Growth of α-plane GaN on lattice-matched ZnO substrates using a room-temperature buffer layer

摘要

Nonpolar α-plane GaN films were grown on nearly lattice-matched a-plane ZnO substrates by pulsed laser deposition. Growth of GaN on α-plane ZnO at conventional growth temperatures (around 700 ℃) resulted in the formation of polycrystalline materials, probably due to the interface reactions between GaN and ZnO. However, single crystalline a-plane GaN with an atomically flat surface can be grown on ZnO at room temperature in the layer-by-layer mode. X-ray diffraction and photoluminescence measurements revealed that high-quality α-plane GaN films can also be grown at elevated substrate temperatures (up to 700 ℃) by using a RT α-plane GaN film as a buffer layer.