Stacked inverted top-emitting green electrophosphorescent organic light-emitting diodes on glass and flexible glass substrates

摘要

Stacked inverted top-emitting green electrophosphorescent organic light-emitting diodes (OLEDs) are demonstrated on glass and flexible glass substrates. A single-unit OLED is shown to have a current efficacy of 46.8 cd/A at a luminance of 1215 cd/m~2. When two of these OLEDs are stacked, the double-unit OLED exhibits a current efficacy more than twice that of the single-unit OLED, with a current efficacy of 97.8 cd/A at a luminance of 1119 cd/m~2. With the addition of an optical outcoupling layer of N,N'-Di-[(1-naphthyl)-N,N'-diphenyl]-1,1′-biphenyl)-4,4'-diamine (α-NPD) on top of the semitransparent gold anode, the double-unit stacked OLED achieves a maximum current efficacy of 205 cd/A at a luminance of 103 cd/m~2, maintaining a high current efficacy of 200 cd/A at a luminance of 1011 cd/m2. These stacked inverted OLED combine the advantages of inverted OLEDs with the benefits of having a stacked architecture.