Optical properties of multiwall boron nitride nanotubes

Abstract

Optical properties of multiwall boron nitride nanotubes are investigated by means of luminescence and absorption spectroscopies. Cathodoluminescence imaging shows that boron nitride nanotubes are highly UV luminescent materials and that the luminescence is located all along the nanotube. In comparison with the related bulk material, hexagonal boron nitride, luminescence and absorption experiments point out the role of excitonic effects in this nanoobject.

Defect-induced blue luminescence of hexagonal boron nitride

“…The LWL is observed in PL and CL spectra of hBN materials with different origin by many authors [9,10,13,[17][18][19][20][21][22][23].…”

Optical absorption of boron nitride nanomaterials

“…In the further investigations performed on multi-wall BN-nanotubes by means of cathodoluminescence and optical absorption spectroscopy the optical bands appeared at 4.5 and 5.5 eV have been reinterpreted [8]. The first line was assigned to impurity centers (due to the Stokes shift of 0.5 eV) and the second line was attributed Frenkel type exitonic transitions.…”

Defect-related photoluminescence of hexagonal boron nitride

“…Accordingly, understanding of the electronic band and exciton structure of hBN becomes even more an important issue as it serves a basic system for single-wall 3,4 and multiwall boron nitride nanotubes. [5][6][7][8][9] Despite of many efforts in the past, the electronic properties of hBN remain largely unknown. They have been earlier studied by luminescence, 1,10-17 optical reflectance and absorption, [18][19][20][21] photoconductivity, 22 x-ray emission, [23][24][25] inelastic x-ray scattering, [26][27][28] x-ray absorption, 25,29,30 and electron energy loss [31][32][33] spectroscopy.…”