A systematic study of the hole mobility in hole-only diodes and field-effect transistors based on poly$\mathbf{(}$2-methoxy-5-($3^{\prime },7^{\prime }$-dimethyloctyloxy)-$p$-phenylene vinylene$\mathbf{)}$ and on amorphous poly(3-hexyl thiophene) has been performed as a function of temperature and applied bias. The experimental hole mobilities extracted from both types of devices, although based on a single polymeric semiconductor, can differ by 3 orders of magnitude. We demonstrate that this apparent discrepancy originates from the strong dependence of the hole mobility on the charge carrier density in disordered semiconducting polymers.

• Received 26 February 2003

DOI:https://doi.org/10.1103/PhysRevLett.91.216601