Simulating the Highly Efficient SbSe Solar Cell with ZnP as a Back Surface Field Layer Using SCAPS-1D.

The recombination losses in the bulk absorber and interfaces limit the power conversion efficiency of antimony selenide (SbSe) solar cells. This study aims to enhance efficiency in a new cadmium-free SbSe-based solar cell by using tungsten disulfide (WS) as the buffer layer and zinc phosphide (ZnP) as the back surface field (BSF) layer, simulated in SCAPS-1D software. It is revealed that the proposal of WS as the buffer and ZnP as the BSF confirms the appropriate band alignment at the SbSe/WS and ZnP/SbSe interfaces, respectively. The recombination of the carrier at both interfaces of the anticipated ZnP/SbSe/WS/FTO structure will be lower than in SbSe devices with other buffers and BSFs. To optimize the proposed SbSe PV device, the impacts of numerous inputs such as thickness, doping concentration, bulk and interface defects, charge transfer characteristics, temperature, and work function along with parasitic resistance on performance parameters have been investigated. The efficiency is improved from 22.09% to 29.5% with an open-circuit voltage () of 0.99 V, a short-circuit current density () of 34.99 mA/cm, and a fill factor (FF) of 85.36% at the optimized condition of the absorber (thickness = 1.0 μm, doping density = 10 cm, and defect density = 10 cm), buffer (thickness = 50 nm and doping density = 10 cm), and BSF (thickness = 100 nm and doping density = 10 cm). In addition, the high defect level of 10 cm is optimized at the SbSe/WS and ZnP/SbSe interfaces. Nickel is the optimal back contact metal, while resistances are found to be 0.5 Ω cm for series resistance and 10 Ω cm for shunt resistance. These findings will motivate researchers and experimentalists to produce low-cost, less toxic, environmentally friendly, and high-efficiency SbSe-based thin-film photovoltaic devices.