title: Sky-Blue Phosphorescent OLEDs with 34.1% External Quantum Efficiency Using a Low Refractive Index Electron Transporting Layer.
abstract: Blue-phosphorescent organic light-emitting diodes (OLEDs) with 34.1% external quantum efficiency (EQE) and 79.6 lm W(-1) are demonstrated using a hole-transporting layer and electron-transporting layer with low refractive index values. Using optical simulations, it is predicted that outcoupling efficiencies with EQEs > 60% can be achieved if organic layers with a refractive index of 1.5 are used for OLEDs.
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul, 151-742, South Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Shin
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul, 151-742, South Korea.
authors.forename: Jeong-Hwan
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul, 151-742, South Korea.
authors.forename: Chang-Ki
authors.initials: CK
authors.lastname: Moon
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul, 151-742, South Korea.
authors.forename: Jin-Suk
authors.initials: JS
authors.lastname: Huh
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul, 151-742, South Korea.
authors.forename: Bomi
authors.initials: B
authors.lastname: Sim
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul, 151-742, South Korea.|Research Institute of Advanced Materials (RIAM), Seoul National University, Seoul, 151-744, South Korea.
authors.forename: Jang-Joo
authors.initials: JJ
authors.lastname: Kim
keywords: blue OLEDs; exciplex forming co-host; low refractive index ETL and HTL; theoretical limit of EQE