Intrinsic electron mobility limits in β-Ga2O3

By systematically comparing experimental and theoretical transport properties, we identify the polar optical phonon scattering as the dominant mechanism limiting electron mobility in beta-Ga2O3 to <200 cm(2)/V s at 300K for donor doping densities lower than similar to 10(18) cm(-3). Despite similar electron effective mass of beta-Ga2O3 to GaN, the electron mobility is similar to 10x lower because of a massive Frohlich interaction, due to the low phonon energies stemming from the crystal structure and strong bond ionicity. Based on the theoretical and experimental analysis, we provide an empirical expression for electron mobility in beta-Ga2O3 that should help calibrate its potential in high performance device design and applications. Published by AIP Publishing.