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Solid‐state white lighting applications with high brightness, low power consumption and long operating life have gradually dominated the modern industrial illumination market. For applications in white light‐emitting diodes (WLEDs) and white‐lighting laser diodes (WLDs), Phosphor‐in‐Glass (PiG), owing to its facile process, high efficiency and excellent chromaticity tunability, stands out as an optimal choice among various types of color converters. Currently, research in yellow‐emitting Y3Al5O12:Ce3+ (YAG: Ce) phosphors combined with different glass system has reached a mature stage and the poor illumination is a major bottleneck. Moreover, to realize high‐quality white lighting, exploiting full‐color PiGs is of great importance for its commercialization. Herein, the multicolour PiGs their successfully obtained by deliberately matching different color‐emitting phosphors with the glass matrix. Glass composition selection rules for specific phosphors their proposed based on investigations of glass protection mechanism and the corrosion reaction between phosphors and glass matrix. In addition, an astonishing YAG: Ce PiG phenomenon (zero thermal quenching) is founded and discussed. As for practical applications, high‐quality 5‐W chip‐on‐board (COB) WLEDs their constructed by utilizing simple matches of colorful PiGs. Assembled WLDs modules also rendered a high‐efficiency and stable lighting source. These results dramatically inspire the development of high‐quality solid‐state white lighting applications. [ABSTRACT FROM AUTHOR]

Phosphor‐in‐glass (PiG) film has been proposed as an ideal color converter in laser diodes (LDs) lighting for its advantages of outstanding thermal conductivity (TC) and superior efficiency. Herein, yellow‐emitting Y1.31Ce0.09Gd1.6Al5O12 (Ce: GdYAG)‐PiG composite films are successfully elaborated through a practical blade‐coating approach. Systematical studies are performed on its microstructure, thermal stability, and luminescence performance pumped by LDs. Noteworthy, the highest internal quantum efficiency of film (94.2%) retains 97.1% of the raw phosphors (97%). Particularly, by further introducing micrometer BN with high TC as light scattering center to enhance heat dissipation and increase porosity, the thermal and optical properties of the sample are greatly improved. The luminescence intensity of the sample at 423 K is increased to 1.8 times that at 298 K. The thermal diffusion (TD) and TC of the sample are increased from 1.571 to 4.227 mm2 s−1 and 6.4 to 13.0 W m−1 K−1, respectively. At the same time, the maximum saturation threshold under laser irradiation of Ce: GdYAG + micrometer BN composite film is raised from 3.12 to 5.42 W mm−2 and 260.6 to 354.1 lm, respectively. The combination of excellent optical and thermal performances, coupled with facile and low‐cost synthetic strategy, could push forward the practical application in solid‐state laser lighting. [ABSTRACT FROM AUTHOR]

The perovskite material has received much attention due to its excellent photoelectric properties. However, the toxicity of Pb has always affected the wide application of perovskite materials. Herein, we proposed to replace Pb ions with the same divalent ions Ba and dope them into the CsPbBr3 perovskite nanocrystals' (PNCs) lattice to reduce the content of Pb elements. In this work, we have successfully prepared a series of CsPb1−xBaxBr3 PNCs (x = 0, 0.1, 0.2, 0.3, and 0.4) and CsPbBr3 PNCs (Ba-doped concentration = x = 0, 0.05, 0.10, 0.15, and 0.20); the best among them were CsPb0.7Ba0.3Br3 PNCs and CsPbBr3 (Ba = 0.1) PNCs, respectively. Compared with CsPbBr3 PNCs, the photoluminescence (PL) intensity of CsPb0.7Ba0.3Br3 PNCs and CsPbBr3 (Ba = 0.1) PNCs has been improved to different degrees. It was worth mentioning that after the addition of a Ba element, the photoluminescent quantum yield (PLQY) of CsPb0.7Ba0.3Br3 PNCs and CsPbBr3 (Ba = 0.1) PNCs was increased to 81% and 65%, respectively. It was due to the high PLQY of CsPb0.7Ba0.3Br3 PNCs that the selected CIE color coordinate monochromatic light encompassed 119.0% of NTSC color gamut. [ABSTRACT FROM AUTHOR]

As a promising optoelectronic material, all-inorganic perovskite nanocrystals (NCs) have attracted much attention, but there are few studies on zero-dimensional Cs4PbBr6 perovskite NCs. Herein, the in situ growth of the CsPbBr3/Cs4PbBr6 NCs inside amorphous glass has been achieved by adjusting the ratios of Cs2CO3 and PbBr2. The effect of different proportions with raw materials on the phase, microstructure, and photoluminescence (PL) characteristics was discussed in detail. Moreover, CsPbBr3/Cs4PbBr6 NCs glass with high photoluminescence quantum yield (PLQY) of ∼58.9% was obtained by optimizing the heat treatment condition. In particular, CsPbBr3/Cs4PbBr6 NCs glass realizes low-threshold amplified spontaneous emission (ASE) at room temperature. Meanwhile, as a green light source, CsPbBr3/Cs4PbBr6 NCs glass makes white light-emitting diode (WLED) presents a wide color gamut. Importantly, CsPbBr3/Cs4PbBr6 NCs glass displays excellent water/thermal stability. All these results prove that CsPbBr3/Cs4PbBr6 NCs glass has broad application prospects in the field of lasers and backlight displays. [ABSTRACT FROM AUTHOR]

All inorganic remote Ce3+:Y3Al3.5Ga1.5O12 (Ce:YAGG) phosphor-in-glass (PIG) is considered to be an ideal robust green-emitting light converter for high-quality laser diode applications. Herein, the preparation of Ce:YAGG PIGs using an economical solid state reaction is reported. The sintered composite materials have the advantages of yielding a high transparency of 53% in the visible region and a high internal quantum efficiency of 92.7%. Benefiting from remarkably superior thermal properties, a high thermal conductivity of 1.712 W m−1 K−1 and a high thermal stability that the luminescence intensity could maintain 91.6% at 503 K, and the PIG can withstand 3.49 W/mm2 blue laser radiation. When pumped by blue laser diodes and by controlling the phosphor content and a thickness of samples, the robust PIG materials produce green light with a luminous flux of 555.6 lm and a stable luminous efficiency of 254.5 lm/W as the blue laser density increasing up to 2.78 W/mm2. The above outstanding performance of Ce:YAGG PIGs indicates a strong perspective for future lighting source. [ABSTRACT FROM AUTHOR]

All‐inorganic perovskite (CsPbX3, X = Cl, Br, I) nanocrystals (NCs) with promising optical properties are recognized as a rising star among photoelectric materials, but their inevitable instabilities limit extensive application. Herein, a new one‐step strategy for encapsulating CsPbX3 NCs with porous zeolite via the hot injection method is explored. By altering the mole ratio of PbX2, the emission wavelength of CsPbX3@zeolite is found to be regularly modulated from blue‐emission (CsPbCl2Br@zeolite, 436 nm) to red‐emission (CsPbBrI2@zeolite, 648 nm), thus enabling full spectrum adjustment. Due to the surface passivation of zeolite to CsPbX3 NCs, CsPbX3@zeolite possess an outstanding quantum yield and display excellent thermal/photo/air stability. Subsequently, white light‐emitting diodes based on green‐CsPbBr3@zeolite and red‐CsPbBrI2@zeolite are constructed and applied to the backlit display, achieving a wide color gamut of 134.2% for NTSC 1953 and 99.8% for Rec. 2020. The CsPbX3@zeolite implanted with a polymethyl methacrylate film is used to realize upconversion emission under an 800 nm laser at room temperature. Furthermore, amplified spontaneous radiation based on CsPbBr3@zeolite films is achieved. These results convincingly indicate broad application prospects for CsPbX3@zeolite prepared via this simple method. [ABSTRACT FROM AUTHOR]

