Enhancement of out-coupling efficiency due to an organic scattering layer in organic light-emitting devices

Abstract

Organic light-emitting devices (OLEDs) with an organic scattering layer (OSL) were fabricated to enhance their out-coupling efficiencies. The OSL was formed through a crystallization process at room temperature after deposition in a vacuum. The luminances of the OLEDs with an 1,3-bis(cabazol-9-yl) benzene (mCP), a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), or a 4,7-diphenyl-1,10-phenanthroline (BPhen) OSL were 2.16, 2.13, and 2.11 times higher than that of the OLED without an OSL due to an increase in the scattering effect at the interface between the glass substrate and the OSL. The current efficiencies of the OLEDs with a mCP, a BCP, or a BPhen OSL were increased by 14.8%, 15.8%, and 14.8% compared to that for the OLED without an OSL. The OSL films in the OLEDs decreased the intensity of the wave-guided light, resulting in enhanced light extraction.