Study On Preparation And Luminescent Property Of YAG-type Phosphor-in-glass Composite For Laser Illumination

LD has attracted more and more attention because of its narrow bandwidth,low power consumption,small size and high excitation efficiency.At present,the commonly used white LED is composed of blue chip and yellow phosphor,which is encapsulated by epoxy resin,but the blue LED chip has the problem of efficiency droop.LD does not have the problem of efficiency droop,so it becomes an ideal substitute for LED.However,temperature of LD exceeds 150°C during operation,and the traditional phosphor converter embedded with organic resin inevitably suffers from serious aging and yellowing problems due to its poor heat resistance and low thermal conductivity(0.1–0.2W/m K),resulting in luminous efficiency reduction,color coordinates drifting,and reliability decrease after long-term use of the light source.In order to give full play to the advantages of LD as pumping or light sources,the packaging materials high thermal stability is an urgent need.Low melting point glass has become an ideal packaging material for phosphor because of its high transparency,low melting temperature,easy forming.Therefore,the phosphor-in-glass(PiG)composite prepared by the combination of phosphor and low melting point glass has an important research value.In this paper,Lu AG-PiG and YAG-PiG were prepared by co-sintering method with tellurite glass as matrix glass.By characterization means of XRD,SEM,spectrophotometer and integrating sphere,the crystal phase,fluorescence spectrum and thermal stability of the composite were tested and analyzed,and the absolute spectrum under laser pumping was quantitatively characterized.Research shows:1.On the basis of tellurite glass,Ce³⁺activated Lu AG-PiG was synthesized.It was proved that the distribution of Lu AG particles in tellurite glass was uniform and the particle size was about?5?m.The introduction of H₃BO₃ flux can promote the growth of polycrystalline and reduce the preparation temperature of phosphor,but it will lead to the generation of Lu BO₃impurity.The different fluorescence emission behaviors of Lu AG:Ce³⁺and Lu AG-PiG indicate that the luminescent ability of Lu BO₃ in the composite is strongly inhibited,accompanied by strong pure green emission.Lu AG-PiG combines the excellent formability of tellurite glass with the good luminescent properties of Lu AG:Ce³⁺,which effectively eliminates the Lu BO₃in the composite and realizes the purification of Lu AG:Ce³⁺.Therefore,Lu AG-PiG has excellent purification ability and strong fluorescence emission ability.2.The Ce³⁺activated YAG-PiG was synthesized,and the YAG:Ce³⁺particles were uniformly distributed in the glass matrix.The introduction of flux H₃BO₃ promoted the crystal growth,but caused the generation of YBO₃ impurity,and the precursor phosphor produced unexpected blue light under ultraviolet(UV)irradiation.Under the excitation of UV,the YAG-PiG composite releases pure yellow light without blue light,which indicates that the luminescence of the impurity is seriously inhibited.The composite combines the excellent formability of tellurite glass and the good luminescent property of YAG:Ce³⁺,and the impurity is effectively eliminated during the preparation of the composite.The excellent thermal stability and remarkable fluorescence purification effect make YAG-PiG a potential candidate light source for the development of yellow light illumination in photoelectric super clean room.3.Ce³⁺doped M₃Al₅O₁₂(MAG,M=Lu,Y)phosphor-in-glasses(PiGs)have been proved to be shapeable phosphors for white lighting driven by 453 nm laser.Quantitative characterization reflects that the net emission powers of 4wt%Lu AG doped PiG and 4wt%YAG doped PiG are 59.99 and 66.22 m W at the pump power of 117.63 m W,and the quantum yields reach up to 71.1%and 78.0%,respectively.Miniaturization of devices can be achieved for Lu AG/YAG-PiGs by optimizing sample size and phosphor concentration with maintaining fluorescence intensity of the samples.Presupposed color coordinate trace reveals that the high-brightness white fluorescence can be realized when the appropriate intensity ratio is determined between residual laser and samples emission.The tunable white fluorescence and the efficient radiation-releasing illustrate that Lu AG/YAG-PiGs are potential candidates for application in solid-state laser illumination.