Diarylamino-substituted heterocyclic compounds (DHCs), 2,6-dicarbazolo-1,5- pyridine (PYD2) and 2,4,6-tricarbazolo-1,3,5-pyrimidine (PYM3), possess a high triplet energy level (T 1 ) of T 1 = 2.93 eV (PYD2) and T 1 = 2.89 eV (PYM3), respectively, in their solid state films. 6wt%-Iridium(III)bis[(4,6-di-fluorophenyl)-pyridinato-N,C 2 ] picolinate (FIrpic):PYD2- and 6wt%-FIrpic:PYM3-doped films showed high photoluminescence (PL) efficiencies of Φ PL = 88±2 % and Φ PL =80±1 %, indicating near perfect confinement of FIrpic triplet excitons. By increasing the FIrpic concentration in DHC hosts, lower driving voltage and higher external electroluminescence (EL) quantum efficiencies (η EL ) were observed, indicating enhancement of electron injection and transport (electron current) in these emitting layers.
All Science Journal Classification (ASJC) codes
- Polymers and Plastics
- Organic Chemistry
- Materials Chemistry