Highly twisted pyrene derivatives for non-doped blue OLEDs

Abstract

New highly twisted rigid blue light-emitting materials were designed, composed of pyrene with a xylene core unit and either naphthalene or phenyl end units. These blue-emitting materials were synthesized via the Suzuki cross-coupling reaction and their structures were confirmed using FT-IR, H-1 NMR, C-13 NMR, and mass spectroscopy. The optical, electrochemical and thermal properties of the materials were investigated. The non-coplanar structure introduced by highly twisted xylene units provides steric hindrance, resulting in very deep blue emission. The fabricated devices exhibited a maximum external quantum efficiency (EQE) of 3.69% with CIE color coordinates (x, y: 0.15, 0.06). (C) 2016 Elsevier Ltd. All rights reserved.