From Tunneling to Hopping: A Comprehensive Investigation of Charge Transport Mechanism in Molecular Junctions Based on Oligo(p-phenylene ethynylene)s

被引：272

作者：

Lu, Qi ^{[1
,2
]}

Liu, Ke ^{[1
]}

Zhang, Hongming ^{[1
]}

Du, Zhibo ^{[1
]}

Wang, Xianhong ^{[1
]}

Wang, Fosong ^{[1
]}

机构：

[1] Chinese Acad Sci, Changchun Inst Appl Chem, State Key Lab Polymer Phys & Chem, Changchun 130022, Peoples R China

[2] Chinese Acad Sci, Grad Sch, Beijing 100039, Peoples R China

来源：

ACS NANO | 2009年 / 3卷 / 12期

关键词：

oligo(p-phenylene ethynylene)s; charge transport mechanism; tunneling conduction; hopping conduction; scanning tunneling microscopy; conducting probe atomic force microscopy; single molecular resistance; ATOMIC-FORCE MICROSCOPY; LENGTH DEPENDENCE; CONDUCTANCE; WIRES; RESISTANCE; TEMPERATURE;

D O I：

10.1021/nn9012687

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The charge transport mechanism of oligo(p-phenylene ethynylene)s with lengths ranging from 0.98 to 5.11 nm was investigated using modified scanning tunneling microscopy break junction and conducting probe atomic force microscopy methods. The methods were based on observing the length dependence of molecular resistance at single molecule level and the current-voltage characteristics in a wide length distribution. An intrinsic transition from tunneling to hopping charge transport mechanism was observed near 2.75 nm. A new transitional zone was observed in the long length molecular wires compared to short ones. This was not a simple transition between direct tunneling and field emission, which may provide new insights into transport mechanism investigations. Theoretical calculations provided an essential explanation for these phenomena in terms of molecular electronic structures.

引用

页码：3861 / 3868

页数：8

共 41 条

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