Electron transport in disordered semiconductors studied by a small harmonic modulation of the steady state
Electron transport in disordered semiconductors studied by a small harmonic modulation of the steady state
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DOI：
10.1103/physrevb.61.4699
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发表时间：
2000-02
影响因子：
3.7
通讯作者：
D. Vanmaekelbergh;P. D. Jongh
中科院分区：
文献类型：
--
作者：
D. Vanmaekelbergh;P. D. Jongh
半导体或绝缘网络形成了一类无序系统，其中电子运动可以通过散射效应（结构无序）和多重捕获（电子无序）而衰减。我们研究了这样一个无序系统的电子输运特性的稳态约束下，通过引入一个小过量的自由载流子，谐波随时间变化。考虑到散射和临时本地化，这个小的过量通过系统的传播。最后，考虑了光调制时的谐波光电流响应。可以区分两种不同的运输制度。在第一个政权的运输似乎是定期的，其特征是由一个单一的渡越时间为所有电子。然而，渡越时间可以通过多次捕获来确定。散射和多重俘获可以通过稳态约束的变化来区分。第二（不规则）政权表现出很强的分散在渡越时间，类似于非稳态条件下观察到的分散运输。
Semiconducting or insulating networks form a class of disordered systems in which electron motion can be attenuated by scattering effects (structural disorder) and multiple trapping (electronic disorder). We studied the electron transport characteristics of such a disordered system under steady-state constraints by introducing a small excess of free carriers, harmonically varying in time. Propagation of this small excess through the system is considered taking into account scattering and temporary localization. Finally, the harmonic photocurrent response upon light modulation is considered. Two different transport regimes could be distinguished. In the first regime transport appears to be regular and is characterized by a single transit time for all electrons. However, the transit time may be determined by multiple trapping. Scattering and multiple trapping can be distinguished by variation of the steady-state constraints. The second (irregular) regime shows a strong dispersion in the transit time, similar to dispersive transport observed under nonsteady-state conditions.