用正电子湮没实验研究PbWO_4新型闪烁晶体绿光发光机理  

Study on mechanism of green luminescence in PbWO_4 crystal by positron annihilation lifetime spectrum

作　　者：祁金林[1] 顾牡[1] 汤学峰 童宏勇 郑万辉 陈玲燕[1] 廖晶莹[2] 沈炳孚 曲向东 沈定中 李培俊 殷之文[2] 王景成 徐炜新 

机构地区：[1]同济大学,上海200092 [2]中国科学院无机功能材料开放实验室,上海200050 [3]上海金属功能材料重点实验室,上海200940

出　　处：《核技术》2000年第7期433-436,共4页Nuclear Techniques

基　　金：国家自然科学基金!19774043;上海市高等学校科学技术发展基金;上海市教育委员会重点学科研究计划资助;中国科学院无机功能材料开放实验

摘　　要：通过正电子湮没寿命谱研究了PbWO_4晶体退火处理前后缺陷的变化；发现氧退火后，晶体正电子寿命值τ_2变小，正电子捕获率κ增大，真空退火反之。并且PbWO_4晶体氧退火后发光主峰位从440nm移到485nm的绿光处，而真空退火晶体发射谱谱形并未变化。从不同退火处理对晶体的影响，提出了PbWO_4晶体中铅空位形成WO_3＋O^-发绿光的发光模型。The change of the defects in PbWO4 crystals before and after annealing was studied by positron annihilation lifetime spectrum. It was found that the lifetime τ_2turned short and the positron capture ability K increased after oxygen annealing.The results for the case of vacuum annealing were the reverse for that of oxygen annealing. Meanwhile, the main emission peak of the crystal after oxygen annealing shifted from 440nm to 485nm, but the peak for the case of vacuum annealing remained at 440nm, i.e. similar to that of an untreated crystal. From the results affected by different treatments, it is proposed that WO_3+O- produced by lead vacancy leads to the green luminescence in PbWO4 crystal.

关 键 词：正电子湮没 发光机理 铅空位 钨酸铅 冰烁晶体 

分 类 号：O771[理学—晶体学] O571.33