A synergistic approach in designing InP/ZnS quantum dot based CIGS solar cell

This research work investigates the implementation of non-toxic InP/ZnS quantum dot (QDs) buffer layer in solar cell. Due to its nontoxic behaviour, it is a better replacement of commonly used CdS buffer layer. InP/ZnS quantum dots buffer layer enhances light absorption, leading to a broader spectral response and improved power conversion efficiency. Graded CIGS (CuIn1xGaxSe2) is used as absorber layer in this study for better utilization of solar spectrum. The combined utilization of an InP/ZnS QD buffer layer and a graded absorber layer results in a synergistic enhancement of the cell's performance. Further optimization of CIGS layers is achieved by varying the gallium content (x) in the Cu(In1_xGax)Se2. For the gallium content (x) in the range of 0.20 to 0.15, maximum efficiency is achieved which is 31.20 %. Numerical modeling is employed in this study to analyze how variations in thickness, doping concentration, and defect density impact the solar cell performances.