Study on the stability of dye doped poly(n-vinylcarbazole) as the emitting layer of light-emitting diodes

Summary form only given. We have observed blue end blue-green light emitting from the light-emitting diodes (LED) utilizing tetraphenylbutadiene(TPB) and tris(8-quinolinolato) aluminum(Alq/sub a/) doped poly(N-vinyl-carbazole)(PVK) as emitting layer. In this paper, the stability of the dioden has been The analysis of DSC and TG for PVK indicates that the glass-transition temperature in 207/spl deg/C and the thermogravimetric temperature is about 305/spl deg/C. For TPB:PVK and Alq/sub s/:PVK complex, a distinct decay of emitting intensity was observed when they were heated to 85/spl deg/C for two hours or irradiated with 40W high pressure mercury lamp for two hours in the air. But the decay can be overcome in vacuum condition. So PVK is a stable polymer as the basis of emitting layer of LED when the cell is driven at room temperature or higher temperature in teh case of being sealed.