Light emission and structural changes in a suspended multiwall carbon nanotube on application of electric current

Abstract Light emission from a suspended multiwall carbon nanotube (MWCNT) on application of electric current was studied by in-situ transmission electron microscopy combined with optical spectroscopy. Excessive Joule heating led to layer-by-layer sublimation of the outer and/or inner shells of the MWCNT. The temperature during sublimation was estimated to be more than 2100 K from the sublimation rate of the MWCNT. Light emission spectra observed while applying an electric current to the MWCNT were composed of blackbody radiation and characteristic peaks. The energies of the peaks in the spectra were close to energy gaps between van Hove singularities calculated from the diameters of the constituent shells of the MWCNT, suggesting that the peaks in the spectra can be attributed to interband transitions between van Hove singularities in the electronic density of states in the MWCNT.