Using first principle electronic structure calculations within density functional theory and the supercell model, we have investigated the nature and formation energies of defect states associated with Ga and Te vacancies and Ge and Sn substitutional impurities in GaTe. We have also calculated the band structure of pure GaTe for comparison with systems with defects and also to find out the importance of spin–orbit interaction (SOI) on its band structure. We find that the top valence band at the Γ-point shifts up in energy by 0.1 eV due to the mixing of Te p x –p y and p z bands, this splitting being considerably smaller than in atoms where it is 0.8 eV. From an analysis of charge densities and band structures associated with the defect states, we find that most of them are strongly localized and lie deep in the band gap region. The calculated binding energy of the deep defect state and the ε(−1 / −2) transition level associated with the Ga vacancy appears to be in good agreement with experiment. Formation energy calculations suggest that V Ga is the preferred intrinsic defect in GaTe.

1 aRak, Zs1 aMahanti, S., D.1 aMandal, Krishna, C1 aFernelius, N.C. uhttps://icer.msu.edu/research/publications/theoretical-studies-defect-states-gate-000488nas a2200157 4500008004100000245004900041210004900090260001200139300001100151490000700162100001200169700002000181700002300201700002000224856008600244 2008 eng d00aTheoretical studies of defect states in GaTe0 aTheoretical studies of defect states in GaTe c01/2009 a0155040 v211 aRak, Zs1 aMahanti, S., D.1 aMandal, Krishna, C1 aFernelius, N.C. uhttps://icer.msu.edu/research/publications/theoretical-studies-defect-states-gate