Long Time Field Emission of Pt/MWCNT Hybrid nanowire for Electron Gun

An isolated electron gun which could stably work at 500nA for more than 30 hours was proposed. The electron gun has a hybrid structure of multi-walled carbon nanotube (MWCNT) covered with Platinum tip. The gap between electrodes was adjusted by a nanomanipulation system to control the growth length and working distance inside a scanning electron microscope (SEM). About 374nm Platinum nanowire was in-situ growth in the tip of a single MWCNT with a precursor of cyclopentadienyl-trimethyl-platinum (IV) (CpPtMe3) to synthesized an electron gun. The working current stable at 500nA transferred from the tip of electron gun protected by the Platinum, with the working distance about 1 um, working voltage below 150V. It can work at a very low vacuum, it is about three orders of magnitude smaller than the vacuum required for a conventional gun. Moreover, the monitoring of SEM and the field emission characteristics shows that the electron gun has excellent stability during continue working which reached 50hours. The electron gun only consumed about 0.002um per working hour. The experimental result showed that the electron gun has broad application prospects in various field emission devices.

I. Introduction

Carbon nanotubes have attracted great attention since they were discovered in 1991 because of their excellent one-dimension material properties [1, 2]. Many top research teams are working on the research of carbon nanotube devices, including CNTs field-effect-transistor [3], carbon nanotube resonator [4], carbon nanotube field emitter [5] and Nano-gyroscope [6]. The CNTs field-effect-transistors (FET) are considered be likely to replace traditional FETs based on silicon substrate for their high carrier velocity and near-ballistic carrier transport property [7]. Furthermore, Due to its large aspect ratio, sharp tips, low turn-on field and easy to fabrication, the field emission application of carbon nanotubes have also become an important direction of researchers [8], [9]. J.M. Kim et al. [10] fabricated a large area and color field emission displays(FEDs) with well aligned CNT emitters. Jain Vaibhav et al. [11] synthesized a hierarchical structure field emitter based on copper substrate successfully. But most of the field emission researches on carbon nanotubes are based on the array of carbon nanotubes [12], [13]. For the Instability and variability of CNTs, it hard to operate in nanoscale.