The emitting properties of polypyridine and various copolymers were measured and prototype light-emitting devices based on pyridine-contg. conjugated polymers and copolymers were assembled in various configurations. The high electron affinity of pyridine based polymers enables the use of relatively stable metals such as Al or even ITO as electron injecting contacts. Bilayer devices utilizing poly(9-vinyl carbazole) (PVK) as hole transporting/electron blocking polymer were assembled, which show improved efficiency and brightness, due to charge confinement and exciplex emission at the PVK/emitting polymer interface. The incorporation of a conducting polyaniline network electrode in the PVK structure, lowers the device turn-on voltage significantly while maintaining high efficiency. Control of aggregate formation in the polymer films by blending with insulating host polymers [PMMA] opens up the possibility of making voltage-controlled multi-color light-emitting devices. [on SciFinder(R)]