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Abstract Mechanoluminescence (ML) sensing technologies open up new opportunities for intelligent sensors, self-powered displays and wearable devices. However, the emission efficiency of ML materials reported so far still fails to meet the growing application requirements due to the insufficiently understood mechano-to-photon conversion mechanism. Herein, we propose to quantify the ability of different phases to gain or lose electrons under friction (defined as triboelectric series), and reveal that the inorganic-organic interfacial triboelectricity is a key factor in determining the ML in inorganic-organic composites. A positive correlation between the difference in triboelectric series and the ML intensity is established in a series of composites, and a 20-fold increase in ML intensity is finally obtained by selecting an appropriate inorganic-organic combination. The interfacial triboelectricity-regulated ML is further demonstrated in multi-interface systems that include an inorganic phosphor-organic matrix and organic matrix-force applicator interfaces, and again confirmed by self-oxidization and reduction of emission centers under continuous mechanical stimulus. This work not only gives direct experimental evidences for the underlying mechanism of ML, but also provides guidelines for rationally designing high-efficiency ML materials.

Abstract Lead‐free halide perovskites possess excellent photoelectric properties, making them widely used in the photoelectric fields. Herein, lead‐free double perovskite crystals (PCs) doped with manganese (Cs2NaInCl6:Mn2+) are successfully prepared by the more energy‐efficient crystallization method. The crystals emit bright orange‐red light under the ultraviolet (UV) lamp, showing unique optical properties. They have the highest photoluminescence quantum yield of 42.91%. The white light‐emitting diodes (LEDs) are fabricated using these perovskite crystals, which show a color rendering index of 92 and external quantum efficiency (EQE) as high as 16.3%. Furtherly, perovskite‐modified fiber paper made of aramid chopped fibers (ACFs) and polyphenylene sulfide (PPS) exhibited fluorescent properties under different conditions. This paper combines fiber composite technology with PPS fiber filter bags, which are widely used in environmental protection, for the first time and demonstrates functional fiber filter bags with fluorescent characteristics. This filter bag provides an idea for the automatic detection of industrial filtration. Meanwhile, after being exposed to industrial waste gas for 60 h, the filter bag can maintain superior fluorescence performance. In this study, lead‐free double perovskites are synthesized using an efficient method for preparing high‐performance LEDs and high‐stability fluorescent fibers. Concurrently, the application of perovskites in environmental protection is expanded.

Ba2La2.85-xTb0.15Smx(SiO4)3F (BLSOF:0.15Tb3+,xSm3+) is a polychromatic phosphor with an apatite structure that was manufactured through a solid-state process. X-ray diffraction (XRD) and a scanning electron microscope (SEM) were utilized to examine the phosphor's phase and morphology. Using the Rietveld technique, the as-prepared phosphor structure was validated. By progressively raising the doping contents of the samarium, the phosphors emitted multicoloured luminescence from short to long wavelengths as indicated by analysis of the optical performance. Overall, the data provide strong evidence that the transfer of energy in BLSOF:0.15Tb3+,xSm3+ is responsible for the phosphor's colour-tunable property.

Phosphors with apatite structure have shown potential applications in solid-state lighting and display industry due to their flexible crystal structure, controllable chemical composition and different crystallographic positions of single doped or co-doped RE ions. The study of natural luminescent apatites play an important role in the development of new apatite phosphors. In this paper, we reviewed the recent progress in the study of apatite phosphors, including our study of some natural apatites and enlightenment gained, research progress in single-doped apatite structure luminescent materials, color tunable single doped apatite luminescent materials, color tuning through energy transfer and density functional theory calculation in apatite-type phosphor study. Our purpose is to demonstrate the way of developing phosphors of natural luminescent minerals. Based on the current progress, we put forward the research prospects of apatite phosphors.

Whitlockite has the advantages of a low sintering temperature, high stability, and a low fabrication cost, and it is widely used as the host for luminescent material. In this study, Ca1.8Li0.6La0.6−x(PO4)2:xDy3+ phosphor was prepared by the high-temperature solid-state method, and its structure, composition, and luminescence properties were systematically studied. The results showed that a new whitlockite type matrix was prepared by replacing Ca2+ in whitlockite with monovalent and trivalent cations. The prepared phosphors belonged to a hexagonal crystal system with a particle size in the range of 5–20 μm. Under the excitation of 350 nm UV light, the samples emitted white light, and there were mainly two stronger emission peaks at 481 nm in the blue band and 573 nm in the yellow band, which correspond to the electron transitions at 4F9/2→6H15/2 and 4F9/2→6H13/2 of Dy3+, respectively. The optimal doping concentration of Dy3+ in Ca1.8Li0.6La0.6(PO4)2 matrix was 0.03 (mol%). The main mechanism of concentration quenching in the sample was dipole–dipole energy transfer. When the temperature was 130 °C, the luminescence intensity of the samples was 78.7% of that at 30 °C, and their thermal quenching activation energy was 0.25 eV. The CIE coordinates of the sample at 30 °C were (0.2750, 0.3006), and their luminescent colors do not change with temperature. All the results indicate that Ca1.8Li0.6La0.6−x(PO4)2:xDy3+ phosphor is a luminescent material with good luminescence performance and thermal stability, which shows a promising application in the field of LED display.

The development of single-component high-quality warm white light-emitting phosphors is a research hotspot and key in the field of white light illumination. In this paper, a series of Ca8ZnGa0.4La0.6 (PO4)7:xEu2+, yMn2+ solid solutions were prepared based on resonance energy transfer to achieve a controlled tuning of the emission color from blue-green to red, and a single-phase white-light-emitting phosphor Ca8ZnGa0.4La0.6(PO4)7:0.003Eu2+,0.02Mn2+ was obtained. The doping of Mn2+ leads to the rearrangement of Eu2+ at different cation positions, while the sensitization effect of different emission peaks of Eu2+ on Mn2+ was inconsistent, and the contribution of the 490 nm emission peak was greater. In addition, the thermal stability properties of the different emission peaks of Eu2+ differed due to different thermal ionization probabilities, and the Mn2+ emission centers showed better thermal stability properties as the non-radiative relaxation between Eu2+ and Mn2+ was enhanced with increasing temperature. Finally, the Ca8ZnGa0.4La0.6(PO4)7:0.003Eu2+,0.02Mn2+ phosphor-converted WLED exhibited a high quality warm white light emission with an ultra-high color rendering index (Ra = 94.7) and a suitable CCT value (4277 K) at an operating current of 300 mA. [ABSTRACT FROM AUTHOR]