Electronic properties of thin BaSi2 films with different orientations

Abstract

By means of ab initio calculations we have investigated surface energies and band structures of BaSi2 thin films with (001), (010), (100), (011), (101), (110), and (111) surfaces. It is found that BaSi2 (111), (010), and (100) surfaces possess the smallest surface energies which are almost twice less than the ones of the other surfaces. All thin films with different orientations and thickness are shown to be semiconductors. The influence of quantum confinement effects on BaSi2thin film band gaps has been traced indicating nontrivial behavior because of the presence of surface states which characterize the top/bottom of the valence/conduction bands. By implementing a simple effective mass approximation model we could define energy positions of surface states for some BaSi2 surfaces.