Release Time:2019-03-12  Hits:

Indexed by: Journal Article

Date of Publication: 2017-10-01

Journal: DYES AND PIGMENTS

Included Journals: Scopus、EI、SCIE

Volume: 145

Page Number: 528-537

ISSN: 0143-7208

Key Words: Organic light-emitting diodes (OLEDs); Iridium complexes; Orange phosphorescence; Benzothiazole based ligand; Triflruoromethyl

Abstract: A series of bis(2-phenylbenzothiozolato-N,C-2')iridium(acetylacetonate) derivatives are developed for use in phosphorescent organic light-emitting diodes (PhOLEDs). Fluorine (-F), trifluoromethyl (-CF3), Nphenylcarbazole-3-yl (-Cz) and diphenylamino (-Ph2N) are incorporated at the 5- or 7-site of the benzothiazole ring to adjust the properties and performance of the complexes. The emitting colors of these iridium phosphors are almost independent of the substituents and the substitution positions, but -F or -CF3 always resulted in increased phosphorescence quantum yields and decreased lifetimes in photoluminescence. Furthermore, the 5-F/CF3-substituted iridium complexes exhibited higher efficiencies than their analogues 7-site isomers in OLEDs. In particular the device based on 1 exhibits a maximum luminance efficiency of 64 cd A(-1) (213%). Theoretical calculations were performed to interpret the negligible color tuning effect. (C) 2017 Elsevier Ltd. All rights reserved.