Exploring the structural properties and the optoelectronic features of RbPbX3 (X = Cl, F) perovskite crystals for solar cells solicitations: Showcasing the DFT predictions.

Abstract

A comprehensive study of the structural, optical, and electronic properties of RbPbX3 (where X is Cl or F) perovskite crystals is reported herein. The calculations of the different physical properties of these two distinguishable RbPbCl3 and RbPbF3 perovskite crystals have been carried within the framework of the Density Functional Theory (DFT) approach for the cubic temperature-dependent phase. The study is motivated by the exploration of innovative perovskites materials for solar cells application due to the marvelous augmentation in power conversion efficiency (PCE) obtained by perovskite crystals (≈ 25% up to date). The investigation were undertaken for determining the perceivable role of the X element in their band gap energy features as well as the band structure proprieties. The simulations were commenced by determining the optimal lattice constants and the lowest total energy of both perovskite crystals. The exploration of the electronic properties of RbPbCl3 and RbPbF3 perovskite crystals have been studied by estimating their variation upon employing spin–orbit-coupling (SOC) and without taking into consideration the SOC interaction by means of LDA-pz and GGA-PBE exchange potentials within the framework of projector augmented wave method (PAW) and the Perdew-Burke-Ernzerh of LDA and (PBE) variant of the generalized gradient approximation (GGA). The integrated suite quantum-ESPRESSO is used for materials modeling, structure calculations, and electronic properties of the studied RbPbCl3 and RbPbF3 perovskite crystals. The thermo_pw driver is employed for the determination of the elastic properties whereas the optical properties were elucidated by aid of Yambo code through solving the many-body perturbation theory (MBPT) approach as introduced in the open-source code. The optical band gap of cubic RbPbCl3 and RbPbCF3 within LDA and PBE, were observed at (2.18, 2.2) eV and (2.4, 2.5) eV respectively. Compared and contrasted with those revealed by the electronic band gap energy of the systems, these obtained values are very consistent with the experimental. The two maximum peaks for the absorption coefficients are found to be within the visible range rending the two perovskite crystals in promising candidate for solar cell applications. Despite some quantitative differences, the material’s enhancement potential is well demonstrated by the absorption coefficient spectrum, refractive index, and conductivity. The study holds promise for solar cell applications and may pave the way for consideration of the RbPbCl3 and RbPbF3 as well as their doped analogs for perovskites-based solar cells as the next generation in the photovoltaic industry.