Sb₂Se₃ as an HTL for Mo/Sb₂Se₃/Cs₂TiF₆/TiO₂ solar structure: performance evaluation with SCAPS-1D

Perovskite-based solar cells (PSCs) have recently gained much attention due to their distinctive optical and electrical properties. Cesium titanium fluoride (Cs₂TiF₆) is an example of lead-free perovskite absorber material with a bandgap of 1.9 eV, making it suitable for a solar device. However, the high cost of the hole transport material (HTM) and other considerations prevent their commercial production. Antimony selenide (Sb₂Se₃) is well suited for HTM as it is low-cost material with a tunable bandgap. The work presents the TiO₂/Cs₂TiF₆/Sb₂Se₃-based solar cell performance using SCAPS-1D simulation software. The effect of all the active layer thicknesses, defect density, hole-electron mobility, and temperature on the device is also simulated. I-V, C-V, and QE curves and energy band diagrams show the photovoltaic device's excellent performance. The outputs are competent enough with an efficiency of 22.10 % when Sb₂Se₃ is used as a hole transport layer (HTL) in the device architecture. The results suggest that the lead-free solar cell is a promising future option for the solar cell community regarding environmental friendliness and high efficiency.