Interfacial Dipole Engineering for Energy Level Alignment in NiOx-Based Quantum Dot Light-Emitting Diodes.

The solution-derived non-stoichiometric nickel oxide (NiO) is a promising hole-injecting material for stable quantum dot light-emitting diodes (QLEDs). However, the carrier imbalance due to the misalignment of energy levels between the NiO and polymeric hole-transporting layers (HTLs) curtails the device efficiency. In this study, the modification of the NiO surface is investigated using either 3-cyanobenzoic acid (3-CN-BA) or 4-cyanobenzoic acid (4-CN-BA) in the QLED fabrication.

Flexible Substrate-Compatible and Efficiency-Improved Quantum-Dot Light-Emitting Diodes with Reduced Annealing Temperature of NiO Hole-Injecting Layer.

The growing demand for wearable and attachable displays has sparked significant interest in flexible quantum-dot light-emitting diodes (QLEDs). However, the challenges of fabricating and operating QLEDs on flexible substrates persist due to the lack of stable and low-temperature processable charge-injection/-transporting layers with aligned energy levels. In this study, we utilized NiO nanoparticles that are compatible with flexible substrates as a hole-injection layer (HIL).