Electroluminescence properties of new multi-functional copolymers containing carbazole, naphthalimide and oxadiazole

We have prepared a new class of copolymers containing carbazole, 1,8-naphthalimide and 1,3,4-oxadiazole. Optical properties of the copolymers are studied in the UV-visible region. Thermogravimetric analysis and differential scanning calorimetry examined their thermal stability. The copolymers are soluble in common organic solvents, and emit blue-green light under the irradiation of UV light in their film states. For these copolymers, there is an intramolecular energy transfer from carbazole and 1,3,4-oxadiazole to 1,8-naphthalimide. Single-layer devices of indium tin oxide/copolymers/ aluminum utilizing these copolymers as emissive materials were fabricated, that emitted blue-green light at 6-8 V under a forward bias. (C) 2002 Elsevier Science B.V. All rights reserved.