ZnxCd1-xSySe1-y as an effective electron transport layer for improving the efficiency of Sb2S3 and Sb2Se3 thin-film solar cells

Sb2Se3 and Sb2S3 are two types of thin-film solar cell (TFSC) absorbers that have drawn considerable interest and advanced quickly. These materials have several advantages over conventional TFSCs, such as suitable bandgap, high absorption coefficient, low cost, and simple structure. However, these materials also face challenges due to the interface recombination and energy band alignment with the electron transport layer (ETL). To address these issues, this study proposes the use of ZnxCd1-xSySe1-y as a tunable ETL that can optimize the conduction band offset at the interface with the absorber layer. Using the Solar Cell Capacitance Simulator, this work simulates the device performance for different values of x and y in the ETL and finds the optimal ratios that maximize the efficiency. Sb2Se3 solar cells achieve an efficiency of 18.7%, representing a 3%-point increase compared to Sb2S3 solar cells, which have an efficiency of 15.8%. This study demonstrates the promising potential of Sb2Se3 and Sb2S3 as materials for thin-film solar cells. Additionally, it highlights the effectiveness of ZnxCd1-xSySe1-y as an ETL in enhancing the performance of these solar cells.