Electrophysical and morphological characteristics of vertically aligned carbon nanotubes array after laser and barium nitrate structuring
Presented technology describes structuring of multilayer carbon nanotubes array using pulsed laser radiation. Method of PECVD from the gas phase was used to synthesize nanotubes array in the H2+He gas environment on a silicon substrate. Sample with array of nanotubes located strictly perpendicular to the silicon substrate was obtained using different irradiation power values of ytterbium fiber laser (1064 nm, pulse duration 100 ns, frequency 30 kHz) with a galvanometric scanner.
Raman spectroscopy of sample was performed. To show a decrease in the defectiveness of carbon nanostructure of the nanotubes after laser irradiation, dependence of ID/IG Raman peaks ratio from irradiation power was studied. SEM images showed, that liquid treatment of the array with Ba(NO3)2 applied with subsequent annealing resulted in sticking of the nanotubes at their tips. Laser scanning of sample with nanotubes led to formation of cellular structure on the surface of the array, which was confirmed by SEM images.
Such array of nanotubes made it possible to increase the electron emission current density up to 150 mA/cm2, wich is more than twice as much as the initial nanotubes array. The dependence of emission current from laser irradiation power was studied.
Structured arrays of nanotubes can be used to create efficient emission cathodes, as well as sensors, solar cells and MEMS structures. This study was supported by the Ministry of Science and Higher Education of the Russian Federation No. 075-03-2020-216 from 27.12.2019.
National Research University of Electronic Technology (MIET)
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