  The room temperature hole conductivity of the ultra wide bandgap
semiconductor beta Ga2O3 is a pre-requisite for developing the next-generation
electronic and optoelectronic devices based on this oxide. In this work,
high-quality p-type beta-Ga2O3 thin films grown on r-plane sapphire substrate
by metalorganic chemical vapor deposition (MOCVD) exhibit Rho = 50000Ohm.cm
resistivity at room temperature. A low activation energy of conductivity as
Ea2=170 meV was determined, associated to the oxygen - gallium native acceptor
defect complex. Further, taking advantage of cation (Zn) doping, the
conductivity of Ga2O3:Zn film was remarkably increased by three orders of
magnitude, showing a long-time stable room-temperature hole conductivity with
the conductivity activation energy of around 86 meV.
