Share Email Print

Proceedings Paper

Strong induced chiroptical effects in light emitting polymer blends (Conference Presentation)
Author(s): Jess Wade; Alasadair Campbell; Li Wan; Matthew Fuchter
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Current OLED displays rely on a circularly polarised (CP) filter to enhance contrast by trapping ambient light inside the display. However, this means that 50% of the randomly polarised light emitted from each OLED pixel never leaves the screen, halving display efficiency and operational lifetime. One simple route to fabricate CP-emitting OLEDs is to use electroluminescent (EL) polymer – small molecule blends. Our approach is to pair a chiral small molecule with a non-chiral device optimised polymer, which allows for CP-dependent applications while retaining much of the performance properties of the original polymer. Previously circularly polarised polymer emission has been achieved via thick cholesteric stacks of liquid crystalline polymers, where linearly polarised light becomes circularly polarised. Here we show that it is possible to control whether cholesteric packing or chiral dipole dominates emission using film thickness; remarkably this allows us to change the handedness of the CP EL emission in the same materials system. We compare how the chemical structure of the non-chiral polymer and post-deposition processing impacts the chiroptical response of the resulting device, in an effort to provide a set of design rules for future high performance CP-OLEDs. We demonstrate a liquid-crystalline light emitting polymer with a record high induced absorption dissymmetry factor, which additionally shows no change in device characteristics (no trapping, etc) in the blends, as well as strong CP-PL and EL emission.

Paper Details

Date Published: 18 September 2018
Proc. SPIE 10736, Organic Light Emitting Materials and Devices XXII, 107360B (18 September 2018); doi: 10.1117/12.2321171
Show Author Affiliations
Jess Wade, Imperial College London (United Kingdom)
Alasadair Campbell, Imperial College London (United Kingdom)
Li Wan, Imperial College London (United Kingdom)
Matthew Fuchter, Imperial College London (United Kingdom)

Published in SPIE Proceedings Vol. 10736:
Organic Light Emitting Materials and Devices XXII
Chihaya Adachi; Jang-Joo Kim; Franky So, Editor(s)

© SPIE. Terms of Use
Back to Top