Degradation Preparation

1. Determine the temperature in which you would like to degrade the cells
   • To degrade a cell at 75 C, the water bath must be at 90 C. This takes 40 minutes to reach the bath temperature
2. Determine which cells you would like to degrade.
   • This will then determine the shape of the covers used when testing each cell so that the rest are not subjected to the light
3. Turn the solar simulator on and give it some time to warm up (30 minutes)
4. It is recommended to arrive 1 hour before desired testing start time.
5. For the first 24 hours, the desired times to take measurements are 0 min, 0.5min 1min, 5 min, 10 min, 20 min, 30 min, 1 hour, 2 hours, 5 hours, 10 hours, 20 hours, 24 hours.
   • The Time Step Excel file contains the desired hours and the predicted times when the tests will be made.
   • Typically, it takes 20-30 minutes to test 6 cells with 6 measurements on each

Degradation test with PIN cells

Note: With PIN cells, you can degrade at any temperature; however, when taking measurements, one can only do so at room temperature with the current rig.

Running Tests

1. Run 10_10_27_stepup and chose a desired save directory
2. When the solar simulator is ready you can start the 0 min run
3. Once the bath is ready you can begin the degradation testing
4. Place the cell on the testing platform and allow it to degrade for the desired time
   • Turn on the shutter
5. Once desired degradation time is complete, stop the timer and close the shutter
6. Remove the cell from the testing platform and place it in the testing holder
7. Place the probes on the aluminum contact and oxide layer
   • Positive on the aluminum contact and negative on the oxide layer
8. Click measure on the program and record the data
   • Note: the files are saved as the time that it was run so write notes to distinguish between files
9. Measure results 2 top, 2 mid and 2 bot
10. Move to the next cell and repeat
11. Once all the cells have been tested place it back onto the testing platform and open the shutter and resume the timer.
12. Repeat testing until the results (FF) have stabilized (usually about a week)

Tips

1. Try to insulate the tygon tubing and the platform as best as possible
2. Take at least 6 measurements for each cell so that you can average results / get a feel for the cell
3. Each group of 6 cells with 6 measurements each takes ~30 minutes which will offset your clock.
4. See time table (excel) for how it works for the first day
5. After the first day only need to measure twice a day and to check on water levels
   • Need to refill water bath every 10-14 hours.
6. When adding more water do it after the cell has been removed form the test set up and the light is off so that the cell is not exposed to a different degradation temperature
7. Make sure to wear proper protection at all times
8. Make sure to warn other lab users that a test is in session