Using infrared absorption spectroscopy of hydrogen passivated β-Ga2O3 the temperature dependence of the dominant O – H vibrational line was measured between 5 and 300 K. With increasing temperature, the vibrational line shifts by Δω = 7.8 cm-1 to lower frequency. This is accompanied by a broadening of the vibrational line from Γ = 0.61 to 8.18 cm-1. The data are discussed in terms of elastic and inelastic phonon scattering and exchange coupling. Moreover, the perturbation of the hydrogen potential is evaluated.
