Evaluation of electrical properties in anodized n-GaN grown on sapphire substrates at different anodization voltages

Abstract

n-GaN grown on sapphire substrates was anodized in an electrolyte solution at different voltages (2 and 4 V) for 3600 s, and the electrical properties of the anodized n-GaN were evaluated. The resistivity of the sample anodized at 2 V increased by a factor of 2.4 at RT, and that of the sample anodized at 4 V increased by a factor of 76 at RT The analysis of temperature dependent Hall effect measurements revealed that anodization changes original donor levels and/or generates energy levels depending on anodization voltages. Anodization has a possibility to transform GaN into GaON-like materials.