论文部分内容阅读
合成了12个OPV分子导线(分成乙酰巯基与氨基端基两个系列),采用导电原子力显微镜和扫描隧道显微镜-裂分结的方法对该类分子导线的电学性能进行了表征.通过分析单分子电阻与分子长度、温度以及电场的依赖关系,发现OPV分子导线的电子传输机理在临界长度为2.0 nm处发生了由隧穿传导向跳跃传导的转变.通过对比分子末端分别为巯基和氨基的单分子电导值,考察了不同的连接基团对OPV分子导线电子传输性能的影响,发现末端基团只影响分子的接触电阻,但不改变分子导线本身的电子传输机理.利用密度泛函理论和非平衡格林函数方法对OPV分子导线的电学特性进行了理论研究,结果表明分子的前线轨道能级与金电极的相对位置决定了OPV分子导线的电子传输机理.
Twelve OPV molecular conductors (divided into two series of acetylmercapto and amino end groups) were synthesized, and the electrical properties of these molecular conductors were characterized by means of conductive atomic force microscopy and scanning tunneling microscopy - cleavage junctions.Through the analysis of single molecule The dependence of the resistance on the molecular length, temperature and electric field found that the electron transport mechanism of the OPV molecular conductor changed from tunneling conduction to jumping conduction at a critical length of 2.0 nm. By comparing the single- The influence of different linker groups on the electron transport properties of OPV molecular conductors was investigated and it was found that the terminal groups only affected the contact resistance of the molecule but did not change the electron transport mechanism of the molecular conductors themselves.Using density functional theory and non- The theoretical analysis of the electrical properties of the OPV molecular wires by the equilibrium Green’s function method shows that the electron transport mechanism of the OPV molecular wires is determined by the position of the frontier orbital of the molecule and the relative position of the gold electrode.