Air-stable polymer organic thin-film transistors by solution-processed encapsulation

✍ Scribed by Yu Fu; Feng-Yu Tsai

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 410 KB
• Volume: 12
• Category: Article
• ISSN: 1566-1199
• DOI: 10.1016/j.orgel.2010.10.021

✦ Synopsis

The air-and encapsulation-induced degradations of poly(3-hexylthiophene) (P3HT) organic thin-film transistors (OTFTs) encapsulated with solution-processed polymer films were systematically analyzed to realize air-stable devices. By studying the potential degradation-inducing factors from air-O 2 , moisture, N 2 , and light, we determined that device degradations could be eliminated by isolating the devices from two of the factors: moisture and light. In terms of encapsulation-induced degradations, we examined 10 types of encapsulating polymers and found that such degradations could be avoided with polymers containing low-polarity function groups, including poly(vinyl methyl ketone), poly(methyl vinyl ether), poly(methyl methacrylate), and polystyrene. Based upon the identified sources of degradations, we demonstrated an encapsulation approach that involved (1) using a low-polarity encapsulating polymer layer to serve as a moisture barrier and to avoid encapsulation-induced degradation, and (2) applying a light-blocking agent. The resultant OTFTs showed no encapsulation-induced degradation while maintaining stable device characteristics for >5500 h of storage in the ambient air.