Narrow-Band Green-Emitting Sr2MgAl22O36:Mn2+ Phosphors with Superior Thermal Stability and Wide Color Gamut for Backlighting Display Applications

Metal halide perovskite nanocrystals (PNCs) have recently garnered tremendous research interest due to their unique optoelectronic properties and promising applications in photovoltaics and optoelectronics. Metal halide PNCs can be combined with polymers to create nanocomposites that carry an array of advantageous characteristics. The polymer matrix can bestow stability, stretchability, and solution-processability while the PNCs maintain their size-, shape- and composition-dependent optoelectronic properties. As such, these nanocomposites possess great promise for next-generation displays, lighting, sensing, biomedical technologies, and energy conversion. The recent advances in metal halide PNC/polymer nanocomposites are summarized here. First, a variety of synthetic strategies for crafting PNC/polymer nanocomposites are discussed. Second, their array of intriguing properties is examined. Third, the broad range of applications of PNC/polymer nanocomposites is highlighted, including light-emitting diodes (LEDs), lasers, and scintillators. Finally, an outlook on future research directions and challenges in this rapidly evolving field are presented.

Recent Advances in Synthesis, Properties, and Applications of Metal Halide Perovskite Nanocrystals/Polymer Nanocomposites

Luminescent materials such as Cd-based quantum dots, CuInS2 quantum dots, and perovskite-based materials play an important role as an exceptional class of optoelectronic materials due to their unique and novel characteristics for optoelectronic applications. However, a key challenge for luminescent materials and devices is their poor long-term stability, which is typically attributed to the irreversible changes of surface ligands or chemical structure against oxygen and moisture when exposed to ambient atmosphere. Thus, this review mainly focuses on recent important work on the stability-enhanced strategies of luminescent materials. Various strategies for their fabrication, including surface engineering and surface coating routes have been summarized, followed by their advantages and challenges. Furthermore, the corresponding optoelectronic applications of these promising stability-enhanced luminescent materials in light-emitting diodes, photodetectors, solid-state lighting chips, and solar cells were also reviewed. Afterward, the outlook and perspective are presented.

A review of stability-enhanced luminescent materials: fabrication and optoelectronic applications

https://www.tandfonline.com/doi/pdf/10.1080/14686996.2020.1752115

Recent advances in synthesis and application of perovskite quantum dot based composites for photonics, electronics and sensors.

Metal oxide semiconductors, exhibiting excellent optical transparency, high carrier mobilities, good mechanical stress tolerance and environmental stability, have been widely used in emerging optoelectronic devices (OEDs), such as dye-sensitized solar cells (DSSCs), perovskite solar cells (PerSCs), organic solar cells (OSCs) and various light-emitting diodes (LEDs). Among them, nickel oxide (NiO) is a typical p-type metal oxide and plays important roles in these emerging OEDs, such as photocathodes in p-type DSSCs, and hole transport layers (HTL) or hole injection layers (HIL) or electron blocking layers (EBL) in PerSCs, OSCs and LEDs. This comprehensive review delivers a summary of recent progress in emerging OEDs with NiO, explains how NiO works in different devices, demonstrates the influence of the electronic structure and surface chemistry of NiO on the device performance, and emphasizes the effects of morphology, components and post-treatment on the optoelectronic properties of NiO. The extant problems and future directions for further development of NiO in OEDs are discussed in the end.

Recent advances and comprehensive insights on nickel oxide in emerging optoelectronic devices

Semiconductor quantum dots (QDs) have attracted extensive attention because of their remarkable optical and electrical characteristics. However, the practical application of QDs and further the QD composite films have greatly been hindered mainly owing to their essential drawbacks of extreme unstability under oxygen and water environments. Herein, one simple method has been employed to enhance enormously the stability of Cd xZn1- xSe yS1- y QD composite films by a combination of Cd xZn1- xSe yS1- y QDs and poly(vinylidene) fluoride (PVDF), which is characteristic of closely arranged molecular chains and strong hydrogen bonds. There are many particular advantages in using QD/PVDF composite films such as easy processing, low cost, large-area fabrication, and especially extreme stability even in the boiling water for more than 240 min. By employing K2SiF6:Mn4+ as a red phosphor, a prototype white light-emitting diode (WLED) with color coordinates of (0.3307, 0.3387), Tc of 5568 K, and color gamut 112.1NTSC(1931)% at 20 mA has been fabricated, and there is little variation under different excitation currents, indicating that the QD/PVDF composite films fabricated by this simple blade-coating process make them ideal candidates for liquid-crystal display backlight utilization via assembling a WLED on a large scale owing to its ultrahigh stability under severe environments.

Ultrastable Quantum Dot Composite Films under Severe Environments.

Efficient multi-shell CuInS2/ZnS/ZnS quantum-dots based light-emitting diodes: Time-controlled synthesis of quantum-dots and carrier balance effects of PEI

The invention relates to a preparation method of a quantum-dot light emitting diode device in which noble-metal/silicon-dioxide composite particles and semiconductor quantum dots are mixed. A simple spin-coating and film-forming technology is adopted to conduct spin coating on a hole injection layer PEDOT:PSS, a hole transmission layer, a noble metal/SiO2 composite particle-semiconductor quantum dot mixed quantum dot layer and an electronic transmission layer separately on a patterned ITO glass substrate; then, electrodes are subjected to vapor deposition through magnetron sputtering, a package technology is conducted, and finally, the quantum-dot light emitting diode device in which the noble-metal/silicon-dioxide composite particles and the semiconductor quantum dots are mixed is prepared. By adopting a metal plasmon enhancement effect, the electric field intensity of the periphery of a semiconductor is improved, and therefore the utilization efficiency of carrier recombination in anelectroluminescence layer is effectively improved, so that the electroluminescence intensity and efficiency of the semiconductor quantum dots are dramatically improved.

Preparation method of quantum-dot light emitting diode device in which noble-metal/silicon-dioxide composite particles and semiconductor quantum dots are mixed

The invention relates to a preparation method of a noble metal/SiO2 composite particle and semi-conductor quantum dot laminated quantum dot luminescent thin film. The preparation method comprises thefollowing steps: on an ITO glass substrate, single-layered metal nano-particles kernels are assembled to serve as a plasma excimer enhancement center, and metal nano-particles are wrapped with SiO2 housings to serve as isolating layers; and a CuInS/ZnS quantum dot semi-conductor quantum dot is taken as a photoluminescence center. The noble metal/SiO2 composite particle and semi-conductor quantum dot laminated quantum dot luminescent thin film is prepared by the spin-coating process, and the quantum dot luminescent thin film is finally prepared by the organic spin-coating and packaging processes. The preparation method is novel, low in manufacture cost and simple in preparation process, and becomes the most effective method which most probably improves the light field intensity of the semi-conductor quantum dot, improves the utilization efficiency of exciting light and accordingly improves the overall luminescence property of the semi-conductor quantum dot luminous optical film at last.

Zhao Zhiwei

Papers

A review of stability-enhanced luminescent materials: fabrication and optoelectronic applications

Ultrastable Quantum Dot Composite Films under Severe Environments.

Efficient multi-shell CuInS2/ZnS/ZnS quantum-dots based light-emitting diodes: Time-controlled synthesis of quantum-dots and carrier balance effects of PEI

Preparation method of quantum-dot light emitting diode device in which noble-metal/silicon-dioxide composite particles and semiconductor quantum dots are mixed

Preparation method of noble metal/SiO2 composite particle and semi-conductor quantum dot laminated quantum dot luminescent thin film