Growth And Spectra Properties Of Ce: YVO₄ Single Crystal

The growth and spectra properties of 1.0at.% Ce³⁺-doped YVO₄ single crystalare reported. The large size(φ10×20mm²)and high quality crystals were grown bythe Czochralski technology in protective atmosphere by DJL-400 stove. The crystal(YVO₄) we got is yellow and the crystal(Ce:YVO₄) is dense red. The sample wasincised and polished for sprctra measurement and the transition theoretical mechanismis illustrated briefly.From the absoption spectrum, it is observed that a very broad absorption bandalmost overlays whole visible light region, indicating that the doping is heavy. Threeabsorption peaks at 473nm, 557nm and 584nm are displayed, besides more intenseabsorptions in ultraviolet region could not be distinguished. From the emissionspectrum, a very square-built emission band in the region of 400-600nm was observed,where two peaks at 424 and 469 nm are displayed vaguely. The difference of twoemission peaks(424 and 469 nm) in the emission spectrumis is about 2263cm^-1, whichis consistent with the theoretical value(2250cm^-1) of the energy gap between F5/2 and2^F_7/2 for a free Ce³⁺ ion. Besides the transition(5d-4f) mechanism is illustrated briefly.To cause the emission from 5d to 4f, two effective excitation bands is indicated by thefigure, which are the blue band and the ultraviolet band respectively. The former(including peaks 341, 403nm) is attributed to the excitation to ²D_3/2, and the latter(including peaks 208, 232nm) is attributed to the excitation to ²D_5/2. As shown by theemission spetrum and excitation spectrum, the strong blue-green-yellow lightemission (corresponding with the wavelength region of 400-600nm) may be causedby a blue light excitation, a blue diode laser may be used as effective excitation source,indicating that the Ce:YVO₄ crystals is with a possible application foreground in thecreating complex white light.