First-principles calculations to investigate Electronic, Optical, Mechanical, and transport characteristics of novel A2BAuCl6 (A = K/Rb/Cs; B = Sc/Y)

By utilizing FP-LAPW, the structure, electronic, optical, mechanical and Transport characteristic of A₂BAuCl₆ (A = K/Rb/Cs, B = Sc/Y) were examined by using DFT. The analysis to the band structure plot of the Halide double perovskites (HDP’s) being studied indicated the existence of indirect band-gaps. The compounds A₂BAuCl₆ (A = K/Rb/Cs, B = Sc/Y) exhibit anisotropic properties, except one compound as seen by their respective shear anisotropy readings of 0.629, 0.532, 1.006, 0.682, 0.803 and 0.977. The materials have inherent ductility, as indicated by their calculated Poisson’s ratios in the range of 0.30 to 0.35. The examined (HDP’s) materials appear to possess indirect band-gaps, as indicated by the band structure plots. The functional inorganic perovskites A₂BAuCl₆ (A = K/Rb/Cs, B = Sc/Y) haven’t similar band-gap values, as determined using the TB-mBJ (modified Becke Johnson) and TB-mBJ + Soc (Spin orbital coupling) assumptions. The visible and ultraviolet domain have prominent peaks, suggesting potential applications of the compounds in solar cells. Moreover, examination of additional optical characteristics such as reflectivity, conductivity, electron energy loss, and absorption coefficients suggest that it possesses the inherent features of a semiconductor. The maximum figure of merit for all the student compounds is above 0.74. The simulated output forms the foundation for A₂BAuCl₆ (A = K/Rb/Cs, B = Sc/Y) and are of practical importance for multijunction solar cells.