Charge transport, carrier balance, and blue electrophosphorescence in diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide devices
Abstract
Diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide (EMPA1) displays a wide highest occupied molecular orbital–lowest unoccupied molecular orbital gap (4.1 eV), singlet (4.3 eV) and triplet (3.4 eV), and an electron-dominated charge transport that follows a trap-free space charge limited model with an average electron mobility of 5.7×10−6 cm2 V−1 s−1 and a hole mobility of 1.1×10−6 cm2 V−1 s−1. At high driving voltages (>6 V), ambipolar charge transport is observed, resulting in a balanced charge density in the active layer. Highly efficient blue phosphorescent organic light-emitting diodes were realized, showing a high external quantum efficiency (21%) and a luminance efficiency of 45 cd/A using a bis[2-(4′,6′-difluorophenyl)-pyridinato-N,C2′]iridium(III) picolinate dopant.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 14, 2011
- Source ID
- 10.1063/1.3555335
Entities
People
- César Pérez-bolívar
- Masashi Mamada
- Pavel Anzenbacher Jr.
- Selin Ergun
Organizations
- Air Force Office of Scientific Research
- Bowling Green State University