Hydrolysis Stability And Luminescent Properties Of Phosphor/low Melting Point Glass Composites

Phosphor/glass composites(Pi G)composed of phosphor and glass matrix have been widely used in the field of semiconductor lighting and display.However,the glass system with both low glass transition temperature(T_g)and stable chemical properties is one of prominent issues to be solved.For this conern,the low T_g glass matrix including stannic chloride system,bismuth borate system and phosphoborate composite system is embedded with the phosphor particles of yellow green-emitting YAG:Ce³⁺and far red-emitting Zn Ga₂O₄ respectively to construct the Pi G luminescent glass ceramics.The emphasis is paid on the composition adjustment and structure modification of the desired glass through adding oxides to optimize the changes of glass transition temperature,softening temperature and crystallization temperature of low melting point phosphor/glass composites.The relationship between hydrolysis stability and luminescent properties of Pi G luminescent glass ceramics and composition adjustment and structure modification was established.The results achieved are as follows:1.The glass of SnCl₂-ZnO-P₂O₅ was used as the matrix of the glass-ceramic by adding the commercial YAG phosphor in the molten state.The phase structure,microstructure,luminescent properties and hydrolysis resistance of the phosphor tin chloride luminescent glass were evaluated by XRD and weight loss method.The results show that with the increase of ZnO content,the glass transition temperature T_g of the obtained samples declines first and then rises,and the hydrolysis reaction also shows the same trend.When the content of ZnO is 0.75 percent,the optimized luminescent performance is achieved with a T_g of 429?and the hydrolysis loss rate of 0.39 percent.2.The powdered Bi₂O₃-ZnO-B₂O₃ glass was used as matrix to prepare Bi₂O₃-ZnO-B₂O₃ phosphor/glass composites by screen printing.The effects of different glass components and reaction conditions on the physical and chemical properties and T_g of the composites were studied.The results show that when the mass ratio of Bi₂O₃/B₂O₃is set to 3:1,the reaction synthesis temperature of glass matrix is optimized as a lower temperature of T_g at 435?;As the ZnO content reached 25 percent,the phosphor/glass composite prepared by screen printing has the optimized luminescent properties with a low preparation temperature of 630? and the loss rate of hydrolysis of 0.5131 perent,the loss rate of alkali hydrolysis of 0.0242 percent,and the loss rate of acid hydrolysis of 10.343 percent.3.Phosphorborate composite luminescent glass-ceramic materials were prepared by mixing P₂O₅-B₂O₃-Na₂O glass-ceramic powder as matrix and ZnO as a structure modifier with far-red emitting phosphor Zn Ga₂O₄ by traditional melting method.The results show that phosphor borosilicate glass has stable luminescent properties and hydrolysis resistance.Compared with the samples without ZnO,the samples with ZnO have obvious amorphous diffraction and excellent luminescent properties,As the ratio of P₂O₅/B₂O₃ is set to be 1:1,the optimum parameters were achieved in a ZnO content of 30 percent,the Na₂O content of 50 percent,the T_g of 438?,and the hydrolysis loss rate of 0.0004 percent.