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

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 approximate to 20 mu A and density as high as approximate to 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 mu s. 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 approximate to 5 x 10(-4) Pa. Even under a rough vacuum of approximate to 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.