Structural and optoelectronic study of MgLiX3 (X= Cl, Br, and I) halide perovskites: A DFT approach

Abstract

This article presents in-depth information on the structural and optoelectronic properties of MgLiX3 (X = Cl, Br, and I) perovskites, and it suggests that MgLiX3 perovskites are promising materials for use in a variety of optoelectronic gadgets. The structural and optoelectronic properties of the compounds are determined utilizing first-principles calculations, with the density functional theory applied through the WIEN2k code. The structural stability was verified by computing the formation energy and binding energy. This study investigated the behavior of electronic conductivity and determined the bandgap values by employing TB-mBJ, which are 3.354 eV (MgLiCl3), 1.728 eV (MgLiBr3), and 0.067 eV (MgLiI3). Furthermore, optical properties such as absorption coefficient, reflectivity, conductivity, loss function, dielectric function, refractive index, and extinction coefficient were calculated and analyzed. In the visible range, MgLiBr3 and MgLiI3 exhibit their primary highest peaks of the absorption coefficient, which are 8.8 × 104 cm−1 for MgLiBr3 and 7.7 × 104 cm−1 for MgLiI3. On the other hand, MgLiCl3 demonstrates its initial highest peaks in the UV range, that is, 9 × 104 cm−1. The findings indicate that among the compounds studied, MgLiBr3 shows promise as a candidate for manufacturing solar cell devices based on the SQ limit, bandgap for typical perovskites (within 0.8–2.2 eV), and absorption in the visible range. MgLiCl3 is suitable for manufacturing several optoelectronic devices, such as laser diodes (LDs) and UV sensors due to having a high absorption coefficient in the ultraviolet region. With its low energy bandgap and high absorption coefficient in the IR to VR regions, MgLiI3 is well-suited for manufacturing photodetectors, LEDs, and other optoelectronic devices.