Monodomain alignment of thermotropic fluorene copolymers

Conjugated copolymers of 9,9-dioctylfluorene alternating with benzothiadiaz ole and dithiophene moieties in the main chain were found to be 'hairy rod' type thermotropic liquid crystalline polymers as well as yellow to red pho toluminescence emitters. Thin films of both copolymers were found to align into monodomains on standard liquid crystal alignment layers as well as on rubbed precursor route poly(para-phenylenevinylene) (precPPV), which is tra nsparent to red light. This observation is of importance for the use of pre cPPV as a hole transporting alignment layer for fluorene copolymers in pola rized electroluminescence devices.