Electrostatic Control of Carrier-Dopant Interactions for Efficient Free Carrier Generation in Doped Conjugated Polymers

Carrier–dopant attraction is examined separately from carrier mobility in doped P3HT films. Larger dopants favor free-carrier generation at low doping levels by weakening Coulomb binding. At higher doping levels, overlapping Coulomb potentials reduce the dissociation barrier, allowing smaller dopants to support higher carrier densities. Dopant selection therefore depends on the intended doping regime.