Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA.
Nat Mater. 2015 May;14(5):517-22. doi: 10.1038/nmat4216. Epub 2015 Feb 16.
The development of molecular-scale electronic devices has made considerable progress over the past decade, and single-molecule transistors, diodes and wires have all been demonstrated. Despite this remarkable progress, the agreement between theoretically predicted conductance values and those measured experimentally remains limited. One of the primary reasons for these discrepancies lies in the difficulty to experimentally determine the contact geometry and binding configuration of a single-molecule junction. In this Article, we apply a small-amplitude, high-frequency, sinusoidal mechanical signal to a series of single-molecule devices during junction formation and breakdown. By measuring the current response at this frequency, it is possible to determine the most probable binding and contact configurations for the molecular junction at room temperature in solution, and to obtain information about how an applied strain is distributed within the molecular junction. These results provide insight into the complex configuration of single-molecule devices, and are in excellent agreement with previous predictions from theoretical models.
在过去的十年中，分子尺度电子器件的发展取得了相当大的进展，已经展示了单分子晶体管、二极管和导线。尽管取得了这一显著的进展，但理论预测的电导值与实验测量值之间的一致性仍然有限。这些差异的一个主要原因在于难以实验确定单分子结的接触几何形状和结合构型。在本文中，我们在单分子器件的形成和击穿过程中对一系列单分子器件施加小振幅、高频正弦机械信号。通过测量该频率下的电流响应，可以确定在室温下溶液中单分子结的最可能的结合和接触构型，并获得有关施加应变如何在分子结内分布的信息。这些结果深入了解了单分子器件的复杂结构，与理论模型的先前预测非常吻合。