Mn‐doped CsPbCl3 perovskite nanocrystal (PeNC) glass was prepared by melt quenching and in situ crystallization. Under the protection of robust glass, PeNCs exhibit excellent moisture resistance and thermal stability. The combination effect of thermal quenching and energy transfer of exciton to Mn2+ enables its promising applications in the field of temperature sensor. Interestingly, by matching with ultraviolet chips, all‐inorganic blue‐red emitting conversion device consisting of PeNC glass was prepared for light‐emitting diodes (LEDs), which can meet the light requirements of plant growth. The cultivation results indicated that the growth of cabbages using PeNC plant cultivation LEDs was greater than those cultivated using commercial w‐LEDs (white light‐emitting diodes). Therefore, Mn‐doped CsPbCl3 PeNCs can be used as a new generation of solid fluorescent materials in the field of indoor plant cultivation LEDs. [ABSTRACT FROM AUTHOR]

We successfully synthesized Mn‐doped CsPbBr0.5I2.5 nanocrystals (NCs) using a traditional hot injection method. The Mn‐doped CsPbBr0.5I2.5NCs have very good luminescence propertie. Unfortunately, they can only be dissolved in nonpolar solvents, and they suffer from the effect of air instability, thermal instability, and water instability. In this study, we used mesoporous SiO2 and Al2O3 coatings to improve the air stability and water stability of these nanocrystals, inhibit the loss of Mn2+. The prepared composite material not only maintains the excellent optical properties of the NCs, but also the most important is to significantly improve the stability of the NCs. Importantly, Mn‐doped CsPbBr0.5I2.5NCs can also be used as a red fluorescent material, with green CsPbBr3NC glass‐emitting white LED under the excitation of an InGaN blue chip. [ABSTRACT FROM AUTHOR]

A double perovskite‐type substrate of La2MgGeO6 (LMGO) was successfully synthesized via a high‐temperature solid‐state reaction method and was codoped with Mn4+ and Dy3+ to form a new deep‐red phosphor (LMGO:Mn4+,Dy3+) for artificial plant growth light‐emitting diodes (LEDs). This extraordinary phosphor can exhibit strong far‐red emission with a maximum peak at 708 nm between 650 and 750 nm, which can be ascribed to the 2Eg → 2A2 g spin‐forbidden transition of Mn4+. The X‐ray diffraction (XRD) patterns and high‐resolution transmission electron microscopy (HRTEM) clarified that the La3+ sites in the host were partly replaced by Dy3+ ions. Moreover, we discovered energy transfers from Dy3+ to Mn4+ by directly observing the significant overlap of the excitation spectrum of Mn4+ and the emission spectrum of Dy3+ as well as the systematic relative decline and growth of the emission bands of Dy3+ and Mn4+, respectively. With the increase in the activator (Mn4+) concentration, the relationship between the luminescence decay time and the energy transfer efficiency of the sensitizer (Dy3+) was studied in detail. Finally, an LED device was fabricated using a 460 nm blue chip, and the as‐obtained far‐red emitting LMGO:Mn4+,Dy3+ phosphors for Wedelia chinensis cultivation. As expected, the as‐fabricated plant growth LED‐treated Wedelia chinensis cultured in the artificial climate box with overhead LEDs demonstrated that after 28 days of irradiation, the average plant growth rate and the total chlorophyll content were better than those of specimens cultured using the commercial R‐B LED lamps, indicating that the as‐prepared phosphor could have a potential application in the agricultural industry. [ABSTRACT FROM AUTHOR]

Abstract: CsPbBr1.5I1.5 quantum dots (QDs) glasses are synthesized by traditional melting and thermal treated method, CsPbBr1.5I1.5 QDs glasses show vast potential as red fluorescence component in warm WLED applications due to their moderate emission wavelength as well as good opacity property. However, the quantum yield of QDs glasses is still low, therefore, Eu3+ ions is chosen to introduce into CsPbBr1.5I1.5 QDs, the quantum yield is enhanced to 64.7%. After a sequence of testing operations, we find that 6.5%CsPbBr1.5I1.5:0.28%Eu3+ QDs glasses is a strong competitor among red fluorescence solid materials. [ABSTRACT FROM AUTHOR]

Various luminescent carbon materials are artificially synthesized and as admirable fluorescent materials because of the increased research of carbon nanodots (CDs). Herein, a novel solvent-dependent red CDs (rCDs) is introduced through solvothermal method. The as-prepared rCDs remain benzene structure and possess abundant surface function groups that endow them well solubility in various solvents. Furthermore, multicolor luminescence are observed when rCDs are dissolved in different solvents, and the emission wavelength of these materials can be well-tuned from 475 to 624 nm, which presents intensity solvent-dependent properties. Red luminescence carbon phosphors are successfully synthesized by mix rCDs with silica powder. Finally, warm white light emitting diodes (WLEDs) are constructed using rCDs powder with Ce3+: YAG single crystal and blue GaN chips. The results demonstrate that the rCDs can act as red component to modify the correlated color temperature (CCT) and the color rendering index (CRI) of WLEDs. [ABSTRACT FROM AUTHOR]

We report the synthesis of CsPbBr3 QDs with great stability and high quantum yield in phospho-silicate glass, which was fabricated by using a heat-treatment approach, for white light emitting devices. QD glasses exhibited excellent photo- and thermal stability, and significantly prolonged the lifetime of light emitters under ambient air conditions. [ABSTRACT FROM AUTHOR]

To relieve the issues of high correlated color temperature and low color rendering index, it is urgent to develop an inorganic color converter materials with both red- and yellow-emission to replace the conventional organic resin/silicon-based color converter and acquire warm white light-emitting diodes (WLEDs). In our work, transparent glass-ceramics (GCs) containing Ce:YAlO (Ce:YAG) yellow phosphors and Eu ions are successfully fabricated by using low temperature co-sintering technique. And then the microstructure and luminescence properties of the GC are investigated in detail. Importantly, the impact of Ce:YAG phosphors concentration, Eu ions concentration, co-sintering time and the GC thickness on optical performances are also systematically demonstrated. Impressively, the as-fabricated samples exhibit an efficient red emission at 611 nm owing to the D→F transition of Eu. Subsequently, the temperature-dependent luminescence and thermal quenching is also investigated. Finally, the constructed WLEDs show an optimal luminous efficacy of 120.85 lm/W, a color rendering index of 70.2 and a correlated color temperature of 5267 K. All the results indicate that the as-fabricated GC would have potential practical applications in high-power WLEDs. [ABSTRACT FROM AUTHOR]

Currently, phosphor-in-glass (PiG) approach draws great attention because of its excellent thermal resistance and facile process in WLED fabrication. However, the red light deficiency results in high correlated color temperature (CCT) and low color rendering index (CRI) in white light-emitting diode (WLED). Herein, a new LuAG:Ce 3+ phosphor-in-glass (Lu-PiG) combining with the CaAlSiN 3 :Eu 2+ red phosphor layer was synthesized by the low temperature co-sintering and screen-printing techniques, which was experimentally demonstrated to replace the conventional polymer-based phosphor converter and realized the chromaticity tuning for LuAG:Ce 3+ phosphor with WLED. The Lu-PiG constructed WLED exhibited excellent thermal stability, but it still showed a typical cold white light resulting from the absence of red light component. Therefore, a stacking geometric configuration by screen-printing a red phosphor layer on the Lu-PiG substrate (R&Lu-PiG) was designed to solve red deficiency problem. The R&Lu-PiG color converter showed an excellent thermal stability with only 8.2% emission loss compared to the Lu-PiG when elevating temperature from 303 K to 433 K. By adjusting the CaAlSiN 3 :Eu 2+ phosphor content in the layer, we obtained a high-performance warm WLED with a luminous efficacy of 102.1 lm/W, a CCT of 3410 K and a CRI of 76.5 under 20 mA current driving. Thus, it is expected that this developed R&Lu-PiG color converters could have large potential applications in high-power warm WLED. [ABSTRACT FROM AUTHOR]

Currently, phosphor-in-glass (PiG) approach draws great attention because of its excellent thermal resistance and facile process in w-LED fabrication. However, the absence of red emissive component results in poor chromaticity quality, which greatly restricts its application in the high-quality indoor lighting. In the present work, a transparent garnet-based PiG was successfully prepared by introducing the Y 3 Al 4.5 Ga 0.5 O 12 :Ce 3+ (YAGG) green phosphor into TeO 2 -based glass matrix, and we demonstrated the possibility offered by the screen-printing technique for warm w-LED applications by coupling the PiG plate stacked with a red phosphor coating on commercial InGaN LED. The microstructures and luminescent properties of them were investigated in detail. After simply varying the red phosphor concentration as well as the YAGG PiG thickness, a facile chromaticity tuning for the thus-fabricated LED was achieved in the range changing from cool white to warm white. Moreover, this developed luminescent material presented an excellent heat-resistance performance. Hopefully, the red phosphor coated PiG color converter is applicable in the long-lifetime high-power color-tunable w-LEDs. [ABSTRACT FROM AUTHOR]

A pivotal step in providing a better fluorescent material that has high luminous efficacy and excellent thermal stability is to utilize inexpensive phosphors for white light-emitting diodes (W-LEDs). Herein, we demonstrate a feasible tape-casting technique for creating phosphor thick films that consist of Ce: YAG phosphor embedded in relatively low melting point glass frits on an ultrathin glass substrate with controllable film thickness. The glass matrix has ideal densification and interfaces with the glass substrate at a relatively low temperature of 580 °C. Subsequently, the structure and optical properties of the phosphor layer are investigated. In addition, the effect of the phosphor concentration, thick film thickness and location (top or bottom) of the phosphor layer on the photoluminescence properties and chromaticity are also discussed with respect to use in W-LEDs. Significantly, this promising structure has excellent thermal stability and the potential to overcome current limitations of phosphors in high-power W-LEDs. Finally, a high-performance W-LED based on the planar phosphor glass exhibits a luminous efficiency of 108.45 lm W −1 , a correlated color temperature of 5408 K and a color rendering index of 76. [ABSTRACT FROM AUTHOR]

In this work, a novel environmentally friendly strategy toward phosphor-converted WLED employing Ce:YAG-doped glass via single-step low-temperature co-sintering technology was successfully synthesized, using low-cost PbO–B 2 O 3 –SiO 2 –ZnO glass as host, which showed good sintering behavior and high visible transparency under the sintering condition of 750 °C without noticeable interaction with phosphors. By simply changing thermal condition, phosphor doped concentration and specimen thickness for the viscous sintering of phosphor in glass (PiG), optical characterization of WLED can be easily tuned. As a result, it can be found that the ideal thermal condition is sintered at 700 °C for 40 min, the optimal amount of phosphor powder is controlled to be 5 wt% of the final mixture, and the best suitable thickness of specimens is 0.8 mm. The constructed PiG based WLED exhibits a high luminous efficiency of 134.33 lm/W, and a correlated color temperature of 4696 K as well as a color rendering index of 68.5. Enhanced thermal quenching property of PiG compared to phosphor with conventional silicone resin reveals the prominent feasibility of the present glass ceramic material in WLED application. [ABSTRACT FROM AUTHOR]

This study outlines a general but convenient approach towards the synthesis of a Ce3+:Y3Al5O12 phosphor-in-glass (PiG) with a relatively low sintering temperature. A comparative study of the as-synthesized PiG and glass ceramic prepared using a conventional route was carried out to explore the structural, morphological and optical properties. In addition, the effect of phosphor concentration and the sintering temperature/time on the luminescence properties was systematically investigated. Notably, we fabricated a high-performance white LED based on PiG with a high luminous efficacy (125 lm W−1), low correlated colour temperature (4329 K) and colour rendering index of 68. Furthermore, the PiG material demonstrates an excellent thermal stability up to 150 °C, superior to the low thermal stability of conventional Ce3+:Y3Al5O12 doped silicone. Therefore, we present a transparent phosphor glass with desirable potential for application in high powered W-LEDs. [ABSTRACT FROM AUTHOR]

• Low toxicity Ca2+ was successfully incorporated into CsPbBr 3 and CsPbBr 1 I 2 NCs. • The PLQY of 40% Ca2+-CsPbBr 3 and 40% Ca2+-CsPbBr 1 I 2 NCs can reach 72.3% and 78.7%. • Ca2+ doping inhibits the non-radiative recombination rate of NCs. • Ca2+ doped NCs encapsulated in superhydrophobic aerogels have excellent stability. • The red-emitting CCPBI@AG-4 makes the CRI of the WLED as high as 92.2. All-inorganic halide perovskite nanocrystals (NCs) have become the most promising next generation luminescent materials due to their excellent properties. However, there are many nonradiative recombination defects in colloidal perovskite NCs, which reduce their luminescent efficiency and stability. In this work, we incorporated the alkaline-earth (AE) metal ion Ca2+ into NCs to further improve the photoluminescence quantum yield (PLQY) of CsPbBr 3 and CsPbBr 1 I 2 NCs. The PLQY of green-emitting CsPbBr 3 and red-emitting CsPbBr 1 I 2 NCs can be boosted to 72.3% and 78.7%, respectively by doping the optimum amount of Ca2+. At the same time, we adopted a simple and low-cost one-pot method to integrate Ca2+-CsPbX 3 (X 3 = Br 3 , Br 1 I 2) NCs and superhydrophobic silica aerogels (AG), not only retaining the high PLQY of NCs, but also greatly improving the water, heat and light stability. Finally, the green-emitting Ca2+-CsPbBr 3 @AG, red-emitting Ca2+-CsPbBr 1 I 2 @AG composites and the blue chip as the light sources show a wide color gamut that accounts for 129% of the NTCS 1953 value and nearly 100% of the Rec.2020 value. Additionally, we fabricated white light-emitting diode (WLED) devices by coupling Ca2+-CsPbBr 1 I 2 @AG composites with commercial YAG:Ce3+ phosphors on blue chips, obtaining bright white light with a color rendering index (CRI) up to 92.2. [ABSTRACT FROM AUTHOR]

It is an important challenge to select suitable color converters and apply them to laser diodes (LDs) lighting field. Sapphire plates are used as substrates for phosphor-in-glass films (PiFs) due to their ultrahigh thermal conductivity (∼ 30 W m−1 K−1). Herein, Y 3 Al 3.5 Ga 1.5 O 12 :Ce3+ (YAGG:Ce) phosphor mixing silicate glass powder is successfully sintered on sapphire plates to fabricate YAGG:Ce phosphor-in-glass film (PiF). The microstructure appearance and photoelectric characteristics of the efficient green color converter are studied in detail. In addition, it is worth noting that the maximum internal quantum efficiency of the prepared PiF is 92%, which is close to that of the original phosphor (98%). Meanwhile, the saturation threshold of YAGG:Ce PiF reaches 38.96 W/mm2 with luminous efficiency (LE) of 230.85 lm/W under the excitation of 460 nm blue LD. Notably, PiF has ultra-high power density while still maintaining such high LE. In order to highlight the application of this color converter in laser lighting, we assemble laser flashlights and fireflies lights. The test of the laser flashlight shows excellent performances such as high brightness, strong focusing effect and wide irradiation range. All indications manifest that YAGG:Ce PiF is an excellent green color converter. [ABSTRACT FROM AUTHOR]

We report the preparation of transparent Ce and Tb co-doped Y 3 Al 5 O 12 single crystal by the Czochralski method. The characterization of the resulting single crystal was accomplished by using X-ray powder diffractometer, scanning electron microscopy and energy dispersive X-ray spectroscopy. Absorption peak of the single crystal at about 460 nm has been obtained from ultraviolet–visible absorption spectrometer and their intensity is changed with different annealing condition. Its optical properties also have been investigated using fluorescence spectrometer. What’s more, its photoelectric parameters were studied by LED fast spectrometer. The constructed single crystal based white-light-emitting diode exhibits a high luminous efficiency of 140.89 lm/W, and a correlated color temperature of 4176 K as well as a color rendering index of 56.7, which reveal the prominent feasibility of the present single crystal material in white-light-emitting diode application. [ABSTRACT FROM AUTHOR]

Currently, the major commercial white light-emitting diode is the phosphor converted LED made of blue-emitting chip and Y 3 Al 5 O 12 :Ce 3+ yellow phosphor dispersed in organic silicone. However, the organic binder in high-power device ages easily and turns yellow due to accumulated heat emitted from chip, which adversely affects the device properties such as luminous efficacy and color coordination, and therefore reduces its long-term reliability as well as lifetime. In this mini-review article, we provide an overview of recent progresses in developing transparent inorganic glass–ceramics phosphors excitable by blue chip, as an alternative to conventional polymer-based phosphor converter, for construction of high-power white light-emitting diodes. Two kinds of synthesis routes, glass crystallization and low-temperature co-sintering, are discussed in detail. Afterwards, the materials design, structure/property optimization as well as glass–ceramic-based WLED devices construction are summarized. Finally, challenges and future advances for the realization of transparent glass–ceramics in commercial applications will be presented. [ABSTRACT FROM AUTHOR]

• HPSs@PVB films were successfully prepared. • HPSs possess superior optical performance after PVB coating. • The thermal cyclability, water and UV resistance of HPSs@PVB films are excellent. • The color gamut is as wide as 126% based on the high color purity HPSs@PVB device, reaching 94% of Rec. 2020. Here, polyvinyl butyral (PVB) films-protected CsPbBr 3 /Cs 4 PbBr 6 halide perovskite solids (HPSs) were successfully synthesized. The optical properties and structure of HPSs@PVB were studied, finding the photoluminescence quantum yields (PLQYs) of this novel composite material is as high as 60.4%. More importantly, HPSs@PVB has excellent thermal cyclability, water and ultraviolet (UV) resistance. In addition, HPSs@PVB was further applied to light emitting diodes (LEDs) and displays. By combining green-emitting HPSs@PVB and red-emitting CsPbBrI 2 NCs@PVB with InGaN 460 nm blue chip, white light emitting diode (WLED) device can be successfully fabricated. And the device exhibits good stability and the color gamut is as wide as 126%, reaching 94% of Rec. 2020. This work proposes a simple approach to solve the challenging stability issue of perovskite nanocrystals (NCs), having a positive implication for their practical application in LEDs and display backlights. [ABSTRACT FROM AUTHOR]

• Composite LuAG&CASN-PiGs have been successfully synthesized. • LuAG&CASN-PiG showed a high IQE of 87 % and EQE of 61 %. • A high quality white light (Ra＝95) in LD based on the PiG was achieved. • The LDs based on the PiG realized high laser saturation threshold (＞2.7 W mm−2). • The converted LDs with heat sink exhibited a superior LE of 216.79 lm W−1. The aim of this study is to investigate a thermally robust white color converter for high-power solid-state lighting, especially laser lighting. Lu 3 Al 5 O 12 :Ce3+/CaAlSiN 3 :Eu2+ phosphor-in-glass samples (LuAG&CASN-PiGs) were synthesized via a low temperature co-sintering technique. The prepared LuAG&CASN-PiGs exhibited remarkably high internal quantum efficiency of 87 %. Tunable warm white light-emitting diodes (wLED) were acquired by tailoring the sample thicknesses and phosphor contents. The optimized sample showed a high luminous flux of 183.68 lm under a blue laser diodes (LDs). In addition, the chromaticity of white LDs based on the LuAG&CASN-PiGs shifted from cool to warm white by changing the sample thicknesses. High quality white light in wLDs was achieved (Ra＝95). More importantly, the constructed LuAG&CASN-PiG converted LDs with a heat sink exhibited the luminous efficiency of 216.79 lm W−1. The results revealed that the prepared LuAG&CASN-PiG had great potential for application in solid-state laser light sources. [ABSTRACT FROM AUTHOR]

Abstract CsPbX 3 perovskite nanocrystals (NCs) are still limited in their use due to their extreme instability in the air as they will deteriorate in a few days, and their thermal stability is not optimistic. In this study, the red CsPbBr x I 3-x (X = 1.5, 1.0, 0.8, 0.5, 0.35, 0) NCs and Mn-doped CsPbBr x I 3-x NC in zinc borosilicate (B 2 O 3 -SiO 2 -ZnO) glass with cubic perovskite crystal structure were successfully synthesized through melt-quenching and heat-treatment method, which exhibited strong red emission in region of 572 nm–708 nm under 365 nm excitation. Additionally they are stable in the air for several months while showing excellent thermal stability. It is worth mentioning that Mn-doped CsPbBr x I 3-x NC glasses are brighter than CsPbBr x I 3-x NC glasses under UV light. Because Mn-doped CsPbBr x I 3-x NC glasses have good thermal and air stability, they can be used as a red fluorescent material. We fabricated glass with Y 3 Al 5 O 12 :Ce3+ (YAG:Ce3+) phosphor-in-glass (PiG) realized the chromaticity tuning for YAG:Ce3+ phosphor with white light-emitting-diodes (WLED). Highlights • Mn-doped CsPbBr x I 3-x NC glass with a strong red fluorescence. • The glass maintains the cubic perovskite crystal structure like NCs. • By changing the ratio of halogen, the emission band was tuned from 572 nm to 708 nm. • The glass overcomes the air instability and poor water resistant properties. • The glass can used as red phosphor and stacked on the Ce-PiG to achieve warm WLED. [ABSTRACT FROM AUTHOR]

Highlights • Sn-doped CsPbBr 3 QDs glasses were successfully synthesized by melt-quenching. • QDs glasses hold excellent luminescent properties while reducing toxicity. • The stability of Sn-doped CsPbBr 3 QDs glasses were greatly improved. • WLED based on Sn-doped CsPbBr 3 QDs glasses realized tunable CCT, CRI and CIE. Abstract CsPbX 3 (X = Cl, Br, I) quantum dots (QDs) are considered to be candidate materials for applications in the field of photoelectric devices due to their remarkable photoelectric properties, such as high photoluminescence quantum yields (PLQYs), narrow emission wavelengths and easy synthesis. However, their instability and high toxicity restrict the further development of QDs. Here, we synthesized Sn-doped CsPbBr 3 perovskite nanocrystals in borosilicate glasses (B 2 O 3 -SiO 2 -ZnO, BSZ) by traditional melt-quenching for the first time. The sample exhibited excellent air stability and thermal stability. Based on these results, white-light-emitting devices were fabricated by incorporating CsPb 0.64 Sn 0.36 Br 3 QDs glasses and commercial red phosphor (CaAlSiN 3 :Eu2+) into a blue LED device. The tunable color coordinates of (0.3179–0.3596, 0.3174–0.3665) and adjustable correlated color temperature (CCT) from 6119 K to 3128 K were successfully achieved in the white light area, which could promote the application of metal ion-doped perovskite QDs in photoelectric devices. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlight • Epoxy resins act as an encapsulant can solve the stability problem of quantum dots. • Epoxy resins also solve the problem of non-uniform luminescence. • CsPbBr 3 QDs in five different substrates has different luminescence is greatly related to the sizes effect. Abstract To research optical properties of materials for light-emitting-diodes (LEDs) fabrication, CsPbBr 3 quantum dots (QDs) were dispersed in five different substrates to investigate their luminescence. The results show that CsPbBr 3 QDs embedded in glass matrices have superior stability, however, the QDs could not be evenly distributed in the matrices, which resulted in uneven luminescence of the glass. To solve this problem, epoxy resin was introduced as cladding material, which yielded a product that had good stability and consistency. CsPbBr 3 QDs embedded in epoxy resin show great potential for green fluorescent components in LED applications. [ABSTRACT FROM AUTHOR]

Abstract In recent times, white-light emitting diodes (W-LEDs) have been widely used as light sources. However, most of the commercial lamps lack the red-light component. Herein, study on a novel blue-light activated alkaline earth ion doped Mn4+:Y 3 Al 5 O 12 (Mn4+:YAG) phosphor, exhibiting a strong red emission that is attributed to the Mn4+: 2E g →4A 2g spin-forbidden transition in the 650–750 nm spectral region, that can be excited by both near-ultraviolet and blue chips is presented. The dopants Be2+, Mg2+, Sr2+, and Ba2+ were found to be significantly beneficial for enhancing Mn4+ luminescence, the related mechanism is systematically discussed here. In addition, the concentration quenching is systematically investigated. The crystal field strength (Dq) and the Racah parameters (B and C) are carefully calculated. After incorporating Mn4+/Be2+:YAG phosphors (glass ceramics) and GaAG phosphors into a blue LED device, white light with a high color rendering index and a low correlated color temperature is successfully obtained. Therefore, the Mn4+/Be2+:YAG phosphor can serve as color converter for application in W-LED. Highlights • Luminescence of Mn4+YAG red phosphor was enhanced via alkali earth ion doping. • Mn4+/Be2+YAG GC was prepared via low temperature co-sintering technique. • Mn4+/Be2+YAG phosphors and GaAG phosphors into a blue LED device. [ABSTRACT FROM AUTHOR]

To achieve efficient phosphors that address the shortage of red emission for use in white light emitting diodes (WLED), a series of red-emitting phosphors of Sr 2 MgGe 2 O 7 doped with different concentrations of Mn 4+ have been successfully fabricated by a high-temperature solid-state method. The crystal structure properties including the phase purity were analysed by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Absolute quantum yield, temperature stability, and lifetime were utilized to characterize the samples. Furthermore, the excitation spectra of the samples exhibit two broad absorption bands with peaks located at approximately 308 nm and 419 nm, which could be excited by near-UV/blue LED light. The emission spectra range from 600 nm to 700 nm and exhibited a sharp peak at 659 nm due to the 4 E→ 4 A 2 spin- and parity-forbidden transition of Mn 4+ . The optimal Mn 4+ doping concentration in the Sr 2 MgGe 2 O 7 host is determined to be 0.7%. The critical energy transfer distance of these phosphors is calculated to be about 26.61 Å, and the concentration quenching mechanism is proved to correspond to a dipole-dipole interaction. The luminescence of the Sr 2 MgGe 2 O 7 :Mn 4+ phosphors decrease gradually with increasing temperature, and the Sr 2 MgGe 2 O 7 :Mn 4+ sample exhibits better thermal stability than the commercial Sr 2 Si 5 N 8 :Eu 2+ red phosphors. The warm WLED is fabricated by combining the Sr 2 MgGe 2 O 7 :0.7%Mn 4+ and YAG:Ce 3+ phosphor with a 420-nm blue LED chip to explore its possible applications in warm WLED. [ABSTRACT FROM AUTHOR]

The rare-earth-free Mn 4+ -activated oxide red phosphors draw great attention for their potential applications in the field of light-emitting diodes (LEDs). In this work, the red-emitting Mn 4+ /Zn 2+ :Y 3 Al 5 O 12 phosphor, showing strong red emission peaked at ∼ 672 nm as a result of the spin-forbidden 2 E 2g → 4 A 2g electron transition of Mn 4+ ions under 478 nm excitation, was synthesized by a traditional solid-state reaction route in air. The microstructure and luminescent performance of this red-emission phosphor was investigated in detail. From the experimentally measured spectroscopic data, the crystal field strength (Dq) and the Racah parameters B and C were calculated, respectively. In addition, Zn 2+ dopant was found to be beneficial for enhancing Mn 4+ luminescence. Subsequently, Mn 4+ /Zn 2+ :YAG glass ceramic was successfully prepared via using Mn 4+ /Zn 2+ :YAG phosphors incorporated into tellurate glass. A tunable lighting device was successfully achieved by coupling the red-emitting Mn 4+ /Zn 2+ :YAG GC with the commercial blue chips and Ce 3+ :Lu 3 Al 5 O 12 GC. [ABSTRACT FROM AUTHOR]

Metal-halide perovskites have been hailed as remarkable materials for photovoltaic devices and, recently, their star has also been on the rise in optoelectronics and photonics. Nevertheless, challenging issues, such as the thermal/chemical stability and high-performance devices with long-term stability, limit their practical applications. Here, we successfully prepared CsPbBr 3 NCs incorporated into mesoporous silica (NCs-MS) by a simple stirred of MS with CsPbBr 3 NCs blended in toluene solution. The resultant NCs-MS nanocomposite exhibit excellent optical performance and good thermal and photostability under illumination of UV light for 120 h. Additionally, NCs-MS nanocomposite is resistant to water, which are beneficial for the fabrication of white light-emitting diode (WLED) devices. Thereby a WLED was constructed by combining NCs-MS nanocomposite with Sr 2 Si 5 N 8 :Eu 2+ red phosphor on an InGaN blue chip, achieving a highly efficient luminous efficacy of 47.6 lm/W. Moreover, the WLED also demonstrate wonderful color stability under 120 mA current. This work opens up the exciting opportunity of using all-inorganic CsPbBr 3 NCs-MS nanocomposite for high performance and low-cost WLEDs applications. [ABSTRACT FROM AUTHOR]

All-inorganic CsPbX 3 (X = Cl, Br, I) perovskite quantum dots (QDs) have been investigated owing to their novel optical properties, such as the high photoluminescence (PL) quantum yields (QYs), narrow line-with and tunable wavelength. However, the usual CsPbX 3 QDs suffer from the instability and the anion-exchange reaction, which hinder their applications. In this work, we present an efficient approach towards stable solid-state QDs composites by coating the CsPbX 3 QDs with the mesoporous silica matrixes (QDs/silica). The as-prepared QDs/silica composite not only maintain the QDs remarkable optical properties, but also improve their stability. Meanwhile, the approach also prevents the anion-exchange reaction between perovskite QDs of various halide compositions mixed together in the solid-state. Therefore, these excellent properties enable the QD/silica composite to improve the color rending index (CRI) and the correlated color temperature (CCT) of the traditional phosphor-converted white light-emitting diodes (WLEDs). Herein, for the first time, the red QD/silica composite was used as red phosphor and stacked on the Ce 3+ :YAG phosphor-in-glass (Ce-PiG) via screen-printing technology (Ce-PiG&R-QDs/silica). Subsequently, warm WLEDs were constructed by blending the Ce-PiG&R-QDs/silica materials with the InGaN blue chips. More importantly, the constructed WLEDs generate a warm white with an optimal luminous efficacy (LE) of 56 l m/W, a high CRI of 92, R9 of 90 and a low CCT of 4718 K. These results indicate that the QD/silica composites would have potential practical applications in warm WLEDs. [ABSTRACT FROM AUTHOR]

Laser lighting technology has become a new star in the field of modern lighting. However, the thermal quenching of optical conversion materials occurs at high incident power density, so it is an urgent problem to improve their heat resistance. In this paper, a kind of Lu 3 Al 5 O 12 :Ce&CaAlSiN 3 :Eu2+ (LuAG&CASN) composite phosphor-in-glass (PiG) suitable for high power laser diode is prepared, which shows high brightness and high display. In addition, the graphene monolayer grown by chemical vapor deposition (CVD) is coated on the surface of LuAG&CASN-PiG to further improve the luminescence performance of PiG. The saturation power threshold of the graphene-PiG (G-PiG) sample can reach 4.5 W and the maximum output lumen flux can reach 317.95 lm when the system is excited with 450 nm blue light using the reflective structure. Compared with the samples without graphene coating, the luminescence efficiency of G-PiG was improved by 23.2%. This single-layer graphene surface coating method provides a new idea for the preparation of high-performance fluorescence conversion materials for laser lighting applications, which may play an important role in the future laser lighting. • Adding CASN phosphor, the chromogenic index of the sample was improved. • A single layer of graphene was coated on the surface of LuAG&CASN-PiG composites. • The graphene-PiG sample has a saturation power threshold of 4.5 W and a maximum output lumen flux of 317.95 lm. • Compared with the samples without graphene coating, the luminescence efficiency of G-PiG was improved by 23.2%. [ABSTRACT FROM AUTHOR]

It is high-profile that the use of phosphor-in-glass (PiG) is extensive because of its excellent advantages in thermal resistance and lifetime aspects, and so on. Here, white light-emitting diodes (WLED) based on LuAG:Ce 3+ PiG coated red-emitting K 2 SiF 6 :Mn 4+ (KSF) phosphors by screen-printing are fabricated. Among all of these, the commercial LuAG phosphors and glass raw materials of TeO 2 -based glass, were weighted and milled in an agate thoroughly. Then, the mixture was melted and sintered at 850 K or so for 20 min in the ambient atmosphere through low temperature co-fired method, cold-forming LuAG PiG clump and cut into different LuAG PiG thicknesses. After that, the commercial red phosphor KSF was coated on LuAG PiG by screen-printing technique. Finally, high-performance WLEDs based on the TeO 2 -based glass were obtained, tested and characterized, which exhibit a highest color rendering index of 94.1, a lowest color temperature of 3744 K and a largest luminous efficiency of 101.02 lm·W −1 . Most noticeably of all, the promising method has excellent developing potential for industrialization in high-power WLED. [ABSTRACT FROM AUTHOR]

A novel gold-carbon dots (GCDs) exhibiting relatively high luminescence have been successfully synthesized by a facile solution cast method. Intriguingly, colloidal Au nanoparticles (Au NPs) present an enhancement effect on the photoluminescence of CDs, which can be attributed to the metal enhanced fluorescence (MEF) included two cooperative mechanisms and near-field interactions. Significantly, the 1.5–3 fold enhancement was obtained in the vicinity of Au NPs. The formation mechanism and chemical structure of the as-prepared GCDs were verified by a series of characterization techniques, such as high-resolution transmission electron microscope (HRTEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The GCDs with optimal fluorescence was acquired by varying volume ratio of colloidal Au NPs to CDs, rendering bright visible light under 460 nm excitation and high quantum yield (QY) of 39%. Given that, a simple spin coating technology was developed for fabricating GCDs film composed of GCDs solution and quartz glass. Subsequently, GCDs-based white light emitting diodes (white LED) was designed through integrating blue LED chips with the yellow light-emitting GCDs film. In addition, the GCDs film at appropriate thickness possesses excellent optical performances with the corresponding optimized color coordinate (CIE) of (0.33, 0.36), the color rendering index (CRI) of 78.2, correlated color temperature (CCT) of 5653 K, and the luminous efficiency (LE) approaching to 43.75 lm W −1 . These superior results demonstrate that GCDs constitute a versatile and effective route for achieving high-performance white LED. [ABSTRACT FROM AUTHOR]

Currently, the non-rare-earth Mn 4+ -activated oxide red phosphor is of great interest as color converter for warm white light-emitting diodes (W-LEDs), owing to its admirable luminescent properties and low price. Herein, a novel blue-light activated Ca 14 Zn 6 Ga 10 O 35 :Mn 4+ (CZG:Mn 4+ ) phosphor, exhibiting strong red emission attributed to Mn 4+ : 2 E g → 4 A 2g spin-forbidden transition in region of 650–750 nm under 462 nm excitation, is successfully synthesized through a traditional solid-state reaction route in air. Subsequently, the microstructure and luminescent performance of this red-emitting phosphor are discussed in detail. The crystal field strength ( Dq ) and the Racah parameters ( B and C ) are carefully calculated to estimate the nephelauxetic effect of Mn 4+ suffering from the CZG host lattice. In addition, the concentration quenching and thermal quenching characteristics are also systematically investigated. After incorporating CZG:Mn 4+ and commercial Y 3 Al 5 O 12 :Ce 3+ (Ce:YAG) phosphors into a blue LED device, warm white light with high color rendering index and low correlated color temperature is successfully achieved. Therefore, the CZG:Mn 4+ phosphor can serve as color converter for use in warm W-LED applications. [ABSTRACT FROM AUTHOR]

In this paper, CsPbX 3 (X = Br, I) quantum dots glasses solid materials are fabricated based on the melting and heat-treatment methods. A series of characterization measurements are carried out to research the microscopic morphology and luminescent properties of solid materials. Finally, the multicolour light-emitting devices (LEDs) are constructed by adhesion commercial InGaN blue chip with as-prepared glasses. [ABSTRACT FROM AUTHOR]

Transparent Ce 3+ and Gd 3+ co-doped Y 3 Al 5 O 12 (Ce,Gd:YAG) single crystal (SC) was successfully grown by the Czochralski method. Meanwhile, the structures and optical properties of single crystal wafers (SCWs) were investigated. When Y 3+ ions were partially substituted by Gd 3+ ions, the emission peak shifted towards the long wavelength direction. Compared with commercial phosphors, SCWs not only showed excellent thermal stability, but also exhibited superior optical performance with a luminous efficacy of 144.11 lm/W, a correlated color temperature of 5639 K and a color rendering index of 69.9. [ABSTRACT FROM AUTHOR]

Highlights: [•] The quantum yield of the obtained ternary AgInS2 QDs was up to 62% with the emission peak of 642nm under the excitation of 460nm. [•] Colorful luminescent Ag–Zn–In–S QDs were obtained by adding Zn salts directly as well as Ag and In precursors. [•] The obtained highly luminescent quantum dots showed promising applications in the white light emitting diodes (W-LED). [•] The electroluminescence (EL) of AgInS2 QDs was observed in QD-LED device. [ABSTRACT FROM AUTHOR]

Abstract: The growth of Mn-doped YAG:Ce (yttrium aluminum garnet doped cerium) single crystal by the Czochralski (CZ) method and the characterization of its spectroscopy and color-electric parameters are presented. The absorption spectra indicate that the crystal absorbed highly in the 300–500nm wavelength range. The emission spectrum of the crystal consists of a peak around 538nm when excited by 460nm blue light, which prove the YAG:Ce,Mn single crystal could be used in the white light emitting doides (LED). The different charges of Mn ions have different luminescence properties, and the air annealing process for the single crystal would change the concentration of Mn ions with different charges, which could influence the emission intensity of the single crystal. [Copyright &y& Elsevier]

• β-Sialon-PiG have been successfully prepared and hold a good thermal stability. • β-Sialon-PiG has a high internal quantum efficiency of 72% after synthesis. • Under the 450 nm blue laser, higher luminous efficiency of 154 lm/W was obtained. • A high threshold of 363 lm of lumen flux was obtained for the sample under laser. [Display omitted] With the high demand of modern people for lighting quality, higher requirements have been put forward for the lighting technology. Compared with traditional light emitting diodes (LEDs), laser diode (LD)-driven lighting technology has more prominent advantages in the fields of industry, military and life. Here, we report a phosphor-in-glass (PiG) material formed by co-firing commercial β-Sialon:Eu2+ phosphor and SiO 2 -Na 2 CO 3 -H 3 BO 3 -CaO (SNBC) glass. It is found that the powder perfectly dispersed in the glass without obvious interface reaction. Fluorescence intensity of PiG sintered at 800 °C is the strongest, and the position of the luminescence peak is around 540 nm. Then through the analysis of different concentrations of PiG phosphors, it is found that the internal quantum efficiency (IQE) can reach 72%. The specific heat capacity decreases with the increase of temperature, indicating that the heat dissipation effect is fine. Under the blue LD irradiation of 450 nm, the luminous flux of the PiG sample reaches 363 lm and the high luminous efficiency of 154 lm/W. Our research found that the prepared β-Sialon-PiG can provide green light for high-power laser illumination and is a stable and efficient fluorescent conversion material. [ABSTRACT FROM AUTHOR]

• TS-1 with mesoporous structure are used as the carrier of perovskite firstly. • The hollow structure of TS-1 isolates the inner from the external environment. • TS-1 is one of the few materials with hydrophobic in molecular sieves. • The PLQYs of CsPbX 3 -TS-1 is excellent (up to 74%). • The matched WLEDs show luminous efficiency of 95 lm/W. CsPbX 3 (X = Br, I) quantum dots (QDs) have gradually become the star materials in light-emitting diodes (LED), but its stability has a big impact on development. Here, a variety of novel CsPbX 3 -TS-1 nanocomposites have been fabricated and the luminescence wavelength can be tunable by varying the halide nanocomposites (Br, I). What's particularly nice is that the original photoluminescence quantum yield (PLQY) of CsPbBr 1 l 2 QDs approaches 82% and it still has close to 74% after being combined with TS-1. Besides, the nanocomposites enhance stability resisting moisture, thermal stressing and light. In addition, a 460 nm InGaN blue chip, YAG:Ce3+ and CsPbBr 1 I 2 -TS-1 were equipped with white light emitting diodes (WLEDs), with a luminous effect of 95 lm/W, a color rendering index of 80, and a color temperature of 5144 K. Meanwhile, wide color gamut (116% of the National Television Standards Committee, 86.3% of the ITU-R Recommendation BT. 2020) and great chromaticity coordinate (0.3425, 0.3408) are realized. This is a very important step to open up the awkward situation of the practical application of perovskite QDs materials in LED. [ABSTRACT FROM AUTHOR]

[Display omitted] • Using OA to etch surface smooth original α-Al 2 O 3 wafer to make the surface appear pore structure. • The PL intensity of CsPbBr 3 @α-Al 2 O 3 composite material exposure to the air after 28 days can maintain over 50%. • The PLQY of CsPbBrI 2 @α-Al 2 O 3 composite material can reach 58%. • The colour purity of CsPbBr 3 @α-Al 2 O 3 and CsPbBrI 2 @α-Al 2 O 3 achieve 97.1% and 99.8%, respectively. • The prepared blue, green, red composites possess a wide color gamut of 114%. Recently, perovskite has received extensive attention due to their excellent photoelectric properties, while the instability of perovskite quantum dots (PQDs) has always troubled us. Herein, we proposed a simple coating mechanism to protect PQDs. Using oleic acid (OA) for etching α-Al 2 O 3 wafer to make the surface appear pore structure, and the PQDs was coated within the modified α-Al 2 O 3 wafer, thereby improving the stability of PQDs. The CsPbX 3 @α-Al 2 O 3 composite material can achieve the emission of blue-green–red (436 nm to 636 nm) through adjustable luminescence wavelength. The photoluminescence (PL) intensity of CsPbBr 3 @α-Al 2 O 3 composite material exposure to the air after 28 days can maintain over 50%. It is worth noticing that the photoluminescent quantum yield (PLQY) of CsPbBrI 2 @α-Al 2 O 3 composite material can reach 58%, the colour purity of CsPbBr 3 @α-Al 2 O 3 and CsPbBrI 2 @α-Al 2 O 3 achieve 97.1% and 99.8%, respectively. It was due to the high colour purity of the composite materials can the selected CIE colour coordinate monochromatic light encompassed 114% of NTSC colour gamut. Moreover, the warm white light-emitting diode (WLED) yielded bright natural white light and showed the luminous efficiency (LE) of 86.58 lm/W, colour rendering index (CRI) of 86.9, correlated colour temperature (CCT) of 4602 K. The LE and CRI reaches a relatively balanced value, which showed that this composite material has a certain development prospect in the WLED field. [ABSTRACT FROM AUTHOR]

Colloidal lead halide perovskite nanocrystals (NCs) have recently emerged as versatile photonic sources. However, their performance stability has been far from the requirements, and this type of material is toxic to the environment after degradation. In this paper, a hot injection strategy was used to prepare a CsPbX 3 perovskite NC solution, wherein the photoluminescence quantum yield (PLQY) of CsPbBrI 2 reached 78% and that of CsPbBr 3 was 63%. Then, CsPbX 3 NCs are successfully adsorbed on natural layered mineral pyrophyllite for improving heat, light, and water stability. Monodispersed CsPbX 3 NCs are evenly distributed on the surface of the pyrophyllite sheet in a high-density manner, which possibly originates from the electrostatic attraction effect of abundant anions on the surface of pyrophyllite to CsPbX 3 NCs. In a series of CsPbX 3 @pyrophyllite nanocomposites prepared, the PLQYs of green-emitting CsPbBr 3 and red-emitting CsPbBrI 2 were 47% and 29%, respectively. The materials were employed to fabricate white light-emitting diodes (WLEDs) with a wide color gamut of 117%. Importantly, because of the swelling and cation-adsorbent properties of pyrophyllite, the dissolution of lead in water was greatly reduced, which plays a certain role in ecological protection. [Display omitted] • CsPbX 3 @pyrophyllite were prepared for the first time with excellent stability. • The WLEDs made of CPX@pyrophyllite produce wide color gamut of 116.7% of NTSC. • Light efficiency and CRI of WLED made of CPX @pyrophyllite and Ce-YAG were above 80. • The Pb2+ overflow concentration in water was reduced to 1/107 of the colloid. [ABSTRACT FROM AUTHOR]

All inorganic CsPbX 3 (X = Cl, Br, I) perovskite quantum dots (QDs) have been widely reported. However, the poor stability of CsPbX 3 QDs limits their application in the field of optoelectronics. In this work, CsPbX 3 QDs were prepared by the hot injection strategy. We compounded CsPbX 3 QDs with mica to improve stability. A series of novel CsPbX 3 @mica composites with high thermal stability and light radiation stability were successfully fabricated and the narrow full width at half maximum (FWHM) of blue, green and red emissions are ~17 nm, ~21 nm and ~37 nm, respectively. What's more, the photoluminescence quantum yield (PLQY) of CsPbBr 3 @mica composite is 38.5%. Notably, the white light-emitting diodes (wLED) device can be manufactured by coupling the red-emitting CsPbBr 1 I 2 @mica composite material and commercial phosphor YAG: Ce3+ with the InGaN chip to produce bright natural white light. Meanwhile, CsPbX 3 @mica composites can be used as color conversion materials to construct a LED device, which exhibits a wide color gamut covering up 115.7% of National Television System Committee (NTSC). This present work provided novel CsPbX 3 @mica composites and could bring the potential inspiration in backlit display and lighting applications. [Display omitted] • The novel CsPbX 3 @mica composites with tunable emission in 468–630 nm were successfully fabricated. • The CsPbBr 3 @mica composite has excellent thermal and light irradiation stability. • The wLED can be manufactured by coupling CsPbBr 1 I 2 @mica and YAG:Ce3+ with InGaN chip to produce bright natural white light. • The CsPbX 3 @mica composites show a wide color gamut (115.7% NTSC). [ABSTRACT FROM AUTHOR]

All-inorganic cesium lead halide perovskite quantum dots (QDs) have attracted widespread attention due to unique photoelectric properties. However, blue-emitting (CsPbCl x Br 3−x , 0 < x ≤ 3) QDs have poor stability and low photoluminescence quantum yields (PLQY), which limits its application in perovskite based light-emitting diodes (LEDs). The chlorine-free CsPbBr 3 QDs have fewer crystal defects and a more stable crystal structure. Here, we prepared CsPbBr 3 QDs with adjustable photoluminescence (PL) (489–519 nm) by controlling the reaction temperature and composited it with natural mineral halloysite (Hal) nanotubes. The as-prepared CsPbBr 3 @Hal (100 °C) have high PL intensity, bright blue emission and enhanced stability. Under an open ambient condition, the CsPbBr 3 @Hal (100 °C) can still maintain 92.4% of original PL intensity after 60 days of storage. In addition, after 280 h of continuous irradiation with 365 nm UV lamp, its PL intensity still maintained 71%. Finally, a white LED (WLED) fabricated by incorporating the CsPbBr 3 @Hal (100 °C) and commercial red CaAlSiN 3 : Eu2+ phosphor on the 395 nm InGaN blue-violet chip showed the CIE chromaticity coordinates of (0.3358, 0.3331). This work provides a new way for the synthesis and application of blue-emitting CsPbBr 3 perovskite materials in WLEDs and display devices. [Display omitted] • Samples prepared at different temperatures have high PL intensity and stability. • The CsPbBr 3 @HNTs (100 °C) has bright blue emission and perfect stability. • The WLEDs made by CsPbBr 3 @HNTs produce high quality white light and are adjustable. [ABSTRACT FROM AUTHOR]

• The prepared multi-color PiGs has a high internal quantum efficiency approaching 90% of original phosphors. • The luminous efficacy of YAG:Ce-PiG reaches 239.3 lm/W, which is almost the best result in WLDs so far. • Kinds of cyan/green/yellow/red phosphors can be composited into an entire PiG frame and full-color emissions from 470 to 700 nm is realized in WLDs. • The ideal white light with a high color rendering index of 94 is obtained in WLDs. Phosphor-in-glass (PiGs) is one of the most important strategies to overcome thermal influence in high-power white light-emitting diodes and laser diodes. By carefully designing the glass composition of Na 2 O-CaO-B 2 O 3 -SiO 2 , the multi-color PiGs are successfully fabricated by a single-step co-sintering strategy at a relative low temperature (850 °C), most of PiGs maintain a high internal quantum efficiency approaching 90% of original phosphors. Under the 450 nm blue laser diodes (LDs) excitation, the luminous efficacy of YAG:Ce-PiG reaches 239.3 lm/W, which is almost the best result in white laser diodes (WLDs) so far. Outstandingly, the designed glass overcomes the oxidation, corrosion and decomposition of commercial nitride red phosphors, and realizes broadband emission from 500 to 700 nm by compositing red/yellow/green phosphors in an entire glass. Correspondingly, this work paves the way to achieve ideal white light with a high color rendering index of 94 in WLDs. [ABSTRACT FROM AUTHOR]

• Gd-doped CsPbBrI 2 NCs were successfully prepared in borosilicate glass matrix. • CsPbBrI 2 NCs@glasses possess superior optical performance through Gd3+ doping. • The water / thermal / light stability of Gd-doped CsPbBrI 2 NCs@glasses are excellent. • High-performance WLEDs was assembled successfully by Gd-doped CsPbBrI 2 NCs@glasses. Here, Gd-doped CsPbBrI 2 nanocrystals (NCs) in borosilicate glass (B 2 O 3 -SiO 2 -ZnO) were successfully synthesized by the traditional melting quenching method. The optical properties of CsPbBrI 2 NCs@glasses at different heat treatment temperatures and the content of Gd3+ were studied. It is found that CsPbBrI 2 NCs@glasses have greatly improved photoluminescence quantum yields (PLQYs) after doping (form 15.3% to 37%) and excellent hydrothermal and light stability. In addition, a white light emitting diode (WLED) was successfully prepared by combining Gd-doped CsPbBrI 2 NCs@glass and Ce3+: YAG phosphors with the blue light emitting diode (LED). After a series of adjustments, the high performance WLED device with a chromaticity coordinate (CIE) of (0.3340, 0.3386), luminous efficiency (LE) of 90.09 lm/W, correlated color temperature (CCT) of 5430 K and the color rendering index (CRI) of 81.4 was fabricated. This work provides a new strategy in the field of metal ion doped perovskite NCs for future reference and has potential applications in LEDs. [ABSTRACT FROM AUTHOR]

• High quality CaAlSiN 3 :Eu2+ PiGs have been successfully synthesized. • CaAlSiN 3 :Eu2+ PiGs presented a higher EQE of 53% and better thermal stability. • The wLEDs with high CRI/LE were assembled successfully based on CaAlSiN 3 :Eu2+ PiGs. • The LDs based on CaAlSiN 3 :Eu2+ PiGs realized enhanced laser saturation threshold. CaAlSiN 3 :0.2%Eu2+ (CASN:Eu2+), an excellent red phosphor, plays a leading part in wide color gamut and high color rendition white light-emitting diodes (wLEDs). However, this phosphor or silicone resin mixture possesses a fatal defect of an intrinsic low thermal performance, which makes it hardly useful in high-power laser lighting and displays. Here, to improve the thermal performance of the CASN:Eu2+ phosphor, a series of red-emitting phosphor-in-glass materials (R-PiGs) with different CASN:Eu2+ concentrations (5–50 wt%) and sintering temperatures (750–850 °C) were successfully synthesized by dispersing the CASN:Eu2+ phosphor into a B 2 O 3 -Na 2 O-SiO 2 -CaO glass matrix. Surprisingly, the prepared R-PiGs showed a high external quantum efficiency (EQE) of 53%, and still maintained 82% efficiency compared with the CASN:Eu2+ phosphor (65%). The R-PiGs are superior to red ceramics for low cost and rapid batch preparation. Considering the densification of the R-PiGs, a systematic study was conducted on 10 wt% R-PiG sample. A facile chromaticity tuning for the configured wLEDs was obtained within the color range change from cool white to warm white when using the R-PiGs with different CASN:Eu2+ concentrations. Besides, we have successfully assembled a warm wLED with high luminous efficacy (90.3 lm/W) and color rendering (Ra = 94.2 and CCT = 5053 K). When irradiated by a blue laser, an optimized R-PiG can show enhanced luminous flux (49.27 lm) at a high laser incident power of 1.90 W/mm2. Therefore, with their excellent performances, R-PiGs are highly promising for use as red color converters for potential applications in tunable wLEDs and high-power laser lighting. [ABSTRACT FROM AUTHOR]