From ultraviolet to mid-infrared region, light-matter interaction mechanisms in semiconductors progressively shift from electronic transitions to phononic resonances and are affected by temperature. Here, we present a parallel temperature-dependent treatment of both electrons and phonons entirely from first principles, enabling the prediction of full-spectrum optical responses. At elevated temperatures, ab initio molecular dynamics is employed to find thermal perturbations to electronic structures and construct effective force constants describing potential landscape. Four-phonon scattering and phonon renormalization are included in an integrated manner in this approach. As a prototype ceramic material, cerium dioxide (CeO2) is considered in this work. Our first-principles calculated refractive index of CeO2 agrees well with measured data from literature and our own temperature-dependent ellipsometer experiment.
@article{arxiv.2211.15571,
title = {Temperature-Dependent Full Spectrum Optical Responses of Semiconductors from First Principles},
author = {Zherui Han and Changkyun Lee and Jiawei Song and Haiyan Wang and Peter Bermel and Xiulin Ruan},
journal= {arXiv preprint arXiv:2211.15571},
year = {2023}
}