Figure 13.

(a) and (b) show the phonon-assisted electroluminescence spectra from SWNT, with diameter from 0.94 to 1.49, (c) the relation between phone flux and biased voltage has been demonstrated, where the blue and red sign present relative peaks of low and high energy emissions. (d) The phonon dispersion along Γ-K direction and Brillouin zone with its symmetry point M, K, and Γ. The momentum for the electronic transition from M to K (red arrow) provided by phonons in the Γ-K direction (blue line). In the relevant momentum range (red dashes), phonons of the L_O branch have energy consistent with that required to explain the electroluminescence data [57].