Fused 6/5/6 Metallocycle-Based Tetradentate Pt(II) Emitters for Efficient Green Phosphorescent OLEDs
Guijie Li, Jianfeng Wen, Feng Zhan, Weiwei Lou, Yun‐Fang Yang, Ying Hu, Yuanbin She
Abstract
Pt(II) complexes are promising phosphorescent materials for organic light-emitting diode (OLED) applications in the fields of display, lighting, healthcare, aerospace, and so on. A series of novel biphenyl (bp)-based tetradentate 6/5/6 Pt(II) emitters using oxygen or carbon as a linking atom was designed and developed. The intermolecular interactions in crystal packing, electrochemical, and photophysical properties of the bp-based Pt(II) emitters and also their excited-state properties were systematically studied, which could be effectively regulated by ligand modification through linking group control; however, their emission spectra nearly showed no change. All the bp-based Pt(II) emitters exhibited vibronically featured emission spectra with dominant peaks at 502–505 nm and photoluminescent quantum yields of 24–34% in dichloromethane solution. Green OLED using Pt(bp-12) as an emitter achieved a maximum brightness (Lmax) of 16,644 cd/m2.