Blue Emissive fac/mer‐Iridium (III) NHC Carbene Complexes and their Application in OLEDs
Abstract
The photophysical and electrochemical properties of N‐heterocyclic carbene complexes of Iridium (III) (Ir(C^C:)3, where C^C: = N‐phenyl,N‐methyl‐pyrazinoimidazol‐2‐yl (pmpz), N,N‐di‐p‐tolyl‐pyrazinoimidazol‐2‐yl (tpz)) are reported. Facial and meridional isomers of Ir(pmpz)3 are prepared, but only the facial isomer can be isolated for Ir(tpz)3. The fac‐Ir(pmpz)3 and fac‐Ir(tpz)3 complexes have emission maxima at 465 nm in polystyrene, whereas the emission maximum of mer‐Ir(pmpz)3 is redshifted to 495 nm. The emission energies and photoluminescent quantum yield (ΦPL) in solution decrease on going from nonpolar to polar solvents; however, all the complexes are efficient emitters in polystyrene at room temperature (ΦPL = 88–96%) and 77 K. Blue phosphorescent organic light emitting diodes employing fac‐Ir(tpz)3 as an emissive dopant achieves a high external electroluminescence efficiency (≈18 ± 1%) and brightness (29 000 cd m−2) at low current density.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 10, 2021
- Source ID
- 10.1002/adom.202001994
Entities
People
- Abegail Tadle
- Caleb Coburn
- Daniel Sylvinson Muthiah Ravinson
- Jongchan Kim
- Mark Thompson
- Muazzam Idris
- Opeoluwa Abimbola
- Peter I. Djurovich
- Savannah C Kapper
- Stephen R. Forrest
- Thilini Batagoda
Organizations
- Air Force Office of Scientific Research
- Universal Display Corporation
- University of Michigan
- University of Southern California