Zhuoming Chen

Microstructure and photoluminescent properties of Y2O3:Eu3+ phosphors synthesised by precipitation and combustion methods

Abstract Y2O3:Eu3+ phosphors were prepared by NH4HCO3 based precipitation method and C2H5NO2–nitrate solution combustion synthesis method respectively. The phosphors were systematically investigated by field emission scanning electron microscope (SEM), X-ray diffractometer (XRD), scanning electron microscope (XPS) and fluorescence spectrometer. Luminescent properties of Y2O3:Eu3+ phosphors synthesised by two different methods were also compared. The results show that Y2O3:Eu3+ phosphor prepared by precipitation technique is spherical with nanometre particle size from 55 to 60 nm, whereas the one synthesised by combustion technique exhibits extensive sheet porosity structure. X-ray diffraction spectra indicate that both of the samples have pure cubic phases and the crystallinity of phosphor synthesised by combustion technique is improved. The main emission peaks of Y2O3:Eu3+ phosphors at 613 nm are due to the 5D0–7F2 transition of Eu3+ ions, and phosphor obtained by precipitation method shows higher emission intensity. The results reveal that Y2O3:Eu3+ phosphor with spherical particle shape can exhibit good luminescent properties and morphology of Y2O3:Eu3+ phosphor is a more crucial factor than crystal structure to the enhanced luminescence.

Influence of annealing temperature on microstructure and luminescent properties of Y2O3: Eu3+ deposited quartz fibre

In this study, Eu3+ doped Y2O3 (Y2O3: Eu3+) phosphor target was deposited on quartz fibre substrates by electron beam evaporation technology, and then the deposited fibres were annealed at different temperatures from 600 to 1000°C. Particle shape was changed, and particle size of Y2O3: Eu3+ was increased with the rise in annealing temperature. Crystallisation and luminescent intensity of the deposited films on quartz fibres were significantly improved by annealing treatment. The most effective crystallisation and the maximum luminescent efficiency of the thin films were obtained when the deposited fibres were treated at 1000°C for 1 h. The luminescent property results indicated that the particle shape, particle size and crystallisation were the important factors affecting luminescent intensity of the deposited fibres.

Microstructures and luminescent properties of CO2 laser annealed Y2O3:Eu3+ thin films grown on quartz fabric by electron beam evaporation:

Trivalent europium ion doped yttrium oxide (Y2O3:Eu3+) luminescent thin films were grown on quartz fabric substrates using electron beam evaporation (EBE) technology, and then annealed by a pulsed CO2 laser with different resolutions from 30 to 45 dpi. Chemical composition, surface morphology, crystal structure, luminescent properties and CIE chromaticity coordinates of the Y2O3:Eu3+ deposited quartz fabric, as a function of laser resolution, were investigated by X-ray photoelectron spectrometer (XPS), Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and PG2000L fiber optic spectrometer, respectively. The results indicate that CO2 laser annealing is an efficient method to improve luminescent properties of Y2O3:Eu3+ thin films. Both the undamaged surface morphology and high crystallinity are positive factors for enhancing luminescent intensity of the deposited fabrics and the optimal luminescent properties of the film can be achieved when annealed at 35 dpi.

CO 2 laser annealing for improved luminescent properties of Y 2 O 3 :Eu 3+ thin film grown on quartz fabric by using EBE

Thin films of yttrium oxide phosphor doped with trivalent europium ion (Y2O3:Eu3+) are grown on a quartz fabric substrate by using electron beam evaporation (EBE) and subsequently annealed by a pulsed CO2 laser with different lengths of pixel time and resolutions. Energy distribution of the laser beam on the thin films is analyzed, and the dependence of surface morphology, crystal structure and luminescent properties of the resultant fabrics on the laser annealing parameters is also studied. The experimental results demonstrate that the microstructure and luminescent properties of the Y2O3:Eu3+ thin films are strongly affected by the CO2 laser annealing, and the increased emission brightness can be realized in the thin films because of the complete melting film with relatively integral topography and the improved crystallinity by controlling the CO2 laser parameters. The highest luminescence is obtained when the Y2O3:Eu3+ thin films are annealed with a resolution of 35 dpi and a pixel time for 120 μs, and the luminescent intensity of the films is increased by 253.27% in comparison to the as-deposited films.