Solid-State Light-Emitting Electrochemical Cells Employing Phosphor-Sensitized Fluorescence
Journal
Journal of Material Chemistry
Journal Volume
20
Journal Issue
26
Pages
5521-5526
Date Issued
2010-07
Author(s)
Su, Hai-Ching
Lin, You-Heng
Chang, Chih-Hao
Lin, Hao-Wu
Fang, Fu-Chuan
Chen, Hsiao-Fan
Abstract
We report highly efficient phosphor-sensitized solid-state light-emitting electrochemical cells (LECs) utilizing a phosphorescent cationic iridium complex [Ir(dFppy)2(SB)]+(PF6-) as the host and a fluorescent cationic dye (R6G) as the guest. Photophysical studies show that R6G retains a high photoluminescence quantum yield (PLQY) in highly polar media, revealing its suitable use as an emitting guest in an ionic host matrix. Such solid-state LECs achieve quantum efficiency (cd A-1) efficiency, and power efficiency up to 5.5% photon/electron, 19 cd A-1 and 21.3 lm W-1, respectively. The device quantum efficiency achieved is among the highest reported for fluorescent LECs and is higher than one would expect from the PLQY of the R6G fluorescent dye in the host film, thus indicating that phosphor-sensitization is useful for achieving highly efficient fluorescent LECs. Moreover, using narrow-band fluorescent emitters, such as R6G (FWHM, ∼50 nm), is effective in improving the color saturation of solid-state LECs based on cationic complexes. © 2010 The Royal Society of Chemistry.
Other Subjects
Cationic complexes; Color saturation; Fluorescent cationic dye; Fluorescent dyes; Fluorescent emitters; Host matrices; Iridium complex; Light-emitting electrochemical cell; Narrow bands; Photoluminescence quantum yields; Photophysical studies; Polar media; Power efficiency; Sensitized fluorescence; Dyes; Electrochemical cells; Electrolytic cells; Fluorescence; Iridium; Iridium compounds; Light emission; Phosphors; Quantum theory; Quantum efficiency
Type
journal article