Single-walled carbon nanotube thermionic electron emitters with dense, efficient and reproducible electron emission

Yuwei Wang; Gongtao Wu; Li Xiang; Mengmeng Xiao; Zhiwei Li; Song Gao; Qing Chen; Xianlong Wei

doi:10.1039/c7nr05388f

Single-walled carbon nanotube thermionic electron emitters with dense, efficient and reproducible electron emission

Nanoscale. 2017 Nov 23;9(45):17814-17820. doi: 10.1039/c7nr05388f.

Authors

Yuwei Wang¹, Gongtao Wu, Li Xiang, Mengmeng Xiao, Zhiwei Li, Song Gao, Qing Chen, Xianlong Wei

Affiliation

¹ Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, P. R. China.

PMID: 29115331
DOI: 10.1039/c7nr05388f

Abstract

Thermionic electron emitters have recently been scaled down to the microscale using microfabrication technologies and graphene as the filament. While possessing several advantages over field emitters, graphene-based thermionic micro-emitters still exhibit low emission current density and efficiency. Here, we report nanoscale thermionic electron emitters (NTEEs) fabricated using microfabrication technologies and single-walled carbon nanotubes (SWCNTs), the thinnest conducting filament we can use. The SWCNT NTEEs exhibit an emission current density as high as 0.45 × 10⁵ A cm^-2, which is superior to that of traditional thermionic emitters and five orders of magnitude higher than that of graphene-based thermionic emitters. The emission characteristics of SWCNT NTEEs are found to strongly depend on the electrical properties of the SWCNTs, with metallic SWCNT NTEEs showing a substantially lower turn-on voltage and more reproducible emission performances than those based on semiconducting SWCNTs. Our results indicate that SWCNT NTEEs are promising for electron source applications.