Densely-packed Aligned Carbon Nanotube Arrays for Field Emission Devices

Field electron emission (FE) is a phenomenon where emission of electrons induced by an electrostatic field. The most common context is field emission from a solid surface into vacuum. However, field emission can arise from solid or liquid surfaces, into vacuum, air, a fluid, or any non-conducting or weakly conducting dielectric. Carbon nanotubes (CNT) have attracted much attention owing to their mechanical, electrical and thermal properties etc. CNTs are promising candidates for use in FE devices and nanoelectronics as they possess sharp tips with unusual characteristics. These types of application will require a fabrication method capable of producing CNTs with well-defined and controllable properties such as the orientation, spatial distribution, diameters and lengths of the CNT. In addition, FE devices would need island-like structured high density and well-ordered nanotube arrays to alleviate screening effect. Our technology demonstrates the production of CNT arrays and producing microislands through ultrafast laser-assisted micromachining to improve FE characteristics.