【International Papers】Electronic structure and properties of trapped holes in crystalline and amorphous Ga₂O₃

      Researchers from the University College London have published a dissertation titled " Electronic structure and properties of trapped holes in crystalline and amorphous Ga₂O₃" in Physical Review B.

Abstract

      Structure and electronic properties of self-trapped holes were studied in both crystalline and amorphous Ga₂O₃ using density functional theory (DFT) and the nonlocal PBE0-TC-LRC density functional. Amorphous (a) Ga₂O₃ structures were generated using classical molecular dynamics and the melt-quench technique and further optimized using DFT. They exhibit an average density of 4.84g/cm³ and band gap around 4.3 eV. Calculations predict deep hole trapping in crystalline and amorphous phases with the hole-trapping energies in the amorphous structures being deeper than those found in the crystalline structure. In a−Ga₂O₃, trapped holes are localized around low-coordinated oxygen atoms (two or three coordinated). We predict the formation of stable hole bipolarons in both the crystalline and amorphous phases facilitated by the formation of O–O bonds with binding energies about 0.2 eV.