On-Chip Thermionic Electron Emitter Arrays Based on Horizontally Aligned Single-Walled Carbon Nanotubes

Abstract

Thermionic electron emitter, a critical component in vacuum electronic devices, usually suffers from bulky size, difficulty to integrate, and slow temporal response. Here, to overcome these problems, we fabricate and test a new miniature electron emitter: on-chip thermionic electron emitter arrays based on horizontally aligned single-walled carbon nanotubes. The devices are fabricated and integrated on a Si chip with microfabrication technologies, providing compactness as well as fast temporal response. Emitter arrays with a packing density of up to ~ 0.4 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> emitters/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and an emission density of 1.73 mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at a bias voltage of 2.64 V are realized. The turn-on/off response times of the devices are measured to be ~150/500 ns, which are 5 orders of magnitude faster than those of their bulky counterparts. The advantages of on-chip nature, high degree of integration, and fast temporal response make the thermionic emitter arrays promising in miniature vacuum electronic devices.