Temperature dependence of band gap in hybrid perovskites: a first-principles study

• Grant number: 20/13172-8
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): October 01, 2021
• Effective date (End): September 30, 2023
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal researcher: Alexandre Reily Rocha
• Grantee: Enesio Marinho da Silva Jr
• Home Institution: Instituto de Física Teórica (IFT). Universidade Estadual Paulista (UNESP). Campus de São Paulo. São Paulo , SP, Brazil
• Associated research grant: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties, AP.TEM

Abstract

Perovskite Solar Cells (PSC) based on hybrid organometallic halide perovskites are currently the most promising technologies for photovoltaics, mainly owing to the unprecedented growth in power conversion efficiency. These materials present excellent sunlight absorption, and good mobility and lifetime of charge carriers. However, the production in industrial scale of these PSC has important limitations, such as the instability of perosvkites in contact with environment humidity and high temperature. This postdoctoral project seeks to study the temperature-dependence on the electronic and optical properties of the main hybrid perovskites applied in the manufacture of PSC. The analyzes will be performed by ab initio calculations based on DFT, and Many Body Perturbation Theory (MBPT). Properties such as electron-phonon interaction, excitonic effects, and spin-orbit coupling will be analyzed in order to understand recent experimental results which show a monotonic growth of the band gap with increasing temperature, anomalous phenomenon to that verified in traditional semiconductors. The results obtained will be of great relevance in the scientific community, and may contribute to the development of photovoltaics based on hybrid perovskites both from the fundamental point of view as well as providing experimentalists with quantitatively accurate parameters. (AU)