We investigate the temperature effect on the electronic band structure and optical absorption property of wide-band-gap ternary nitride MgSiN2 using first-principles calculations. We find that electron-phonon coupling leads to a sizable reduction in the indirect gap of MgSiN2, which is indispensable in understanding the optoelectronic properties of this material. Taking the band gap renormalization into account, the band gap of MgSiN2 determined by the quasiparticle GW0 calculations shows good agreement with recent experimental result. The predicted phonon-assisted indirect optical absorption spectra show that with increasing temperature the absorption onset undergoes a red-shift. Our work provides helpful insights to the nature of the band gap of MgSiN2 and facilitates its application in ultraviolet optoelectronic devices.
@article{arxiv.2108.07545,
title = {Band gap renormalization and indirect optical absorption in MgSiN$_2$ at finite temperature},
author = {Dangqi Fang},
journal= {arXiv preprint arXiv:2108.07545},
year = {2021}
}