A benzene-thermal metathesis route to pure metastable rocksalt GaN

Here, pure metastable rocksalt GaN was first prepared via a benzene-thermal metathesis route through the reaction of GaI3 and NaNH2 at 210 degreesC and under 3 MPa pressure, in which I-2 acted as the transporting agent. The as-prepared product was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), selected-area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM). X-Ray photoelectron spectra (XPS) were used to determine the average composition ratio, which is Ga: N = 1.14: 1. The photoluminescence spectrum shows that the rocksalt GaN emits two PL peaks positioned at 330 and 348 nm.