We identify and characterize a novel type of quantum emitter formed from InGaN monolayer islands grown using molecular beam epitaxy and further isolated via the fabrication of an array of nanopillar structures. Detailed optical analysis of the characteristic emission spectrum from the monolayer islands is performed, and the main transmission is shown to act as a bright, stable, and fast single-photon emitter with a wavelength of ~400 nm.

PEDOT:PSS (polyethylene dioxythiophene:polystyrenesulfonate) is a commonly used hole injection 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 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 7071 h, or approximately twice that of traditional QLEDs with PEDOT:PSS HILs. The proposed method is an uncomplicated, reliable, and low-cost way to achieve long operational lifetimes without sacrificing efficiency in optoelectronic devices.

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.

Colloidal alloy quantum dots (QDs) with tunable emission wavelengths and tailorable structures are promising candidates for high-performance QDs light-emitting diodes (QLEDs). However, the uneven growth of alloy QDs leads to inhomogeneous structures and morphologies, resulting in lattice defect accumulation and suppressed photoluminescence quantum yields (PLQYs). Here, we present a versatile strategy for synthesizing high-quality alloy QDs with enhanced emission properties and reduced lattice defects. By rapidly injecting high-temperature anion precursors, we achieve uniform lattice growth and mitigate defects while preserving superior emission properties. The high-temperature (230°C) anion-injected synthetic alloy QDs (H-QDs) reach a PLQY up to 95%, significantly higher than the 82% obtained from room-temperature (25°C) anion-injected synthetic QDs (R-QDs). We fabricate green QLEDs based on CdSe@ZnS H-QDs, which demonstrate a maximum external quantum efficiency (EQE) of 22.4% and a lifetime of 506,000 h at 529 nm—outperforming R-QD-based devices (EQE: 11.3%, lifetime: 108,900 h). This method provides a new way for optimizing alloy QDs for advanced visible optoelectronic devices.