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Schematic illustration of energy transfer from the STE excitons, deep traps, and shallow traps to Mn2+. This simply and clearly explains the phenomenon of abnormal luminescence at high temperatures.

Broadband emission with a large Stokes shift is important to obtain an excellent color rendering index of the solid-state lighting device. Among low-dimensional material and perovskite-like phosphors with broadband self-trapped emission, Sn-based phosphors have attracted much attention due to their high photoluminescence quantum yield (PLQY). However, the disadvantage is that the synthesis of Sn-based phosphors needs to be performed in a glovebox. Upon photoexcitation, the broadband emission of self-trapped excitons results from exciton-phonon coupling induced by the transient distortion of the lattice. Low-dimensional material structures often promote self-trapped emission because of more vibrational degrees of freedom and easier polarization under photoexcitation. Here, zero-dimensional (0D) SnX

A near-infrared emitting phosphor-converted light-emitting diode (NIR pc-LED) attracts much attention for its promising applications in night vision, biosensors, food composition and freshness measurement areas and so on, while the discovery of broadband NIR phosphors remains a challenge. Herein, an efficient broadband NIR-emitting Ca2YHf2Al3O12:Cr3+ (CYHA:Cr3+) garnet phosphor is successfully developed. Under 460 nm light excitation, the developed Ca2YHf2Al3O12:Cr3+ (CYHA:Cr3+) shows broadband NIR emission from 650 to 1000 nm peaking at ∼775 nm, with a full width at half maximum (FWHM) of ∼137 nm, an internal quantum efficiency (IQE) of ∼75%, and good thermal stability (I423k ∼ 80%). To further improve and tune the photoluminescence (PL) properties of Cr3+-activated CYHA, a strategy of energy transfers (ETs) is designed in CYHA. Through the ET of Ce3+ → Cr3+, the absorption of Cr3+ can be effectively enhanced. Utilizing the Cr3+ → Yb3+ ET, the spectral intensity of Yb3+ is obviously strengthened and the NIR emission bandwidth is broadened. In addition, Yb3+-codoping improves the thermal stability from ∼80% to ∼90% at 423 K, principally originating from the efficient ET from Cr3+ to more thermally stable Yb3+ emitters. Here, ETs of Ce3+ → Cr3+, Ce3+ → Yb3+, Cr3+ → Yb3+, and Ce3+ → Cr3+ → Yb3+ in CYHA are systematically analyzed based on PL lifetime and ET mechanisms are proposed. Finally, as-fabricated NIR pc-LED combining CYHA:Cr3+,Yb3+ with a blue LED chip, gives a maximum NIR output power of ∼18 mW at a drive current of 100 mA. These results indicate the great potential of CYHA:Cr3+ phosphor in NIR pc-LED applications.

The combination of a broadband near-infrared (NIR) phosphor and phosphor-converted light-emitting diodes (pc-LEDs) has proven to be an ideal choice for a high-efficiency NIR light source. Here, a garnet-type NIR Ca2LaHf2Al3O12:Cr3+ phosphor is obtained and its emission covered most of the NIR spectral range. Excited by 460 nm blue light, the maximum peak was located at 780 nm with a full width at half maximum (FWHM) of ∼141 nm and an internal quantum efficiency (IQE) of 33%. Moreover, the NIR spectra can be broadened by doping Yb3+ into the Ca2LaHf2Al3O12:Cr3+ garnet phosphor. A super broad FWHM of 300 nm and reduced thermal quenching were acquired, originating from the energy transfer of Cr3+→ Yb3+. The energy transfer process of Cr3+ and Yb3+ is described by means of an energy level diagram and time-resolved spectrum. Finally, a NIR pc-LED is fabricated by combining the Ca2LaHf2Al3O12:Cr3+,Yb3+ phosphor with blue chips, which has a photoelectric conversion efficiency of 10%. These results demonstrate the great potential of Ca2LaHf2Al3O12:Cr3+,Yb3+ in super broadband NIR pc-LED applications.

