溶胶-凝胶法制备有机/无机复合荧光粉及其发光性能

以正硅酸乙酯(TEOS)和有机荧光染料(Calcein等)为原料,采用溶胶-凝胶(Sol-gel)法制备了有机/无机复合荧光粉。探讨了有机染料的掺杂浓度、反应体系pH值、H₂O与TEOS的比值等控制参数对反应时间和材料性能的影响。利用XRD、TEM、PL光谱分析手段对纳米复合荧光粉的结构、粒度、形貌、光谱进行了表征。结果表明:制备的粉体在纳米尺寸范围内是透明的;材料的发射光谱为宽带,激发峰值波长为450nm,发射波长为520nm;峰值波长的位置不随掺杂浓度的变化而改变,但光谱强度会发生相应的变化;最佳掺杂浓度为5×10^-4mol/L。

Sol-gel Synthesis of Organic-inorganic Composite Phosphor and Luminescence Properties

Efficient blue-LED was successfully manufactured by Nichia Company of Japan,in 1996,then it made that the solid-state lighting went into the field of white light illumination.Subsequently the white-LED came true,it was made from InGaN blue-LED and YAG:Ce³⁺ phosphor,hereafter the internationally scientific research institute paid great attention to it.And it was also arranged in the “863” Program in China.When the organic dyes were doped into silicon dioxide(SiO₂),it can be synthesized organic-inorganic composite luminescence material,which had both the excellent luminous property of the organic luminescent molecule and the stability of the inorganic material for the heat,chemistry and mechanism.So this kind of composite phosphor was considered as the ideal fluorescence transforming material.Composite phosphor is easy to product and the production cost is very low,and there is not any pollution in the fabrication procession.Because of all the advantages,the people were further to be favor of this method.Because the Sol-gel Gateway has many advantages compare to the traditional method of solid phase reaction.It can provide a simple,economic and effective method to produce high quality material.Many chemical reactions can be finished in a low temperature and the reaction procession is easy to be controlled.The doping distribution is even in the composite material.The organic-inorganic composite phosphor was synthesized with the Sol-gel Gateway in this paper,which based on the raw material of TEOS and organic fluorescent dye.The procession of fabrication was discussed and some of the properties were researched,including the influence of the doping concentration of the organic fluorescent dyes,the ratio of H₂O to TEOS and the pH value on the reaction time and the material performance.Using the testing method of PL spectra,XRD and TEM,the properties of composite phosphor were identified,including spectrum,structure,granularity and appea-rance.It can be seen from the TEM image of the phosphor that the powder is transparent in nanometer size.The spectra of the phosphor at the different doping concentration indicates that the excitation wavelength is 450 nm and the emission wavelength is 520 nm,the excitation spectra peak is not changed with the doping concentration but the intensity of fluorescence is inflected by it,and the best doping concentration is 5×10^-4mol/L.The excitation band is wide so that it satisfies the requirement of the white-LED.