白光LED用VO4：Ce^3＋荧光粉的制备与表征

白光LED中YAG荧光粉专利权为日本Nichia所有，各国研究者为了规避专利，争相研究替代产品。本文首次采用高温固相法制备了YVO4：Ce^3＋荧光粉，对不同Ce^3＋掺杂浓度下XRD图样与国际标准衍射卡对比后发现在1100℃保温9小时合成的Ce^3＋：YVO4为四方晶系结构，随保温时间延长，结晶程度更好，但时间再长时，结晶变化已不大。荧光光谱表明，激发光谱为双峰结构，主峰在232nm和403nm。发射光谱为一宽带，峰值在424nm附近。发现最佳Ce^3＋掺杂浓度为5mol％。结论是Ce^3＋：YVO4荧光粉可以满足与蓝光LED复合产生自然白光的要求。

Synthesis and Spectral Properties of Ce^3＋ Doped YVO4 Phosphor for White Light-Emitting Diodes

Most commercial white LED is in the manner of light conversion, which is fabricated by coating YAG phosphors on the chip of blue LED. The YAG phosphors emit yellow light excited by the blue light and the two lights mix into white light. In this thesis, the synthesis and properties of YVO4 ：Ce^3＋ phosphor are studied. In this work, several methods of synthesizing phosphors are Ce^3＋ introduced, and the YVO4 ： phosphor is synthesized by sohd-state reaction in reductive atmosphere. XRD pattern shows that the structure of the phosphor is tetragonal which is formed under the sintering of 1100℃. The excitation spectra of YVO4 ：Ce^3＋ phosphor transitions of Ce The have two peaks, the major one is around 232nm which is attributed to the 4f- 5d transitions of Ce^3＋ ions.The emission band is quite wide, ranged yellow-green light region and with a center at 424nm. Experimental results shows that the concentration of Ce^3 ＋ ions effects the luminescent properties of YVO4 ：Ce^3＋ phosphor. In this thesis, the best concentration of Ce^3＋ is optimized by comparing the luminescent intensities of YVO4 phosphors with different Ce^3＋ concentrations.