Lead-free double perovskites have recently received increasing attention due to their variable band gap. In this work, tin was doped into Cs2BiAgCl6 successfully. The doping of Sn2+ cations can make the weak white luminescent host to produce pure blue emission peaking at around 464 nm. The internal carrier changes after Sn2+ doping and the origin of blue emission in Cs2BiAgCl6:Sn2+ was analyzed by ultrafast transient absorption (TA) techniques and time-resolved spectra. To further study the substitution feasibility of Sn2+–Sn4+ for Bi3+–Bi3+ pair cations, Rietveld refinement and density functional theory (DFT) calculations were performed, which proved that the crystal structures of Cs2BiAgCl6:Sn2+ can exist stably. Based on these observations, we introduced blue-emitting Cs2BiAgCl6:Sn2+ powder into a white LED fabricated by combining a 340 nm chip to generate stable white light with CIE coordinates of (0.31, 0.34) and a color rendering index value of 83. This work provides the methods to develop environmentally friendly blue emission from lead-free double perovskites at low cost.

The stability of perovskite quantum dots (PQDs) plays a vital role in practical devices. Besides silica coating, embedding PQDs in zeolites is another strategy to improve their stability significantly. Although the zeolite rigid framework has been reported to protect PQDs, there are few reports on the in situ synthesis of PQDs in zeolites. In this work, cubic phase CsPbX3 (X = Br, I) nanocrystals were successfully prepared by the ion exchange method combined with a non-polar organic trigger. Dropping a certain amount of ZnM2 (M = Br, I) solution into the intermediate product Cs4PbCl6 nanocrystals resulted in the formation of the final CsPbX3 nanocrystals. The ZnM2 solutions were prepared in non-polar solvents (hexane, octane, or chloroform). The highest photoluminescence quantum yield (PLQY) of the synthesized CsPbX3@zeolite composites can reach 83%, with a lifetime of 1.37 μs. The stability of the CsPbX3@zeolite composites thin film against damage from air and light is significantly improved. We fabricated white light-emitting diodes (WLEDs) using CsPbBr3@zeolite as the green light source and CsPbI3@zeolite as the red light source to further emphasize the practical application effect of the CsPbX3@zeolite composites. This work not only provides a new method for the synthesis of CsPbX3 nanocrystals but also involves the in situ synthesis of high stability CsPbX3@zeolite composites within the zeolite.

Dual-emitting manganese ion doped LaM1-xAl11-yO19 (M = Mg, Zn) phosphors were prepared by substituting Zn2+/Mg2+ with Mn2+ and replacing Al3+ with Mn4+. The LaM1-xAl11-yO19:xMn2+,yMn4+ phosphors show a narrow green emission band of the Mn2+ ions at 514 nm and a red emission band of the Mn4+ ions at 677 nm. In addition, the thermal stability of luminescence shows that the response of Mn2+ and Mn4+ to the temperature is obviously different in LaMAl11O19, implying the potential of the prepared phosphors as optical thermometers. The decay lifetime of Mn4+ was changed with temperature due to the different fluorescence intensity ratios of Mn2+ and Mn4+, and a dual-mode optical temperature-sensing mechanism was studied in the temperature range of -50-200 °C. The maximum relative sensitivities (Sr) are calculated as 3.22 and 3.13% K-1, respectively. The unique optical thermometric features demonstrate the application potential of LaMAl11O19:Mn2+,Mn4+ in optical thermometry.

