In this study, Al-doped ZnO (AZO) and NiAZO films were deposited on p-type GaN films followed by thermal annealing to form ohmic contacts. After thermal annealing, the resistivities of AZO films reduced from 5× 10-3 to 4-6× 10-4 Ω cm. Both as-deposited AZO and NiAZO contacts on p-GaN displayed a non-ohmic characteristic. Only the 800°C-annealed NiAZO contacts exhibited a linear current-voltage characteristic, showing a specific contact resistance of around 1.2× 10-2 Ω cm2. After undergoing the annealing in nitrogen ambience, the light transmittance of the NiAZO films increased from 70% to higher than 90% in the visible range. These results revealed that the NiAZO contact can serve as a suitable transparent current spreading layer for the fabrication of GaN-based light-emitting devices.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry