氧化物红色荧光粉Sr_(3)Ga_(4)O_(9):Eu^(2+)中Eu^(2+)的格位工程调控机制  

Site Occupation Engineering Regulation of Eu^(2+) in Oxide-Based Red Phosphor Sr_3Ga_4O_9:Eu^(2+)

作　　者：邝宇航 朱英泽 夏志国 KUANG Yuhang;ZHU Yingze;XIA Zhiguo(State Key Laboratory of Luminescent Materials and Devices,Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques,School of Physics and Optoelectronics,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]华南理工大学,发光材料与器件国家重点实验室,广东省光纤激光材料与应用技术重点实验室,物理与光电学院,广州510641

出　　处：《硅酸盐学报》2024年第11期3482-3491,共10页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(51972118)。

摘　　要：稀土离子Eu^(2+)在无机固体基质占据低配位数(六配位)阳离子格位可引起较大晶体场劈裂,进而产生红光乃至近红外发射。采用上述理论模型,设计并制备了一种可被蓝光激发的氧化物红色荧光粉Sr_(3)Ga_(4)O_(9):Eu^(2+),其发射峰值为618 nm,半峰宽为81 nm。研究发现,红光发射源由具有5d→4f跃迁的Eu^(2+)占据了2个低配位数多面体Sr1O_(6)和Sr3O_(6)所致。同时,Sr_(3)Ga_(4)O_(9)中引入Zn^(2+)产生Zn^(2+)/Ga^(3+)异价离子取代,提高了发光热稳定性;结合荧光衰减寿命和热释光光谱,证明了上述异价取代策略引入了缺陷能级,使荧光粉的热稳定性得到了改善。采用Sr_(3)Ga_(4)O_(9):Eu^(2+),0.05Zn^(2+)红色荧光粉、商用绿色荧光粉Lu_(3)Al_(5)O_(12):Ce^(3+)和蓝光芯片制备的白光LED器件,具有较高的显色指数Ra=87和较低的相关色温CCT=3500 K,表明这类氧化物红色荧光粉在暖白光照明领域的应用潜力。本工作为开发高性能荧光粉的性能调控提供了有益的结构设计思路。Introduction White light emitting diode(LED)is widely used as a high-quality lighting source,and its performance depends critically on the selected light-emitting materials.Early white LEDs were mainly composed of a combination of blue light chips and yellow light emitting phosphors,but suffered from low color rendering index,high color temperature,and blue light hazards.To solve these problems,researchers have turned to improving the color rendering performance of white LEDs by using red phosphors that can be excited by blue light.Professor Zhiguo Xia's group at the State Key Laboratory of Luminescent Materials and Devices,South China University of Technology,has proposed a new material design principle for Eu^(2+)-activated oxide phosphors that are difficult to obtain red light emission:Eu^(2+)occupying a low coordination number of polyhedra can cause a large crystal field cleavage,which can in turn realize red light or even near-infrared emission.A novel Sr_(3)Ga_(4)O_(9)phosphor matrix with multiple low-coordination cation lattice sites was designed and synthesized,and broadband red light emission under 450 nm blue light excitation was successfully achieved by doping Eu^(2+),with the emission peak located at 618 nm.Methods Sr_(3)Ga_(4)O_(9):Eu^(2+)and Sr_(3)Ga_(4)O_(9):Eu^(2+),0.05Zn^(2+)phosphors were prepared by high-temperature solid-phase method.According to the proportional content of the different raw materials in the chemical formula,SrCO_(3)(A.R.:99.5%analytically pure),Ga_(2)O_(3)(A.R.),H_(3)BO_(3)(A.R.)and Eu_(2)O_(3)(99.99%)were weighed and ground in an agate mortar for half an hour.The mixture was transferred to an alumina crucible and fired at 900℃in an air atmosphere for 6 h,then cooled naturally to room temperature.The mixture was ground again to powder form and refilled into the crucible,which was placed in a tube furnace with a continuous flow of reducing gas([V(N_(2)):V(H_(2))]=80%:20%).The samples were burned at 1200℃for 10 h,cooled to room temperature naturally,and then ground carefull

关 键 词：稀土发光材料 红色荧光粉 晶体场劈裂 缺陷能级 白光照明 

分 类 号：O614.338[理学—无机化学]