GOPOWER / GALLIA research consortium - Research

Point Defects study by EPR spectroscopy

Person in charge :

EPR Studies on Defects and Conduction Band electrons in Ga2O3

                                                     Interest of EPR spectroscopy

  • It gives access to the chemical nature of the defect  (CHF interaction)
  • The electronic configuration (spin state) allows the determination of the charge state
  • The g-tensor anisotropy reveals the local point symmetry and thus the lattice site
  • Photoinduced EPR can determine the level position in the gap
  • EPR is quantitative / absolute defect concentrations

Examples of previous studies

  • Ga vacancy defects
  • Neutral Shallow donor  centers
  • Transition metals

    Polytypes studied: a, b, ε thin films and bulk Ga2O3 crystals

    Transition metals                                                                                                                                                                                                                                                                                

    Fe3+ ,Mn2+on Ga1 and Ga2 lattice sites

    Cr3+ on Ga2; Ir4+; Ti3+; Gd3+

    Shallow donors

    Si, SnGa1

    Deep acceptors

    Zn°Ga2, Mg°Ga

      Intrinsic defects/radiation induced defects

    VGa2-   S=1/2  /  S=1


    Free electrons


    Self trapped holes