Poly(3,4-ethylenedioxythiophene) Derived from Poly(ionic liquid) for the Use as Hole-Injecting Material in Organic Light-Emitting Diodes

Taeyoung Kim; Minwon Suh; Soon Jae Kwon; Tae Hee Lee; Jong Eun Kim; You Jong Lee; Joo Hyung Kim; Munpyo Hong; Kwang S Suh

doi:10.1002/marc.200900234

Poly(3,4-ethylenedioxythiophene) Derived from Poly(ionic liquid) for the Use as Hole-Injecting Material in Organic Light-Emitting Diodes

Macromol Rapid Commun. 2009 Sep 1;30(17):1477-82. doi: 10.1002/marc.200900234. Epub 2009 Jul 21.

Authors

Taeyoung Kim¹, Minwon Suh, Soon Jae Kwon, Tae Hee Lee, Jong Eun Kim, You Jong Lee, Joo Hyung Kim, Munpyo Hong, Kwang S Suh

Affiliation

¹ Department of Materials Science and Engineering, Korea University 5-1 Anam-dong, Seongbuk-gu, Seoul 137-713, Korea.

PMID: 21638408
DOI: 10.1002/marc.200900234

Abstract

We report that poly(3,4-ethylenedioxythiophene) derived from poly(ionic liquid) (PEDOT:PIL) constitutes a unique polymeric hole-injecting material capable of improving device lifetime in organic light-emitting diodes (OLEDs). Imidazolium-based poly(ionic liquid)s were engineered to impart non-acidic and non-aqueous properties to PEDOT without compromising any other properties of PEDOT. A fluorescent OLED was fabricated using PEDOT:PIL as a hole-injection layer and subjected to a performance evaluation test. In comparison with a control device using a conventional PEDOT-based material, the device with PEDOT:PIL was found to achieve a significant improvement in terms of device lifetime. This improvement was attributed to a lower indium content in the PEDOT:PIL layer, which can be also interpreted as the effective protection characteristics of PEDOT:PIL for indium extraction from the electrodes.