Influence of Zn doping on the morphology and luminescence of Ga2O3 low-dimensional nanostructures

Abstract Zn-doped Ga2O3 nanostructures were synthesized by thermal evaporation. SEM results show that there are plenty of nanorods in the samples. The EDS analysis of the samples demonstrate that the nanostructures are mainly composed of Ga and O elements, and a small amount of Zn element is also observed. The Raman spectra indicate that the samples still keep the monoclinic structure consistent with the pure Ga2O3 crystal structure. A broad-band blue-green luminescence centered around at 2.3 eV was observed at room temperature. The luminescence intensity of the PL spectra of the Zn-doped Ga2O3 nanostructures varied with the amount of Zn doping. Besides, the PL spectra of the Zn-doped Ga2O3 nanostructures have a red-shift compared to that of the pure Ga2O3 nanostructures. The analysis of the PL spectrum of Zn-doped Ga2O3 nanostructures with a mass ratio of Ga2O3 powder to zinc powder of 10:1 indicates that the broad-band blue-green luminescence of the Zn-doped Ga2O3 nanostructures is composed of one blue luminescence (2.8 eV, 450 nm) band, one green luminescence (2.3 eV, 533 nm) band, one yellow luminescence (2.1 eV, 592 nm) band, and one red luminescence (1.9 eV, 638 nm) band, respectively. Further, their luminescence mechanisms will be discussed.