中文摘要：

采用简化的对称势垒连续隧穿模型模拟复合分子线电子器件低偏压下电子隧穿过程，并由电子透射谱随垒宽、垒距、垒高及电子有效质量的变化规律推断低偏压下分子器件的电导规律．结果发现：随着势垒增宽或增高，分子器件的低偏压电导G明显变小；但是随着垒距或电子有效质量增大，则分子器件的低偏压电导G反而变大．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低偏压输运性质．

英文摘要：

The electronic tunneling process in a molecular device consisting of a composite symmetric multiple potential barriers in series is modeled by a simplified successive tunneling model. Patterns of the low-bias conductance of a molecule are inferred by the changing patterns of electronic transmission spectra with variations of the width,height of the barrier,the distance of the two neighboring barriers,and the efficient mass of electron. It is found that the low-bias conductance of a molecule decreases remarkably with an increase in either the width or height of a barrier,instead the low-bias conductance of a molecule increases substantially with an increase in either the distance of the two neighboring barriers or the efficient mass of electron. The results presented here suggest that the transport behaviors of molecular electronic devices under a low bias can be greatly modified in a controlled way （for exam- ple, altering the constituents or/and configurations of a composite molecule）.