Enhanced photoluminescence of Ga2O3:Dy3+ phosphor films by Li+ doping -: art. no. 033511

Ga2O3:Dy3+ and Li+-doped Ga2O3:Dy3+ phosphor films were prepared by a Pechini sol-gel process. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy, and photoluminescence (PL) spectra as well as lifetimes were used to characterize the resulting thin films (and powder samples for comparison). The results of the FTIR and XRD indicated that the films began to crystallize at 700 degreesC and the crystallinity increased with the elevation of annealing temperatures. Upon excitation into band gap of beta-Ga2O3 at 250 nm, the Ga2O3:Dy3+ and Li+-doped Ga2O3:Dy3+ films show similar emission spectra, which mainly consist of the characteristic emission bands of Dy3+ ions (F-4(9/2)-H-6(13/2) transition at 492 nm and F-4(9/2)-H-6(15/2) transition at 580 nm) due to an efficient energy transfer from the beta-Ga2O3 host lattice to the doped Dy3+ ions. The incorporation of Li+ ions into the Ga2O3:Dy3+ film have enlarged the grain size and enhanced the photoluminescence intensities. The highest emission intensity was observed in Ga1.86Dy0.04O3:0.1Li(+) film, whose PL intensity is more than twice that of the Ga1.96Dy0.04O3 film. (C) 2005 American Institute of Physics.