Analysis of power conversion limitation factors of Cu (InxGa1−x) (Se)2 thin-film solar cells using SCAPS

While the first generation of silicon solar cells offers a clean and unlimited energy source, the technology has matured where costs dominate, and the theoretical power conversion efficiency is reaching its limits. The new generation of thin-film solar cells is emerging as an affordable alternative to their bulky counterparts. The technology offers a much cheaper method to quickly fabricate solar cells that use less material with good optical and electronic properties on a wide range of substrates, including flexible materials. In particular, Cu (In_xGa_1−x) (Se)₂ thin-film solar cells are investigated using SCAPS simulation to study the impact of series resistance and doping levels of different layers of the cell structure on the short-circuit current, open-circuit voltage, power conversion efficiency, and fill factor. It was found that an increase in the series resistance of the solar cell layers results in a decrease in the power conversion efficiency with a dependency on light intensities. In addition, the doping level in the absorber and buffer layers plays a significant role in controlling the solar cell’s power conversion efficiency and fill factor values with maximum values when acceptor doping levels are approximately equal to donor doping levels.