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The study on phosphors‐converted white light‐emitting diodes (pc‐WLEDs) using lead‐free double perovskites (DPs) as single‐component white phosphors is widely concerned. However, the photoluminescence quantum yields (PLQY) of white luminescence and color rendering index (CRI) of WLED are not satisfactory. Herein, a new Sb/Ho: Cs2Na0.9Ag0.1(In/Bi)Cl6 single‐component white phosphor with the highest PLQY of 93% and a record CRI of 97.4 is reported. Experimental data and theoretical calculations evidence that in addition to broadband yellow emission of the self‐trapped exciton (STE) recombination, the material also exhibits blue emission from Sb3+: 3P1→1S0 transition and red one assigned to Ho3+: 5F5→5I8 transition. Steady‐state and time‐resolved PL spectra verify the existence of two energy transfer channels from both Sb3+ and STE to Ho3+ dopants. As a demo, Sb/Ho: Cs2Na0.9Ag0.1(In/Bi) Cl6‐based WLED is constructed, showing excellent comprehensive optical performance with specially improved saturation red index R9 and blue one R12. This work provides a novel single‐component rare‐earth doped DP white phosphor for high CRI full‐spectrum solid‐state lighting. [ABSTRACT FROM AUTHOR]

Lead halide perovskite quantum dots (PeQDs) have garnered increasing attention due to their extraordinary optoelectronic properties. In recent years, femtosecond (fs) laser direct writing shows to be an effective way of inducing localized crystallization of PeQDs inside glass matrix while remaining their structural stability and optical performance. This article reviews the research progress on fs laser irradiation‐induced nucleation/growth of PeQDs in glass and discusses the latest advancements in the use of the technology for optical data storage, micrometer‐scale light‐emitting diode (LED), information security protection, and other related fields. It offers novel insights and perspectives for exploring new functionality and device application of fs laser‐printed PeQDs glass composite structures. [ABSTRACT FROM AUTHOR]

Eu2+‐doped phosphors have attracted the great attention of researchers in the past decade. However, Eu2+ dopant in inorganic hosts often suffers from the self‐oxidation effect, therefore causing the attenuated emission intensity and quantum efficiency. In this regard, developing Eu2+ doped phosphors with the prohibited self‐oxidation effect of Eu2+ and increased thermal stability is urgently required. Herein, an innovative cyan‐light emitting Li2CaSiO4:Eu2+/Eu3+, Lu3+ (LCSO) phosphor is designed. Both experimental results and theoretical calculations demonstrate that adding Lu3+ restricts the self‐oxidation of Eu2+ into Eu3+, thus improving the emission of Eu2+. Meanwhile, the Lu3+ introduction brings out excellent thermal stability. Finally, an efficient WLED with a color temperature (CCT) of 4573 K and a high color rendering index (Ra) of 84.2 is obtained using the as‐prepared phosphor due to the perfect compensation of the cyan light. As the introduction of Lu3+ improves the stability of Eu2+, a much greater difference in PL decay rate between Eu2+ and Eu3+ in LCSO is reached, thereby improving their sensitivity in temperature sensing. The strategy of Lu3+ introduction for prohibiting the self‐oxidation of Eu2+ for efficient and stable Eu2+ emission may stimulate some new ideas in designing high‐performance phosphors for more diverse applications. [ABSTRACT FROM AUTHOR]

Halogen‐mixed CsPb(Br/I)3 perovskite quantum dots (PeQDs) embedded glass can address the issue of stability, but suffers from low photoluminescence quantum yields (PLQYs) for the hindered in situ nucleation/growth inside the robust glass network. Uncovering the exact mechanism is highly desirable to develop high‐performance CsPb(Br/I)3@glass for commercial applications, but the topic remains unexplored. Here, based on femtosecond transient (fs‐TA) absorption, temperature‐dependent PL spectra, and theoretical calculations, a comprehensive understanding on heat‐treatment (HT) temperature‐induced modification of microstructures and carrier dynamics in the CsPb(Br/I)3@glass is build. It is evidenced that high‐temperature HT will promote more I− ions diffusion from glass matrix into CsPb(Br/I)3 lattice, leading to the retarded hot carrier (HC) cooling, and improved exciton recombination. This is attributed to the synergistic effect of the reduced effect carrier mass, the weakened carrier‐phonon coupling, the inhibited Klemens channel, and the eliminated defect states. Revealing these underlying mechanisms will empower to exert precise control and optimize PLQY of CsPb(Br/I)3@glass up to near unity. [ABSTRACT FROM AUTHOR]

Next‐generation high‐brightness lighting faces a big challenge in developing laser‐drivable color‐converting materials with effective thermal management. Herein, a new material architecture of Al2O3‐Y3Al5O12: Ce3+ (YAG: Ce) transparent composite ceramics coated with Al film (TCC@Al) is proposed. The as‐prepared material shows the highest thermal conductivity (29.3 W m−1 K−1) among YAG: Ce‐related transparent ceramics (TC) ever reported owing to the combination role of short‐range thermal conduction of Al2O3 microcrystals and long‐range thermal conduction of Al film. Temperature‐dependent photoluminescence (PL) spectra and femtosecond transient absorption (fs‐TA) spectra evidence the importance of thermal management, whereby the luminescent loss of TCC@Al is only 8.92% at 450 K and is far smaller than TC counterpart (15.86%). Importantly, no obvious luminescence saturation is detected upon 20 W mm−2 blue laser irradiation and the inhomogeneous angular color distribution is suppressed by the scatter of Al2O3 microcrystals, yielding uniform white light with ultra‐high luminous flux (LF) of 4294 lm@20 W mm−2 and luminous efficacy (LE) of 215 lm W−1. As a consequence, the present TCC@Al‐converted laser‐driven lighting prototype exhibits much better optical performance than the commercial TC‐based one. [ABSTRACT FROM AUTHOR]

White light‐emitting diodes (WLEDs) with high color‐rendering index (CRI, >90) are important for backlight displays and solid‐state lighting applications. Although the well‐developed colloidal quantum dots (QDs) based on heavy metals such as cadmium and lead are promising candidates for WLEDs, the low CRI still remains a significant limitation. In addition, the severe toxicity of heavy metals greatly limits their widespread use. Herein, the study demonstrates low‐cost and environmentally friendly carbon quantum dots (CQDs)‐based WLEDs that exhibit a high CRI of 94.33, surpassing that of conventional cadmium/lead‐containing QD‐based WLEDs. This achievement is attained through the employment of a binary host‐induced exciplex strategy. The high hole/electron mobility and suitable energy levels of the donor and acceptor give rise to a broadband orange–yellow emission stemming from the exciplex. As the host, the binary exciplex is capable of contributing blue and orange–yellow emission components while efficiently mitigating the aggregation‐induced quenching of CQDs. Meanwhile, CQDs effectively address the deep‐red emission gap, enabling the realization of CQDs‐based WLEDs with high CRI. These WLEDs also exhibit a remarkably low turn‐on voltage of 2.8 V, a maximum luminance exceeding 2000 cd m−2, a correlated color temperature of 4976 K, and Commission Internationale de l'Eclairage coordinates of (0.34, 0.32). [ABSTRACT FROM AUTHOR]

Developing violet‐light‐excitable deep‐red (650–660 nm) Eu2+‐activated phosphor is essential for full‐spectrum lighting. However, the related phosphors with facile synthesis, excellent optical performance, and superior thermal stability are scarce. Herein, a new class of (Sr,Ba)Lu2O4: Eu2+ deep‐red phosphor (660 nm) excitable by violet light via Ba2+‐induced local structure engineering is reported. Impressively, tunable emission from 615 to 682 nm, accompanied by significant improvement of thermal stability (81%@423 K), is achieved by partially substituting Sr2+ by Ba2+ in SrLu2O4: Eu2+. Crystal field analysis, density functional theory calculations, and thermoluminescence spectra confirm that the strong distortion and enhanced covalency of [EuO6] octahedron are responsible for spectral tunability, and the formation of shallow trapping states is beneficial for electron compensation to inhibit thermal quenching in the Sr0.85Ba0.15Lu2O4: Eu2+ phosphor. Finally, a white light‐emitting diode prototype fabricated by coupling of the Sr0.85Ba0.15Lu2O4: Eu2+ deep‐red phosphor and commercial blue/green phosphors with violet chip can yield sunlight‐like white light with an ultra‐high color rendering index (Ra = 95.2, R9 = 97.0) and an appropriate correlated color temperature of 4121 K, verifying its significant application potential in full‐spectrum solid‐state lighting. [ABSTRACT FROM AUTHOR]

