Optical and Electrical Properties of Electrochemically Doped n- and p-Type Polythiophenes

Abstract

Absorption spectra have been measured on polythiophene films subjected to electrochemical Bu 4 N + doping. The spectra show essentially the same evolution as those for BF - 4 doping, i.e., peaks at 0.6∼0.7 eV and 1.5∼1.8 eV appear upon doping in addition to the band-to-band absorption peak at 2.6 eV. Propagation velocities of electrochemical doping of Bu 4 N + and BF - 4 along polythiophene films were estimated to be on the order of 10 -3 cm/sec.