Organic light emitting diodes
Organic light-emitting diodes (OLEDs), which emit coloured light by electroluminescence, are intrinsically brighter,
faster and more legible over wider viewing angles than liquid crystal displays. We combine liquid
crystal and electroluminescence technology in a unique fashion to make full-colour, multilayer
OLEDs. These incorporate thin films of polymerisable light-emitting liquid crystals which are
crosslinked by ultraviolet light. The self-assembling properties of liquid crystals give improved
carrier transport and polarised electroluminescence. We design, and synthesise new materials, study material and device properties and design new OLED configurations.
Photoalignment layers for Liquid crystal displays
.jpg)
An alignment film is commonly used to provide the macroscopic alignment of liquid crystals
in displays. We study photoalignment techniques whereby the alignment direction is imposed
by irradiation of the alignment layer with ultraviolet light. This non-contact method allows
the alignment direction to be spatially patterned. We design and synthesise new photoalignment materials, characterise their surface and bulk properties and study the liquid-crystal alignment mechanism.
Semiconductor Nanoparticles
In the nanometre scale the optical and electrical properties of semiconductor
particles become increasingly governed by their physical size (quantum
confinement), e.g. light emission can be tuned from blue to red just by
changing the radius of the nanocrystal. The group aims to combine these new
types of light emitters with organic materials in order to produce novel
electroluminescent devices. Of particular interest are cadmium telluride (CdTe) and mercury telluride (HgTe) for visible and infra-red applications respectively. Theoretical modelling is also involved in the studies of these materials.