One-shot calculation of temperature-dependent optical spectra and phonon-induced band-gap renormalization

Here, the authors demonstrate a new first-principles computational method for performing predictive calculations of the optical absorption spectra of solids at finite temperature, including both zero-point fluctuations and phonon-assisted optical transitions. The comparison between calculations and measurements for the case of silicon, diamond, and gallium arsenide shows that this new method is not only efficient, but also very accurate, and is capable of yielding absorption coefficients in agreement with experiment over several orders of magnitude.