A theoretical study of effective mass of electrons in the Iron-doped CsPbBr3 perovskite using VASP

Abstract

Over the last few decades, computational based quantum-mechanical illustration of the interaction between electrons and ions has advance in impacting the material science significantly – not only in extensive understanding but also in developing the new material design for future technologies. The development is based on two considerable factors: first is improvement in illustration of electronic many bodies problem within the frameworks of Density Functional Theory (DFT) methods and second one is other new functional and technique to solve many bodies with highly efficient, stable, and computer codes which unlocks the potential of modern-day architectures. The Vienna Ab Initio Simulation Package (VASP) is a simulation package which is used for atomic scale material modeling to study the electronic structure calculations with the properties like band structure, density of state, wave function, charge density etc. for different material. VASP code is just the implementation of the DFT approach for the calculation of electronic structure of material represented by wave function of the electron in the plane wave basis sets and the interaction between electron and ion are represented by PAW model that are ultra-soft pseudo potentials considering valence electron interaction and use the frozen core approximation. This approximation is the inner electron are strongly bound to the nucleus. The VASP code uses iterative technique for the DFT Hamiltonian diagonalization and allows performing the energy calculation and optimization structure for the large crystal system even containing thousands of atoms and ions. These computational methods have many applications in many different areas like magnetism, nanostructure, optimization, mechanical and dynamical properties, semiconductor, interface, and catalysis. Over the last decade, there is re-emergence of halide perovskite caught the attention due to its versatile merits as photovoltaic materials exhibiting high absorption coefficient, bandgap tenability, and low-cost processing. To study the conductivity of the material, we use the concept of the effective mass which comes from the band theory of solids. Effective mass is one of the main factors to estimate the curvature of the electronic band by one-band approximation. Here, we have studied Cesium lead tribromide and Cesium lead other halides (CsPbX3) perovskites.