中国物理B ›› 2009, Vol. 18 ›› Issue (6): 2514-2522.doi: 10.1088/1674-1056/18/6/066

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Current-voltage characteristics of individual conducting polymer nanotubes and nanowires

龙云泽1, 尹志华1, 李蒙蒙1, DuvailJean-Luc2, 万梅香3, 顾长志4, 金爱子4   

  1. (1)College of Physics Science, Qingdao University, Qingdao 266071, China; (2)Institut des Mat '{eriaux Jean Rouxel, Universit '{e de Nantes, 44322 Nantes, CNRS, France; (3)Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; (4)Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2008-10-10 修回日期:2008-12-04 出版日期:2009-06-20 发布日期:2009-06-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 10604038) and the Program for New Century Excellent Talents in University of China (Grant No NCET-07-0472).

Current-voltage characteristics of individual conducting polymer nanotubes and nanowires

Long Yun-Ze(龙云泽)a)†, Yin Zhi-Hua(尹志华)a), Li Meng-Meng(李蒙蒙)a), Gu Chang-Zhi(顾长志)b), Duvail Jean-Lucc), Jin Ai-Zi(金爱子)b), and Wan Mei-Xiang(万梅香)d)   

  1. a College of Physics Science, Qingdao University, Qingdao 266071, China; b Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; c Institut des Matériaux Jean Rouxel, Université de Nantes, 44322 Nantes, CNRS, France; d Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2008-10-10 Revised:2008-12-04 Online:2009-06-20 Published:2009-06-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 10604038) and the Program for New Century Excellent Talents in University of China (Grant No NCET-07-0472).

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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.

关键词: conducting polymers, I--V curves, nanotubes/wires

Abstract: 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.

Key words: conducting polymers, I--V curves, nanotubes/wires

中图分类号:  (Nanotubes)

  • 73.63.Fg
66.70.-f (Nonelectronic thermal conduction and heat-pulse propagation in solids;thermal waves) 73.20.At (Surface states, band structure, electron density of states) 73.22.-f (Electronic structure of nanoscale materials and related systems) 73.23.Hk (Coulomb blockade; single-electron tunneling)