Low In solubility and band offsets in the small-x beta-Ga2O3/(Ga1-xInx)(2)O-3 system

Using first-principles calculations, we show that the maximum reachable concentration x in the (Ga1-xInx)(2)O-3 alloy in the low-x regime (i.e., the In solubility beta-Ga2O3) is around 10%. We then calculate the band alignment at the (100) interface between beta-Ga2O3 and (Ga1-xInx)(2)O-3 at 12%, the nearest computationally treatable concentration. The alignment is strongly strain-dependent: it is type-B staggered when the alloy is epitaxial on Ga2O3 and type-A straddling in a free-standing superlattice. Our results suggest a limited range of applicability of low-In-content GaInO alloys. (C) 2015 The Japan Society of Applied Physics