中国物理B ›› 2012, Vol. 21 ›› Issue (5): 57901-057901.doi: 10.1088/1674-1056/21/5/057901

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Field emission properties of capped carbon nanotubes doped by alkali metals:a theoretical investigation

靳磊1,付宏刚1 2,谢颖2,于海涛2   

  1. 1. School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001, China;
    2. Key Laboratory of Functional Inorganic Material Chemistry of Ministry of Education, Heilongjiang University, Harbin 150080, China
  • 收稿日期:2011-11-14 修回日期:2012-04-27 出版日期:2012-04-01 发布日期:2012-04-01
  • 基金资助:
    Project supported by the Key Program of the National Natural Science Foundation of China (Grant Nos. 21031001 and U1034003), the National Natural Science Foundation of China (Grant Nos. 20971040 and 21173072), and the Cultivation Fund of the Key Scientific and Technical Innovation Project, Ministry of Education of China (Grant No. 708029)

Field emission properties of capped carbon nanotubes doped by alkali metals:a theoretical investigation

Jin Lei(靳磊)a), Fu Hong-Gang(付宏刚)a) b)†, Xie Ying(谢颖)b), and Yu Hai-Tao(于海涛)b)   

  1. a. School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001, China;
    b. Key Laboratory of Functional Inorganic Material Chemistry of Ministry of Education, Heilongjiang University, Harbin 150080, China
  • Received:2011-11-14 Revised:2012-04-27 Online:2012-04-01 Published:2012-04-01
  • Supported by:
    Project supported by the Key Program of the National Natural Science Foundation of China (Grant Nos. 21031001 and U1034003), the National Natural Science Foundation of China (Grant Nos. 20971040 and 21173072), and the Cultivation Fund of the Key Scientific and Technical Innovation Project, Ministry of Education of China (Grant No. 708029)

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摘要： The electronic structures and field emission properties of capped CNT55 systems with or without alkali metal atom adsorption were systematically investigated by density functional theory calculation. The results indicate that the adsorption of alkali metal on the center site of a CNT tip is energetically favorable. In addition, the adsorption energies increase with the introduction of the electric field. The excessive negative charges on CNT tips make electron emittance much easier and result in a decrease in work function. Furthermore, the inducing effect by positively charged alkali metal atoms can be reasonably considered as the dominant reason for the improvement in field emission properties.

关键词: field emission, density functional theory, carbon nanotube, alkali metal

Abstract: The electronic structures and field emission properties of capped CNT55 systems with or without alkali metal atom adsorption were systematically investigated by density functional theory calculation. The results indicate that the adsorption of alkali metal on the center site of a CNT tip is energetically favorable. In addition, the adsorption energies increase with the introduction of the electric field. The excessive negative charges on CNT tips make electron emittance much easier and result in a decrease in work function. Furthermore, the inducing effect by positively charged alkali metal atoms can be reasonably considered as the dominant reason for the improvement in field emission properties.

Key words: field emission, density functional theory, carbon nanotube, alkali metal

中图分类号:  (Field emission, ionization, evaporation, and desorption)

  • 79.70.+q
31.15.es (Applications of density-functional theory (e.g., to electronic structure and stability; defect formation; dielectric properties, susceptibilities; viscoelastic coefficients; Rydberg transition frequencies)) 61.48.De (Structure of carbon nanotubes, boron nanotubes, and other related systems) 71.20.Dg (Alkali and alkaline earth metals)