Solution-processable organic-inorganic hybrid hole injection layer for high efficiency phosphorescent organic light-emitting diodes

The presence of a solution-processed hybrid PEDOT:PSS-MoO₃-based hole injection layer (HIL) promotes a good interfacial contact between the indium tin oxide anode and hole-transporting layer for efficient operation of organic light-emitting diodes (OLEDs). This work reveals that the use of the hybrid HIL benefits the performance of phosphorescent OLEDs in two ways: (1) to assist in efficient hole injection, thereby improving power efficiency of OLEDs, and (2) to improve electron-hole current balance and suppression of interfacial defects at the organic/anode interface. The combined effects result in the power efficiency of 89.2 lm/W and external quantum efficiency of 23.9% for phosphorescent green OLEDs. The solution-processed hybrid PEDOT:PSS-MoO₃-based HIL is beneficial for application in solution-processed organic electronic devices.