Electric-Field-Induced Excimer Formation at the Interface of Deep-Blue Emission Poly(9,9-dioctyl-2,7-fluorene) with Polyelectrolyte or Its Precursor as Electron-Injection Layer in Polymer Light-Emitting Diode and Its Prevention for Stable Emission and Higher Performance

ACS Applied Materials & Interfaces
Kuen-Wei TsaiShow-An Chen

Abstract

Conjugated polyelectrolytes and their precursors as electron-injection layer (EIL) in polymer light-emitting diode have attracted extensive attention because they allow the use of environmentally stable high work function metals as cathode with efficient electron injection. Here, for the first time, we find that an undesirable green emission component (470-650 nm) in the electroluminescence spectra is observed during continuous operation of deep-blue emission β-phase poly(9,9-dioctyl-2,7-fluorene) (β-PFO) device upon introducing polyelectrolyte poly[9,9-bis(6'-(18-crown-6)methoxy)hexyl fluorene] chelating to potassium ion (PFCn6:K+) as EIL. This phenomenon also happens to nonchelating PFCn6, poly[(9,9-bis(3'-( N, N-dimethylamino)propyl)-2,7-fluorene)- alt-2,7-(9,9-dioctylfluorene)], or even nonemissive poly[4-((18-crown-6)methoxy)methyl styrene] chelating to K+ (PSCn6:K+). It can be ascribed to electric-field induction accompanied by thermal motion of a highly polar side chain in the polyelectrolyte leading to local segmental alignment of PFO main chains at the emitting layer (EML)/EIL interface and thus formation of green emission excimer, which is supported by the following observations: appearance of green emission component...Continue Reading

References

Mar 24, 2005·Physical Review Letters·W ChunwaschirasiriM J Winokur
Jul 21, 2006·The Journal of Physical Chemistry. B·Xiwen ChenShow-An Chen
Nov 9, 2006·Journal of the American Chemical Society·Renqiang YangGuillermo C Bazan
Aug 21, 2007·Journal of the American Chemical Society·Corey HovenGuillermo C Bazan
Feb 28, 2008·Journal of the American Chemical Society·Renqiang YangGuillermo C Bazan
Jul 12, 2008·Journal of the American Chemical Society·Jung Hwa Seo, Thuc-Quyen Nguyen
Aug 30, 2008·Proceedings of the National Academy of Sciences of the United States of America·Corey V HovenThuc-Quyen Nguyen
Jun 2, 2009·Journal of the American Chemical Society·Justin M HodgkissRichard H Friend
Dec 22, 2010·Journal of the American Chemical Society·Junfeng FangWilhelm T S Huck
Oct 27, 2016·Accounts of Chemical Research·Yao LiuThomas P Russell

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