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Title: Long term stable deep red light-emitting electrochemical cells based on an emissive, rigid cationic Ir(iii) complex

Abstract

Here, the new cationic iridium complex [Ir(bzq) 2(biq)][PF 6] (bzq = benzo[ h]quinolinato and biq = 2,2'-biquinoline) has been synthesized for application as an emitter in light emitting electrochemical cells (LECs). The molecular structure and crystal packing of this complex were established by single X-ray diffraction (SXRD). The electrochemical and photophysical properties of the complex were examined to determine the frontier orbital energies as well as the optical transitions that led to photoemission. The complex was found to emit at 644 nm and 662 nm for powder and thin films, respectively. A high powder photoluminescence quantum yield of 25% was determined, which is attributed to a reduction in vibrational modes of the complex due to the use of the rigid cyclometalated (C^N) bzq ligand. A LEC with [Ir(bzq) 2(biq)][PF 6] as the emitter was fabricated which showed a deep red emission (662 nm) with a luminance of 33.65 cd m –2, yielding a current efficiency of 0.33 cd A –1 and a power efficiency of 0.2 lm W –1. Most importantly, the LEC based on [Ir(bzq) 2(biq)][PF 6] demonstrated a lifetime of 280 hours which is among the longest device lifetimes reported for any deep red light emitting LEC.

Authors:
 [1];  [2];  [3];  [4];  [4];  [5]
  1. OSRAM GmbH, Augsburg (Germany)
  2. (Germany)
  3. OSRAM OLED GmbH, Regensburg (Germany)
  4. Ruhr-Univ. Bochum, Bochum (Germany)
  5. (United States)
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1350070
Report Number(s):
IS-J-9086
Journal ID: ISSN 2050-7526; JMCCCX
Grant/Contract Number:  
AC02-07CH11358
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Materials Chemistry. C
Additional Journal Information:
Journal Volume: 5; Journal Issue: 12; Journal ID: ISSN 2050-7526
Publisher:
Royal Society of Chemistry
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Namanga, Jude E., Ruhr-Univ. Bochum, Bochum, Gerlitzki, Niels, Mallick, Bert, Mudring, Anja -Verena, and Iowa State Univ., Ames, IA. Long term stable deep red light-emitting electrochemical cells based on an emissive, rigid cationic Ir(iii) complex. United States: N. p., 2017. Web. doi:10.1039/C6TC04547B.
Namanga, Jude E., Ruhr-Univ. Bochum, Bochum, Gerlitzki, Niels, Mallick, Bert, Mudring, Anja -Verena, & Iowa State Univ., Ames, IA. Long term stable deep red light-emitting electrochemical cells based on an emissive, rigid cationic Ir(iii) complex. United States. doi:10.1039/C6TC04547B.
Namanga, Jude E., Ruhr-Univ. Bochum, Bochum, Gerlitzki, Niels, Mallick, Bert, Mudring, Anja -Verena, and Iowa State Univ., Ames, IA. Fri . "Long term stable deep red light-emitting electrochemical cells based on an emissive, rigid cationic Ir(iii) complex". United States. doi:10.1039/C6TC04547B. https://www.osti.gov/servlets/purl/1350070.
@article{osti_1350070,
title = {Long term stable deep red light-emitting electrochemical cells based on an emissive, rigid cationic Ir(iii) complex},
author = {Namanga, Jude E. and Ruhr-Univ. Bochum, Bochum and Gerlitzki, Niels and Mallick, Bert and Mudring, Anja -Verena and Iowa State Univ., Ames, IA},
abstractNote = {Here, the new cationic iridium complex [Ir(bzq)2(biq)][PF6] (bzq = benzo[h]quinolinato and biq = 2,2'-biquinoline) has been synthesized for application as an emitter in light emitting electrochemical cells (LECs). The molecular structure and crystal packing of this complex were established by single X-ray diffraction (SXRD). The electrochemical and photophysical properties of the complex were examined to determine the frontier orbital energies as well as the optical transitions that led to photoemission. The complex was found to emit at 644 nm and 662 nm for powder and thin films, respectively. A high powder photoluminescence quantum yield of 25% was determined, which is attributed to a reduction in vibrational modes of the complex due to the use of the rigid cyclometalated (C^N) bzq ligand. A LEC with [Ir(bzq)2(biq)][PF6] as the emitter was fabricated which showed a deep red emission (662 nm) with a luminance of 33.65 cd m–2, yielding a current efficiency of 0.33 cd A–1 and a power efficiency of 0.2 lm W–1. Most importantly, the LEC based on [Ir(bzq)2(biq)][PF6] demonstrated a lifetime of 280 hours which is among the longest device lifetimes reported for any deep red light emitting LEC.},
doi = {10.1039/C6TC04547B},
journal = {Journal of Materials Chemistry. C},
number = 12,
volume = 5,
place = {United States},
year = {Fri Feb 17 00:00:00 EST 2017},
month = {Fri Feb 17 00:00:00 EST 2017}
}

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