Native defect association in beta-Ga2O3 enables room-temperature p-type conductivity

TL;DR

This paper demonstrates room-temperature p-type conductivity in beta-Ga2O3 thin films through native defect complexes and Zn doping, achieving significant conductivity improvements suitable for electronic applications.

Contribution

It reports the first high-quality p-type beta-Ga2O3 thin films with stable conductivity at room temperature, enhanced by native defect engineering and Zn doping.

Findings

Resistivity of 50000 Ohm·cm at room temperature

Activation energy of 170 meV for native defect conduction

Three orders of magnitude increase in conductivity with Zn doping

Abstract

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.