New semiconducting KMgSiH (H = Cl & Br) halides have been investigated via DFT approach; their mechanical, optical, and structural properties were studied in detail.

Researchers are now avoiding perovskite materials containing lead due to their toxicity and instability in open air and heat. In this study, our research group worked on potassium-based KMgSiCl & KMgSiBr perovskite compounds and thoroughly investigated these materials' basic behaviours. Goldschmidt and formation energy results certify the structure and thermodynamic stabilities of the studied compounds. The band gaps noted for the KMgSiCl & KMgSiBr perovskites were 2.42 eV & 1.88 eV, respectively. After the mechanical observations of the investigated compounds, it became apparent that both the studied compounds own brittle and anisotropic nature. Based on the tendency to absorb electromagnetic radiations both in the ultra-violet and visible range, it enables the KMgSiCl & KMgSiBr perovskites suitable for detectors, solar cells, and many other optoelectronic devices. The KMgSiBr material showed the first response to the electromagnetic radiations in the visible range and acquired the optical conductivity value of 1219 (Ω.cm); however, KMgSiCl material showed its response to a bit higher energetic photons in the visible range than KMgSiBr material, but its optical conductivity was higher (i.e., 1270 (Ω.cm)) than the KMgSiBr material in the visible range.