Synthesis, characterization, and photo- and
electro-luminescence of Ir(
III) complexes
containing carrier transporting group-substituted
b-diketonate ligand†
Tianzhi Yu,
*
a
Yanlong Shi,
a
Haifang Chai,
ab
Lixia Niu,
b
Peng Liu,
ab
Yuling Zhao,
b
Jundan Kang,
b
Bin Gao
b
and Hui Zhang
a
Two new iridium organometallic compounds based on acetylacetone derivative ligands containing carrier-
transporting groups, Ir(L)
2
(acac-Ox) and Ir(L)
2
(acac-Cz), where L ¼ 3-(pyridin-2-yl)coumarinato N, C
4
,
acac-Ox ¼ 3-(4-(5-(4
0
-tert-butylphenyl)-1,3,4-oxadiazole)benzyl)-pentane-2,4-dionate and acac-Cz ¼
3-((4-(9H-carbazol-9-yl)phenyl)methyl)pentane-2,4-dionate, have been successfully synthesized and
characterized by elemental analysis,
1
H NMR and FT-IR. The structure of the free ligand acac-Ox was
established by single-crystal X-ray analysis as a cis-configurational enol of b-diketone. The photophysical
properties of the complexes were examined by using UV-vis, photoluminescence spectroscopic analysis.
The doped light-emitting devices with a configuration of ITO/MoO
3
(2 nm)/NPB (35 nm)/TCTA (5 nm)/
CBP:Ir(
III) complex (x wt %, 20 nm)/TPBi (40 nm)/LiF (1 nm)/Al (150 nm) were fabricated. The devices
based on Ir(L)
2
(acac-Cz) with a 9 wt% doping concentration showed the best EL efficiency performance,
and exhibited green emission with a maximum external quantum efficiency (EQE) of 7.77% and a
maximum luminous efficiency of 28.2 cd A
1
at a current density of 2.27 mA cm
2
, and a maximum
luminance of 6348.7 cd m
2
at 11 V. When the doping concentration is 6 wt%, a maximum brightness of
4230 cd m
2
at 16 V and a maximum current efficiency of 20.33 at 1.23 mA cm
2
and a maximum
external quantum efficiency (EQE) of 5.54% were achieved in the devices based on Ir(L)
2
(acac-Ox).By
comparison of the electroluminescent performances of the devices based on Ir(L)
2
(acac-Ox) and
Ir(L)
2
(acac-Cz), it was shown that the introduction of the hole-transporting group into the ligand
improves the performance of Ir(L)
2
(acac-Cz) doped devices.
1. Introduction
Research on organic light-emitting diodes (OLEDs) has attrac-
ted tremendous interest in the last two decades due to their
potential applications in low-cost, full-color, at-panel displays
and portable electronic devices.
1–4
Phosphorescent organic
light-emitting devices (PhOLEDs) based on transition metal
complexes have attracted considerable attention because they
can harvest singlet and triplet excitons, enabling internal
quantum efficiencies approaching 100%.
5–7
In the phospho-
rescent metal complexes, cyclometalated iridium complexes are
the most valuable emitting materials due to their high quantum
efficiency, brightness, color diversity and short excited-state
lifetime.
8–14
It is previously found that the color of the emission
from cyclometalated Ir(
III) complexes can be tuned either
through the design and synthesis of cyclometalating
ligands
9,15,16
or by modulating the ancillary ligands.
17,18
Coumarin derivatives can realize easy tuning of e nergy
gaps of the corresponding Ir(
III)complexesduetothe
synthetic possibilities of a large variety of coumarin deri va-
tives, the class of coumarin ligands could be a promising
candidate for t he preparation of iridium(
III)complexesfora
variety of photonic applications, such as optical sensing
technology
19,20
and OLED technology.
21–23
Cyclometalated
iridium(
III) coumarin complexes represent new type of
phosphorescence materi als for organic lighting emitting
diodes (OLEDs), whi ch possess efficient visible absorption,
higher quant um y ields and higher brightnesses. In our
previous works, we have reported some coumarin-based iri-
dium(
III) complexes,
24,25
in which 3-(pyridin-2-yl)coumarin or
3-(benzothiazol-2-yl)coumarin was used as a cyclometalated
ligand and acetylacetonat e and t henoyltriuoroacetonate
were used as ancillary monoanionic ligands, respectively.
a
Key Laboratory of Opto-Electronic Technology and Intelligent Control (Ministry of
Education), Lanzhou Jiaotong University, Lanzhou 730070, China. E-mail:
yutianzhi@hotmail.com; Fax: +86-931-4938756; Tel: +86-931-4956935
b
School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou
730070, China
† CCDC 944929. For crystallographic data in CIF or other electronic format see
DOI: 10.1039/c3ra47746k
Cite this: RSC Adv.,2014,4, 11680
Received 18th December 2013
Accepted 11th February 2014
DOI: 10.1039/c3ra47746k
www.rsc.org/advances
11680 | RSC Adv.,2014,4,11680–11688 This journal is © The Royal Society of Chemistry 2014
RSC Advances
PAPER
下载后可阅读完整内容，剩余8页未读，立即下载
weixin_38746574
- 粉丝: 10
- 资源: 937
我的内容管理
展开
最新资源
- 51单片机驱动DS1302时钟与LCD1602液晶屏万年历设计
- React 0.14.6版本源码分析与组件实践
- ChatGPT技术解读与应用分析白皮书
- 米-10直升机3D模型图纸下载-3DM格式
- Tsd Music Box v3.02：全面技术项目源码资源包
- 图像隐写技术：小波变换与SVD数字水印的Matlab实现
- PHP图片上传类源码教程及资源下载
- 掌握图像压缩技术：Matlab实现奇异值分解SVD
- Matlab万用表识别数字仪表教程及源码分享
- 三栏科技博客WordPress模板及丰富技术项目源码资源下载
- 【Matlab】图像隐写技术的改进LSB方法源码教程
- 响应式网站模板系列：右侧多级滑动式HTML5模板
- POCS算法超分辨率图像重建Matlab源码教程
- 基于Proteus的51单片机PWM波频率与占空比调整
- 易捷域名查询系统源码分享与学习交流平台
- 图像隐写术：Matlab实现SVD数字水印技术及其源码
资源上传下载、课程学习等过程中有任何疑问或建议，欢迎提出宝贵意见哦~我们会及时处理！
点击此处反馈
