Ti-A nd Fe-related charge transition levels in β-Ga 2 O 3

Tutkimustuotos: Lehtiartikkelivertaisarvioitu


  • Christian Zimmermann
  • Ymir Kalmann Frodason
  • Abraham Willem Barnard
  • Joel Basile Varley
  • Klaus Irmscher
  • Zbigniew Galazka
  • Antti Karjalainen
  • Walter Ernst Meyer
  • Francois Danie Auret
  • Lasse Vines


  • University of Oslo
  • University of Pretoria
  • Lawrence Livermore National Laboratory
  • Leibniz Institute for Crystal Growth


Deep-level transient spectroscopy measurements on β-Ga 2 O 3 crystals reveal the presence of three defect signatures labeled E 2 a, E 2 b, and E 3 with activation energies at around 0.66 eV, 0.73 eV, and 0.95 eV below the conduction band edge. Using secondary ion mass spectrometry, a correlation between the defect concentration associated with E 3 and the Ti concentration present in the samples was found. Particularly, it is found that E 3 is the dominant Ti-related defect in β-Ga 2 O 3 and is associated with a single Ti atom. This finding is further corroborated by hybrid functional calculations that predict Ti substituting on an octahedral Ga site, denoted as Ti GaII, to be a good candidate for E 3. Moreover, the deep level transient spectroscopy results show that the level previously labeled E 2 and attributed to Fe substituting on a gallium site (Fe Ga) consists of two overlapping signatures labeled E 2 a and E 2 b. We tentatively assign E 2 a and E 2 b to Fe substituting for Ga on a tetrahedral or an octahedral site, respectively.


JulkaisuApplied Physics Letters
TilaJulkaistu - 18 helmikuuta 2020
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

ID: 41441516