分子旋转对分子器件电子输运性质的影响

Effect of Rotation on the Electronic Transport Properties of a Molecular Device

利用基于非平衡格林函数和密度泛函理论相结合的第一性原理计算方法,研究了一种可旋转分子跨接在金电极上的电子输运性质。计算结果表明:分子中的转子与定子间的旋转角度可以有效调控分子器件的电子输运性质。当夹角从30°变化到150°,分子器件的导电性呈现出增强、减弱的震荡变化。此外,当夹角变化到90°,分子器件的电流电压曲线打破其他角度呈现的线性变化特性,其电流值在2.4 V以后随着电压的增大而减小,表现出强烈的负微分电阻效应。

Using nonequilibrium Green′s functions in combination with density-functional theory,we investigate the electronic transport properties of a molecular motor device.The calculations show that the transport behavior of the device is sensitive to the rotational orientation of the rotor component.As the angle between the rotor and the stator is varied between 30° and 150°,the conductance of the molecular device oscillates between high and low.Moreover,when the rotor revolves to become vertically aligned with the stator,the current-voltage characteristics of the device display nonlinear behavior.The current decreases when the bias voltage is increased beyond 2.4 V and displays negative differential resistance behavior.