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Cesium zirconium halide (e.g., Cs2ZrCl6:Te or CZCT) perovskites have garnered significant interest due to their unique optical properties. However, there have been no reports of CZCT perovskite nanoparticles (PNPs) that simultaneously offer high efficiency and thermal stability. Here, a comprehensive defect suppression strategy is reported to achieve CZCT PNPs with these attributes. First, the inner defects of CZCT perovskite microcrystals (PMCs) are minimized by controlling crystallization kinetics precisely. Second, the PNPs are obtained from PMCs via top‐down fabrication, and the surface defects of PNPs are passivated via the hydroxyl groups of alkyl‐terminated silica‐oligomer shell (ASO). The resulting CZCT@ASO PNPs show the highest photoluminescence quantum yield (PLQY) of 96% and high thermal stability among the reported conventional CZCT emitters. Finally, white light‐emitting diodes (WLEDs) are integrated by using CZCT@ASO PNPs as the down‐color converters, achieving a color coordinate of (0.31, 0.33) and a color rendering index of 86. These results demonstrate that core/shell CZCT@ASO PNPs have great potential as phosphors for lighting applications. [ABSTRACT FROM AUTHOR]

The low hole injection efficiency severely constrains the operational capability of blue quantum‐dot light‐emitting diodes (QLEDs). Constructing the structure of stepped energy levels is an effective approach to enhance the hole injection efficiency. Here, the dual hole injection structure is fabricated through the introduction of Ti3C2Tx film, in which its function is modulated by controlling the size of Ti3C2Tx nanosheets. Benefitting from a matched Fermi energy of Ti3C2Tx film, the Ti3C2Tx‐modified devices achieve a peak external quantum efficiency (EQE) of 15.89%, exhibiting a 67% increase compared to the reference devices with an EQE of 9.72%. The enhanced EQE can be attributed to the reduced energy barrier between indium tin oxide (ITO) and PEDOT:PSS, resulting from the incorporation of a Ti3C2Tx hole injection layer. In addition, the Ti3C2Tx layer effectively avoids the corrosion of the ITO electrode by acidic PEDOT:PSS, thereby enhancing the electrical stability of the ITO/PEDOT:PSS interface. The results provide a new approach to realize the high‐performance blue QLEDs devices. [ABSTRACT FROM AUTHOR]

Quantum‐dot light‐emitting diodes (QLEDs) are proposed as one of the most promising candidates for next‐generation displays, but their commercial application is seriously limited due to the poor performance of blue QLEDs (B‐QLEDs). Herein, this work uses Ti3C2Tx nanosheets to tune the work function (WF) of ZnMgO and to engineer the quantum dot (QD)/electron transport layer (ETL) interface. The B‐QLEDs with ZnMgO‐Ti3C2Tx hybrid ETL exhibit a maximum EQE of 15.81% and a remarkable T50 operation lifetime of 3284 h at 100 cd m−2. In addition to that, ultraviolet photoemission spectroscopy and density functional theory calculations both confirm that the addition of Ti3C2Tx to ZnMgO can effectively tune the ZnMgO's work function, further give rise to the reduction of QD/ETL energy barrier, which finally results in the alleviation of charge accumulation at the QD/ETL interface. The findings of interface engineering by Ti3C2Tx not only provide a promising strategy for the application of 2D materials in optoelectronic devices, but also pave the way to construct high‐performance light‐emitting diodes. [ABSTRACT FROM AUTHOR]

Quantum dot light‐emitting diodes (QLEDs), based on the solution‐processable colloidal quantum dots (QDs), are the high potential candidate for next generation display and lighting due to their high color purity, wide color gamut, low power consumption, and wide angle of view. Efforts have been made to improve the performance of the devices in order to achieve the goals of practical applications. This review focuses on the research progress in the materials and device physics of QLEDs, with the aims to accelerate the process of overcoming the obstacles to commercialization. Herein, the unique optical properties of QDs and the evolution of device structures are first reviewed. Then carrier dynamics, which has a decisive impact on device performance, is discussed in detail. In addition, the main obstacle to commercialization is emphasized as device stability, including operational stability, shelf stability, and efficiency roll‐off. Finally, unresolved issues in device physics are discussed, along with suggestions for future research directions. This review is expected to encourage further research in device physics and promote the development of QLEDs in the field of display and solid‐state lighting. [ABSTRACT FROM AUTHOR]

The low hole injection efficiency severely constrains the operational capability of blue quantum‐dot light‐emitting diodes (QLEDs). Constructing the structure of stepped energy levels is an effective approach to enhance the hole injection efficiency. Here, the dual hole injection structure is fabricated through the introduction of Ti3C2Tx film, in which its function is modulated by controlling the size of Ti3C2Tx nanosheets. Benefitting from a matched Fermi energy of Ti3C2Tx film, the Ti3C2Tx‐modified devices achieve a peak external quantum efficiency (EQE) of 15.89%, exhibiting a 67% increase compared to the reference devices with an EQE of 9.72%. The enhanced EQE can be attributed to the reduced energy barrier between indium tin oxide (ITO) and PEDOT:PSS, resulting from the incorporation of a Ti3C2Tx hole injection layer. In addition, the Ti3C2Tx layer effectively avoids the corrosion of the ITO electrode by acidic PEDOT:PSS, thereby enhancing the electrical stability of the ITO/PEDOT:PSS interface. The results provide a new approach to realize the high‐performance blue QLEDs devices. [ABSTRACT FROM AUTHOR]