The structural, magnetic, optoelectronic, and mechanical characteristics of NaGeX3 perovskites under pressure for soler-cell applications

Abstract This study examines the physical properties of germanium-based halide perovskite through Density Functional Theory (DFT) computations. The physical, optical, mechanical, and magnetic properties of NaGeX 3 (X = Cl, Br, and I) were examined with the effects of hydrostatic pressure applied externally. The compounds were subjected to pressure variations ranging from 0 to 5 GPa. The results indicate a decrease in the band gap from the infrared to the visible spectrum. For NaGeCl 3 , NaGeBr 3 , and NaGeI 3 the band gap decreased from 0.766 eV, 0.497 eV, and 0.400 eV to 0 eV, respectively, indicating the metallic behavior. The mechanical properties of NaGeX 3 (X = Cl, Br, and I) demonstrate that for all three compounds, Bulk Modulus (B), Shear Modulus (G), Young’s Modulus (E), Poisson’s ratio (ν), and Pugh’s ratio B / G all increase with increasing pressure. It demonstrates that all these NaGeX 3 (X = Cl, Br, I) compounds are ductile in nature. The compounds are determined to be diamagnetic based on their magnetic property investigation, which reveals no notable changes in behavior up to 5 GPa of rising pressure. To gain a better understanding of the properties of the material when incident light strikes its surface, researchers also looked in at optical absorption, reflectivity, dielectric constants, refractive index, conductivity, and loss functions. Pressure-induced NaGeX 3 perovskite compounds, where X = Cl, Br, and I, show an increase in dielectric constant as pressure rises, suggesting a decrease in charge carrier recombination rates and a possibility for higher optoelectronic device efficiency. For all NaGeX 3 compounds (where X = Cl, Br, and I), the maximum absorption coefficient peaks are located around 3 eV, indicating that increasing pressure increases optical conductivity. Additionally, they have significantly low reflectance throughout the visible spectrum and very narrow band gap, which indicates significant absorption and the possibility of effective Near-Infrared (NIR) Sensors, photodetector etc applications.