Study On The Synthesis Characterization And Application Of Poly(3-alkylthiophenes)

Poly (3-alkylthiophene)(P3AT) as an important conducting polymer, ithas been widely used in the optical and electrical fields. P3AT has so manyadvantages, such as good solubility, excellent electrochemical activity, goodenvironmental stability and processed easily, etc. The main preparationmethods for P3AT are chemical polymerization and electrochemicalpolymerization. The dissertation adopted this two preparation methods tosynthesize three kinds of poly(3-alkylthiophene), such as poly-(3-butylthiophene)(P3BT), poly(3-hexylthiophene)(P3HT) and poly-(3-dodecylthiophene)(P3DDT). Their chemical structures and relativemolecular mass were characterized by gel permeation chromatography (GPC)and hydrogen spectrum of nuclear magnetic resonance (1H-NMR). Theirsurface morphologies were observed by scanning electron microscope (SEM),and their optical properties were characterized by Uv-visible spectra (Uv-vis)and fluorescence spectrum (FL). These films, which synthesized byelectrochemical polymerization, had been directly made into organic thin film solar cells. And the performance of the solar cells has been researched. Theresults of the experiment are as follow:1. P3BT, P3HT and P3DDT were synthesized by the method of Fe IIIcatalytic oxidation which have large relative molecular mass high neatdegrees in their molecular structure and good optical performance. Thecharacterization results show that P3HT`s effective conjugate length is longer,the rigidity of its main chain is stronger, and its ring plane between sexual isbetter, so that, P3HT is the most suitable polymer material which can be usedfor solar cells, among the three polymer materials.2. P3BT, P3HT and P3DDT films had been electrochemical synthesizedon indium-tin oxide (ITO) glass substrate in boron trifluoride diethyl etherate(BFEE) solvent. These polymer films showed good electrochemical activityand stability. The energy gap of P3BT, P3HT and P3DDT films are1.84eV,1.88eV and2.16eV respectively, and the highest average conductivity of theirfilms is0.15S/cm0.19S/cm and0.17S/cm respectively.3. P3BT, P3HT and P3DDT films which had been electrochemicalsynthesized on ITO glass substrate in BFEE solvent, had been directly used tofabricate organic thin film solar cells. And the Photovoltaic characteristics ofthese organic thin film solar cells had been researched. The experimentalresults show that, in the same reaction conditions, the photoelectric conversionefficiencies of P3BT and P3HT thin film solar cells are slightly higher, thepoorest is P3DDT thin film solar cell. Analysis and calculation results show that, the fill factors of the three kinds of organic thin film solar cells, whichmade respectively by P3BT, P3HT and P3DDT films, respectively are0.315,0.388and0.327. And their photoelectric conversion efficiencies are0.133%,0.160%and0.131%, respectively.