Exploring the influence of M-anion modifications on the physical properties of lead-free novel halide inorganic compounds Ba₃MCl₃ (M = N, P, As, Sb)

This study investigates the effects of M-anion modifications on lead-free halide inorganic compounds, specifically Ba₃MCl₃ (M = N, P, As, Sb), using DFT and SCAPS-1D software. It focuses on analyzing their optical, electronic, and structural properties. The lattice parameters for Ba₃MCl₃ were found to be <i>a</i> = 6.14, 6.44, 6.51, and 6.69 Å, respectively, which is consistent with previous research. Initially, GGA with the PBE functional theory was used. The materials displayed semiconductor characteristics, with direct band gaps of 0.551 eV for Ba₃NCl₃, 0.927 eV for Ba₃PCl₃, 0.980 eV for Ba₃AsCl₃, and 0.996 eV for Ba₃SbCl₃. Optical characteristics such as absorption, loss function, dielectric function, electrical conductivity, reflectance, and refractive index were also examined. Additionally, the SCAPS-1D software was exploited to thoroughly estimate the efficiency of absorber-based PV cell structures Ba₃NCl₃, Ba₃PCl₃, Ba₃AsCl₃, and Ba₃SbCl₃ with a CdS ETL layer at varying thicknesses, defect densities, and doping levels. QE and <i>J</i>-<i>V</i> characteristics were assessed, with maximum PCEs of 23.06%, 19.93%, 17.12%, and 15.71% for Ba₃NCl₃, Ba₃PCl₃, Ba₃AsCl₃, and Ba₃SbCl₃, respectively. These computational findings offer valuable insights for developing efficient, lead-free, durable, and cost-effective solar cells based on Ba₃MCl₃ compounds.