Electroluminescent nematic polymer networks with polarised emission

Electroluminescence with a polarisation ratio of 12:1 from a uniformly alig ned nematic network is reported. Diene photo-active end-groups were used, w hich polymerise by a selective cyclisation reaction. Surface alignment was achieved for the first time using a doped polymer photoalignment layer, ori ented by exposure to polarised UV light. Threshold voltages between 2 V and 8 V were found and a brightness of 90 cd m(-2) was obtained. Both the PL a nd EL intensities were higher after photochemical crosslinking.