Machine learned analysis of pnictides based Sr3PnCl3 (Pn = P, As, Sb) halide perovskites for next-generation solar applications

This study provides an in-depth investigation into the structural, electronic, mechanical, and optical properties of Sr(3)PnCl(3) (Pn = P, As, Sb) halide perovskites using QuantumATK tool. The computed equilibrium lattice constants for these materials are 6.28 angstrom, 6.32 angstrom, and 6.36 angstrom for Sr3PCl3, Sr3AsCl3, and Sr3SbCl3 respectively. The mechanical stability of these perovskites is confirmed by their elastic constants, adhering to the Born-Huang criteria with C-11 values of 45.21 GPa, 46.98 GPa, and 64.74 GPa for Sr3PCl3, Sr3AsCl3, and Sr3SbCl3 respectively. Their direct bandgaps of 2.137 eV, 1.950 eV, and 2.082 eV highlight their suitability for solar and optoelectronic applications. The absorption coefficients are notably high in the visible to near-UV region, with peak values of 406,483 cm(-1) for Sr3PCl3, 413,432 cm(-1) for Sr3AsCl3, and 435,860 cm(-1) for Sr3SbCl3. The refractive indices are reported as 1.76, 1.787 and 1.9 for Sr3PCl3, Sr3AsCl3 and Sr3SbCl3 respectively.