Effects of doping agents on optical and conductive properties of poly(3-hexylthiophene)

Abstract

This research investigated various doping methods of poly(3-hexylthiophene) including acid, oxidative and, solvato-controlled doping. The doped products were subjected to many spectroscopic analysis and conductivity measurements in the form of either a solution or a film. The acid doping was found to increase the conductivity of both the solution and film of poly (3-hexylthiophene). For oxidative doping, premixed urea hydrogenperoxide and trifluoroacetic acid could oxidize poly (3-hexylthiophene) to yield the polymer with bathochromic shift of λ[subscript max]. Solvato-controlled doping with methanesulfonic acid and thiophene gave the film of dope polymer without pre-precipitation problem. The AC-index calculation was used for monitoring the change in UV-visible absorption induced by doping that could be related to the effective conjugation length of the polymer. It was found that AC-index calculation was applicable with the monitoring of acid and oxidative doping process. Their values corresponded well with the results from λ[subscript max]. Of UV-visible spectra and conductivity.