抄録
Improvement of stability for electroluminescent device(EL) was achieved by a rectangular drive scheme. An EL device was composed as Al/Al tris(8-hydroxyquinoline) (Alq3)/PVCz/ITO. This composed EL device showed half lifetimes 2 hours in atmosphere and 100hrs in vacuum. However, 1100hrs of lifetime was achieved by operating the EL device by the rectangular drive scheme. It is found that lifetime of the EL device is extended to 11 times as the normal do operation. Curve analysis of luminance from the EL device operated by a rectangular wave showed that luminous decay curve is caused by two species. One of both species depends on the rectangular scheme, while another is independent. Decay time for the independent species was found to be 1.1ms which is correspondent to recombination time between electrons and holes in EL layer..
