Infrared Excitation Yag:re³⁺ Materials For White Led

RE³⁺(RE=Er,Ho,Tm)-doped Y3Al5O12 (YAG) materials will be applied abroad to infrared excitation white LED. In the experiment, samples of YAG:RE³⁺ were prepared by sol-gel method; up-conversion luminescence and up-conversion mechanism were described, and some effective factors of up-conversion luminescence were investigated, including active ion, excitation current and the matrix composition.Samples of YAG:RE³⁺ materials were prepared by a sol-gel method which includes preparing Y3Al5O12 and doping active ion RE³⁺. At last, technologic parameter of sol-gel process and sintering conditions of YAG:RE³⁺ materials were determined.The characteristic structure of YAG and doping conditions of active ion RE³⁺ were described by XRD, FT-IR, TG-DTC and TEM. The structure of RE³⁺-doped YAG materials was also cubic.The up-conversion emission was discussed by absorption spectrum and up-conversion emission spectrum. The up-conversion spectroscopic properties of the YAG: RE³⁺ materials were investigated under the excitation of a 980 nm continuous wave diode laser. When active ion was Er³⁺, strong red and green up-conversion emissions which centered at 666nm and 552nm respectively were observed. The red and green emission respectively was assigned to the transition of energy levels 4 F9 /2â†'4I15/2and 4 S 3/2â†'4I15/2of Er³⁺ ions. When active ion was Ho³⁺, strong green up-conversion emissions which centered at 547 nm was observed. The green emission was assigned to the transition of energy levels 5 F4â†'5I8of Ho³⁺ ions. When active ion was Tm³⁺, strong blue up-conversion emission which centered at 487 nm was observed. The blue emission was assigned to the transition of energy levels 1 G 4â†'3H6of Tm³⁺ ions.The up-conversion emission spectrum of YAG:RE³⁺ materials indicated that the up-conversion emission intensity of YAG:RE³⁺ materials ascended as rare earth ion concentration increased. And the contemporaneous event was that the up-conversion emission intensity of YAG:RE³⁺ materials ascended as excitation current increased.