A series of novel electroluminescent polycarbazole-based main chain copolymers with varieties of aromatic rings and heterocycles as comonomer has been synthesized by Suzuki coupling reaction, The copolymers are soluble in common organic solvents and are highly fluorescent. Conjugated carbazole segment provides good hole-injection and hole-transport properties. Narrow band-gap heterocycles and aromatic rings, such as benzothiadiazole, benzoselenadi-azole, 4,7- dithien-2-yl-2,l,3-benzothiadiazole, thiophenes and anthracene in less than 50% of molar ratio in the copolymer were incorporated as a trapping center, The efficient energy transfer due to exciton trapping on the narrow band-gap sites was observed. The emission color can be tuned in entire visible region by carefully selecting the narrow band- gap comonomers. The use of conjugated polycarbazole as wide band-gap segment could provide a new way to combine good hole-injection properties along with color tuning ability.

Key words: POLYMER, CARBAZOLE, ELECTROLUMINESCENCE, LUMINESCENT DEVICES, COUPLING REACTION, ENERGY TRANSFER