Rectifying Electron-Transport Properties through Stacks of Aromatic Molecules Inserted into a Self-Assembled Cage
Rectifying Electron-Transport Properties through Stacks of Aromatic Molecules Inserted into a Self-Assembled Cage
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DOI：
10.1021/jacs.5b00086
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发表时间：
2015-05-13
影响因子：
15
通讯作者：
Kiguchi, Manabu
中科院分区：
文献类型：
--
作者：
Fujii, Shintaro;Tada, Tomofumi;Kiguchi, Manabu
通过自组装形成的芳香族堆叠是用于构建具有可调节电子功能的分子电子器件的有希望的构建块，其中非共价键合的π堆叠充当可替换的模块化组件。在这里，我们使用扫描探针显微镜和断裂连接方法描述了在自组装笼中排列的单分子芳香族堆叠的电子传输特性。相同和不同的模块化芳族对以非共价键结合并堆叠在分子笼支架内，从而产生不同的电子功能。相同对的插入会产生高电子电导率（10(-3)-10(-2) G(0), G(0) = 2e(2)/h），而不同对会产生额外的电子整流特性。在固定偏压下的电流电压特性和分子取向相关电导测量中，整流比估计分别为 1.4-2 和 >10。理论计算表明，这种整流行为源于内部芳香族成分相对于电子传输方向的不同堆叠顺序以及位于分子结一侧的相应最低未占据分子轨道传导通道。
Aromatic stacks formed through self-assembly are promising building blocks for the construction Of molecular electronic devices with adjustable electronic functions, in which noncovalently bound pi-stacks act as replaceable modular components. Here we describe the electron-transport properties of single-molecule aromatic stacks aligned in a self-assembled cage, using scanning probe microscopic and break junction methods. Same and different modular aromatic pairs are noncovalently bound and stacked within the molecular cage holder, which leads to diverse electronic functions. The insertion of same pairs induces high electronic conductivity (10(-3)-10(-2) G(0), G(0) = 2e(2)/h), while different pairs develop additional electronic rectification properties. The rectification ratio was, respectively, estimated to be 1.4-2 and >10 in current voltage characteristics and molecular orientation-dependent conductance measurements at a fixed bias voltage. Theoretical calculations demonstrate that this rectification behavior originates from the distinct stacking order of the internal aromatic components against the electron-transport direction and the corresponding lowest unoccupied molecular orbital conduction channels localized on one side of the molecular junctions.