FIRST-PRINCIPLE MODELING OF STRUCTURAL, ELECTRONIC, AND OPTICAL PROPERTIES OF CH3NH3PbBr3

Abstract

Електроніка та інформаційні технології. 2022. Випуск 18 77 perovskites showed a similar DOS distributions, which may be divided by three regions. The first region is formed by the methylammonium ion p-states, which forms narrow bands located deep about at −8eV. The second region at −6.0 -0 eV within the valence band complex, characterizes with the largest contribution being observed from hybrid Br p-orbitals and Pb s-orbitals. The third region is placed from 2.44 to 7.0 eV for cubic, from 2.24 to 6.9 eV for tetragonal, and from 2.35 to 6.3 eV for orthorhombic phases, respectively. The conduction band minimum is mainly formed by hybridized states of the Pb p-orbitals and a small contribution of Br p-orbitals.Calculations of the values of the effective masses in the three main directions for all crystalline phases were also carried out. The optical properties show that the CH3NH3PbBr3 perovskite has a good ability for photon absorption and demonstrates the possibility of its use in a wide temperature range.