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This report examines the thermal stability of luminescent quantum rods under high optical flux LED conditions, analyzing degradation mechanisms and key factors. Findings reveal that smaller shell volumes and effective thermal management enhance reliability and practicality in high‐power LED applications. [ABSTRACT FROM AUTHOR]

The synthesis of blue quantum rods (QRs) is challenging due to fast kinetics and a significant shift in color during the synthesis of w‐CdSe seeds. Herein, we synthesized highly bright CdSe/ZnxCd1‐xS/ZnS core/shell blue QRs with an emission wavelength of 480 nm and fabricated blue QRLEDs. We found that the aging process of the QRLEDs significantly improved their performance by slowly reacting Al with ZnMgO and forming an AlOx interlayer among the ZnMgO/Al, which increased electron injection by over 3x times. The AlOx layer minimized the electron injection barrier and produced highly conductive ZnMgO by forming oxidation deficiency. Additionally, the exciton quenching suppressed at the QRs/ZnMgO/Al interface, and film morphology also changed among the QRs/ZnMgO stacks with the time. As a result, the aged QRLEDs showed an EQE of 9.4% and luminance of 61500 cd/m2, which is 2.6x and 3x times higher than the freshly made QRLEDs. These are the highest reported numbers in EQE and luminance of blue QRLEDs. Additionally, the durability of the blue QRLEDs significantly improved from 50 to 300 hours at 100 cd/m2 initial luminance. Overall, the use of QRs in LEDs greatly improves device efficiency and brightness. [ABSTRACT FROM AUTHOR]

Despite substantial efforts, the maximum external quantum efficiency (EQE) of red, green, and blue quantum dots remains close to 25%, limited by the outcoupling efficiency of specific device optical structures. Further improvements have primarily focused on optimizing light management. In this study, we employed rod‐shaped nanocrystals instead of sphere‐like quantum dots as the light‐emitting layer. The theoretical device outcoupling efficiency significantly increased to nearly 41% due to the intrinsic horizontal dipole alignment within the quantum rod film, nearly doubling the efficiency compared to quantum dot light‐emitting diodes (QDLEDs). As a result, we achieved record‐high EQEs of 14.1% for green quantum rod light‐emitting diodes, with maximum brightness exceeding 150,000 cd/m 2 , respectively. Our research demonstrates the immense potential of QRLEDs for display and lighting applications, paving a new way for the commercialization of nanocrystal particles. [ABSTRACT FROM AUTHOR]

This study reports a method to fabricate linearly polar ized color filters (CFs) using quantum rods (QRs) as emitters. Direct photolithography is employed with a li quid crystal polymer matrix to align QR‐CFs. Red and green CFs are developed using CdSe/CdS and CdSe/CdZnS QRs. Optimization of the curing agent concent ration improves QR dispersion and emission. The fabr icated single‐pixel CFs demonstrate a polarization deg ree of 0.33. This novel patterning technique produces high‐quality polarized CFs with applications in next‐ge neration displays. [ABSTRACT FROM AUTHOR]

Perovskite materials, celebrated for their exceptional optoelectronic properties, have seen extensive application in the field of light-emitting diodes (LEDs), where research is as abundant as the proverbial "carloads of books." In this review, the research of perovskite materials is delved into from a dimensional perspective, with a focus on the exemplary performance of low-dimensional perovskite materials in LEDs. This discussion predominantly revolves around perovskite quantum wires and perovskite nanorods. Perovskite quantum wires are versatile in their growth, compatible with both solution-based and vapor-phase growth, and can be deposited over large areas-even on spherical substrates-to achieve commendable electroluminescence (EL). Perovskite nanorods, on the other hand, boast a suite of superior characteristics, such as polarization properties and tunability of the transition dipole moment, endowing them with the great potential to enhance light extraction efficiency. Furthermore, zero-dimensional (0D) perovskite materials like nanocrystals (NCs) are also the subject of widespread research and application. This review reflects on and synthesizes the unique qualities of the aforementioned materials while exploring their vital roles in the development of high-efficiency perovskite LEDs (PeLEDs)., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

Quantum dot (QD) light-emitting diodes (QLEDs) have attracted extensive attention due to their high color purity, solution-processability, and high brightness. Due to extensive efforts, the external quantum efficiency (EQE) of QLEDs has approached the theoretical limit. However, because of the efficiency roll-off, the high EQE can only be achieved at relatively low luminance, hindering their application in high-brightness devices such as near-to-eye displays and lighting applications. Here, this article reports an ultralow roll-off QLED that is achieved by simultaneously blocking electron leakage and enhancing the hole injection, thereby shifting the recombination zone back to the emitting QDs layer. These devices maintain EQE over 20.6% up to 1000 mA cm -2 current density, dropping only by ≈5% from the peak EQE of 21.6%, which is the highest value ever reported for the bottom-emitting red QLEDs. Furthermore, the maximum luminance of the optimal device reaches 320 000 cd m -2 , 2.7 times higher than the control device (L max : 128 000 cd m -2 ). A passive matrix (PM) QLED display panel with high brightness based on the optimized device structure is also demonstrated. The proposed approach advances the potential of QLEDs to operate efficiently in high-brightness scenarios., (© 2023 Wiley-VCH GmbH.)