ABSTRACT
This chapter focuses on phonon-assisted excited charge carrier relaxation in semiconducting single-walled carbon nanotubes. Pure dephasing provides a measure of the coupling of the electronic and phonon subsystems and is responsible for the linewidths observed experimentally. The slower timescale, on the order of tens of picoseconds, was attributed to phonon-induced relaxation of the electrons to the lattice temperature. The electronic structure of nanomaterials and its changes upon photoexcitation effect many important characteristics of nanoscale optoelectronic devices, including carrier transport and luminescence efficiency. In the absense of decoherence, the non-adiabatic mixing of the electronic states can occur to a much greater extent, creating significantly larger transition probabilities. Assuming laser excitation energies that are less than the ionization threshold, the relaxation of excited carriers to the ground state may occur radiatively or nonradiatively. The electron-phonon coupling is generated in the ideal carbon nanotube by the high frequency G-modes, both at high and at low temperatures.
