分子电子器件简化模型的电子透射谱的计算  

Calculation of the electronic transmission spectra of a molecular device using a simplified model

作　　者：李巧华[1] 张振华[1] 刘新海[1] 邱明[1] 丁开和[1] 

机构地区：[1]长沙理工大学物理与电子科学学院,长沙410076

出　　处：《物理学报》2009年第10期7204-7210,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60771059);湖南省自然科学基金(批准号:08JJ4002);湖南省优秀博士论文基金(批准号:200526);湖南省教育厅科技项目(批准号:08A005;05B023);长沙理工大学重点学科建设项目资助的课题~~

摘　　要：基于分子线耦合到电极的构成特点,采用简化的非对称多势垒连续隧穿模型模拟复合分子器件偏压下的电子隧穿过程,推导电子透射谱的解析表达式,同时计算垒宽、垒距、垒高、电子有效质量和所加偏压等参数与透射系数的关系,结果发现:当电子的能量为某些值时,出现明显的共振隧穿,且透射系数对这些参数的变化非常敏感,这表明可以通过适当的控制方式(如改变复合分子组成、构型等)来修改分子电子器件的输运性质.Based on the structural characteristics of a molecular wire coupled to electrodes,the electronic tunneling process in a molecular device consisting of such a composite molecule under a bias is modeled by a simplified successive tunneling model with asymmetric multiple potential barriers in series.An analytical expression for the electronic transmission spectrum is obtained.Then,the relations between the transmission coefficient and various parameters,such as the width and height of the barrier,the distance between two neighboring barriers, the effective mass of electron, and the bias voltage, are calculated. It is found that when the electron energies are equal to some special values, obvious resonant tunneling occurs, and the transmission coefficient is very sensitive to the parameters mentioned above. The results presented here suggest that the transport behaviors of molecular electronic devices can be significantly modified in a controlled way, for example, by altering the constituents or/and the configurations of the composite molecule.

关 键 词：分子器件 非对称势垒模型 电子透射谱 共振隧穿 

分 类 号：TN103[电子电信—物理电子学]