Annealing effects on the structural and optical properties of β-Ga2O3 nanobelts synthesized by microwave plasma chemical vapor deposition

We have synthesized β-Ga2O3 nanobelts on the silicon substrates by microwave plasma chemical vapor deposition (MPCVD). The morphology and structure of β-Ga2O3 nanobelts characterized by scanning electron microscopy (SEM) were not influenced through the thermal annealing. The photoluminescence properties of β-Ga2O3 nanobelts measured under different excitation wavelength, annealing temperature and annealing time indicated that as-prepared and annealed nanobelts had a blue and an ultraviolet emission (under excitation wavelength of 250 nm at 316 and 432 nm, under excitation wavelength of 325 at 428 nm), but the relative peak intensities of ultraviolet and blue emission, respectively, increase and decrease by the thermal annealing.