Theory of Ga, N and H terminated GaN [formula omitted] surfaces

Abstract

We present a theoretical study of atomic structures, electrical properties and formation energies for a variety of possible reconstructions with 1 × 1 and 2 × 2 periodicity of the GaN (0 0 0 1) and (0 0 0 1 ) surfaces. We find that during MBE growth in the (0 0 0 1) direction 2 × 2 structures become stable under N rich growth conditions while Ga rich environment should yield structures with 1 × 1 periodicity. Considering MBE growth on (0 0 0 1 ) surfaces reconstructions with 1 × 1 periodicity have low energies. During MOCVD growth where H terminated surfaces may occur 1 × 1 periodicities are found to be stable for both growth directions.