采用共沉淀法合成了Ce,Pr:YLu AG粉末,在1450℃下煅烧可获得石榴石结构纯相。经过压制成型、固相烧结等工艺制备了多晶料棒,TEM显示二次烧结获得的料棒具有良好的结晶性。采用光学浮区法生长了Ce,Pr:YLu AG晶体。晶体通体透明,呈浅黄色,肩部有少量裂纹。透过率达到81.8%,接近于理论值84.2%。晶体在460 nm波长激发下呈现530 nm发射带和610 nm发射峰,分别对应Ce3+和Pr3+的特征发射,表明Ce3+可以向Pr3+进行能量转移;在487 nm激发下晶体仅出现Pr3+离子的特征发射峰。Ce,Pr:YLu AG晶体色坐标为(0.474,0.495),比商用Ce:YAG荧光粉更靠近红光区域,可以弥补现有荧光粉不足,更适合制造白光LED。
Ce,Pr:YLu AG pure phase powder was synthesized by co-precipitation method and calcined at 1450℃, which had a garnet structure. The feed rod was prepared by press forming and solid state sintering. TEM showed that the sintered rod had good crystallinity and density. Ce,Pr:YLu AG single crystal was grown by the floating zone method. The as-grown crystal was transparent with a pale yellow color, and small cracks were observed in the shoulder. The transmittance of the crystal is 81.8%, which is close to the theoretical value 84.2%. Under 460 nm excitation, Ce,Pr:YLu AG crystal shows the emission band of Ce3+ at 530 nm and peak of Pr3+ at 610 nm, which shows that Ce3+ can transfer the energy to Pr3+. However, only Pr3+ emission peak appears when it is excitated at 487 nm. The color coordinate is located at(0.474, 0.495) which shifts to red zone compared with commercial Ce:YAG yellow phosphor. As a result, Ce,Pr:YLu AG crystal is more suitable to fabricate white LED.