Fast UV sensing properties of n-ZnO nanorods/p-GaN heterojunction

n-type ZnO nanorods are vertically grown over p-type Mg:GaN substrate by simple hydrothermal process to form a p-GaN/n-ZnO nanorods heterojunction. The heterojunction showed good rectifying behavior. The defect states in the heterojunction are analyzed in detail using photoluminescence studies. The device response is studied for various biasing conditions and UV light pulse illumination frequencies. The present device has the fastest UV response on comparison with devices based on solution grown ZnO nanorods. The device showed reproducible results even after long exposure to room temperature and humidity environment.