Enhanced Performances of Quantum Dot Light-Emitting Diodes with an Organic–Inorganic Hybrid Hole Injection Layer

PEDOT:PSS (polyethylene dioxythiophene:polystyrenesulfonate) is a commonly used hole injec-tion layer (HIL) in optoelectronic devices due to its high conductive properties and work function. However, the acidic and hygroscopic nature of PEDOT:PSS can be problematic for device stability over time. To address this issue, in this study, we have demonstrated the potential of an organic-inorganic hybrid HIL, by incorporating solution-processed WOx nanoparticles (WOx NPs) into the PEDOT:PSS mixture. This hybrid solution was found to have a superior hole transport ability and low Ohmic contact resistance, contributing to higher brightness (~62 000 cd m-2) and current efficiency (13.1 cd A-1) in the manufactured quantum-dot based light-emitting diodes (QLEDs). In addition, the resulting devices achieved a relative operational lifetime of 7,071 hours, or approxi-mately twice that of traditional QLEDs with PEDOT:PSS HILs. The proposed method is an un-complicated, reliable and low-cost way to achieve long operational lifetimes without sacrificing efficiency in optoelectronic devices.