Selection of efficient HTL for lead-free Cs₂TiBr₆-based PSC with relative permittivity, & carrier life time optimization: a theoretical study

This research work represents a comparative study of the regular n-i-p heterojunction structure ofCs₂TiBr₆ single halide Perovskite solar cells (PSCs) using the SCAPS-1D software framework under ambient conditions.We have studied the performance optimization of different hole transfer layers (HTLs)P3HT, CuO, Cu₂O, and MoO₃ respectivelyfollowed by optical, and electronic properties analysis to identify the appropriate HTL for the FTO/TiO₂/Cs₂TiBr₆/HTL/Ag-based PSC module.Other performance parameters, C-V (Capacitance–voltage), and M-S (Mott-Schottky) plot analysisshows thatMoO₃HTL has better photovoltaic (PV) performance characteristics. Cs₂TiBr₆/MoO₃ based PSC shows higher open circuit voltage (V_OC = 0.2434 V), power conversion efficiency (PCE = 4.8%)compares to Cs₂TiBr₆/ P3HT, Cs₂TiBr₆/CuO, Cs₂TiBr₆/Cu₂O based PSC. On the other look, investigated PSC material Cs₂TiBr₆/MoO₃has shown visible light emission edge at 190 nm wavelength, superior semi-circular shape, higher PV parameters in the context of variation in relative permittivity, carrier lifetime, diffusion length, and defect density at the interfaces.The optimized carrier lifetime of Cs₂TiBr₆/MoO₃-based PSC has been recorded as 50 ns at 500 nm thickness of active material.