Large area patterned arrays of aligned carbon nanotubes via laser trimming

Abstract

We develop a simple to implement, inherently parallel and high throughput technique for the fabrication of large areas of patterned aligned multi-wall carbon nanotube (CNT) arrays deposited on silicon or quartz substrate. This technique makes use of a parallel or converging laser beam from a high power pulsed laser for the destruction of aligned CNTs with a copper grid as lithography mask to define patterned aligned CNT arrays. The wavelength of the laser beam used is 248 nm and the average energy per pulse is 500 mJ. Using this technique, an extensive area of patterned CNT arrays as large as 3 × 5 mm2 can be fabricated without the use of any pre-patterned substrate. In addition, we were able to control the size of the features created by (1) using different copper grids and (2) using a converging beam. Exposing the sample to different numbers of laser pulses allows us to generate families of CNTs with different uniform lengths. Furthermore, using two overlapping grids as a lithography mask, we managed to create a regular array of features with sizes as small as 2.5 μm.