In recent years, the demand for near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) has increased rapidly, leading to more and more attention being paid to the research of broad-band near-infrared phosphors. In this work, Cr3+-doped Ca2LuScGa2Ge2O12 (CLSGG:Cr3+) phosphors with broad-band NIR emission were prepared through traditional high-temperature solid-state reactions. The crystal structures of the phosphors were analyzed by X-ray diffraction (XRD) and Rietveld refinement. The photoluminescence excitation (PLE) spectra of the synthesized CLSGG:Cr3+ phosphors exhibit a strong absorption band in the 400-500 nm region, which matches well with a blue-light-emitting chip. The photoluminescence (PL) spectra of the phosphors show broad-band emission ranging from 650 to 1100 nm with a full width at half-maximum (fwhm) of about 150 nm. At 423 K, the integrated emission intensity of CLSGG:0.02Cr3+ is about 59% of that at room temperature. A NIR pc-LED device was fabricated by combining a mixture of as-synthesized CLSGG:0.02Cr3+ phosphor and silicone with a 460 nm blue-light-emitting chip. Under a driving current of 100 mA, the output power of the device can achieve 1.213 mW, indicating that the as-prepared phosphors are promising for NIR pc-LED applications.

Background. Pulmonary ischemia reperfusion- (I/R-) induced dysfunction is a significant clinical problem after lung transplantation. In this study, we aim to explore the molecular mechanism of lung I/R injury (LIRI). Methods. Bioinformatic analysis of gene involved in oxidative stress. A HUVEC oxygen glucose deprivation/reoxygenation (OGD/R) model and I/R mouse model were first established via I/R. The cellular proliferation, migration, reactive oxygen species (ROS), and parameters of lung injury were assessed via CCK-8, EdU staining, Transwell, cellular ROS kit, and H&E staining. We also confirmed related gene expressions and protein levels and the interaction between the tissue factor pathway inhibitor (TFPI) promotor and ZNF354C. Results. Bioinformatic analysis results showed TFPI contributed to oxidative stress. OGD/R caused a reduction in cell viability and migration, hypermethylation of TFPI, increased ROS, and downregulation of ZNF354C, TFPI, and DNA methyltransferases (DNMTs) in HUVECs. Besides, ZNF354C could directly bind to the TFPI promoter, enhance proliferation and migration, and inhibit ROS in OGD/R-induced HUVECs by upregulating TFPI. More importantly, we discovered that 5-Aza could reduce TFPI methylation, upregulate TFPI, and enhance the binding of ZNF354C to the TFPI promoter in LIRI. Furthermore, DNMT1 silencing could induce proliferation and migration and prevent ROS in OGD/R-induced HUVECs by upregulating ZNF354C. Additionally, we verified that ZNF354C could alleviate LIRI by preventing DNA methylation in vivo. Conclusions. ZNF354C overexpression induced proliferation and migration, as well as suppressed ROS in OGD/R-induced HUVECs, and alleviated LIRI in mice by inhibiting TFPI promoter methylation to upregulate TFPI. Therefore, ZNF354C and TFPI methylation might be promising molecular markers for LIRI therapy.

In view of their excellent luminescence properties, nanocrystalline metal halide perovskites have diverse optoelectronic applications, including those related to anticounterfeiting. However, high-quality optical anticounterfeiting typically requires multiple encryptions relying on several optical modes to ensure information security. Herein, an efficient anticounterfeiting strategy based on dual optical encryption is realized by combining up- and downconversion luminescence in a nanocomposite with NaYF

Serine/threonine kinase 16 (STK16) is crucial in on regulating tumor cell proliferation, apoptosis, and prognosis. Activated M1 macrophages regulate lung adenocarcinoma (LUAD) growth by releasing exosomes. This study aims to investigate the role of STK16 and then focus on the possible mechanisms through which exosomes derived from M1 macrophages play their roles in LUAD cells by targeting STK16. Clinical LUAD samples were used to evaluate the expression of STK16 and its association with prognosis. Exosomes were isolated from M0 and M1 macrophages by ultracentrifugation and were then identified by electron microscopy and western blotting. In vitro gain- and loss-of-function experiments with LUAD cells were performed to elucidate the functions of miR-181a-5p, ETS1, and STK16, and mouse xenograft models were used to verify the function of STK16 in vivo. Western blotting, quantitative real-time PCR, CCK-8 assay, cell apoptosis, immunohistochemistry staining, luciferase assay, ChIP assay, and bioinformatics analysis were performed to reveal the underlying mechanisms. High expression of STK16 was observed in LUAD tissues and cells, and higher expression of STK16 was associated with worse prognosis. Silencing STK16 expression inhibited cell proliferation and promoted apoptosis via the AKT1 pathway. Exosomes from M1 macrophages inhibited viability and promoted apoptosis by inhibiting STK16. Moreover, miR-181a-5p is the functional molecule in M1 macrophage-derived exosomes and plays a vital role in inhibiting cell proliferation and promoting apoptosis by targeting ETS1 and STK16. Hence, exosomes derived from M1 macrophages were capable of inhibiting viability and promoting apoptosis in LUAD via the miR-181a-5p/ETS1/STK16 axis.

