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The phosphor-converted light emitting diode (pc-LED) is an efficient light source to adjust growth rhythm and raise yield of plant. Blue and red light play the dominant role in the process of plant growth, thus it is meaningful to search the blue-red dual emission phosphors with high quantum field and better thermal stability for developing plant growth LED. Herein, the blue-red dual emission phosphors were synthesized by co-doping Sb3+ and Ho3+ into the Cs 2 NaLuCl 6 , which emitted blue (454 nm) to red (657 nm) light with increasing the content of Ho3+ to 25% and their relative intensity could be tuned through adjusting the concentration of Ho3+ due to the efficient energy transfer from Sb3+ to Ho3+. The intensity of blue emission from Sb3+ and red emission from Ho3+ could maintain 78.4 and 75.8% of the room temperature at 150 °C, respectively. Furthermore, the spectra of fabricated blue and red LEDs match well with the absorption of carotenoid, Phytochrome and Chlorophyll b , implying the samples possess great application potential in plant growth LED. Blue-red double color emitting phosphor Cs 2 NaLuCl 6 :Sb3+, Ho3+. [Display omitted] [ABSTRACT FROM AUTHOR]

• Cs 2 NaScCl 6 : Yb3+, Er3+ was prepared through solvothermal method. • UC and DC properties of sample were investigated. • Potential application in anti-counterfeiting was evaluated. At present, most fluorescent anti-counterfeiting technologies on the market are based on single-mode luminescence, which generally have poor anti-counterfeiting capabilities. Thus, developing multi-mode luminescent anti-counterfeiting materials that combine dynamic and static luminescence is a particularly urgent task. In this study, Cs 2 NaScCl 6 : Yb3+, Er3+phosphors were successfully prepared using the solvothermal method. These materials can emit bright green light under 980- or 1550-nm infrared laser irradiation and red light under 365-nm ultraviolet lamp illumination. In addition, by increasing the 980-nm laser power density from 20 to 309 mW/cm2, the luminescence colour can be adjusted from green to yellow, which equips this sample with an outstanding potential for dynamic anti-counterfeiting. Finally, screen printing technology was used to assess the sample's anti-counterfeiting capacity, and the sample was found to be an excellent anti-counterfeiting luminescent material. Stimulus-mode dependent multi-color emitting phosphor Cs 2 NaScCl 6 : Yb3+, Er3+exhibits green emission with the irradiation of 1550 and 980 nm laser and red emission under excitation of 365 nm UV lamp, but yellow emission with the increase of 980 nm laser power density, which present great potential application in anti-counterfeiting field. [Display omitted] [ABSTRACT FROM AUTHOR]

Obtaining phosphors with white-light emission is a promising and economical approach for phosphor-conversion light emitting diodes (pc-LEDs), but traditional single-phase white light emission phosphors are inefficient. Here a white-light-emission phosphor was prepared via a co-precipitation method by doping Sb3+ into lead-free and vacancy-ordered double perovskite Cs 2 ZrCl 6. X-ray diffraction, X-ray photoelectron spectroscopy, and formation energy calculations confirmed that Sb3+ ions replaced the Zr4+sites in the [ZrCl 6 ]2− octahedron. The optical properties of Cs 2 ZrCl 6 :Sb3+ were investigated and compared with those of blank Cs 2 ZrCl 6. The origination of the emission bands was determined according to their fluorescence spectra and decay-time at an approximate temperature of 4 K Sb3+-doped Cs 2 ZrCl 6 exhibited white-light emission with double emission bands at 495 and 622 nm due to the 1P 1 → 1S 0 and 3P 2, 1, 0 → 1S 0 transitions of Sb3+, respectively. The intensity ratios of cyan light (495 nm) and the red light emission bands (622 nm) were tunable by adjusting the Sb3+concentration. The red component increased with increasing Sb3+ concentration in the present experimental range. Moreover, 10% Sb3+-doped Cs 2 ZrCl 6 showed the strongest emission with a photoluminescence quantum yield of approximately 78% under excitation of 333-nm light White LED devices with different correlated color temperatures were achieved by combining 1% or 10% Sb3+-doped Cs 2 ZrCl 6 with a 310-nm ultraviolet chip, suggesting that the synthesized samples have potential applications in white-illumination LEDs. Single-phased white emitting phosphor Cs 2 ZrCl 6 : Sb3+ and corresponding LEDs. [Display omitted] [ABSTRACT FROM AUTHOR]

