Electroluminescent Performance and Spectral Characteristics of a Novel (t-bt)2Ir(acac) Phosphorescent Iridium Complex
ZHAO Juan, YU Jun-sheng*, WEN Wen, JIANG Ya-dong
State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054, China
Abstract:The photoluminescence (PL) spectra and UV-Visible absorption spectra of a novel yellow phosphor dye of bis[2-(4-tert-butylphenyl)benzothiazolato-N,C2′] iridium (acetylacetonate) denoted as (t-bt)2Ir(acac) were systematically investigated, which were measured in solution and film states with various concentrations. The results showed that the highest PL intensity was achieved when the solution concentration was 3×10-4 mol·L-1, and it decreased dramatically when the concentration kept on increasing because of concentration quenching of the phosphor dye. A red shift for PL spectra and UV-Vis absorption spectra of films compared to those of solutions were found, which is due to the shorter distance, aggregation effect, and stronger interaction of dye molecules in solid state. Based on the spectrum characterization, organic light-emitting diode was fabricated with an ultrathin structure based on this phosphor dye, which showed a high luminescence of 18 367 cd·m-2 at a bias of 13.2 V.
[1] Hsiao C H, Lee J H. Journal of Applied Physics, 2009, 106(2): 024503. [2] Ulbricht C, Beyer B, Friebe C, et al. Advanced Materials, 2009, 21(44): 4418. [3] Jou J H, Shen S M, Chen S H. Applied Physics Letter, 2010, 96(14): 143306. [4] Jeon S O, Yook K S, Joo C W, et al. Advanced Functional Materials, 2009, 19(22): 3644. [5] Reineke S, Lindner F, Schwartz G, et al. Nature, 2009, 459: 234. [6] Seidler N, Reineke S, Walzer K, et al. Applied Physics Letter, 2010, 96(9): 093304. [7] Mi Baoxiu, Wang Pengfei, GAO Zhiqiang, et al. Advanced Materials, 2010, 22(3): 339. [8] YU Jun-sheng, LI Lu, LI Yi, et al(于军胜,李 璐,李 仪, 等). Chemical Journal of Chinese Universities(高等学校化学学报), 2009, 30(10): 2045. [9] Chou H H, Cheng Ch H. Advanced Materials, 2010, 22(22): 2468. [10] Reineke S, Lindner F, Schwartz G, et al. Nature, 2009, 459: 234. [11] Lee J, Lee J I, Lee J Y, et al. Applied Physics Letter, 2009, 94(19): 193305. [12] Xu Minghui, Chen Zhijian, Xiao Lixin, et al. Journal of Physics D: Applied Physics, 2009, 42(5): 055116. [13] ZHANG An-qi, ZOU Jian-hua, YING Lei, et al(张安琪,邹建华,应 磊, 等). Acta Chimica Sinica(化学学报), 2009, 67(23): 2745. [14] Wang Qi, Ding Junqiao, Ma Dongge, et al. Applied Physics Letter., 2009, 94(10): 103503. [15] Wang Jun, Yu Junsheng, Li Lu, et al. Journal of Physics D: Applied Physics, 2008, 41(4): 045104. [16] HUANG Jia, TANG Xian-zhong, LI Yuan-xun, et al(黄 嘉,唐先忠,李元勋,等). Journal of Molecular Science(分子科学学报), 2007, 23(5): 310. [17] Chen Zhuqi, Bian Zuqiang, Huang Chunhui. Advanced Materials, 2010, 22(13): 1534. [18] GUO Xiao-xia, HAO Yu-ying, LEI Jun-feng, et al(郭晓霞,郝玉英,雷俊峰, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2010, 30(1): 170. [19] Wang Qi, Ding Jun-qiao, Ma Dong-ge, et al. Advanced Functional Materials, 2009, 19(1): 84. [20] Kondakova M E, Deaton J C, Pawlik T D, et al. Journal of Applied Physics, 2010, 107(1): 014515. [21] Lee T C, Chang C F, Chiu Y C. Chemistry-An Asian Journal, 2009, 4(5): 742. [22] Deng Jiyong, Liu Yu, Hu Zhengyong, et al. Journal of Central South University of Technology, 2007, 14(3): 344. [23] Lee S J, Park J S, Song M, et al. Advanced Function Materials, 2009, 19(14): 2205.