摘要
以金属硝酸盐为原料,使用NH3·H2O-NH4HCO3混合沉淀剂,开展了以反滴化学共沉淀方式和两步煅烧法合成掺铈的钇铝石榴石(Y3Al5O12∶Ce3+)黄色荧光粉研究。采用DTA-TGA和XRD研究共沉淀法制备的前驱体粉末热分解与钇铝石榴石晶相形成过程,通过荧光光谱和SEM研究荧光粉光致发光及添加剂对其发光和形貌影响规律。结果表明,采用化学共沉淀法合成温度比传统高温固相法降低300℃以上;荧光粉粒径0.3～1μm,颗粒规则呈类球状;468nm激发下荧光粉发射峰为532nm;煅烧阶段添加氟化物,可使荧光粉的发射强度等发光特性明显提高,对控制Y3Al5O12∶Ce3+荧光粉的形貌有显著作用;与蓝光LED芯片封装后形成的白光LED色温Tc为5571K,光效率为45lm·W-1,显色指数Ra为79.9,色坐标为(0.3308,0.3476)。
By using metal nitrates as starting materials,cerium-doped yttrium aluminium garnet （Y3Al5O12∶Ce^3＋） yellow phosphors were prepared by coprecipitation method with NH3·H2O-NH4HCO3 system as the precipitating agent. The formation process and structure of the phosphor powders were investigated by means of DTA-TGA and XRD. And the effect of fluoride as additive on the morphology,crystallite and photoluminescent properties of Y3Al5O12∶Ce3＋ was studied by photoluminescent excitation and emission spectra and SEM. The result shows that completely crystallized phosphors are obtained at 900 ℃,which is more than 300 ℃ lower than the temperature of solid-state method. The phosphor particles have spheroidal shapes with uniform distribution,and their sizes are 0.3-1 μm. The emission spectrum excited by 468 nm shows a characteristic wide band with the peak at about 532nm. A small quantity of fluoride as additive is necessary for enhancing photoluminescent intensity of Y3Al5O12∶Ce^3＋ phosphors,and improving the morphology. The Y3Al5O12∶Ce^3＋ phosphors prepared can be used together with a InGaN blue LED to achieve white light when excited by blue light of the LED. The achieved color temperature is 5 571 K,with a device luminous efficacy of 45 lm·W^-1,a color rendering index of 79.9 and a color point near the coordinate x=0.330 8,y=0.347 6.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2007年第8期1409-1414,共6页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.10476035)
重庆市自然科学基金重点(No.2005BA4016)资助项目。
