Patterning quality control of inkjet printed PEDOT:PSS films by wetting properties
Ely, Fernando; Avellaneda, Cesar O.; Molina, Celso; Paredez, Pablo; Nogueira, Viviane C.; Santos, Thebano E. A.; Mammana, Victor P.; Brug, Jim; Gibson, Gary; Zhao, Lihua
Keyword(s): Display, printed electronics
Abstract: In this contribution, we describe the development of inkjet printable PEDOT:PSS polymer-based inks for fabrication of polymeric organic light-emitting devices (OLEDs). By using a 10 x 10 array of SU8 wells on ITO/glass substrates, guided deposition of PEDOT in a simulated OLED pixel structure was possible. The quality of the printed patterns was controlled by fine tuning of the surface wetting properties using self-assembled monolayers (SAMs) and/or oxygen reactive plasma. All the investigated surface treatments improved the quality of the printed pattern. However, the O2 plasma treated surfaces, which had the highest free energy, resulted in smoother and more uniform PEDOT films than did the SAM-coated surfaces. Rainbow-like features observed at the edges were attributed to the well-known coffee stain effect. An impressive reduction of such features was achieved by decreasing PEDOT content in the inks.
External Posting Date: October 21, 2010 [Fulltext]. Approved for External Publication
Internal Posting Date: October 21, 2010 [Fulltext]