Electrical and structural properties of GaN films and GaN/InGaN light-emitting diodes grown on porous GaN templates fabricated by combined electrochemical and photoelectrochemical etching
•Porous GaN template was prepared by electrochemical and photoelectrochemical etching scheme.
•InGaN/GaN light-emitting diode (LED) structure was overgrown on the etched GaN template.
•Overgrown GaN films and LEDs showed lower strain and lower density of surface defects.
•The overgrown LED structures showed enhanced electroluminescence efficiency.
Porous GaN templates were prepared by combined electrochemical etching (ECE) and back-side photoelectrochemical etching (PECE), followed by the overgrowth of GaN films and InGaN/GaN multiple quantum well (MQW) light-emitting diode (LED) structures. Structural, luminescent, and electrical properties of the GaN and LED structures were studied and compared with the properties of structures grown under the same conditions on templates not subjected to ECE–PECE treatment. Overgrowth of LED structures on the ECE–PECE templates reduced strain, cracking, and micropits, leading to increased internal quantum efficiency and light extraction efficiency. This luminescence enhancement was observed in overgrown GaN films, but was more pronounced for InGaN/GaN LED structures due to suppression of piezoelectric polarization field in QWs.
- Electrochemical etching;
- Photo-electrochemical etching;
- Porous GaN;
- Light-emitting diodes