High‐Performance On‐Chip Thermionic Electron Micro‐Emitter Arrays Based on Super‐Aligned Carbon Nanotube Films

• Published in: Advanced functional materials Vol. 30; no. 7
• Main Authors: Wang, Yuwei, Xiang, Li, Yang, Wei, Li, Zhiwei, Fang, Zheng, Zhou, Duanliang, Liu, Peng, Wei, Xianlong
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.02.2020
• Subjects: aligned carbon nanotube; Arrays; Carbon nanotubes; Electric potential; Electron emission; Electron sources; Electronic devices; Emitters; Emitters (electron); Filaments; Low vacuum; Materials science; on‐chip; Reproducibility; thermionic electron emitter; Variation; Voltage
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201907814

An important advancement towards the realization of miniaturized and fully integrated vacuum electronic devices will be the development of on‐chip integrated electron sources with stable and reproducible performances. Here, the fabrication of high‐performance on‐chip thermionic electron micro‐emitter arrays is demonstrated by exploiting suspended super‐aligned carbon nanotube films as thermionic filaments. For single micro‐emitter, an electron emission current up to ≈20 µA and density as high as ≈1.33 A cm−2 are obtained at a low‐driven voltage of 3.9 V. The turn‐on/off time of a single micro‐emitter is measured to be less than 1 µs. Particularly, stable (±1.2% emission current fluctuation for 30 min) and reproducible (±0.2% driven voltage variation over 27 cycles) electron emission have been experimentally observed under a low vacuum of ≈5 × 10−4 Pa. Even under a rough vacuum of ≈10−1 Pa, an impressive reproducibility (±2% driven voltage variation over 20 cycles) is obtained. Moreover, emission performances of micro‐emitter arrays are found to exhibit good uniformity. The outstanding stability, reproducibility, and uniformity of the thermionic electron micro‐emitter arrays imply their promising applications as on‐chip integrated electron sources. High‐performance on‐chip thermionic electron micro‐emitter arrays on a 1 cm × 1 cm chip are realized by exploiting suspended super‐aligned carbon nanotube films as thermionic filaments. Compared with field electron micro‐emitter arrays, the thermionic micro‐emitter arrays show much better stability, reproducibility, and uniformity, which are believed to make them promising in on‐chip integrated electron sources.