【摘要】 用高温固相反应法制成了Sr2SiO4:xEu2+荧光粉。随着Eu2+掺杂浓度的增加,Sr2SiO4晶体结构从β相转换为α′相。Eu2+掺杂浓度小于等于0.5mol%时,Sr2SiO4:Eu2+为β相,大于等于2mol%时是α′相。β-Sr2SiO4:Eu2+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:Eu2+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Eu2+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-Sr2SiO4:0.0035Eu2+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′-Sr2SiO4:0.02Eu2+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。更多还原

【Abstract】 Sr₂SiO₄:xEu²⁺ phosphors doped with different Eu2+ concentrations have been synthesized and Eu2+ 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 diodes（LEDs） are fabricated with NUV chips and α’-Sr2SiO4:Eu2+ and β-Sr2SiO4:Eu2+ phosphors.For β-Sr2SiO4:Eu2+ 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’-Sr2SiO4:Eu2+ 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.更多还原