As a new generation of near-infrared (NIR) light source, phosphor-converted NIR light emitting diodes (NIR pc-LEDs) have broad application prospects in biological tissue imaging, night vision and chemical composition analysis. However, most NIR emitting phosphors are still limited to short-wavelength, narrow-band emission and low efficiency. Here, based on the multi-site occupation strategy, the NIR phosphor Mg 2 LaTaO 6 :Cr3+ (MLT:Cr3+) achieves an efficient broadband NIR emission with the full width at half maximum (FWHM) of 203 nm in the range of 600–1300 nm under the excitation of 468 nm blue light. The phosphor MLT:0.01Cr3+ not only exhibits an excellent internal quantum efficiency (IQE) of 85.6 %, but also has good thermal stability and remains about 64.2 % photoluminescence (PL) intensity of room temperature at 423 K. Furthermore, the MLT:0.01Cr3+ phosphor was combined with a blue LED chip to fabricate the NIR pc-LED device, and its potential applications were successfully realized in information encryption, bioimaging and the qualitative or quantitative analysis of mixture of ethanol and water. NIR LED fabricated with broadband emitting phosphor Mg 2 LaTaO 6 :Cr3+ together with its potential application. [Display omitted] [ABSTRACT FROM AUTHOR]

An accurate deep-tissue thermometer with excellent photothermal conversion efficiency is desired for effective photo-thermal therapy (PTT), which will minimize collateral damages to normal cells from overheating or ineffective treatment from insufficient heat. Herein, a nano-thermometer with Nd3+/Yb3+/Ho3+ tri-doped Na 3 InF 6 was designed by hydrothermal method to real-time monitor tissue temperature, and its luminescent performance and temperature sensing behavior based on the luminescence intensity ratio (LIR) technology in the visible and near infrared regions were analyzed under 808 nm excitation. The advantage of temperature probes located in the near infrared (NIR) biological window region was demonstrated by the penetration depth in simulating biological tissue agar. Furthermore, the feasibility of the sample as a self-monitoring photothermal platform was verified by in vitro bactericidal experiments, which expressed excellent photothermal conversion performance and sterilizing rates reached 59.8 % (E. coli) and 53.6 % (S. aureus), respectively. Results demonstrated that the present single-phased Na 3 InF 6 :Nd3+/Yb3+/Ho3+ nanophosphor could serve as a bifunctional photothermal agent with internal tissue temperature measurement and photothermal conversion. Na 3 InF 6 : Nd3+, Yb3+, Ho3+ UC nanoparticles with multimode temperature detection and photothermal conversion functions. [Display omitted] [ABSTRACT FROM AUTHOR]

Non-invasive photo-thermal therapy (PTT) has been proposed as a powerful method for cancer treatment, in which accurate temperature monitoring is necessary to prevent ineffective therapy or damage to normal cells during the process of PTT. This promotes the design and development of photothermal agents (PTAs) with real-time temperature control and excellent photothermal conversion. Here, the designed dual-function photothermal agents YVO 4 : Nd3+, Yb3+@IR-780 were obtained, while the temperature detection behavior based on the fluorescence intensity ratio (FIR) of Nd3+ (4F 3/2 → 4I 11/2) to Yb3+ (2F 5/2 → 2F 7/2) and the temperature-dependent Yb3+ lifetime were investigated in detail. The advantages of fluorescence lifetime thermometry in the biological field were confirmed by the internal temperature detection of pork tissue through comparison with fluorescence intensity ratio technology. The photo-thermal conversion efficiency of samples YVO 4 : Nd3+, Yb3+@IR-780 reached about 34.3% and its potential application was also evaluated by the sterilization of E. coli and S. aureus, which shows that IR-780 coated nano-materials have excellent photo-thermal conversion performance. Results illuminated that the present photothermal agents with temperature self-monitoring had a bright future in the process of photothermal therapy. The NIR-Multifunctional photo-thermal therapeutic nanoplatform YVO 4 : Nd3+, Yb3+@IR-780 under 808 was developed, which offers the functions of temperature sensing and photo-thermal ablation. [Display omitted] [ABSTRACT FROM AUTHOR]