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arXiv 0912.3161cond-mat.dis-nn
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电场对无序材料中扩散的影响I。一维跳跃输运

Effect of Electric Field on Diffusion in Disordered Materials I. One-dimensional Hopping Transport

A. V. Nenashev, F. Jansson, S. D. Baranovskii, R. Österbacka, A. V. Dvurechenskii, F. Gebhard

摘要:

本文建立了一个精确的解析理论,用于计算具有一维跳跃输运模式的强各向异性无序固体中载流子的扩散系数,其跳跃速率随空间和能量的变化是任意的。到目前为止,这种理论只存在于计算载流子迁移率。扩散系数对电场的依赖性证明了所有考虑的无序模型在低场下的线性、非解析行为。流动性,相反,展示了一个抛物线,分析场的随机势垒模型的依赖性,是线性的,非分析的随机能量模型。对于这两个模型的爱因斯坦之间的关系的扩散系数和迁移率被证明是违反在任何有限的电场。关于输运系数的这些非解析场依赖性和爱因斯坦公式的伴随违反是由于空间的维数还是由于所考虑的无序模型的问题在以下论文中得到解决[Nenashev等人,arXiv:0912.3169],其中对二维和三维系统进行分析计算和计算机模拟。

英文摘要:

An exact analytical theory is developed for calculating the diffusion coefficient of charge carriers in strongly anisotropic disordered solids with one-dimensional hopping transport mode for any dependence of the hopping rates on space and energy. So far such a theory existed only for calculating the carrier mobility. The dependence of the diffusion coefficient on the electric field evidences a linear, non-analytic behavior at low fields for all considered models of disorder. The mobility, on the contrary, demonstrates a parabolic, analytic field dependence for a random-barrier model, being linear, non-analytic for a random energy model. For both models the Einstein relation between the diffusion coefficient and mobility is proven to be violated at any finite electric field. The question on whether these non-analytic field dependences of the transport coefficients and the concomitant violation of the Einstein's formula are due to the dimensionality of space or due to the considered models of disorder is resolved in the following paper [Nenashev et al., arXiv:0912.3169], where analytical calculations and computer simulations are carried out for two- and three-dimensional systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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