Optical absorption from solvation-induced polarons on nanotubes.
When an excess charge carrier is added to a one-dimensional (1D) wide-band semiconductor immersed in a polar solvent, the carrier can undergo self-localization into a large-radius adiabatic polaron. We explore the local optical absorption from the ground state of 1D polarons using a simplified theoretical model for small-diameter tubular structures. It is found that about 90% of the absorption strength is contained in the transition to the second lowest-energy localized electronic level formed in the polarization potential well, with the equilibrium transition energy larger than the binding energy of the polaron. Thermal fluctuations, however, can cause a very substantial--an order of magnitude larger than the thermal energy--broadening of the transition. The resulting broad absorption feature may serve as a signature for the optical detection of solvated charge carriers.
Ussery
G L
GL
Department of Physics, The University of Texas at Dallas, P.O. Box 830688, EC36, Richardson, Texas 75083, USA.
Gartstein
Yu N
YN