Exclusive inkjet printed poly(3,4-ethylenedioxythiophene): polystyrenesulfonate as anode in polymer light-emitting diodes

As general practice, Poly(3,4-ethylenedioxythiophene):Polystyrene Sulfonate (PEDOT:PSS) is the most widely used conducting polymer as electrode material in organic (polymer) devices. PEDOT: PSS film is fabricated by solution processes such as spin-coating, dip-coating, inkjet printing (IJP), contact printing, etc. One of the most complex operations in the fabrication process is forming conduction electrode lines or isolate devices from each other with the pattern of polymeric film IJP, which is a non-impact printing technology in which droplets of ink are jetted directly on a media to create a pattern. In this paper, PEDOT:PSS films, prepared by inkjet-printing and spin-coating methods, have been studied by using atomic force microscopy (AFM), micro-Raman spectroscopy and photoelectron spectroscopy measurements (PL). PEDOT:PSS films formed with the inkjet-printing method are appropriate for using as an anode for simplification of the fabrication process of polymer light-emitting diodes whose performance is about 1.2 cd/A. The performance is the same as spin-coating method. The performance was attributed to longer effective conjugation length of PEDOT chains in inkjet-printing PEDOT:PSS films, as suggested by their micro-Raman spectroscopy.

[1]  Giuseppe Zerbi,et al.  Optical spectra and structure of oligomeric models of polyparaphenylenevinylene , 1991 .

[2]  M. Kawasaki,et al.  High-resolution full-color LCD driven by OTFTs using novel passivation film , 2006, IEEE Transactions on Electron Devices.

[3]  J. Duvail,et al.  Transport and vibrational properties of poly(3,4-ethylenedioxythiophene) nanofibers , 2002 .

[4]  U. Schubert,et al.  Inkjet Printing of Polymers: State of the Art and Future Developments , 2004 .

[5]  N. Huby,et al.  Correlation between the Indium Tin Oxide morphology and the performances of polymer light-emitting diodes , 2005 .

[6]  Peter Andersson,et al.  The Origin of the High Conductivity of Poly(3,4-ethylenedioxythiophene)−Poly(styrenesulfonate) (PEDOT−PSS) Plastic Electrodes , 2006 .

[7]  R. Friend,et al.  Morphological and electronic consequences of modifications to the polymer anode ‘PEDOT:PSS’ , 2005 .

[8]  Stephan Kirchmeyer,et al.  Electrochromic Window Based on Conducting Poly(3,4‐ethylenedioxythiophene)–Poly(styrene sulfonate) , 2002 .

[9]  Jean-Luc Duvail,et al.  Spectroelectrochemical studies of poly(3,4-ethylenedioxythiophene) in aqueous medium , 2001 .

[10]  J. Travas-sejdic,et al.  Spectroscopic and conductivity studies of doping in chemically synthesized poly(3,4-ethylenedioxythiophene) , 2005 .

[11]  Tatsuya Shimoda,et al.  Inkjet printing of polymer thin film transistors , 2003 .

[12]  T. Wen,et al.  Polymer light-emitting diodes with thermal inkjet printed poly(3,4-ethylenedioxythiophene):polystyrenesulfonate as transparent anode , 2007 .

[13]  K. Guarini,et al.  High-Resolution Inkjet Printing of All-Polymer Transistor Circuits , 2009 .

[14]  Yang Yang,et al.  On the mechanism of conductivity enhancement in poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) film through solvent treatment , 2004 .

[15]  David Nilsson,et al.  Electric current rectification by an all-organic electrochemical device , 2002 .

[16]  J. C. Scott,et al.  Degradation and failure of MEH‐PPV light‐emitting diodes , 1996 .

[17]  R. Friend,et al.  Surface conditioning of indium-tin oxide anodes for organic light-emitting diodes , 2003 .

[18]  Andrew J. Steckl,et al.  A comparative study of electrode effects on the electrical and luminescent characteristics of Alq3/TPD OLED: Improvements due to conductive polymer (PEDOT) anode , 2007 .

[19]  King-Fu Lin,et al.  Structural characterization and luminescent properties of poly(p-phenylene vinylene) and poly(ethylene glycol) blends , 1999 .

[20]  W. R. Salaneck,et al.  Electroluminescence in conjugated polymers , 1999, Nature.