Synthesis and Raman characteristics of hexagonal AlxGa1-xN alloy nanocrystalline solids through ammonothermal routes

The AlxGa1-xN alloy nanocrystalline solids with x = 0 - 1 were successfully synthesized through ammonothermal routes. The alloys were formed only in the form of nanocrystalline solids, and not in other forms, i.e. of nanopowders or micro-crystals. The Raman scattering spectra of the alloy solids within the whole range of x values were investigated. One-mode-type behavior of A I(LO) phonon and two-mode-type behavior of E-2 phonon were clearly demonstrated. The intensity of E-2(GaN) mode decreases as x increases up to x = 0.8. For A(1)(TO), A(1)(LO), and E-2(GaN) phonon modes, the linewidth behaviors follow a pattern that exhibits a maximum at composition x = 0.5.