Relaxation of stored charge carriers in a Zn0.3Cd0.7Se mixed crystal.
Relaxation of stored charge carriers in a Zn0.3Cd0.7Se mixed crystal.
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Zn0.3Cd0.7Se 混合晶体中存储电荷载流子的弛豫。
DOI：
10.1103/physrevb.41.5178
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Jiang
中科院分区：
文献类型：
--
作者：
Lin;Jiang
研究了Zn{sub 0.3}Cd{sub 0.7}Se混晶的持续光电导特性。观察到两种不同的温度电导率状态。在不同的条件下，研究了对PPC有贡献的存储载流子的弛豫。我们发现PPC的衰减遵循通常在广泛的一类无序材料中观察到的拉伸指数函数。在{italT}{lt}220 K时，弛豫时间随温度的升高而增加.在恒定温度下，弛豫时间随着激发光子剂量的增加而增加，这是两种不同导电状态存在的结果。然而，在恒定温度下，衰减指数是激发光子剂量无关，而特征衰减时间常数取决于激发光子剂量。因此，这里观察到的PPC表现出无序系统的特征现象，这表明随机局部电位波动，这引起的组成波动，是负责PPC。PPC的衰减行为也分析了一些以前发表的其他材料的数据。我们发现，拉伸指数函数描述的PPC在各种材料在低温下的衰减。
Persistent photoconductivity (PPC) has been investigated in detail in a Zn{sub 0.3}Cd{sub 0.7}Se mixed crystal. Two different temperature conductivity states have been observed. Relaxation of stored charge carriers, which contribute to PPC, has been studied at different conditions. We find that the decay of PPC follows the stretched-exponential'' function that is usually observed in a wide class of disordered materials. At {ital T}{lt}220 K, the relaxation time increases with increase of temperature. At a constant temperature, the relaxation time increases with increase of excitation photon dose, which is a consequence of the presence of the two different conductivity states. However, at a constant temperature, the decay exponent is excitation-photon-dose independent, while the characteristic decay time constant depends on excitation photon dose. The PPC observed here thus exhibits characteristic phenomena of disordered systems, which suggests that the random local-potential fluctuations, which arise from the compositional fluctuations, are responsible for PPC. PPC-decay behavior is also analyzed for some of the previously published data on other materials. We find that the stretched-exponential function describes the PPC decay in various materials at low temperatures.