Assoc. Prof. Jianxiong Li, School of Materials Science and Engineering, South China University of Technology, Guangzhou, China

Speech Title: Effects of reaction conditions on structure and properties of PEDOT/PET film synthesized by liquid phase depositional polymerization of EDOT

Abstract:Due to the brittleness and scarcity of ITO, current ITO based FTCF has poor lifetime and high price. It cannot afford the development of flexible optoelectronic. PEDOT may exhibit high electrical conductivity and optical transparency. It is a good candidate to replace ITO to fabricate FTCF at low cost. However, PEDOT is neither fusible nor soluble. It is difficult to convert virgin PEDOT to thin films. Here, PEDOT coating on PET film was synthesized by Liquid Phase Depositional Polymerization of EDOT.

PET film was irradiated with 172 nm VUV to improve the wetting ability, then dipped in Fe(OTs)3 solution to adsorb Fe(OTs)3 and finally suspended in EDOT solution to synthesize PEDOT coating. The effects of reaction conditions on structures and properties of the coating were investigated. The conductivity, transparency and adhesion of the coatings were discussed in terms of conjunctive length, doping level and condensed structure.

High polymerization temperature benefited the conjunctive length and doping level, so did the conductivity and transmittance, but promoted the diffusion of EDOT oligomers and reduced the coating thickness. Imidazole increased the conjunctive length but depressed the doping level. The conductivity and sheet resistance gets extremes as imidazole increased. Trace acetonitrile in petroleum ether enhanced the conjunctive length but reduced the doping degree. Post oxidation eliminated EDOT oligomers on the top layer and improved the doping degree, thereby enhanced the conductivity greatly. By LPDP, PEDOT/PET film with transmittance 85 % and sheet resistance 140Ω/ can be prepared.