Abstract

Based on the first-principles calculation method combining the density functional theory (DFT) and the nonequilibrium Green’s function (NEGF) method, the negative differential resistance (NDR) and rectification effect of the benzoquinone molecules junction sandwiched between the graphene nanoribbon electrodes are systematically investigated. The current of the device with the central o-benzoquinone and p-benzoquinone molecule has been demonstrated to decrease with the increase of the bias voltage in the range of [± 0.9 V, ± 1.5 V] and [± 0.6 V, ± 1.1 V], respectively, exhibiting a significant NDR effect. In addition, the interesting NDR effect of the device with the central carbon (C) and nitrogen (N) connected o- and p-benzoquinone molecules has been observed in the bias voltage range of [0.9 V, 1.2 V] and [\(-0.8\) V, \(-1.0\) V] , respectively. The current of the device with the central sulfur (S) and oxygen (O) connected o- and p-benzoquinone molecules should decrease with the increase of the bias voltage at the regime of [0.8 V, 1.0 V] while that should be forbidden when a negative bias voltage is applied, illustrating an interesting rectification effect, and the maximum rectification ratio is observed to be up to 57.85 and 55.85, respectively. The obtained NDR and rectification effect are physically explained from the integral of the transmission coefficient in the bias voltage window and the distribution of the real space charge density, and the demonstrated results are believed to be vital for the designing of the molecular switches, molecular rectifying devices and negative differential resistance devices based on benzoquinone molecules junction.

Graphic abstract

中文翻译：

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夹在石墨烯纳米带电极之间的苯醌分子结的负微分电阻和整流效应

摘要

基于密度泛函理论（DFT）和非平衡格林函数（NEGF）方法的第一性原理计算方法，系统地研究了夹在石墨烯纳米带电极之间的苯醌分子连接的负微分电阻（NDR）和整流效应。 。在[±0.9 V，±1.5 V]和[±0.6 V，±1.1 V]范围内，随着偏置电压的增加，带有中心邻苯甲醌和对苯醌分子的器件电流被证明减小。分别显示出显着的NDR效果。此外，装置的有趣的NDR效应是中心碳（C）和氮（N）连接到o-和p在[0.9 V，1.2 V]和[ \（-0.8 \）  V，\（-1.0 \）  V]的偏压范围内分别观察到-苯醌分子。中心硫（S）和氧（O）连接到o-和p的设备电流-苯醌分子应在[0.8 V，1.0 V]范围内随偏压的增加而减少，而在施加负偏压时则应禁止这样做，这说明了有趣的整流效果，并且观察到最大整流比为-分别达到57.85和55.85。从偏置电压窗口中的传输系数的积分和实际空间电荷密度的分布来物理解释获得的NDR和整流效果，并且据信所证明的结果对于分子开关的设计，分子整流是至关重要的。苯醌分子结的电子器件和负微分电阻器件。

图形摘要