Pressure-dependent optoelectronic properties of antiperovskite derivatives X₃AsCl₃ (X = Mg, Ca, Sr, Ba): a first-principles study

The success of halide perovskites in the field of optoelectronics has sparked extensive exploration of perovskite-type compounds, including antiperovskites and perovskite derivatives. Recently, a class of antiperovskite derivatives, X₃MA₃, has been proposed as potential photovoltaic absorbers. These antiperovskite derivatives share a similar crystal structure with perovskites, featuring a corner-sharing octahedral framework. In this work, we employed first-principles calculations to investigate the evolution of the structural and optoelectronic properties of four antiperovskite derivatives X₃AsCl₃ (X = Mg, Ca, Sr, Ba) under hydrostatic pressures ranging from 0 to 4 GPa. Our results show that these properties change linearly with pressure, with the structure and electronic properties of Ba₃AsCl₃ being particularly sensitive to pressure. At 4 GPa, its band gap and lattice constant decrease by 0.37 eV and 0.251 Å, respectively. Notably, Ba₃AsCl₃ achieves a high theoretical conversion efficiency exceeding 30% under moderate pressure. Our research suggests that Ba₃AsCl₃ may be a promising candidate for future optoelectronic devices, particularly under compressed epitaxial strain.