The effects of hydrogen incorporation into beta-Ga2O3 thin films have been
investigated by chemical, electrical and optical characterization techniques.
Hydrogen incorporation was achieved by remote plasma doping without any
structural alterations of the film; however, X-ray photoemission reveals major
changes in the oxygen chemical environment. Depth-resolved cathodoluminescence
(CL) reveals that the near-surface region of the H-doped Ga2O3 film exhibits a
distinct red luminescence (RL) band at 1.9 eV. The emergence of the H-related
RL band is accompanied by an enhancement in the electrical conductivity of the
film by an order of magnitude. Temperature-resolved CL points to the formation
of abundant H-related donors with a binding energy of 28 +/- 4 meV. The RL
emission is attributed to shallow donor-deep acceptor pair recombination, where
the acceptor is a VGa-H complex and the shallow donor is interstitial H. The
binding energy of the VGa-H complex, based on our experimental considerations,
is consistent with the computational results by Varley et al [J. Phys.:
Condens. Matter, 23, 334212, 2011].Comment: 3 figure
