Influence of laser structuring and barium nitrate treatment on morphology and electrophysical characteristics of vertically aligned carbon nanotube arrays

摘要

The technology of structuring arrays of multilayer carbon nanotubes using pulsed laser radiation is presented. Arrays of two types nanotubes (long and short) with different morphologies were synthesized on a silicon substrate by the method of plasma enhanced chemical vapor deposition from the gas phase. Samples with arrays of nanotubes located strictly perpendicular to the silicon substrate were obtained using an ytterbium fiber laser (1064 nm) with a galvanometric scanner. Raman spectroscopy showed a decrease in the defectiveness of the carbon nanostructure of the tubes after laser irradiation. Liquid treatment with Ba(NO3)(2) applied to the array with subsequent annealing resulted in sticking of the nanotubes at their tips. The formation of cellular structure from array of carbon nanotubes with a greater length after laser scanning of the sample was observed. Such arrays of nanotubes made it possible to increase the current of electron emission by more than two times at lower threshold voltage compared with the original arrays of nanotubes. The current density increased from 65 to 150 mu A/cm(2). Structured arrays of nanotubes can be used to create efficient emission cathodes, as well as sensors, solar cells and MEMS structures.