Análise Teórica-Experimental das Propriedades Eletrônicas e Estruturais da Perovskita de Haleto Cs2AgSbCl6.

Abstract

The growing demand for alternative energies has become important for preserving the environment. To solve this problem, photocatalysis enabled by some semiconductors has been found to be a low-cost and sustainable approach. Semiconductors are characterized by separate valence and conduction bands, and the energy difference between these bands is called bandgap. New materials that fall within this class have been synthesized and studied, as is the case of halide-based perovskites. In the last few years, a new class of solar cells based on halide perovskites has been presented, showing themselves as photovoltaic devices with high power conversion efficiencies above 30 %. Theoretical studies conducted using Density Functional Theory, and also conducted to describe the electronic structure of the Cs2AgSbCl6 double perovskite, which was synthesized and characterized Cs2AgSbCl6 powder samples designed for solar cell applications. The crystalline phase and morphological characteristics were investigated using powder X-ray diffraction, neutron diffraction, scanning electron microscopy, in complement with UV-vis spectroscopy. The UV-vis spectrum yielded a bandgap of 2.7 eV, this value was accurately estimated by the theoretical model using the HSE06 functional using the CRYSTAL17 program. The synthesis and evaluation were carried out in a systematic and unprecedented way, and the electronic properties were evaluated with the main objective of energy conversion applications.