Role of intrinsic defects in the electronic and optical properties of α-HgI2

Abstract

We investigated the role of intrinsic defects in the electronic and optical properties of mercuric iodide using ab initio methods. The calculations were performed using the total energy all electron methodology, considering full atomic relaxation. We computed the band structure, spin, formation and transition energies, and the dielectric function of isolated iodine and mercury vacancies in several charge states. Our results were compared to available experimental data on photoluminescence and photoplasticity in HgI2. We propose a microscopic model which can explain most of the data on those luminescent centers, unifying experimental results which suggested conflicting conclusions.