First-Principles Investigation of the Semiconducting Behavior in Hybrid CH3NH3PbBr3 Perovskite Using the Quantum ESPRESSO Suite

Peñalva J.; Bolaños J.; Larico R. · Proceedings of the LACCEI international Multi-conference for Engineering, Education and Technology (2026) · DOI: 10.18687/laccei2026.1.1.945

Resumen

This study explores the electronic and structural characteristics of cubic methylammonium lead bromide (CH3NH3PbBr3) through Density Functional Theory (DFT) calculations performed with Quantum ESPRESSO. Following rigorous convergence benchmarks (Ecutwfc = 45 Ry, Ecutrho = 300 Ry, and a 3 × 3 × 3 k-point grid), the simulated X-ray diffraction pattern is consistent with a single-phase cubic perovskite structure. Our results identify a direct band gap of 2.01 eV situated at the R high-symmetry point. Analysis of the Partial Density of States (PDOS) reveals that the Valence Band Maximum is primarily composed of Pb(s) and Br(p) states, while the Conduction Band Minimum is governed by Pb(p) anti-bonding orbitals. These findings underscore the material's suitability for optoelectronic devices operating in the visible spectrum (λ ≈ 617 nm).

Instituciones: Universidad Tecnológica del Perú