Study on the interfacial layer in ZnO/GaN heterostructure light-emitting diode

Heterostructure light-emitting diodes (LEDs) were fabricated by growing Ga-doped n-ZnO and undoped ZnO layers on p-GaN/Al2O3 templates. The p–n junction showed a diode like I–V characteristic and emitted electroluminescence (EL) peaks at 430 nm, 440 nm and 480 nm along with a broad band of yellow light. An interfacial layer was observed between ZnO and GaN, identified as ZnGa2O4 by transmission electron microscopy and X-ray diffraction analysis. It was observed that thickness of the interfacial layer did not significantly affect EL characteristics of the ZnO/GaN heterostructure LED.