Schottky barrier height of Au on the transparent semiconducting oxide β-Ga2O3

The Schottky barrier height of Au deposited on (100) surfaces of n-type beta-Ga2O3 single crystals was determined by current-voltage characteristics and high-resolution photoemission spectroscopy resulting in a common effective value of 1.04 +/- 0.08 eV. Furthermore, the electron affinity of beta-Ga2O3 and the work function of Au were determined to be 4.00 +/- 0.05 eV and 5.23 +/- 0.05 eV, respectively, yielding a barrier height of 1.23 eV according to the Schottky-Mott rule. The reduction of the Schottky-Mott barrier to the effective value was ascribed to the image-force effect and the action of metal-induced gap states, whereas extrinsic influences could be avoided. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4755770]