Electrochemical And Spectroelectrochemical Properties Of A New Donor-Acceptor Polymer Containing 3,4-Dialkoxythiophene And 2,1,3-Benzothiadiazole Units

A new heteroarylene-vinylene donor-acceptor low bandgap polymer, the poly(DEHT-V-BTD), containing vinylene-spaced efficient donor (dialkoxythiophene) and acceptor (benzothiadiazole) moieties, is presented. Electropolymerization has been carried out by several electrochemical techniques and the results are compared. In particular, the pulsed potentiostatic method was able to provide layers with sufficient amounts of material. Cyclic voltammetries showed reversible behavior towards both p- and n-doping. The HOMO, LUMO, and bandgap energies were estimated to be -5.3, -3.6 and 1.8 eV, respectively. In situ UV-Vis measurements have established that the presence of the vinylene group stabilizes the formation of polaronic charge carriers even at high doping levels.