从热释光曲线同时确定电子复合与俘获之比及陷阱深度  

Simultaneous Determination of Rate Ratio of Recombination to Capture and Trap Depth from Thermo-Luminescence of ZnS:Cu,Co

作　　者：王丽伟[1] 徐征[1] 滕枫[1] 张福俊[1] 孟立建 徐叙瑢[1] 

机构地区：[1]北京交通大学光电子技术研究所信息存储与显示重点实验室,北京100044 [2]波尔图理工大学工程学院

出　　处：《光谱学与光谱分析》2005年第10期1537-1541,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金(10374001);"973"计划项目(2003CB314707);中国博士后基金(2003034324);北京市自然科学基金(2032015);博士点基金(20020004004)资助项目

摘　　要：复合发光的本质是两种载流子的复合,但其衰减规律则视具体情况可以从一个极限(指数)变到另一个极限(抛物线),即复合发光是一个连续变化的过程。这主要取决于导带电子的行为,导带电子的行为可以用电子与离化发光中心复合与被陷阱俘获之比来表示。加热发光是在变化温度下的发光弛豫,它既与复合与俘获之比有关,还是陷阱深度的函数,因此在利用加热发光曲线测定陷阱深度时,要同时确定这两个参数。利用热释光动力学模型及其原理,对其发光过程进行了分析,解释了热释光过程既不是一个单分子过程也不是一个双分子过程,这两个过程实际是两个极端情形,都是近似。文章同时利用一些工具软件具体计算了ZnS:Cu,Co的陷阱深度及电子复合与俘获概率之比,精确的计算了这些参数,得-n0=2.6,ε=0.86eV。The recombination luminescence is in nature a bimolecular process, but the decay rule may be changing from that of mono-molecular to bimolecular rule, i.e. , from exponential to hyperbolic rule, depending on the behavior of conduction electrons. This behavior is represented by relative rate of recombination with ionized centers to that of capture by traps. This relative rate depends partly on the intrinsic parameters of the specified materials, and partly on the concentration of conduction electrons supplied by traps. Each point of the TL curve is related to the material parameters and the release of electrons from traps. The ratio of relative rate of recombination to that of capture γ（ε）=^σ0n0/σ（v-n） involves the parameter ε. They are inseparable and must be determined at the same time. In the present report, starting from the same sample ZnS：Cu, Co which has only one peak in its TL（i. e. , only one kind of luminescent center and only one kind of traps）, and the experimental value of σ/σ0=0.005,the authors use thermo-luminescence kinetics models and some mathematic tools to exactly estimate the ratio σ0n0/σv and the trap depth e simultaneously from the glow curve. The authors found that σ0n0/σv=2.6 and e=0.86 eV.

关 键 词：发光衰减动力学 单分子过程 双分子过程 热释光曲线 陷阱深度 

分 类 号：O433.4[机械工程—光学工程]