Boosting the performance of SnSe-based solar cells through electron and hole transport layers: A qualitative study and perspectives

The SnSe compound is garnering considerable interest as a potential solar absorber for developing highly efficient thin-film solar cells. Using one experimental report as a foundation and employing the one-dimensional solar cell capacitance simulator (SCAPS-1D), we examined the elements that impact the efficiency of solar cells utilizing tin selenide as the base material. The base structure consists of Anode/SnSe/CdS/i-ZnO/ZnO:Al/Cathode. A 0.5 μm thick SnSe film demonstrated an efficiency of 2.51 %. In the initial phase, we optimized the device efficiency to 18.65 % through parameter adjustments, utilizing toxic CdS as a buffer layer. In the subsequent phase, earth-abundant and non-toxic Zn_1-xMg_xO, SnO₂, and TiO₂ alternatives were explored as electron transport materials (ETL) to replace CdS. Zn_1-xMg_xO (with x = 0.1875) exhibited the highest efficiency at 19.03 %. In the final phase, various hole transport materials (HTL) were studied to enhance the SnSe-based solar cell's performance. Among the HTL materials investigated, NiO yielded the best efficiency of 20.59 % when using Zn_1-xMg_xO (with x = 0.1875) as a buffer layer.