Institute for Materials Science, Max Bergmann Center of Biomaterials, TU Dresden, 01069 Dresden, Germany.
Nanoscale. 2018 Sep 20;10(36):17131-17139. doi: 10.1039/c8nr05031g.
We investigate the conductance of optimized donor-acceptor-donor molecular wires obtained by on-surface synthesis on the Au(111) surface. A careful balance between acceptors and donors is achieved using a diketopyrrolopyrrole acceptor and two thiophene donors per unit along the wire. Scanning tunneling microscopy imaging, spectroscopy, and conductance measurements done by pulling a single molecular wire at one end are presented. We show that the conductance of the obtained wires is among the highest reported so far in a tunneling transport regime, with an inverse decay length of 0.17 Å-1. Using complex band structure calculations, different donor and acceptor groups are discussed, showing how a balanced combination of donor and acceptor units along the wire can further minimize the decay of the tunneling current with length.
我们研究了在 Au(111)表面上通过表面合成得到的优化给体-受体-给体分子线的电导。通过在每个单元中使用二酮吡咯并吡咯受体和两个噻吩给体，在受体和给体之间实现了精细的平衡。通过在一端拉动单个分子线进行扫描隧道显微镜成像、光谱和电导测量。我们表明，所得到的分子线的电导在隧道输运模式下是迄今为止报道的最高的之一，其倒数衰减长度为 0.17 Å-1。使用复杂的能带结构计算，讨论了不同的供体和受体基团，表明沿分子线平衡组合供体和受体单元如何进一步最小化电流随长度的衰减。
