中文摘要：

用高温固相反应法制成了Sr2SiO4：xEu^2＋荧光粉。随着Eu^2＋掺杂浓度的增加,Sr2SiO4晶体结构从β相转换为α′相。Eu^2＋掺杂浓度小于等于0.5mol%时,Sr2SiO4：Eu^2＋为β相,大于等于2mol%时是α′相。β-Sr2SiO4：Eu^2＋的发光颜色为黄绿色,发射光谱由两个谱带组成,分别位于470nm,535nm处。α′-Sr2SiO4：Eu^2＋发光颜色为黄色,发射光谱由两个谱带组成,分别位于490nm,570nm处。这两个谱带具有不同的荧光寿命,归结为处于不同格位上Eu^2＋的发射。用近紫外芯片和这两种荧光粉制成了白光二极管。正向驱动电流为20mA时,用β-Sr2SiO4：0.0035Eu^2＋制成的白光LED色温为5562K;色坐标为x=0.32,y=0.40;显色指数为61;流明效率为15.7lm/W。用α′-Sr2SiO4：0.02Eu^2＋制成的白光LED色温为4707K;色坐标为x=0.36,y=0.37;显色指数为73;流明效率为6.7lm/W。

英文摘要：

St2 SiO4 xEu^2＋ phosphors doped with differem Eu^2＋ concentrations have been synthesized and Eu^2＋ concentration manipulated crystal phase has been observed. The β single phase is only formed as x≤0. 005, and the α′ single phase demands x≥ 0.02. The yellow band in the α′phase （at 570 nm） is located at longer wavelength side of the β phase （at 535 nm）. The luminescent mechanism of the two phases is discussed based on crystal structure analysis. White light emitting di odes （LEDs） are fabricated with NUV chips and α′-Sr2 SiO4 ：Eu^2＋ and βSr2 SiO4： Eu^2＋ phosphors. For β-Sr2 SiO4： Eu^2＋ white LED the color temperature is 5 662 K, the color coordinates are x= 0.32, y= 0.40, the color rendering index is 61, the luminous efficiency is 15.7 lm/W as the forward-bias current is 20 mA. For α′-Sr2 SiO4 ：Eu^2＋ white LED the color temperature is 4 707 K,the color coordinates are x=0.36,y=0.37,the color rendering index is 73,the luminous efficiency is 6.7 lm/W.