Field emission behavior study of multiwalled carbon nanotube yarn under the influence of adsorbents

Abstract

The authors have studied the field emission (FE) behavior of multiwalled carbon nanotube (MWCNT) yarn at different temperatures. By analyzing how the FE characteristics change with temperature and the residual gas spectra of the vacuum chamber, it was concluded that the intrinsic FE of MWCNTs follows the Fowler–Nordheim theory fairly well, and the deviation from the theory at low temperature (below ∼700 K) is caused by the influence of adsorption. Water is deduced to be the dominant species that influences the FE. It was found that the adsorbents can be desorbed at high voltage due to the Joule heating of the FE current. The adsorption was deduced to be physical from the value of the desorption temperature. The FE current recovery time at different pressures shows that monolayer adsorption is enough to cause obvious FE current changes.

Carbon Nanotube Film Gate in Vacuum Electronic Devices

“…Clearly, the IV curves are very smooth, and the FN curve is a straight line, which shows that the field emission follows the FN law very well. Due to the baking procedure during the fabrication process and using an evaporable getter, the influence of adsorbates is greatly alleviated. , Figure d–f shows the corresponding emission performance of all 32 × 32 pixels, which is very similar to that of an individual pixel. By assuming the distance between the SACNT film and the bottom CNT paste field emitter tip is approximately 100 μm, we can calculate the field enhancement factor of an individual pixel to be approximately 5306.…”