Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft, 2628 CJ, The Netherlands.
Nanoscale Res Lett. 2013 May 16;8(1):234. doi: 10.1186/1556-276X-8-234.
Interference effects on charge transport through an individual molecule can lead to a notable modulation and suppression on its conductance. In this letter, we report the observation of quantum interference effects occurring at room temperature in single-molecule junctions based on oligo(3)-phenylenevinylene (OPV3) derivatives, in which the central benzene ring is coupled to either para- or meta-positions. Using the break-junction technique, we find that the conductance for a single meta-OPV3 molecule wired between gold electrodes is one order of magnitude smaller than that of a para-OPV3 molecule. Theoretical calculations confirm the occurrence of constructive and destructive interference in the para- and meta-OPV3 molecules respectively, which arises from the phase difference of the transmission coefficients through the molecular orbitals.
干扰效应对单个分子中的电荷输运会产生显著的调制和抑制作用。在这封信件中，我们报告了在室温下基于寡聚（3）-苯乙炔（OPV3）衍生物的单分子结中观察到量子干涉效应，其中中央苯环连接到对位或间位。使用断键技术，我们发现连接在金电极之间的单个间位 OPV3 分子的电导比对位 OPV3 分子小一个数量级。理论计算证实了对位和间位 OPV3 分子中分别发生了建设性和破坏性干涉，这是由通过分子轨道的传输系数的相位差引起的。
