摘要
本文采用高温固相反应法制备了Ba5SiO4Cl6:Yb3+,Er3+,Li+荧光粉,并对其上转换发光性质及其发光机理进行了研究.在980 nm激光的激发下,Ba5SiO4Cl6:Yb3+,Er3+荧光粉呈现较强的红色(662 nm)和较弱的绿色(550 nm)的上转换发光,红色和绿色的上转换发光分别对应于Er3+离子的4S3/2/2H11/2→4I15/2和4F9/2→4I15/2跃迁,且随着掺杂的Er3+和Yb3+离子浓度增加,样品的上转换发光强度增加,这是因为Yb3+离子和Er3+离子之间的能量传递效率增加引起的.在0.5—0.8 W功率激发下,样品属于双光子发射,而在0.9—1.2 W功率激发下样品具有新的上转换发光机理——光子雪崩效应.探讨了Li+掺杂对Ba5SiO4Cl6:Yb3+,Er3+样品的上转换发光性质的影响,Li+离子的掺杂引起Ba5SiO4Cl6:Yb3+,Er3+上转换发光强度增加,这是由于Li+离子的掺入降低了晶体场的对称性引起的.
The Ba5SiO4Cl6： Yb3＋, Er3＋, Li＋ phosphor has been prepared by high temperature solid state reaction, and their upconversion （UC） luminescence properties and mechanisms are investigated. The UC emission bands located at 525 nm （2H11/2→4I15/2）, 548 nm （4S3/2→4I15/2）, and 662 nm （4F9/2→4I15/2） due to Er3＋are observed under the excitation of 980 nm. UC luminescence of Ba5SiO4Cl6： Yb3＋, Er3＋ phosphors is increased with increasing Er3＋ and Yb3＋ concentration due to the energy transfer enhancement of Er3＋ and Yb3＋. Based on the relations of UC luminescence intensity and excitation light power, the UC luminescence mechanisms are discussed. At a low excited power （below 0.8 W）, the two-photon processes are involved in both green and red UC emission mechanisms. When the power exceeds 0.9 W, the green and red UC emission is a four-photon process. One new and interesting UC emission mechanism may occur in the Ba5SiO4Cl6： Yb3＋, Er3＋ phosphors. Both green and red UC emissions at a higher pumping power are generated by photon avalanche UC process. Influence of Li＋ doping on the UC luminescence of Ba5SiO4Cl6： Yb3＋, Er3＋ phosphors is investigated. Result demonstrates that Li＋ ion doping could enhance the UC luminescence of Ba5SiO4Cl6： Yb3＋, Er3＋, which is attributed to the distortion of the local symmetry around Er3＋.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第13期394-399,共6页
Acta Physica Sinica
基金
云南省中青年学术与技术带头人后备人才培养项目(批准号:2013HB068)
云南省应用基础研究面上项目(批准号:2014FB127)资助的课题~~
