Synthesis and characteristics of pure β-Ga2O3 and Tb3+ doped β-Ga2O3 hollow nanostructures

The pure β-Ga2O3 and Tb3+ doped β-Ga2O3 hollow nanostructures with various Tb3+ concentrations were prepared by hydrothermal and cacination processes. The X-ray diffraction patterns indicate that the core-shell structures are amorphous phase before calcination and perfectly crystallized β-Ga2O3 hollow nanostructures were obtained at 800 °C. The sharp and intense band absorption at 1384 cm−1, which was attributed to the Ga(OH)CO3 shell, was observed by Fourier transform infrared. Field-emission scanning electron microscopy and high-resolution transmission electron microscopy investigations showed β-Ga2O3 hollow nanostructures with diameters of about 200 nm and thicknesses of about 20~30 nm. The green emission spectra of Tb3+ doped β-Ga2O3 hollow nanostructures as a function of Tb3+ ions were observed due to the 5D4→7FJ transition. The Tb3+-doped β-Ga2O3 hollow nanostructures showed the highest green emission intensity at 7 mol% of Tb3+ ions.