arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0704.0408cond-mat.mes-hall
收藏

有机单分子接触的光电导

Photoconductance of organic single-molecule contacts

J. K. Viljas, F. Pauly, J. C. Cuevas

摘要:

我们研究了有机单分子接触在外部电磁辐射(光电导)存在下的直流电导。在与以前的预测一致,我们发现,辐射可以导致大的增强这种接触的电导,通过光辅助过程,使非共振能级共振。在我们的分析中,我们利用简化的事实,即在某些假设下,光电导可以表示在没有辐射的透射函数。利用密度泛函理论计算了低聚亚苯基分子在金电极之间的电子结构,证明了低聚亚苯基分子的电导增强。结果表明,在辐射的存在下,电导随分子长度的指数衰减可以由长度无关的值代替。

英文摘要:

We study the dc conductance of organic single-molecule contacts in the presence of external electromagnetic radiation (photoconductance). In agreement with previous predictions, we find that the radiation can lead to large enhancements of the conductance of such contacts by bringing off-resonant levels into resonance through photoassisted processes. In our analysis we make use of the simplifying fact that, under certain assumptions, the photoconductance can be expressed in terms of the transmission function in the absence of the radiation. The conductance enhancement is demonstrated for oligophenylene molecules between gold electrodes, whose electronic structure is calculated based on density-functional theory. It is shown that the exponential decay of the conductance with the length of the molecule can be replaced by a length-independent value in the presence of radiation.

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。

↑