The stability of perovskite quantum dots (PQDs) plays a vital role in practical devices. Besides silica coating, embedding PQDs in zeolites is another strategy to improve their stability significantly. Although the zeolite rigid framework has been reported to protect PQDs, there are few reports on the

Herein, we report a new series of Ba1+xSr1−xGa4O8:Bi3+ (x = 0–0.7) phosphors that exhibit extremely broadband emission, covering almost the entire visible region and extending to the deep-red region, when excited by ultraviolet light. BaSrGa4O8:Bi3+ exhibits two emission bands located at 470 and 570 nm originating from different emission centers. With the gradual substitution of Ba for Sr, both of the emission bands show a red-shift, from 470 to 510 nm and from 570 to 630 nm, respectively. The corresponding full width at half maximum (FWHM) increases from 192 to 283 nm, which is attributed to a superposition of multiple emission centers via crystal field regulation. As a result, the emission can be tuned from cyan to orange across the warm white light region in Ba1+xSr1−xGa4O8:Bi3+ (x = 0–0.7) systems. Simultaneously, this series of phosphors presents good thermal stability (97% intensity at 150 °C for the Ba1.5Sr0.5Ga4O8:Bi3+ sample) and the thermal quenching will decrease with the formation of a solid solution due to the increasing rigidity of the lattice structure. Interestingly, the two emission bands in the representative Ba1+xSr1−xGa4O8:Bi3+ (x = 0–0.7) sample exhibit different thermal responses to increasing temperature, thus an optical thermometer with color discrimination and good sensitivity is designed. The maximum relative sensitivity (Sr) is 1.295% K−1 in the temperature range of 7–400 K. The corresponding emission color can be tuned from blue-cyan to orange, including white light. This work presents a rational design strategy for controllable ultra-broadband emission tuning across the white light region and to further explore potential optical sensor applications.

It is necessary to develop novel high-efficiency red or far-red-emitting LEDs in order to facilitate the phosphor-converted light-emitting diodes (pc-LEDs) for plant growth. This work reports a series of novel far-red emitting (Ba,Sr)LaZnTaO6:xMn4+ phosphors with double perovskite structure synthesized by the traditional high-temperature solid-state reaction (SSR). The crystal structure and morphology of (Ba,Sr)LaZnTaO6 were investigated by high-resolution TEM, SEM, and XRD Rietveld refinement. The photoluminescence properties were systematically explored and analyzed by diffuse reflectance (DR) spectra, photoluminescence emission (PL) and excitation (PLE) spectra, decay curves, and temperature-dependent spectra. Mn4+ ions occupy Ta5+ sites located at the [TaO6] octahedral emitting red light with the peak at 698 nm in BaLaZnTaO6:Mn4+ and 695 nm in SrLaZnTaO6:Mn4+ under n-UV and blue light excitation. The critical quenching concentration of Mn4+ was determined to be 0.008. The concentration quenching mechanism could be a dipole–dipole interaction between the Mn4+ ions. In addition, the PL intensity of (Ba,Sr)LaZnTaO6:xMn4+ phosphors decreases with increasing temperature. The SrLaZnTaO6:xMn4+ sample has better thermal stability than BaLaZnTaO6:xMn4+. Interestingly, (Ba,Sr)LaZnTaO6:0.008Mn4+ exhibits outstanding internal quantum efficiency (IQE ≥ 80%). Finally, the fabricated LEDs were combined with SrLaZnTaO6:0.008Mn4+ phosphors combined with 460 nm InGaN chips, which emit blue and red light. Based on the above properties, the rare-earth-free (Ba,Sr)LaZnTaO6:xMn4+ phosphors have great potential in being applied as far-red emitting phosphors in high-power plant growth LEDS.

