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Author Kuwae, Hiroyuki ♦ Kasahara, Takashi ♦ Nitta, Atsushi ♦ Yoshida, Kou ♦ Inoue, Munetomo ♦ Matsushima, Toshinori ♦ Adachi, Chihaya ♦ Shoji, Shuichi ♦ Mizuno, Jun
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY ♦ ANNIHILATION ♦ CURRENT DENSITY ♦ DIFFUSION LENGTH ♦ ELECTRON BEAMS ♦ LIGHT EMITTING DIODES ♦ LINE WIDTHS ♦ QUANTUM EFFICIENCY
Abstract We developed organic light-emitting diodes (OLEDs) with nanopatterned current flow regions using electron-beam lithography with the aim of suppressing singlet–polaron annihilation (SPA). Nanopatterns composed of lines and circles were used in the current flow regions of nano-line and nano-dot OLEDs, respectively. Excitons partially escape from the current flow regions where SPA takes place. As such, current densities where external quantum efficiencies were half of their initial values (J{sub 0}) increased as line width and circle diameter were decreased to close to the exciton diffusion length. Circles were more efficient at enhancing exciton escape and increasing J{sub 0} than lines. The J{sub 0} increase in the nano-dot OLEDs containing nanopatterned circles with a diameter of 50 nm was approximately 41-fold that of a conventional OLED with a current flow region of 4 mm{sup 2}. The dependence of J{sub 0} on the size and shape of the nanopatterns was well explained by an SPA model that considered exciton diffusion. Nanopatterning of OLEDs is a feasible method of obtaining large J{sub 0}.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-10-21
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 118
Issue Number 15


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