Pulsed cathodoluminescence and Raman spectra of MoS2 nanocrystals at different excitation electron energy densities and laser wavelengths

Bozheyev, Farabi; Valiev, Damir; Nemkayeva, Renata; Farabi, Bozheyev

Pulsed cathodoluminescence and Raman spectra of MoS2 nanocrystals at different excitation electron energy densities and laser wavelengths

Date

2017-08-01

Authors

Bozheyev, Farabi

Farabi, Bozheyev

Valiev, Damir

Nemkayeva, Renata

Publisher

Journal of Luminescence

Abstract

Abstract Molybdenum disulfide nanocrystals exhibit direct dependencies of the Raman peaks' intensities and their positions on the thicknesses of the nanocrystals. This indicates dependencies of the electronic structure on the thickness of the flakes, which scatter differently various laser wavelengths (473nm, 532nm and 633nm). Pulsed cathodoluminescence spectra of MoS2 nanocrystals under the action of high-energy electron pulse show an increase in the luminescence intensities with the increasing input of electron energy densities, where higher electron densities induce greater amount of electron-holes, which afterwards recombining release the energy in the form of luminescence. Irradiation of nanocrystals at maximum electron energy density of 200mJcm−2 leads to a strong luminescence band at 655nm (1.88eV), which is explained by recombination of A exciton. The luminescence decay kinetics of the nanocrystals under the action of different electron energy densities is presented.

Keywords

MoS2, Nanocrystal, Nanopowder, Pulsed cathodoluminescence, Raman spectra, Electron-holes, Electron energy density

Citation

Farabi Bozheyev, Damir Valiev, Renata Nemkayeva, Pulsed cathodoluminescence and Raman spectra of MoS2 nanocrystals at different excitation electron energy densities and laser wavelengths, In Journal of Luminescence, Volume 188, 2017, Pages 529-532