Nano Express

Nanoscale Research Letters

, Volume 5, Issue 6, pp 941-948

Open Access This content is freely available online to anyone, anywhere at any time.

Synthesis and Enhanced Field-Emission of Thin-Walled, Open-Ended, and Well-Aligned N-Doped Carbon Nanotubes

  • Tongxiang CuiAffiliated withLaboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University
  • , Ruitao LvAffiliated withLaboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University
  • , Feiyu KangAffiliated withLaboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University Email author 
  • , Qiang HuAffiliated withDepartment of Electronic Engineering, Tsinghua University
  • , Jialin GuAffiliated withLaboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University
  • , Kunlin WangAffiliated withDepartment of Mechanical Engineering, Key Laboratory for Advanced Manufacturing by Materials Processing Technology of Ministry of Education, Tsinghua University
  • , Dehai WuAffiliated withDepartment of Mechanical Engineering, Key Laboratory for Advanced Manufacturing by Materials Processing Technology of Ministry of Education, Tsinghua University

Abstract

Thin-walled, open-ended, and well-aligned N-doped carbon nanotubes (CNTs) on the quartz slides were synthesized by using acetonitrile as carbon sources. As-obtained products possess large thin-walled index (TWI, defined as the ratio of inner diameter and wall thickness of a CNT). The effect of temperature on the growth of CNTs using acetonitrile as the carbon source was also investigated. It is found that the diameter, the TWI of CNTs increase and the Fe encapsulation in CNTs decreases as the growth temperature rises in the range of 780–860°C. When the growth temperature is kept at 860°C, CNTs with TWI = 6.2 can be obtained. It was found that the filed-emission properties became better as CNT growth temperatures increased from 780 to 860°C. The lowest turn-on and threshold field was 0.27 and 0.49 V/μm, respectively. And the best field-enhancement factors reached 1.09 × 105, which is significantly improved about an order of magnitude compared with previous reports. In this study, about 30 × 50 mm2 free-standing film of thin-walled open-ended well-aligned N-doped carbon nanotubes was also prepared. The free-standing film can be transferred easily to other substrates, which would promote their applications in different fields.

Keywords

Carbon nanotubes Thin-walled open-ended and aligned Thin-walled index Bamboo-shaped carbon nanotubes Field emission Free-standing