Design and analysis of a SnS2/WS2/V2O5 double-heterojunction toward high-performance photovoltaics

Abstract

Tungsten disulfide (WS₂) transition metal dichalcogenide (TMDC) absorber-based solar cells comprising tin disulfide (SnS₂) buffer and vanadium (V) oxide V₂O₅ back surface field (BSF) layers have been designed and analyzed using a SCAPS-1D simulator in this study. The initial experimentation on back metal contact (BMC) and front metal contact (FMC) optimization involved the use of different materials to obtain the least resistive junction at the semiconductor–metal (M–S) interface, where the best potential was found. Following an extensive investigation nickel (Ni) and aluminum (Al) is determined to be the optimal material for the back and front contact, respectively. Subsequently, the impact of major parameters which affecting the photovoltaic (PV) performance, such as absorber layer thickness, doping concentration, bulk defect density, interface defect density, operating temperature, and surface recombination velocity, were studied systematically. An improved photoconversion efficiency (PCE) of over 32% (around 9% higher) was obtained with the open-circuit voltage (V_OC) of 1.1 V, short-circuit current (J_SC) of 37.2 mA cm⁻², and fill factor (FF) of 84% with the Al/FTO/SnS₂/WS₂/V₂O₅/Ni heterostructure, compared to 23.4%, 0.89 V, 31.2 mA cm⁻² and 81% for the pristine cell (without V₂O₅ BSF). These outcomes obtained from comprehensive studies reveal the huge potential of the SnS₂/WS₂/V₂O₅ double-heterostructure to be applied as a PV cell and pave a resourceful pathway for the experimental fabrication of WS₂-TMDC absorber-based high-performance photonic devices.