Organic electroluminescent devices by high-temperature processing and crystalline hole transporting layer

Crystallization and interdiffusion of organic layers have been widely considered to be important causes for performance degradation of organic electroluminescent devices. By using high substrate temperature during vapor deposition, we have fabricated organic electroluminescent devices with crystalline organic layers. Contrary to the common belief, substantial increases in luminescent efficiency and brightness have been observed in the device thus fabricated. Such devices also showed much improved storage stability against high humidity compared to the conventional ones with amorphous organic layers. (C) 1999 American Institute of Physics. [S0003-6951(99)05122-0].