Inverted Red Quantum Dot Light-Emitting Diodes with ZnO Nanoparticles Synthesized Using Zinc Acetate Dihydrate and Potassium Hydroxide in Open and Closed Systems.

We developed inverted red quantum dot light-emitting diodes (QLEDs) with ZnO nanoparticles synthesized in open and closed systems. Wurtzite-structured ZnO nanoparticles were synthesized using potassium hydroxide and zinc acetate dihydrate at various temperatures in the open and closed systems. The particle size increases with increasing synthesis temperature.

Effect of Oxidizing Agent on the Synthesis of ZnO Nanoparticles for Inverted Phosphorescent Organic Light-Emitting Devices without Multiple Interlayers.

Inverted organic light-emitting devices (OLEDs) have been aggressively developed because of their superiorities such as their high stability, low driving voltage, and low drop of brightness in display applications. The injection of electrons is a critical issue in inverted OLEDs because the ITO cathode has an overly high work function in injecting electrons into the emission layer from the cathode. We synthesized hexagonal wurtzite ZnO nanoparticles using different oxidizing agents for an efficient injection of electrons in the inverted OLEDs.

Highly Efficient All-Solution-Processed Quantum Dot Light-Emitting Diodes Using MoO Nanoparticle Hole Injection Layer.

This paper presents a study that aims to enhance the performance of quantum dot light-emitting didoes (QLEDs) by employing a solution-processed molybdenum oxide (MoO) nanoparticle (NP) as a hole injection layer (HIL). The study investigates the impact of varying the concentrations of the MoO NP layer on device characteristics and delves into the underlying mechanisms that contribute to the observed enhancements. Experimental techniques such as an X-ray diffraction and field-emission transmission electron microscopy were employed to confirm the formation of MoO NPs during the synthesis process.

Performance Improvement of Quantum Dot Light-Emitting Diodes Using a ZnMgO Electron Transport Layer with a Core/Shell Structure.

Highly efficient and all-solution processed quantum dot light-emitting diodes (QLEDs) with high performance are demonstrated by employing ZnMgO nanoparticles (NPs) with core/shell structure used as an electron transport layer (ETL). Mg-doping in ZnO NPs exhibits a different electronic structure and degree of electron mobility. A key processing step for synthesizing ZnMgO NPs with core/shell structure is adding Mg in the solution in addition to the remaining Mg and Zn ions after the core formation process.

The Effect of Particle Size on the Charge Balance Property of Quantum Dot Light-Emitting Devices Using Zinc Oxide Nanoparticles.

Zinc oxide nanoparticles (ZnO NPs) have been widely used as an inorganic electron transport layer (ETL) in quantum dot light-emitting devices (QLEDs) due to their excellent electrical properties. Here, we report the effect of ZnO NPs inorganic ETL of different particle sizes on the electrical and optical properties of QLEDs. We synthesized ZnO NPs into the size of 3 nm and 8 nm respectively and used them as an inorganic ETL of QLEDs.

High Efficiency Quantum Dot Light-Emitting Diode by Solution Printing of Zinc Oxide Nanoparticles.

Quantum dot light-emitting diodes (QLEDs) have attracted considerable attention owing to the narrow emission spectra, wide color gamut, high quantum yield and size-controlled emission wavelength. Zinc oxide nanoparticles have been widely used as an electron transport layer (ETL) in QLEDs due to their excellent electrical properties. In this study, we compared the efficiency of QLEDs with organic and zinc oxide ETLs in viewpoint of the charge balance.

Effect of Electron Injection Layer on the Parasitic Recombination at the Hole Transport Layer/Quantum Dot Interface in Quantum Dot Light-Emitting Diodes.

Zinc oxide (ZnO) nanoparticles layers are used as a substitute for organic electron transport layer due to high electron mobility, higher thermal stability and less sensitivity to the oxygen/moisture. In this study, we investigated the electron injection properties of ZnO nanoparticles in QLED compared with TPBi commonly used as injection layer in OLEDs. The expected electron injection barrier from energy diagram is similar in both devices, but the current density of the ZnO injection layer was slightly high compared with the TPBi injection layer.

Effect of Poly-TPD Molecular Weight on the Characteristics of Quantum-Dot Light-Emitting Devices.

We have investigated the effect of poly-TPD molecular weight (Mw) on the characteristics of CdSe/ZnS quantum-dot light-emitting devices (QD-LEDs). The poly-TPDs with Mw = 24000 and 84000 were used for hole-transporting layer. The Mw = 24000 poly-TPD layer was seriously dissolved by toluene which was used for the dispersion of QDs, resulting in substantial thickness reduction during the spin-coating of QD layer.