Phenomenological model for charge dynamics and optical response of disordered systems: Application to organic semiconductors
Phenomenological model for charge dynamics and optical response of disordered systems: Application to organic semiconductors
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DOI：
10.1103/physrevb.89.235201
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发表时间：
2014-06-05
影响因子：
3.7
通讯作者：
Mayou, D.
中科院分区：
文献类型：
--
作者：
Fratini, S.;Ciuchi, S.;Mayou, D.
我们提供了一个唯象的公式，描述了在无序系统中的局域化的电荷载流子的低频光吸收。这使我们能够提取，从实验数据的光学电导率，相关的微观参数确定的传输特性，如载流子的本地化长度和弹性和非弹性散射时间。这个一般公式进行测试，并在这里应用到有机半导体，其中动态分子无序是已知的输运性质中发挥关键作用。目前的治疗抓住了基本的想法，最近提出的瞬态本地化的情况下，电荷传输，扩展它从直流迁移率的频域。当应用到现有的红荧烯场效应晶体管的光学测量，我们的分析提供了定量的证据的瞬态本地化现象。对其他无序电子系统的可能应用进行了简要讨论。
We provide a phenomenological formula that describes the low-frequency optical absorption of charge carriers in disordered systems with localization. This allows us to extract, from experimental data on the optical conductivity, the relevant microscopic parameters determining the transport properties, such as the carrier localization length and the elastic and inelastic scattering times. This general formula is tested and applied here to organic semiconductors, where dynamical molecular disorder is known to play a key role in the transport properties. The present treatment captures the basic ideas underlying the recently proposed transient localization scenario for charge transport, extending it from the dc mobility to the frequency domain. When applied to existing optical measurements in rubrene field-effect transistors, our analysis provides quantitative evidence for the transient localization phenomenon. Possible applications to other disordered electronic systems are briefly discussed.