Preparation And Application Of Organic Conducting Thin Films

Since discovery in the1970s, conducting polymers have gathered considerableattention due to a number of attractive features, such as tunability of physicalproperties, flexibility, easy synthesis and low cost. The conducting polymers mainlyare conjugated polymers where pi-electrons are delocallized on backbone of thepolymer chain, and become electron carriers after suitable chemical doping. Ingeneral, a drawback of conducting polymers is the lack of solubility in solvents.Poly(3,4-ethylenedioxythiophene)(PEDOT) is one of the most promising conductingpolymers as an attractive conductive polymer material since good conductivity andchemical/thermal stability as well as transparency for visible lights. However, thePEDOT is not soluble, limiting wide applications as films. In1991colloidaldispersion was realized by using a water-soluble polyelectrolyte poly(4-styrenesulfonate)(PSS), then, the poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate)(PEDOT/PSS) has been extensively studied from viewpoints of bothacademic and technologic aspects. To date the PEDOT/PSS has been a widelyavailable conductive polymer thanks to the colloidal dispersion of the PEDOT/PSS.The PEDOT/PSS dispersion in water enables easily providing films on varioussubstrates by simple means such as solution casting and spin/bar-coating techniques.This research work is consisted of three parts in a viewpoint of experiments.Firstly, the PEDOT/PSS dispersion was synthesized through chemical oxidation ofEDOT. Secondly, transparent thin PEDOT/PSS films were prepared on plasticsubstrates by spin-coating of PH1000(a commercial PEDOT/PSS dispersion). Lastly,application of the transparent PEDOT/PSS thin film as a transparent electrode inorganic photovoltaic cells was preliminarily investigated.