A bias-assisted photoelectrochemical (PEC) etching method is developed to roughen the p-GaN surface of GaN-based light-emitting diodes (LEDs). According to the atomic force microscopy images obtained, the morphology of the p-GaN surface can be effectively roughened by using the bias-assisted photoelectrochemical etching method. The relative threshold voltage and leakage current of LEDs with and without the PEC treatment were virtually similar, indicating that the electrical performances had not been damaged by the bias-assisted PEC etching method. The enhancement of the light output power of LEDs subjected to the PEC treatment with durations of 5, 10. and 15 min compared with conventional LEDs had been determined to be 13.5, 19.1, and 22.7%, respectively. The foregoing results evidently demonstrated that an increase in the light output power critically depends on the surface morphology.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry