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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]

In this study, a simple low‐temperature self‐assembly strategy is used to synthesize the CsPbBr3/Cs4PbBr6 nanocomposite with a relatively high photoluminescence quantum yield (PLQY, 72%) and product yield (87%). As expected, the nanocomposite exhibits good photoluminescence (PL) performance and stability. Further, 90% of the PLQY is maintained even when heating at 100 °C for 24 h, and almost no emission degradation is observed after storage in ethanol for 10 days. Furthermore, the prepared CsPbBr3/Cs4PbBr6 nanocomposite exhibits the reversible luminescence phenomenon by simply applying the wetting and drying process. This abnormal phenomenon is due to the internal phase transformation of the CsPbBr3/Cs4PbBr6 nanocomposite. The potential application of the nanocomposite in anti‐counterfeiting has been demonstrated. This work facilitates the production and application of inorganic metal halide perovskite‐based functional materials. [ABSTRACT FROM AUTHOR]

All-inorganic CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (NCs) are the most promising next generation photoelectric materials owing to their excellent properties. Although embedding perovskite NCs into a glass matrix improves their stability, different applications require perovskite nanocrystal glasses (PNGs) with different properties. In this work, we controlled the network structure of the precursor glass by changing the content of ZnO (3.8–11.4 mol. %) in the raw materials, thus inhibiting the direct precipitation of CsPbCl2Br NCs in the glass (i.e., the self-crystallization process), and obtained samples with local emission and high transmittance. In addition, we incorporated rare-earth (RE) Yb3+ into a CsPbCl2Br PNG to achieve efficient ultraviolet (UV) to near-infrared quantum cutting emissions and boost the UV response of silicon photodetectors (PDs). Finally, after combining the Yb3+-doped CsPbCl2Br PNG on the Si PDs, the responsivity of the latter increased to 0.014 A/W at 320 nm, which is 14 times higher than that of the bare Si PDs. Moreover, Si PDs based on Yb3+-doped CsPbCl2Br PNG exhibited excellent photocurrent stability. [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]

Perovskite nanomaterials have attracted significant attention in the field of nanoscale laser field, however, poor environmental stability is the biggest challenge that restricts their applications. In this study, an in situ synthesis method was used to encapsulate CsPbBr3 nanocrystals (NCs) in titanium silicalite molecular sieve (TS-1). Owing to the hollow structure and the hydrophobicity of the TS-1, the hydro and thermal stabilities of the perovskite NCs were significantly improved. Using AB glue, we prepared thin films using a one-step spin coating method, and synthesized highly compact and smooth CsPbBr3 nanocomposite thin films. Amplified spontaneous emission (ASE) was achieved with a low-threshold under two-photon excitation at room temperature, and a stable emission under continuous intense laser shots in an ambient atmosphere was maintained. The influence of the perovskite concentration and calcination temperature on the ASE threshold was also investigated. This study will significantly broaden the application of perovskite nanocrystals in practical nonlinear optical devices. [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]

Currently, high optical purity, perfect stability, and high photoluminescence quantum yield (PLQY) are very important, being the key to obtain high‐quality luminescent materials. The research of perovskite nanocrystals (NCs) as optical materials is in full swing. Nevertheless, the low PLQY value, especially for the red‐emitting perovskite NCs, is a main obstacle to applications in display. This work reports the optimized components to synthesize CsPb(Br/I)3 NCs glasses whose PLQY achieves a big boost from 15.4% to ≈60% for the first time. Furthermore, the specimens exhibit exceptional tolerance to water and thermal and hence contribute to applicability in high‐performance light‐emitting diode (LED) and 3D printing. By combining CsPb(Br/I)3 NCs glass powder and yttrium aluminum garnet (YAG):Ce phosphor with blue chips, the assembled white LEDs reach a high luminous efficiency at 113.0 lm W−1. The resulting high PLQY is to the benefit of a substantial step toward the practical application of inorganic perovskite materials in the fields of optoelectronic devices and additive manufacturing. [ABSTRACT FROM AUTHOR]

