Electrochemical Polymerization And Application Of Polythiophene Derivatives

The polythiophene derivatives usually have desirable electrochemical activity, environmental stability and easy processibility, which provide potential applications in various fields as electronics and optics. Electrochemical polymerization had been proved to be one of the most useful approaches for conducting polymer synthesis. The electrochemical syntheses of conducting polymer were mainly preformed in neutral organic solvents or in aqueous solution. It is widespread use that the oxidation potentials of a series of aromatic or heteroaromatic compounds can be fairly low when the solvent is boron trifluoride diethyl etherate (BFEE). This dissertation was focused on the electrochemical polymerization of several polythiophene derivatives on indium tin oxide (ITO) glass substrate in boron trifluoride diethyl etherate, and these films had been directly used to fabricate organic-inorganic hybrid solar cells with the structure of ITO/PTh/ZnO: MDMO-PPV/Al. The related tests had been studied and the results are as follows.1. The poly(3,4-ethylenedioxythiophene) (PEDOT), polythiophene (PTh), poly(3-methylthiophene) (P3MT) and poly(3-hexylthiophene) (P3HT) films had been electropolymerized on ITO glass substrate in BFEE solvent. These polymer films showed electrochemical activity and had been directly used to fabricate organic-inorganic hybrid solar cells. In the same reaction condition, the comprehensive properties of the solar cell fabricated by PEDOT film was best and the energy conversion efficiency was highest, the second place were P3HT and PTh films, the poorest was P3HT film.2. The influence of PSSNa concentration on the solar cells made of electrochemically polymerized PEDOT film had been studied. The photoelectric properties of the solar cells made of polymer films exhibit good performances when BFEE solvent contains PSSNa, especially PEDOT and P3HT, the energy conversion efficiencies improved one order of magnitude, from 0.011% and 0.0003% to 0.33% and 0.0022%, respectively. Specially, the efficiency increases sharply with the increasing of PSSNa concentration and reaches the maximum value (0.33%) while PSSNa concentration is approximately 0.2 g L-1.3. Compared with traditional spin-coating PEDOT: PSS film, the solar cell fabricated by the electrochemical polymerized PEDOT film obtained in pure BFEE gave a quite lower energy conversion efficiency, but the electropolymerized PEDOT film obtained in BFEE containing PSSNa gave a better performance when the PSSNa concentration beyond 0.1g/L. This method could give a new approach to fabricate photovoltaic devices easily, and would be great potential applications.4. Free-standing conducting polymer films were electrochemically polymerized by direct anodic oxidation in pure BFEE, and the conductivity of the polymer is 10-2S/cm. According to the quantum chemistry calculation and testing results, the polymer was poly(1,4-Diphenoxybenzene) and the studies indicated that the polymerization occurred at 2, 18 position. This polymer is a novel conducting polymer, which has not been reported.