Aggregation-induced phosphorescence enhancement in deep-red and near-infrared emissive iridium(iii) complexes for solution-processable OLEDs. Issue 14 (9th March 2020)

• Record Type: Journal Article
• Authors: Kim, Hae Un; Jang, Ho Jin; Choi, Wanuk; Park, Sungjin; Park, Taiho; Lee, Jun Yeob; Bejoymohandas, K. S.
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 14(2020)
• Page Start: 4789
• Page End: 4800
• Publication Date: 2020-03-09
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9tc06813a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : AIPE active deep-red and near infrared iridium(iii ) complexes were developed using electron withdrawing substituents and effectively utilized them in solution processable PhOLEDs. Abstract : To fight against the counteractive triplet–triplet annihilation and vibrational deactivation faced by low bandgap phosphorescent emitters, aggregation-induced phosphorescent enhancement (AIPE)-active deep-red and NIR emissive iridium(iii ) complexes are designed by suitably anchoring electron-withdrawing substituents such as -phenyl (Ir2 ), -ethyl ester (Ir3 ), and -trifluoromethyl (Ir4 ) groups on the N-coordinating quinoline moiety of a (benzo[ b ]thiophen-2-yl)quinoline cyclometalated ligand along with ancillary picolinate. The fundamentals of the origin of AIPE on Ir2 and Ir4 and its associated excited-state properties are deeply studied through comparison with unsubstituted Ir1 with the help of density functional theory and single-crystal X-ray diffraction analysis. Most importantly, AIPE-active Ir2 is employed for the development of efficient deep-red and NIR PhOLEDs by hybrid solution-processable methods, in which the AIPE effect of Ir2 reaches a maximum external quantum efficiency (EQE) of 7.29% at high doping ratios.