Sijoong Kwon

Nanofilms based on vapor deposition of polymerized polypyrrole and its characteristics

Nanofilms of polypyrrole (PPy) were prepared chemically by vapor deposition polymerization (VDP). It was found from the analysis of the morphological structure by atomic force microscopy that ultra thin films of PPy with thicknesses between 30 and 80 nm could be formed by VDP as well as by casting. These thin films showed surface features of highly ordered structural regularity. The surface resistance of PPy films more than 60 nm thick was enhanced up to 103 Ω/ and light transmittance was increased up to 90% in the case of a film less than 40 nm thick. From the electronic absorption and Raman scattering spectra, it was found that the charged domains (chemical defects) dispersed in polymer chains of PPy nanofilms are due more to bipolarons than to polarons.

Highly Conductive and Transparent Poly(3,4-ethylenedioxythiophene):p-Toluene Sulfonate Films as a Flexible Organic Electrode

Highly transparent and conductive poly(3,4-ethylenedioxythiophene):p-toluene sulfonate (PEDOT:PTS) films were prepared by gas-phase polymerization using the chemical vapor deposition (CVD) technique for flexible organic electrodes. These conductive PEDOT:PTS films have a high transparency (up to 80%), and possess a very low sheet resistance of a 100 Ω/ (up to 2500 S cm-1) at 150 nm thickness. Their sheet resistance attained 27 Ω/ at 350 nm thickness with O2 plasma doping. The 1–3 mm pitched pattern can also be easily formed by plasma etching and/or the selective exposure technique of O2 plasma. This electrode film has a higher transmittance than an amorphous indium–tin oxide (a-ITO) electrode film with thickness under 120 nm, and their conductivities were comparable with the a-ITO layer. We report on the fabrication and characterization of a flexible organic light-emitting diode (OELD) using PEDOT:PTS for the electrodes. The device is demonstrated to exhibit light emission and a brightness level up to 1800 cd/m2 at 25 V.

Preparation and Characterization of Conductive Polymer Nano-Films

We investigate the electrically conductive polypyrrole(PPy)and poly(3,4-ethylenedioxythiophene, PEDOT)nano-films prepared in a continuous roll-to-roll process by vapor-phase polymerization method. Thin films of ferric chloride doped conductive PPy and PEDOT on plastic substrates, in which neither matrix polymers nor binders are used for the film forming process, are obtained at nano-level thickness. PPy and PEDOT film thickness was varying depend on reaction time and reaction temperature. The surface resistance change with time of exposure to monomer vapors, and the value was in the range of 103 ∼ 105 Ω/sq. at 20–60 nm thick films and showed up to 600Ω/sq. for the > 600 nm thick films. These thin films had a very highly ordered surface morphology. Especially, in the case of PEDOT film, the growth of highly ordered conductive PEDOT crystalline microstructure, which high anisotropy, parallel to the substrate film was fabricated, was observed by AFM.

P‐179: Flexible Organic Electroluminescent Displays with Optical Transparency Using Electrically Conducting Polymers

Flexible OELDs were fabricated by using highly conductive poly(3,4-ethylenedioxy thiophene): p-toluene sulfonate(PEDOT: PTS) nano-films, as electrode layers. These conductive PEDOT: PTS films have a high transparency up to 80%, and possess a very low sheet resistance of 100 Ω square−1 at 160-nm thickness. We report on the fabrication and characterization of a OELD using a PEDOT: PTS for the electrodes and demonstrate its superior performance relative to that of a similar device using the a-ITO layer. The device has been demonstrated to exhibit light emission in green, brightness level up to 1800 cd/m2 at the 25 V.

P-77: Polymer-Based Plastic Electrode Film for PDLC Applications

Plastic electrode films composed of poly (3,4-ethylenedioxythiophene):p-toluene sulfonate (PEDOT:PTS) have been fabricated by using depositing polymerization method in gas-phase. These conductive PEDOT:PTS films have a high transparency up to 80%, and possess a very low sheet resistance down to 100 Ω/squre at 100-nm thickness. We report on the fabrication and characterization of a PDLC device using a highly conductive PEDOT: PTS for the electrodes and demonstrate its superior performance relative to that of a similar device using the ITO layer as the electrodes.

P-163: Polymer Electrode and Micro-patterning using PEDOT and its Organic Display Applications

The conductive ultrathin films of poly (3, 4-ethylenedioxythiophene) (PEDOT) prepared by using depositing polymerization are prepared in gas-phase. The selective growth of polymer nanofilms can also be easily prepared by deposition of self-assembled PEDOT layers on patterned oxidant layers formed using a micro contact printing method. These conductive nano-films have a high transparency up to 80%, possess a very low sheet resistance down to 100 Ω/square. Using this new procedure, 1μm pitched pattern can also easily realize and these are capable of being applied to organic opto-electronic films used in electrical devices such as the EL and touch screen.