Tailored efficient and reliable double luminescent layer hybrid WOLEDs via doping engineering

Abstract

Abstract Doping engineering has been widely utilized to increase the efficiency of White organic light-emitting diodes (WOLEDs). In this study, a blue phosphor material named DMAC-DPS and an orange phosphor material named PO-01 are integrated into the host materials Bis[2-(diphenylphosphino)phenyl] ether oxide (DPEPO) and carbazole-based 4,4′-biscarbazole-p-biphenyl (CBP) by incorporating the principle of complementary color luminescence, resulting in a doped double-luminescent layer hybrid WOLED. The developed device structure consists of ITO/MoO3/TCTA/DPEPO:DMAC-DPS/CBP:PO-01 (or CBP:PO-01/DPEPO:DMAC-DPS)/TAZ/Alq3/LiF/Al. The transfer of energy between the host and guest materials is achieved by controlling the thickness and position of the emitting layer, leading to a more balanced emission of blue and yellow light and an overall increase in device efficiency. The developed WOLED exhibits a maximum current efficiency of 26.8 cd A−1, a power efficiency of 16.8 lm W−1, and an external quantum efficiency of 10.95%. The stable color coordinates of the device remains consistent, varying from (0.34, 0.40) to (0.33, 0.39) at brightness levels ranging from 100 to 1000 cd m−2. Technically, the incorporation of blue and orange phosphor materials into the host materials DPEPO and CBP, respectively, resulting in a doped double-luminescent layer hybrid WOLED, has shown a more balanced emission of blue and yellow light and resulted in increased efficiency. The reliable color coordinates corroborate the good color stability, making it a promising candidate for various applications. Furthermore, the controlled transfer of energy between the host and guest materials has led to a more balanced emission of blue and yellow light. Our developed doping engineering methods have shown potential for increased efficiency and good color stability, making the developed WOLED a promising candidate for various applications.