Ultra‐broadband near‐infrared (NIR) luminescent materials are the most important component of NIR light‐emitting devices (LED) and are crucial for their performance in sensing applications. A major ...challenge is to design novel NIR luminescent materials to replace the traditional Cr3+‐doped systems. We report an all‐inorganic bismuth halide perovskite Cs2AgBiCl6 single crystal that achieves efficient broadband NIR emission by introducing Na ions. Experiments and density functional theory (DFT) calculations show that the NIR emission originates from self‐trapped excitons (STE) emission, which can be enhanced by weakening the strong coupling between electrons and phonons. The high photoluminescence quantum efficiency (PLQY) of 51 %, the extensive full width at half maximum (FWHM) of 270 nm and the stability provide advantages as a NIR luminescent material. The single‐crystal‐based NIR LED demonstrated its potential applications in NIR spectral detection as well as night vision.
An all‐inorganic bismuth halide perovskite Cs2AgBiCl6 single crystal achieves efficient broadband NIR emission by introducing Na ions. Experiments and DFT calculations show that the emission originates from self‐trapped excitons emission. The role of Na is to weaken the strong coupling between electrons and phonons and to localize the electron and hole wave functions to enhance this emission.
Yb3+ doped lead‐free double perovskites (DPs) with near‐infrared (NIR)‐emitting have attracted extensive attention due to their wide application prospects. Unfortunately, they still suffer from weak ...NIR emission due to undesirable resonance energy transfer between the sensitizers and Yb3+ ions. Herein, a new effective NIR‐emitting DP is developed by co‐doping Sb3+ and Yb3+ into Cs2AgInCl6. Experiments and theoretical calculations reveal that induced by co‐doping Sb3+ ions, the self‐trapped excitation (STE) emission intensity of Cs2AgInCl6 is greatly enhanced by 240 times, and the STE emission shifts from 600 nm to 660 nm, which contributes to a larger spectral overlap between STE emission and the absorption of Yb3+ ions. As a result, the absolute NIR photoluminescence quantum yield reaches an unprecedented 50% in lead‐free DPs via high‐efficiency STE sensitization (>30%). The excellent optical performance of Cs2AgInCl6: Sb, Yb with high ambient, thermal and light stability makes it suitable for application in night‐vision devices. Moreover, an ingenious dual‐modal optical information encryption based on the combination of visible and NIR fluorescence printing patterns utilizing Cs2AgInCl6: Sb and Cs2AgInCl6: Sb, Yb respectively is successfully demonstrated. This study provides inspiration for designing highly efficient NIR‐emitting Ln3+‐doped DPs and illustrates their great potential in versatile optoelectronic applications.
A new design strategy of Sb3+ ions co‐doping in Cs2AgInCl6:Yb3+ is proposed to expand absorption region to longer wavelengths and effectively enhance the near‐infrared emission of Yb3+ ions. The excellent sensitization efficiency from self‐trapped exciton to Yb3+ ions (>30%) gives Sb3+, Yb3+ co‐doped Cs2AgInCl6 unprecedented near‐infrared emission with a photoluminescence quantum yield of up to 50%.
Compared to solid scintillators and organic liquid scintillators, aqueous‐based liquid scintillators (AbLS) have more superiority in highly flexible scalability, yet are now limited by their low ...light yield (≈100 photons MeV−1). Here, aqueous‐based inorganic colloidal halide perovskites with high photoluminescence quantum yield (PLQY) of three primary color luminescence up to 88.1% (red), 96% (green), and 81.8% (blue) are respectively synthesized, and a new generation of colloidal perovskite‐mediated AbLS (PAbLS) with light yield increased in comparison with the commercial scintillator AbLS is fabricated. This paper exhibits that the excellent PLQY and colloidal dispersion of halide perovskites benefit from poly(ethylene glycol) modification and this modification ensures the vacancy inhibition and formation of defect–free surfaces in an aqueous solution. Moreover, their high luminescent emission can be maintained for 100 days at low temperatures, and such modification also promises the heat‐to‐cold customization of operating temperature even in ice below 0 °C. Finally, depending on the light yield of around 3058 and 8037 photons MeV−1 at room temperature and low temperature, PAbLS with shape/size scalability exhibit their robust radiation hardness (dose rate as high as 23 mGy s−1) and conceptual application potential in high‐energy ray radiation detection from every angle of 360°.
A new generation of perovskite‐mediated aqueous‐based liquid scintillators (PAbLS) with light yield increased in comparison with the commercial scintillator AbLS is fabricated. PAbLS with shape/size scalability exhibit their bright emission (photoluminescence quantum yield > 90%), robust stability (100 days), robust radiation hardness (82.8 Gy), and conceptual potential applied in radiation detection from every angle of 360°.
Microbial cell factories reinvigorate current industries by producing complex fine chemicals at low costs. Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is the main reducing power to ...drive the biosynthetic pathways in microorganisms. However, insufficient intrinsic NADPH limits the productivity of microorganisms. Here, we report that supplying microorganisms with long‐lived electrons from persistent phosphor mesoporous Al2O3 (meso‐Al2O3) can elevate the NADPH level to facilitate efficient fine chemical production. The defects in meso‐Al2O3 were demonstrated to be highly efficient in prolonging electrons’ lifetime. The long‐lived electrons in meso‐Al2O3 can pass the material–microorganism interface and power the biosynthetic pathways of E. coli to produce jet fuel farnesene. This work represents a reliable strategy to design photo‐biosynthesis systems to improve the productivity of microorganisms with solar energy.
A hybrid photo‐biosynthesis system was constructed for the overproduction of jet fuel farnesene by interfacing engineered E. coli with persistent phosphor mesoporous Al2O3 (meso‐Al2O3). meso‐Al2O3 with rich defects prolonged the lifetime of photo‐excited electrons that were passed to E. coli and improved the farnesene production by a factor of over 100 %.
Development of a solar water splitting device requires design of a low‐cost, efficient, and non‐noble metal compound as alternative to noble metals. For the first time, we showed that CoSe2 can ...function as co‐catalyst in phototoelectrochemical hydrogen production. We designed a heterostructure of p‐Si and marcasite‐type CoSe2 for solar‐driven hydrogen production. CoSe2 successively coupled with p‐Si can act as a superior photocathode in the solar‐driven water splitting reaction. Photocurrents up to 9 mA cm−2 were achieved at 0 V vs. reversible hydrogen electrode. Electrochemical impedance spectroscopy showed that the high photocurrents can be attributed to low charge transfer resistance between the Si and CoSe2 interfaces and that between the CoSe2 and electrolyte interfaces. Our results suggest that this CoSe2 is a promising alternative co‐catalyst for hydrogen evolution.
Heterostructures of semi‐metallic CoSe2 nanorods and p‐Si microwires behave as an efficient photocathode for the solar‐driven hydrogen evolution reaction. Photocurrents as high as 9 mA cm−2 have been achieved at 0 V vs. reversible hydrogen electrode. The high photocurrents can be attributed to low charge transfer resistance between the Si and CoSe2 interfaces and between the CoSe2 and electrolyte interfaces.
With the increased use of neoadjuvant chemotherapy (NAC) in breast cancer, the timing of sentinel lymph node biopsy (SLNB) has become increasingly important. In this study, we aimed to evaluate the ...feasibility and accuracy of SLNB for initially clinically node-negative breast cancer after NAC by conducting a systematic review and meta-analysis.
We searched PubMed, Embase, and the Cochrane Library from January 1, 1993 to November 30, 2015 for studies on initially clinically node-negative breast cancer patients who underwent SLNB after NAC followed by axillary lymph node dissection (ALND).
A total of 1,456 patients from 16 studies were included in this review. The pooled identification rate (IR) for SLNB was 96% 95% confidence interval (CI): 95%-97%, and the false negative rate (FNR) was 6% (95% CI: 3%-8%). The pooled sensitivity, negative predictive value (NPV) and accuracy rate (AR) were 94% (95% CI: 92%-97%, I2 = 27.5%), 98% (95% CI: 98%-99%, I2 = 42.7%) and 99% (95% CI: 99%-100%, I2 = 32.6%), respectively. In the subgroup analysis, no significant differences were found in either the IR of an SLNB when different mapping methods were used (P = 0.180) or in the FNR between studies with and without immunohistochemistry (IHC) staining (P = 0.241).
Based on current evidence, SLNB is technically feasible and accurate enough for axillary staging in initially clinically node-negative breast cancer patients after NAC.
Laser sources have been considered to be better light sources compared to traditional lamps or light‐emitting diodes used in projectors, which enables the projector to create images with higher color ...saturation, brightness, and energy efficiency. However, the speckle noise caused by the coherent nature of the laser is a major technology obstacle for laser projection, which severely affects the image quality. To suppress laser speckle, a TiO2‐sapphire composite (TSC) with rough and high reflectivity surface and high thermal conductivity substrate is designed, which reduces the laser speckle by creating spatial diversity. Moreover, combined with a micro motor, the design and fabrication of the TSC rotating wheel are realized, which further reduces the laser speckle by creating time diversity. The experimental results show that the laser speckle contrast can be reduced from 9.0% to 2.2% when placing the TSC rotating wheel in the light path, which is below the speckle perception limit of the human eye (<4%). This new type of laser speckle suppression device is simple to use, low in cost, high in energy utilization, high in thermal conductivity, easy to mass production, and has great application potential in high‐power laser projection.
