First principles study on electronic structure of β-Ga2O3

We have studied the electronic structure of beta-Ga2O3 using the first principles full-potential linearized augmented plane wave method. It is found that beta-Ga2O3 has an indirect band gap with a conduction band minimum (CBM) at Gamma point and a valence band maximum on the E line. The anisotropic optical proper-Lies are explained by the selection rule of the band-to-band transitions. On the other hand, the shape of the CBM is almost isotropic and, therefore, the observed electronic anisotropy in the n-type semiconducting state should not be attributed to the properties of a perfect lattice. The Burstein-Moss shift is discussed using the effect of several allowed transitions between the levels of the valence band and the CBM. (C) 2004 Elsevier Ltd. All rights reserved.