Utilizando a Teoria do Funcional da Densidade para Investigar Propriedades Estruturais e Eletrônicas de Perovskitas com Aplicações em Células Fotovoltaicas

Abstract

The perovskite, the subject of investigation in this study, is a mineral that has gained attention due to its use as an active layer in the fabrication of high-efficiency photovoltaic solar cells. The main objective here is to investigate the structural and electronic properties of certain perovskite halides, utilizing the methodology of Density Functional Theory (DFT) to solve the Schr ̈odinger equation. The obtained results include calculations of lattice parameters, energy gaps, density of states (DOS), and the corresponding Projection of Density of States (PDOS). Our results reveal that the cubic structure is not the one of lowest energy for lead methylammonium iodide (CH3NH3P bI3), lead methylammonium chloride (CH3NH3P bCl3), or lead methylammonium bromide (CH3NH3P bBr3). These halides can also crystallize in orthorhombic and tetragonal phases. In all cases, the calculations show that the electronic states in the bandgap do not have contributions from the organic part of these perovskites. Additionally, we demonstrate the dependence of the energy gap values on the substitution of I by Br or Cl, as well as the variation with the geometry of the studied crystals.