Impact of A-Cations Modified on the Structural, Electronic, Optical, Mechanical, and Solar Cell Performance of Inorganic Novel A3NCl3 (A = Ba, Sr, and Ca) Perovskites

Recently, lead-free halide perovskites have exhibited outstanding optical absorption, enhanced stability, tunable bandgap, high carrier mobility, nontoxicity, availability of raw materials, and low cost. In this research, A-cations modified the structural, electronic, optical, mechanical, and solar cell performance of inorganic novel A(3)NCl(3) (A = Ba, Sr, and Ca) perovskites, which were deeply investigated using DFT and SCAPS-1D simulation software. Initially, we employed the Perdew-Burke-Ernzerhof (PBE) and hybrid functional (HSE) within the quantum espresso theory framework. The electronic structures are utilized to analyze and provide explanations for the real and imaginary portions of the dielectric function, absorption coefficient, and energy loss function. After profound investigation, the materials exhibit a semiconducting nature with a direct bandgap and are mechanically stable. Phonon studies have also confirmed the stability of the A(3)NCl(3) perovskites. The direct bandgap values have found to be 0.58(1.20), 1.258(1.75), and 1.683(2.30) eV with PBE(HSE), respectively, for Ba3NCl3, Sr3NCl3, and Ca3NCl3 absorbers, which decreased as the A-cation changed from Ba to Sr to Ca. Subsequently, all optimized DFT values are applied to the proposed structure of Al/FTO/SnS2/A(3)NCl(3)/Au for the analysis of solar cell performance via SCAPS-1D. Additionally, we analyzed the effects of varying absorber thickness, acceptor density, as well as bulk defect density on the configuration's overall performance. We also analyzed the optimized J-V and QE characteristics. After deep analysis, the structure of Al/FTO/SnS2/Ba3NCl3/Au has shown the highest power conversion efficiency (PCE) of 28.81% with a J(SC) of 38.26 mA/cm(2), FF of 79.91%, and V-OC of 0.94 V. Although the PCE was found at 18.11% and 8.54% with a J(SC) of 16.79 and 7.04 mA/cm(2), FF of 86.44% and 88.10%, V-OC of 1.24 and 1.37 V for Al/FTO/SnS2/Sr3NCl3/Au and Al/FTO/SnS2/Ca3NCl3/Au structures, respectively. The outcomes of these simulations offer insightful information that will be helpful in the experimental construction of effective A(3)NCl(3)-based inorganic perovskite solar cells.