Computational investigation on physical properties of lead based perovskite RPbBr (R = Cs, Hg, and Ga) materials for photovoltaic applications.

In the modern era, the major problem is solving energy production and consumption. For this purpose, perovskite materials meet these issues and fulfill energy production at a low cost. Density functional theory and the Cambridge Serial Total Energy Package (CASTEP) are used to examine the characteristics of the cubic inorganic perovskites RPbBr (R = Cs, Hg, and Ga). In the context of the generalized gradient approximation (GGA), the ultrasoft pseudo-potential plane wave technique and the Perdew-Burke-Ernzerhof exchange-correlation functional are used for investigations. Structural, mechanical, electronics, and optical properties are investigated using CASTEP code. According to structural properties, compounds have a cubic nature with space 221 (Pm3m). Compounds formation energy (- 3.46, - 2.21, and - 3.14 eV)of (CsPbBr, HgPbBr, and GaPbBr) and phonon calculations are studied and find that compounds are stable. The results of our investigation show that the compounds have narrow bandgaps of direct kind, with 1.85 eV for CsPbBr, 1.56 eV for HgPbBr, and 1.71 eV for GaPbBr respectively, indicating that they may be used to improve conductivity. Additionally, anisotropy (2.135, 3.651, 10.602), Pugh's ratio (1.87, 2.25, 2.14), and Poison's ratio (0.27, 0.31, 0.29) are traits that the compounds (CsPbBr, HgPbBr, GaPbBr) display a ductile nature. The CsPbBr compound showed significant optical conductivity and absorption in terms of their optical properties, especially in the visible region, which makes them suitable for use in solar cell applications as well as for LED applications.