Photogeneration of free charge carriers in π-conjugated polymers with bulky side groups

Abstract

Photogeneration of free charge carriers in poly{1-[4-(trimethylsilyl)phenyl]-2-phenylacetylene} has been studied theoretically. In our work we have utilized our data obtained previously using photoinduced discharge experiment, which showed a steep slope of the dependence of the free charge carriers photogeneration yield on the applied electric field at the low electric field limit, but no saturation plateau. For the theoretical explanation we have utilized our recently developed model (Menšík et al., 2011) [20] that generalizes the model of Arkhipov et al. (2003) [19] by adding an assumption of a resonant reversible coupling of localized excitation to charge transfer states and, consequently, and dependence of internal parameters (permittivity, effective mass of the hole, rate constants) on electric field. Compared to our previous article this work provides a refined analysis of the experimental results on a large variety of intervals of the model parameters.