Thermal conductivity and temperature-induced bandgap renormalization in crystalline and amorphous Ga2O3

Abstract

The lattice thermal conductivity (LTC) and electron–phonon interactions in crystalline and amorphous gallium oxide are herein determined by coupling a machine-learned interatomic potential, namely the moment tensor potential model, to first-principles calculations. Crystalline β-Ga2O3 exhibits a substantial bandgap renormalization (BGR) of ∼0.45 eV at 700 K, with ∼0.2 eV caused by zero-point BGR. The computed temperature dependence of BGR induced by classical nuclear motion in β-Ga2O3 is stronger than that in amorphous Ga2O3, with the difference in BGR reaching ∼0.18 eV at 900 K. Thermal transport calculations reveal that the LTC of amorphous Ga2O3 remains near 0.9 W m−1 K−1 for temperatures between 300 and 700 K, which is approximately an order of magnitude lower than that of crystalline β-Ga2O3. Overall, the presented framework provides a computationally tractable and reliable route for predicting properties of semiconductors (both crystalline and amorphous) under operating conditions relevant to microelectronics and optoelectronics.

The authors' abstract, as published at the source. Applied Physics Letters, 2026 · DOI ↗