul National Centre for Photovoltaic Research and Education (NCPRE), Indian Institute of Technology-Bombay, Powai, Mumbai- 400076 INDIA Contamination Category: Litho/Analytical Safety Precautions:
Do not look directly onto the light source. If under any circumstances you need to look in the light, please wear the UV protection goggles placed near the system. Do not bring or place any liquid especially water near the system. Please take all necessary cautions needed when working with electrical equipments. Operating Instructions: TURN ON Sequence: 1. Check whether the power supply cable is plugged in the switchboard and then turn the switchboard ON. 2. Turn the knob to 75% (Upto the mark on the power supply). 3. Only after this is done, Press the switch at the back which will power ON both the lamp and the fan. 4. Make sure that the units knob is set to Watts. 5. Wait for 5 mins, you will see the units increasing. 6. After 5 minutes, very gently, slightly rotate the knob so that the power supply unit shows a stable 148 Watts on the display before proceeding with the experiment. 7. This completes the lamp turn ON procedure. 8. Switch ON the power supply to the computer, Keithley 2400 SMU and the Vacuum pump. 9. Switch ON the Keithley 2400 SMU by pressing the Power switch located on the front panel. 10. Place your sample onto to the chuck. 11. For organic solar cells, place the 4.3cm chuck below the light source such that the sample is exactly at the center of the light beam (Dia - 4 cm). Connect the leads of the chuck to the Keithley SMU. 12. For silicon solar cells, place the vacuum chuck below the light source. i) Place the sample onto the chuck and turn ON the vacuum pump which is located below the table. ii) Ensure that the sample is at the center of the light beam. iii) Make front and back contacts using micromanipulator and connect the leads to Keithley SMU. 13. Switch ON the PC and click icon Lab Tracer 2 14. You will be getting a screen as shown below:
15. Check the settings by clicking the SETUP 2401 link before performing the IV sweep. You will get the window shown below. 16. Click on the Source tab. Enter the start and stop values of voltage according to the measurement (dark and illuminated) in the Source tab as shown in the image above. More sweep delay is useful only for devices like organic solar cells. 17. After that clicking on Advanced tab, make the four wire measurement as shown below
18. After making sure the Settings are correct, click Run Test to start the sweep. 19. By default, the I-V plot will be displayed at the end of the sweep, if not, then click on the Graph tab. You can save the graph if needed. To save the data, click on the Datasheet tab. On this tab, there is a Save data button. On clicking that, you will be asked for the filename against which you want to save the data. Data can be saved in.txt format. Please save data in a directory having your name in E:\. Please do not save data on the desktop. 20. To do another measurement, if you are using Keithley 2401 Sourcemeter, goto File -> Exit as shown below. This will exit you from Labtracer software.
21. If you are using Keithley 2400 sourcemeter, then click on the Close datacenter button. You will exit from Datacenter window only. 22. The GPIB connects the Labtracer setup to the Keithley 2400 SMU. 23. On clicking Run Test, the Keithley 2400 SMU should start the sweep. If this does not happen, refer to Annexure I for troubleshooting. 24. To Measure DARK IV, please close the shutter that blocks illumination and do the measurement. 25. During dark I-V measurement Si solar cell please keep the compliance 100 ma. TURN OFF Sequence: 26. Turn the knob slowly to zero. 27. Wait for 15mins for the lamp to cool down. 28. Turn OFF the lamp and fan switch at the back. 29. Turn off the computer and the Keithley Sourcemeter. 30. Turn OFF the switchboard. 31. For Solar cells with top and back metal contacts like Silicon Solar cells, use the probing manipulator to probe the top contact and the vacuum chuck will act as the back contact as shown below.
For Solar Cells with both contacts on top and light falling on the top, use two probing manipulators to probe both the contacts. Annexure I Troubleshooting for Keithley 2400 issue. 1. Click Menu. In the Main Menu enter Communication. 2. In Communications setup, click GPIB. 3. Make sure that the Address is seen as 24. If 24 is seen blinking, then it is OK. 4. Press ENTER and you will get GPIB Protocol. If 488.1 is blinking, then it is OK. 5. Press EXIT to come out of the Main Menu