Dependence of Electron-Phonon Interactions on Doped Carriers in the Negatively Fractionally Charged Polyacene Molecular Crystals

摘要

The dependence of dimensionless electron-phonon coupling constants (λ_x), which play an important role in electrical conductivity and spectroscopy, on doped carriers are systematically discussed in the fractionally charged (-3.00 ≤ x ≤ -2.00) polyacene molecular crystals. The λ_x values for x (-2.86 ≤ x ≤ -2.71) are much larger than the λ_(-3.00) value. This is because the density of states at the Fermi level (N_(NM,intra) (ε_F)_x) values of 8 (states per molecule) for x (-2.86 S. x S -2.71) are estimated to be much larger than the N_(NM,intra) (ε_F)_(-3.00) value of 2 (states per molecule). In general, the λ_x value becomes very large if 0.50-1.00 charge of carrier with respect to the closed-shell electronic states can be doped.