Three Types of Charged-Ligand-Based Blue-Green to Near-Infrared Emitting Iridium Complexes: Synthesis, Structures, and Organic Light-Emitting Diode Application

作者：Shi, Chao^*; Huang, Hong; Li, Qiuxia; Yao, Jingwen; Wu, Cuicui; Cao, Yibo; Sun, Fangxiang; Ma, Dongge^*; Yan, Hong^*; Yang, Chuluo^*; Yuan, Aihua^*

来源：Advanced Optical Materials, 2021, 9(8): 2002060.

DOI：10.1002/adom.202002060

• charged ligands
• iridium complexes
• near&#8208
• infrared emission
• organic light&#8208
• emitting diodes
• phosphorescence

The development of a class of simple-structure-based small molecule iridium complexes with adjustable color emission from blue to near-infrared (NIR) remains a major challenge. A novel straightforward strategy toward a series of three types of charged ligand (0, -1, -2)-based neutral iridium(III) complexes is described, as it can be easily obtained by efficient three-step synthesis. All the complexes contain an unusual dianionic ligand (-2) biphenyl and show a great color variation from blue-green (465-503 nm) to NIR (688-706 nm) by controlling different neutral (0) and monoanionic (-1) ligands. Notably, all the NIR-emitting iridium(III) complexes have excellent chemical and thermal stability, which makes them easy to sublimate and purify, and are eventually applied to organic light-emitting diode device with a good external quantum efficiency of 2.5%, and low efficiency roll-off and turn-on voltage (3 V). This study opens an important avenue for the construction of novel phosphorescent iridium(III) complex materials with tunable properties featuring three types of charged ligands (0, -1, -2), thus providing new opportunities for their optoelectronic applications.

• 单位
  江苏科技大学; 南京大学