Lead halide perovskite CsPbX3 (X = Cl, Br, and I) nanocrystals (NCs) are widely used in the newest generation of lighting display equipment because of their excellent optical properties. However, their poor stability remains an urgent issue to overcome. Encapsulation has become a significant and effective strategy to promote the stability of perovskite NCs, particularly by the package coating of polymer and porous materials. Herein, a simple two-step encapsulation strategy is adopted to fabricate CsPbBrI2@zeolite/PMMA composite films to replace the previous preparation methods of perovskite films. A highly efficient and stable red-emitting material with great colour purity and excellent PLQY of ∼53.9% is manufactured by this simple and effective packaging method. Furthermore, because of the first-encapsulation with zeolite, the CsPbBrI2@zeoite/PMMA composite films not only reduced the agglomeration of NCs but also obtained better optical performance and environmental stability compared to that of pure CsPbBrI2/PMMA. Ultimately, WLEDs constructed by the red-emitting CsPbBrI2@zeolite/PMMA composite material achieve an outstanding colour rendering index, luminous efficiency and correlated color temperature (CRI = 94.5, LE = 77.22 lm W−1 and CCT = 5354 K), and realize tunable colour coordinates of (0.3359–0.32912, 0.3455–0.3336) in the white light area, implying that CsPbBrI2@zeolite/PMMA is very promising for obtaining a high CRI of WLEDs instead of traditional phosphor. The facile two-step encapsulation method proposed in this study provides a prospect for obtaining high-quality perovskites. [ABSTRACT FROM AUTHOR]

By increasing the heat treatment temperature, the average size of CsPbBr3 quantum dots (QDs) in the glass matrix was increased, which contributed to a 5.5 fold increase of the optical gain coefficients. And the corresponding lasing threshold decreased from 0.752 mJ cm−2 to 0.138 mJ cm−2. [ABSTRACT FROM AUTHOR]

In this report, a mixed‐metal cation‐based halide perovskite (HP) CsPb1−xTixBr3 quantum dots (QDs) were first embedded in the B–Si–Zn glasses using a traditional approach of melt quenching and heat treating. A battery of test results such as photoluminescence, X‐ray diffraction, and time‐resolved attenuation prove that Ti ions do not destroy the properties of CsPbBr3, and they are successfully doped into CsPbBr3. At the same time, the doping of Ti ions also reduces the toxicity of lead. By altering the ratio of Pb/Ti, we determined the optimum ratio of CsPb0.7Ti0.3Br3 QDs through experimental data. Due to the excellent optical properties and stability of CsPb0.7Ti0.3Br3 QDs glass, it was designed to construct the white‐light emitting diode device with tunable color coordinate, color rendering index, correlated color temperature, and a high luminous efficiency compared with CsPbBr3 QDs glass, which may be a promising candidate for the field of lighting and displays. [ABSTRACT FROM AUTHOR]

All-inorganic cesium lead halide perovskite CsPb2Br5 nanocrystals (NCs) have attracted tremendous attention owing to their unique optoelectronic properties. However, their tolerance to atmospheric moisture is limited by their corresponding poor stability, which has drastically prevented the broad application of the materials in lasers, light-emitting diodes (LED) and, most recently, photocatalysis. To address this issue, we have successfully demonstrated the design and synthesis of a nanocomposite material, CsPb2Br5 NCs coated in mesoporous silica (NCs-MS), with high photoluminescence (PL) intensity, bright emission and enhanced water stability, thermal stability and photostability versus naked CsPb2Br5 NCs. The components and structure of the prepared CsPb2Br5 NCs-MS nanocomposite were investigated in detail by PL, XRD, TEM and HAADF-STEM studies. Furthermore, the mechanism behind the outstanding stability and optical properties of the prepared NCs-MS nanocomposite is discussed. Owing to the ultrahigh stability of the NCs-MS nanocomposite, the white LED (WLED) assembled by coating the CsPb2Br5 NCs-MS nanocomposite and commercial red CaAlSiN3:Eu2+ phosphor powder on an InGaN blue chip showed CIE chromaticity coordinates of (0.3377, 0.3309) and presented excellent optical parameters with a CRI of 82.9, a CCT of 5035 K and an LE of 64.9 lm W−1. This work provides a new pathway for the synthesis and application of all-inorganic cesium lead halide perovskite materials in WLEDs and display devices. [ABSTRACT FROM AUTHOR]