Exploring Sb2S3 as a hole transport layer for GeSe based solar cell: a numerical simulation

Germanium selenide (GeSe) and antimony sulfide (Sb2S3) both are technological intriguing semiconductor material for green and economical photovoltaic devices. In this study, GeSe and Sb2S3 have been utilized as the absorber layer and hole transport layer, respectively, to constructed a heterojunction thin film solar cell consisting of FTO/TiO2/GeSe/Sb2S3/Metal. The GeSe and Sb2S3 are binary compounds and can adopt the same film deposition method, for instance, thermal evaporation, which is expected to improve process compatibility and to reduce production costs. The TiO2 (electron transport layer) and Sb2S3 can form small spike-like conduction band offset and valence band offset with the GeSe, respectively, which possesses potential to suppress carrier recombination at the heterointerfaces. Subsequently, the effects of main functional layer material parameters, heterointerface characteristics and back contact metal work function on the performance parameters of the proposed solar cell were simulated and analyzed using wxAMPS software. After numerical simulation and optimization, the proposed solar cell can reach an open circuit voltage of 0.872 V, a short circuit current of 40.72 mA<middle dot>cm(-2), a filling factor of 84.16%, and a conversion efficiency of 28.35%. According to the simulation results, it is anticipated that the Sb2S3 can serve as a hole transport layer for GeSe based solar cell and enable device to achieve high efficiency. Simulation analysis also provides some meaningful references for the design and preparation of heterojunction thin film solar cells.