The Study On The Growth And Charge Transfer Luminescence For Cerium Doped YVO₄

The YVO₄crystal is an excellent birefringent uniaxial crystal. Compare withother optical crystals, YVO₄crystal has much excellent performance, such as hightransmittance, higher laser destructive threshold value, higher mechanical property,excellent chemical stability, low pump threshold value and larger emission crosssection. The results of experiments show that YVO₄crystals doped with rare earthions have a larger application perspective in the development of white LEDfluorescent materials.The Ce:YVO₄crystal doped with Ce₂（CO₃）₃is grown by the Czochralskimethod in nitrogen atmosphere. The growth, crystal defects and spectral analysis ofCe:YVO₄crystal are studied in this paper. The XRD measurement of Ce:YVO₄crystalidentifies that the YVO₄crystal phase do not change after doping with Ce₂（CO₃）₃.The emission of the charge transfer state of Ce doped YVO₄crystal is reportedfor the first time. In the luminescence spectra of Ce:YVO₄crystal, there are a broademission band around450nm and an obvious emission peak at620nm which has notreported before. The optical spectra tests and analysis show that there may be twoluminescence mechanism. The wide band emission band around450nm originatesfrom the4f→5d electronic transition of Ce³⁺; and the620nm emission originatesfrom the charge transfer state. The Cerium ions exist in two forms of trivalent andtetravalent in the YVO₄crystal doped with Ce₂（CO₃）₃. The trivalent cerium ionsreflect as intrinsic photoluminescence of Ce³⁺, and the620nm emission shows thatthere is a charge transfer state（CTS）formed by electron exchange between Ce⁴⁺andthe coordination of oxygen ions.