Acta Chim. Sinica ›› 2017, Vol. 75 ›› Issue (9): 893-902.DOI: 10.6023/A17050195 Previous Articles     Next Articles



贺园园, 程娜, 赵健伟   

  1. 嘉兴学院材料与纺织工程学院 中澳先进材料与制造研究院 嘉兴 314001
  • 投稿日期:2017-05-03 发布日期:2017-06-15
  • 通讯作者: 赵健伟

Electron Transport Pathways Through One-Dimensional Conjugated Carbon Chain Doped by Thiophene Ring

He Yuanyuan, Cheng Na, Zhao Jianwei   

  1. College of Material and Textile Engineering, China-Australia Institute for Advanced Materials and Manufacturing, Jiaxing University, Jiaxing 314001
  • Received:2017-05-03 Published:2017-06-15
  • Contact: 10.6023/A17050195

Represented by graphene and carbon nanotubes, one-dimensional (1D) conjugated carbon materials are potential ones to be used in molecular electronic devices. The further application of 1D conjugated carbon materials in optoelectronic devices requires that they have electron-poor/electron-rich characteristics, with the premise of high conductivity. Most of 1D conjugated carbon materials are constructed by aromatic rings as the basic units. Substitutional S atoms into benzene ring is an effective method to achieve electron doping into 1D conjugated carbon materials. Herein, to simulate the doping effect of 1D conjugated carbon materials, a series of oligobenzo[1,2-b:4,5-b'] dithiophene (BmT) and oligothiophene (TnP) molecules were designed by substitutional doping thiophene ring into conjugated carbon skeleton. The influence of doping position and concentration on the electron transport properties were studied based on the nonequilibrium Green's function approach and density functional theory. Static electronic properties indicate that HOMO orbitals have higher delocalization on trans-configurations of BmT and TnP molecules as compared with cis-conjugations, indicating the higher conductivity of trans-BmT and trans-TnP. Dynamic transport behaviors demonstrate that the substitutional doping of thiophene rings can significantly improve the electron transport efficiency of carbon skeleton. The conductance trend of BmT and TnP molecules indicates that the electron transport efficiency through the compounds is dependent on their conjugation. The conductance of BmT and TnP molecules are not only dependent to the chain length, but also related to the energy gaps and electron transport pathways. Trans-BmT and trans-TnP are conjugated molecules with multiple pathways, however, cis-BmT and cis-TnP are conjugated molecules that can transform from a single pathway to multiple pathways, with the increase of chain length. The diversity of the electron transport behaviors of the thiophene-doped carbon skeletons is directly dominated by the electron transport pathways. Our work gives insight into the development of novel carbon-based molecular optoelectronic materials with high performance.

Key words: thiophene, benzene ring, conjugated carbon materials, electron transport, substitutional doping