Lead halide perovskite quantum dots (PeQDs) generally show slow hot carrier (HC) cooling because of the retarded relaxation of longitudinal optical (LO) phonons induced by hot phonon bottleneck effect. Although the feature is beneficial for designing photovoltaic devices beyond Schottky–Queisser limitation by manipulating HC excess energy, it would be hostile toward light‐emitting applications where fast HC cooling is preferred. Herein, a Ni2+ doping strategy is reported to effectively boost HC cooling in CsPbI3 PeQDs and inhibit Auger recombination, giving rise to near unity photoluminescent quantum yield (PLQY) for the Ni: CsPbI3 sample. Femtosecond transient (fs‐TA) absorption, temperature‐dependent PL spectra and theoretical calculations evidence that Ni2+ doping results in the enhancement of electron‐LO phonon coupling, the introduction of extra energy states at band edges, the increasement of effective carrier mass, and the modification of phonon dispersion spectra as well as density of states (DOS) of LO phonon modes. These synergistic roles ensure efficient Klemens decay within Ni: CsPbI3, which facilitates fast decay of hot phonons and break hot phonon bottleneck. These findings provide a valid route to tackle HC dynamics and pave a way for PeQDs‐based efficient light‐emitting applications. [ABSTRACT FROM AUTHOR]

Perovskite quantum dots (PeQDs) are seen as the credible alternative to traditional QDs ascolor converter in liquid crystal display (LCD). Unfortunately, PeQDs sufferfrom instability and color separation, and the prepared PeQDs enhanced films(PQDFs) need the protection of expensive barrier layers, which significantly increases price and limits their application. Herein, large‐area yellow monolithic PQDF is fabricated with both green CsPbBr3 and red CsPbBr1I2QDs encapsulated in the dual matrices of inorganic glass and polypropylene (PP) via an industrialized melt extruding & rolling method. The PQDF shows high photoluminescence quantum yield (PLQY) of 92% and narrow full width at half maximum (FWHM) of 19 nm (green) and 33 nm (red). Importantly, the bare PQDF without barrier layers can pass harsh aging test at 85 °C/85% RH and reach anoperating T90 lifetime over 1000 h. Finally, a white backlit unit is designed by coupling yellow monolithic PQDF with blue light guide panel, and the constructed prototype display shows superior color rendering performance forits narrow green/red emissions, reaching a color gamut of 110% National Television System Committee (NTSC). This work provides a novel and easy‐to‐industrialize route to prepare PQDFs to realize their commercial application in backlit display. [ABSTRACT FROM AUTHOR]

Currently, narrowband light‐convertor is critically urgent for preeminent color representation in lighting and display fields, however, the development of target materials still remains challenging. Herein, glass ceramic (GC) composite based on in situ glass crystallization, where the condense glass network structure acts as effective obstructors for long distance ion diffusion, is elaborately designed to inhibit activators' multi‐sites occupation for acquiring narrowband emitting. Following this strategy, an unprecedented narrowband blue emission of Eu2+‐activators with a peak at 447 nm and full‐width of half maximum (FWHM) of ≈30 nm is developed in a new type of Sr5(PO4)3Cl (SPOCl) GC composite. The Eu2+‐activators' hindered diffusion inside the GC composite makes preferential and limit occupation of the [Sr1O9] sites, enabling narrowband blue luminescence. Furthermore, the GC composite highlights remarkable performance in high‐power violet‐excitable full‐spectrum lighting and transparent display (TD) prototype fields, due to its high color purity (≈98.1%), photoluminescence quantum field (PLQY, ≈80.5%) and thermal stability (≈82.1%@150 °C). This work not only promotes the profound understanding of the relationship between light manipulation and glass crystallization, but also paves the way toward the implementation of high‐quality lighting and display of GC composites. [ABSTRACT FROM AUTHOR]

Orthogonal three‐color luminescence materials designed based on lanthanide doping multi‐component nano‐systems have exhibited great potential in volume display technology. Previous studies devoted to integrate the different color emitters within a single core‐shell nanoparticle, which suffers complexity in synthesis and difficulty in repeatability. In this work, an alternative is proposed. Three kinds of upconversion nanocrystals (UCNCs) with relatively simple configurations are prepared separately. Each kind of nanocrystals takes charge of emit a specific color upon one particular excitation (i.e., 808, 980, and 1540 nm pumps). Luminescent property of the mixture containing these nanocrystals are investigated. Excitation wavelength driven orthogonal three‐color luminescence property is found in this mixture. With the combination excitation, the emission color can be modulated, covering a gamut with its aera of 110% sRGB, superior to the previous reports. In addition, a quantized strategy to evaluate the orthogonality of the luminescence is also proposed, which will be useful for the further investigation and development of remote‐type controlled luminescent materials. Finally, the demonstration of colored 3D display application is conducted and presented in this work. [ABSTRACT FROM AUTHOR]