GaSe films grown on a GaAs(001) surface at high temperature using a thermal evaporation of GaSe

The initial stage of heteroepitaxial growth of GaSe films on GaAs(001) surface using a single evaporation source of GaSe has been studied as a function of growth temperature by means of in-situ LEELS (low-energy electron-loss spectroscopy), XPS (X-ray photoemission spectroscopy) and AES (Auger electron spectroscopy). The thick films were studied ex-situ by XRD (X-ray diffraction). In the LEELS spectra, the film grown at 450°C had a different structure from the film grown at 400°C. In the XRD pattern, weak but clear signals of Ga2Se3 were observed. The AES intensity ratio of Ga and Se also showed that the films were composed of Ga-rich Ga2Se3. The film grown at 430°C evolved the structure from high temperature phase (mainly Ga-rich Ga2Se3) to low temperature phase (GaSe) with increase in thickness. At 450°C, not the Ga2Se3 but the crystalline GaSe film grew on a GaAs(111)A surface.