In the field of white LEDs, the research and development of red phosphors have been confronting a challenge. In this paper, a novel red-emitting Ca9MnNa(PO4)7 (CMNPO) phosphor, whose emission was attributed to the 4T1(4G)–6A1(6S) transition of Mn2+ ions, was prepared by a high-temperature solid-state reaction. We utilized a chemical co-substitution strategy to optimize the luminescence properties and realize an impressive red emission in our CMNPO phosphor. The introduction of Zn2+/Mg2+ into CMNPO could break the intrinsic structural confinement of Mn2+, which improved the red emission from Mn2+ in the narrow confines. The novelty of this work lies in realizing an efficient red phosphor by doping trace amounts of Eu2+. By partially replacing Mn2+ ions with trace amounts of Eu2+, we obtained a CMNPO phosphor that emitted a dazzling red light, and the quantum yield reached up to 82%. The intensity dependence of this red emission on the trace amounts of doped Eu2+ was quantitatively analyzed. The substitution of Eu2+ ions played a dual role in improving the luminescence properties, not only disturbing the structural confinement of Mn2+ but also transferring energy to Mn2+ efficiently. By employing it as a red phosphor, we fabricated various high-performance white LEDs with low correlated color temperatures (4642–4956 K) and high-color-rendering indices (80.5–83.4). These findings show the potential promise of the CMNPO phosphor as a red phosphor in warm white LEDs and open up new avenues for the exploration of novel red-emitting phosphors.

Currently, the study of Mn4+-doped oxide red phosphor is a hot research topic to solve the lack of red component in phosphor-converted white-light-emitting diodes (pc-WLEDs). In this Article, we designed Gd3+/Nb5+ cation substitution by Bi3+/Mn4+ in Ba2GdNbO6 with double-perovskite structure based on the radius and coordination of the cations through high-temperature solid-state reaction. The phase purity and microstructure of double-perovskite Ba2GdNbO6:Bi3+,Mn4+ phosphors were characterized by X-ray diffraction and scanning electron microscopy examination. The crystal structures were also determined by the Rietveld refinement, and the photoluminescence (PL) properties were systematically studied. Bi3+ and Mn4+ ions can be effectively doped in the Ba2GdNbO6 matrix with an optical band gap of 3.94 eV. Upon 315 nm UV excitation, the Ba2GdNbO6:Bi3+,Mn4+ phosphor shows two emission bands at 464 nm from Bi3+ and 689 nm from Mn4+, respectively. By the design of Bi3+ → Mn4+ energy transfer, systematic luminescence tuning from blue to red could be achieved because of spectral overlap between the emission spectrum of Bi3+ and the excitation spectrum of Mn4+. The corresponding mechanism of the Bi3+ → Mn4+ energy-transfer process was investigated in detail by the fluorescence decays and PL spectra. The red emission intensity of Mn4+ has been greatly improved by Bi3+ → Mn4+ energy transfer. Moreover, the phonon vibration and zero phonon line of Mn4+ were studied through temperature-dependent PL. Finally, a WLED was fabricated using a 460 nm blue chip with a yellow YAG:Ce3+ phosphor and a red Ba2GdNbO6:0.01Bi3+,0.01Mn4+ phosphor, which has a low correlated color temperature (3550 K) and a high color rendering index (89.6). The above results imply that the improved red emission phosphors have a potential application in warm pc-WLED lighting.

Dual-emitting manganese ion doped LaM