Large area patterned arrays of aligned carbon nanotubes via laser trimming

Abstract

We develop a simple to implement, inherently parallel and high throughputtechnique for the fabrication of large areas of patterned aligned multi-wall carbonnanotube (CNT) arrays deposited on silicon or quartz substrate. This techniquemakes use of a parallel or converging laser beam from a high power pulsed laserfor the destruction of aligned CNTs with a copper grid as lithography mask todefine patterned aligned CNT arrays. The wavelength of the laser beam used is248 nm and the average energy per pulse is 500 mJ. Using this technique, anextensive area of patterned CNT arrays as large as 3 × 5 mm2can be fabricated without the use of any pre-patterned substrate. In addition, wewere able to control the size of the features created by (1) using different copper gridsand (2) using a converging beam. Exposing the sample to different numbers oflaser pulses allows us to generate families of CNTs with different uniform lengths.Furthermore, using two overlapping grids as a lithography mask, we managed tocreate a regular array of features with sizes as small as 2.5 μm.