Effect of \u3cem\u3eCdCl\u3csub\u3e2\u3c/sub\u3e\u3c/em\u3e Treatment on CdTe and CdS Solar Cell Characteristics after Exposure to Light for 1000 Hours

The CdTe solar cell is a leading candidate for cost-effective thin-film solar cells having demonstrated small area cell effciencies of 16.4%. A Key issue associated with CdTe thin film photovoltaic modules is the analysis of degradation behavior of the device. The analysis is complicated as changes due to degradation may be reversible. Solar cell measurement techniques were used to understand the changes in device parameters after light soaking for 1000 hours. An automated measurement setup was implemented as part of this thesis work. The main objective of this thesis was to study the effect of CdCl2 heat treatment on the device stability. The temperature for this heat treatment was varied from 360oC to 400oC. Cells were stressed under illumination at both short circuit and open circuit conditions. It was found that the increase CdCl2 heat treatment temperature slowed down the degradation rate.This was true for both short and open circuit stress conditions. Also short circuit stress condition slowed down the degradation of the device when compared with the open circuit condition. It became evident that the recombination current mainly got affected when the device was said to be degraded