声子模式与电子-声子结合强度对Dy^(3+)掺杂硒化物玻璃荧光效率的影响  

Phonon Mode and Electron-phonon Coupling Strengths Controlling the Fluorescence Efficiency of Dy^(3+)-doped Selenide Glasses

作　　者：应祥岳[1] 聂秋华[1] 戴世勋[1] 徐铁峰[1] 金珍娟[1] 

机构地区：[1]宁波大学信息科学与工程学院,宁波315211

出　　处：《无机材料学报》2008年第6期1125-1130,共6页Journal of Inorganic Materials

基　　金：浙江省自然科学基金(Y104498);浙江省科技攻关计划(2005C31014;2006C21082);宁波大学王宽诚幸福基金

摘　　要：用熔融-淬冷法制备了无稀土掺杂与Dy^(3+)(0.04mol%)掺杂Ge_(30)Ga_5Se_(65)和0.9Ge_(30)Ga_5Se_(65)+0.1CsBr玻璃样品.采用Judd-Ofelt理论计算了0.9Ge_(30)Ga_5Se_(65)+0.1CsBr玻璃样品中Dy^(3+)跃迁的强度系数、自发辐射几率与荧光分支比.为了研究多声子弛豫(MPR)随温度的变化,测试了Dy^(3+)的~6H_(11/2)能级在20～300K温度范围内的荧光寿命,分析了Ge_(30)Ga_5Se_(65)玻璃中声子模式与电子-声子结合强度对Dy^(3+)1.72μm处荧光强度和效率的影响.在硒化物玻璃中引入CsBr使玻璃中形成了Ga-Br键,有效声子能量降低到268cm^(-1).通过计算得到Ge_(30)Ga_5Se_(65)与0.9Ge_(30)Ga_5Se_(65)+0.1CsBr样品的电子-声子结合强度分别为0.456与0.048.CsBr的引入降低了电子-声子结合强度.声子模式与电子-声子结合强度的改变决定了MPR的变化.Pure and Dy（3＋）-doped Ge30Ga5Se65 and 0.9Ge（30）Ga5Se（65）＋0.1CsBr glasses were prepared by conventional melt-quenching method.The intensity parameters,spontaneous emission probability and branching ratio of Dy（3＋）ions in Ge（30）Ga5Se（65）＋CsBr glass were calculated by Judd-Ofelt theory.The lifetime of 6H（11/2）level at temperatures from 20K to 300K were measured to investigate the temperature dependence of multiphonon relaxation（MPR）rates.The influence of the local phonon mode and electron-phonon（e-p）coupling strength on the 1.72μm fluorescence efficiency of Dy（3＋）-doped selenide glasses was investigated.The frequency of the phonon vibration is changed to 268cm（-1）due to the formation of Ga-Br bonds with the addition of CsBr to selenide glasses.The values of e-p coupling strengths in Ge（30）Ga5Se（65）and 0.9Ge30Ga5Se65＋0.1CsBr glasses are 0.456 and 0.048,respectively.It is clear that the e-p coupling strengths decrease considerably with the addition of CsBr to Ge（30）Ga5Se（65） glass.This reduced e-p coupling together with a large change in the local phonon mode result in the change of the MPR rate.

关 键 词：熔融-淬冷法 荧光分支比 电子-声子结合强度 硒化物玻璃 

分 类 号：TQ171[化学工程—玻璃工业]