Methylammonium lead halide perovskite nanocrystals offer attractive optoelectronic properties but suffer from fast degradation in the presence of water. In contradiction to this observation, we ...demonstrate the possibility of a direct aqueous synthesis of CH3NH3PbX3 (X=Br or Cl/Br) nanocrystals through the reaction between the lead halide complex and methylamine when the pH is maintained in the range of 0–5. Under these synthetic conditions, the positively charged surface of the perovskite nanocrystals and the proper ionic balance help to prevent their decomposition in water. Additional surface capping with organic amine ligands further improves the photoluminescence quantum yield of the perovskite nanocrystals to values close to 40 %, ensures their stability under ambient conditions for several months, and their photoluminescence performance under continuous 0.1 W mm−2 405 nm light irradiation for over 250 hours.
Defiance! Methylammonium lead halide perovskite nanocrystals (NCs) undergo fast degradation in the presence of water, yet an aqueous synthesis of stable, reasonably strongly emitting CH3NH3PbX3 (X=Br, Cl/Br) perovskite NCs has been developed, in which the lead halide complex, pH value, and added ligands affect the formation of the nanocrystals.
Silicon (Si) photodetectors (PDs) have attracted more attention due to their wide applications, but are limited by their extremely weak ultraviolet (UV) photo‐response. Herein, Dy3+‐CsPbCl2Br1 ...nanocrystals glass (Dy3+‐CPCB NCsG) is synthesized in borosilicate glass by traditional melt‐quenching. The doping of Dy3+ exceedingly improves the PL intensity of CsPbCl2Br1 nanocrystals glass (CPCB NCsG) with enhancing photoluminescence quantum yield from 8.0% to 30.2%, ascribed to the improved crystallinity and reduced defects. Meanwhile, the stability of CPCB NCsG exposed to air, light, and high temperature is largely boosted. After integrating with Dy3+‐CPCB NCsG, the responsivity, external quantum efficiency, detectivity, and stability of Si PDs are significantly enhanced. The responsivity (R) of Si PDs‐5% Dy3+‐CPCB NCsG is 0.006 A W−1 at 320 nm, which is sixfold higher than that of bare Si PDs. This work develops a blue Dy3+‐CPCB NCsG, which has great potential as a new luminescent material for the next generation of Si PDs.
Silicon (Si) photodetectors have received much attention for their wide range of applications, but are limited by their extremely weak UV light response. The doping of Dy3+ greatly improves the photoluminescence quantum yield of CsPbCl2Br1 nanocrystalline glasses (NCsG). Meanwhile, after integration with Dy3+‐CsPbCl2Br1 NCsG, the responsiveness, external quantum efficiency, detection, and stability of Si photodetectors are significantly improved.
Filterless narrowband near-infrared photodetectors (NIRPDs) offer significantly reducing cost and the system volume for various applications, but limited by the poor photosensitivity. Herein, we ...theoretically and experimentally demonstrate a novel class of sensitive filterless NIRPDs in CsPbF3: Zn2+-Yb3+- Tm3+ (or Er3+) perovskite nanocrystals (PeNCs)/Au nanorods (NRs) array hybrid via direct photon-electric upconverion (UC) from ground state of Yb3+- Tm3+ (or Er3+) to conduction band of PeNCs. It shows the selectively spectral photodetection at 980-nm NIR region with all full-width at half-maximum of 20 nm, high responsivity of 106 A/W, detectivity of 1.52 × 1012 Jones, and external quantum efficiency of 135%. The excellent performance can be mainly ascribed to (1) direct photon-electric UC mechanism; (2) the reduced trapping-center density, high carrier mobility, and increased extraction and separation efficient of election-hole pairs of PeNCs; (3) localized surface plasmon enhancement. Our findings open the exciting potential for developing the next-generation narrow NIRPDs.
Schematic illustration of electron injection process of CsPbF3: Zn2+ - Yb3+ - Er3+PeNCs for NIRPDs. Display omitted
•Herein, we theoretically and experimentally demonstrate a novel class of sensitive filterless NIRPDs in CsPbF3: Zn2+-Yb3+- Tm3+ (or Er3+) perovskite nanocrystals (PeNCs)/Au nanorods (NRs) array hybrid via direct photon-electric upconverion (UC) from ground state of Yb3+- Tm3+ (or Er3+) to conduction band of PeNCs.•It shows the selectively spectral photodetection at 980-nm NIR region with all full-width at half-maximum of 20 nm, high responsivity of 106 A/W, detectivity of 1.52 × 1012 Jones, and external quantum efficiency of 135%.•The excellent performance can be mainly ascribed to (1) direct photon-electric UC mechanism; (2) the reduced trapping-center density, high carrier mobility, and increased extraction and separation efficient of election-hole pairs of PeNCs; (3) localized surface plasmon enhancement.•This work is of general interests to researchers working in perovskite nanocrystals, upconversion luminescence materials, solar energy harvesting, photodetectors.
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