Boosting electrical performance of CIGS solar cells: Buffer layer effect

Abstract

The effect of the buffer layer in two different solar cell configurations such as ZnO/CdS/CIGS and ZnO/SnS/CIGS on the current density (J-V), generated power (P-V), and efficiency of the solar cells has been studied. Solar cell with SnS as buffer layer shows better performance and therefore the effect of the ambient temperature on the characteristics of this solar cell has been studied. Additionally, the effect of series and shunt resistance has been studied. The current density, generated power, and the efficiency of the solar cell increase when the buffer layer SnS is used. The thickness of the absorbent layer is also found to affect the efficiency of the solar cell significantly and optimal thickness is found to be 18 µm. We found substantial improvement in power conversion efficiency from 12.5% to 22.5% due to a decrease in series resistance. The increase in the ambient temperature decreases the current density of the solar cells significantly.