Single-phase hexagonal GaN grown on AlAs/GaAs(001)

This letter describes successful growth of single-phase hexagonal GaN (h-GaN) layers on cubic GaAs(001) nominally singular substrates with the assistance of thin AlAs intermediate layers. The crystallographic relationship between h-GaN and GaAs is extracted from a pole figure to be h-GaN[0001]∥GaAs[001] in the growth direction and h-GaN[101̄0]∥GaAs[11̄0] in the in-plane direction. In a photoluminescence spectrum measured at 20 K, excitonic emission from the h-GaN layer is detected at 3.47 eV.