Current-voltage characteristics of individual conducting polymer nanotubes and nanowires  

作　　者：龙云泽 尹志华 李蒙蒙 顾长志 Duvail Jean-Luc 金爱子 万梅香 

机构地区：[1]College of Physics Science, Qingdao University [2]Institute of Physics,Chinese Academy of Sciences [3]Institut des Mat'eriaux Jean Rouxel,Universit'e de Nantes [4]Institute of Chemistry, Chinese Academy of Sciences

出　　处：《Chinese Physics B》2009年第6期2514-2522,共9页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant No 10604038);the Program for New Century Excellent Talents in University of China (Grant No NCET-07-0472)

摘　　要：We report the current-voltage （I-V） characteristics of individual polypyrrole nanotubes and poly（3,4- ethylenedioxythiophene） （PEDOT） nanowires in a temperature range from 300 K to 2 K. Considering the complex structures of such quasi-one-dimensional systems with an array of ordered conductive regions separated by disordered barriers, we use the extended fluctuation-induced tunneling （FIT） and thermal excitation model （Kaiser expression） to fit the temperature and electric-field dependent I-V curves. It is found that the I-V data measured at higher temperatures or higher voltages can be well fitted by the Kaiser expression. However, the low-temperature data around the zero bias clearly deviate from those obtained from this model. The deviation （or zero-bias conductance suppression） could be possibly ascribed to the occurrence of the Coulomb-gap in the density of states near the Femi level and/or the enhancement of electron-electron interaction resulting from nanosize effects, which have been revealed in the previous studies on low-temperature electronic transport in conducting polymer films, pellets and nanostructures. In addition, similar I--V characteristics and deviation are also observed in an isolated K0.27MnO2 nanowire.We report the current-voltage （I-V） characteristics of individual polypyrrole nanotubes and poly（3,4- ethylenedioxythiophene） （PEDOT） nanowires in a temperature range from 300 K to 2 K. Considering the complex structures of such quasi-one-dimensional systems with an array of ordered conductive regions separated by disordered barriers, we use the extended fluctuation-induced tunneling （FIT） and thermal excitation model （Kaiser expression） to fit the temperature and electric-field dependent I-V curves. It is found that the I-V data measured at higher temperatures or higher voltages can be well fitted by the Kaiser expression. However, the low-temperature data around the zero bias clearly deviate from those obtained from this model. The deviation （or zero-bias conductance suppression） could be possibly ascribed to the occurrence of the Coulomb-gap in the density of states near the Femi level and/or the enhancement of electron-electron interaction resulting from nanosize effects, which have been revealed in the previous studies on low-temperature electronic transport in conducting polymer films, pellets and nanostructures. In addition, similar I--V characteristics and deviation are also observed in an isolated K0.27MnO2 nanowire.

关 键 词：conducting polymers I-V curves nanotubes/wires 

分 类 号：TB383.1[一般工业技术—材料科学与工程]