摘要 |
A composition capable of emitting circularly polarised light comprises a medium including a chiral, helical liquid crystalline phase with a substantially fixed, temperature independent helical pitch. The liquid crystalline phase is comprised of calamatic liquid crystal molecules having a luminescent moiety and the composition is such that excitation of the luminescent moiety causes the medium to emit light in the bandwidth of selective reflection of the liquid crystalline phase. To achieve the substantially temperature independent helical pitch, the chiral helical liquid crystalline phase may be in the form of a glass or a polymerised network. The composition may be used to produce a light emitting device, e.g. and OLED. |