All-inorganic CsPbBr 3 perovskite quantum dots (PQDs) exhibit excellent photoelectric properties and application prospects in the field of lightemitting diodes (LEDs) and display devices. However, these possess poor long-term stability to UV irradiation, water, heat, and oxygen. Using polymethyl methacrylate (PMMA) as the matrix along with CH 3 (CH 2 ) 16 COOCs, [CH 3 (CH 2 ) 16 COO] 2 Pb, and KBr as the perovskite sources, CsPbBr 3 PQDs/ PMMA composites are for the first time prepared via an in situ polymeric melt encapsulation method. Special attention is paid to the effects of synthesis conditions on the photoluminescent quantum yield (PLQY) of the composites. The optimized CsPbBr 3 PQDs/PMMA composite reveals excellent performance with ≈82.7% PLQY and ≈18.6 nm full width at a half-maximum (FWHM). In particular, after 90 h of UV irradiation or 35 days of heating at 60 °C, the luminous intensity remains almost unchanged. In addition, after soaking in water for 15 days, it retains up to ≈53% of the initial luminous intensity, meaning that the composite possesses long-term stability to UV irradiation, heat, and water. The as-prepared white LED (WLED) based on the composite evidences the wide color gamut (126.5% National Television System Committee (NTSC)) and a luminous efficiency of 32 lm W −1 . This work offers a novel, easily industrialized one-step, and solvent free route for lowtemperature synthesis of all-inorganic PQDs with broad application prospects.

As the core component of this emerging field, the broadband NIR light source needs to be small and exquisite to meet the application requirements. Compared with traditional broadband NIR light sources such as the bulky tungsten-halogen lamps, broadband NIR phosphor-converted light-emitting diodes (NIR pc-LEDs) is proposed as an ideal compact light source due to their advantages of environmental protection, energy-saving, long lifetime, and small size. [2] The strategy of NIR pc-LEDs is mainly realized by coating broadband NIR phosphor on a blue LED chip. Among them, one of the important research topics is the exploration of broadband NIR phosphors that can be excited by blue light.Cr 3+ ion with d 3 electron configuration is the commonly used activator for NIR emitting phosphors. When it's located in a weak octahedral crystal field in a host, broadband NIR emission can be obtained due to the 4 T 2 → 4 A 2 transition. [3] The Cr 3+ -doped garnet phosphors are a typical broadband NIR luminescent material, showing high quantum efficiency and robust thermal stability. For example, Ca

Perovskite quantum dots are emerging as new generation functional materials for display applications. The issue of perovskite “red wall” has been an obstacle for their use in display technology. In this study, the fabrication of γ‐RbxCs1–xPbI3 gradient‐alloyed quantum dots in polymeric matrix through a rational designed in situ fabrication process is reported. The formation of γ‐RbxCs1–xPbI3 gradient‐alloyed structure can be explained by considering the lattice mismatch and solubility difference between γ‐CsPbI3 and RbPbI3. The photoluminescence emission of γ‐RbxCs1–xPbI3 gradient‐alloyed quantum dots can be tuned from 675 to 620 nm with full width at half maximum of 31 nm and maximum quantum yields up to 91%. Importantly, the packaged films retained about 95% of its original photoluminescence intensity after 1000 h aging at the test conditions of 60 °C, 90% RH and 40 °C, 90% RH with 3 mW cm−2, 455 nm blue light irradiation, respectively. By integrating a red and green dual emissive film with blue Mini LEDs, a LCD backlight of a color space of ≈130% of NTSC 1931 standard is achieved with matching rate of 100%.

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