Design and simulation of a high-performance Cd-free Cu2SnSe3 solar cells with SnS electron-blocking hole transport layer and TiO2 electron transport layer by SCAPS-1D

Abstract

AbstractThis article presents numerical investigations of the novel (Ni/SnS/Cu2SnSe3/TiO2/ITO/Al) heterostructure of Cu2SnSe3 based solar cell using SCAPS-1D simulator. Purpose of this research is to explore the influence of SnS hole transport layer (HTL) and TiO2 electron transport layer (ETL) on the performance of the proposed cell. Based on the proposed device architecture, effects of thickness and carrier concentration of absorber layer, SnS HTL, TiO2 ETL, absorber layer defect density, operating temperature and back-contact metal work function (BMWF) are studied to improve the cell performance. Our initial simulation results show that if SnS HTL is not introduced, the efficiency of standard Cu2SnSe3 cell is 1.66%, which is well agreed with the reported experimental results in literature. However, by using SnS and TiO2 as HTL and ETL, respectively and optimizing the cell parameters, a simulated efficiency of up to 27% can be achieved. For Cu2SnSe3 absorber layer, 5 × 1017 cm−3 and 1500 nm are the optimal values of carrier concentration and thickness, respectively. On the other hand, the BMWF is estimated to be greater than 5.2 eV for optimum cell performance. Results of this contribution can provide constructive research avenues for thin-films photovoltaic industry to fabricate cost-effective, high-efficiency and cadmium-free Cu2SnSe3-based solar cells.