Query: Application of near-infrared luminescent materials

title: Multi Site Cation Control of Ultra Broadband Near Infrared Phosphors for Application in Light Emitting Diodes.
abstract: Near infrared (NIR) phosphors are fascinating materials that have numerous applications in diverse fields. In this study, a series of La3Ga5GeO14:Cr3+ phosphors, which was incorporated with Sn4+ Ba2+ and Sc3+ was successfully synthesized using solid state reaction to explore every cationic site comprehensively. The crystal structures were well resolved by combining synchrotron X ray diffraction and neutron powder diffraction through joint Rietveld refinements. The trapping of free electrons induced by charge unbalances and lattice vacancies changes the magnetic properties, which was well explained by a Dyson curve in electron paramagnetic resonance. Temperature and pressure dependent photoluminescence spectra reveal various luminescent properties between strong and weak fields in different dopant centers. The phosphor converted NIR light emitting diode (pc NIR LED) package demonstrates a superior broadband emission that covers the near infrared (NIR) region of 650 1050 nm. This study can provide researchers with new insight into the control mechanism of multiple cation site phosphors and reveal a potential phosphor candidate for practical NIR LED application.

title: Highly stretchable and fast self healing luminescent materials.
abstract: Nowadays, the flourishing exploitation of multi function luminescent materials with simultaneously fast self healing and superior mechanical features greatly broadens scopes available to wide applications in optical and display devices, but this is still a formidably challenging task. Herein, we realize color tunable luminescent materials functionalized with lanthanide ions (Ln3+ and terpyridine ligands coordination complexes that show highly stretchable and rapid self healing performance, simultaneous broaden its application prospect both optically and mechanically. The multiple color emission, including visible and near infrared luminescence, can be achieved by energy transfer from the coordinating terpyridine unit to Ln3+ via the so called "antenna effect" The dynamic Ln N coordination affords extreme stretchability and fast self healing at ambient conditions. Of particular interest is that the healing process is not significantly affected by surface ageing and atmospheric moisture. The multi function materials open up a new pathway for future development of the next generation wearable electronics including flexible and self healable conductors.

title: Research Progress of Europium Complexes Luminescent Materials
abstract: Rare earth is a general term for 17 chemical elements with atomic numbers of 21, 39 and 57~71 in group IIIB in the periodic table. Lanthanide complexes can show unique linear emission bands and have very long luminous lifetime. Lanthanide complexes can be used in electroluminous (EL) devices, lasers and light emitting biosensors in visible and near infrared spectra. Therefore, it is of great significance to find new lanthanide luminous complexes. The emission peak of rare earth europium complex is mainly located in the characteristic emission wavelength of 5D0 7F2 of Eu3+ The emission wavelength is about 613nm, and it shows the fluorescence characteristics of europium ions. In order to further study the subject, this paper will focus on the current research on luminous rare earth complexes organic complexes centered on Eu3+(emission red light) This paper summarizes the luminous principle of rare earth europium and its application in some fields, and expounds the existing problems at present and looks forward to its application prospect in the future.

title: Codoping of Lead Free Double Perovskites Promotes Near Infrared Photoluminescence.
abstract: In the rapidly developing smart era, near infrared luminescent materials have important applications in various fields that are closely related to people. Nag and co workers provided a first codoping strategy to achieve efficient near infrared photoluminescence in lead free double perovskite materials. Through the introduction of Bi3+ ions, a new energy state is formed that leads to the absorption of lower energy light. The excited state formed by this light absorption subsequently excites f electrons of Er3+ or Yb3+ ions, and the relaxation of these f electrons results in near infrared photoluminescence. This may open a new chapter in the application of perovskites for infrared detection and human sensing.

title: Review of long wavelength luminescent carbon based nanomaterials: preparation, biomedical application and future challenges
abstract: Carbon based luminescent nanomaterials have attracted much attention in the biomedical field. Compared to traditional photoluminescent materials (such as rare earth based semiconductors and organic dyes) they have excellent biocompatibility, low toxicity, excellent optical stability and site targeting properties in addition to their low cost and environmentally friendly features. Carbon dots, a typical carbon based luminescent material, have great application potential in biomedicine, biological imaging and optoelectronics. Actual biological imaging, however, uses low level photon scattering and light absorption to avoid self fluorescence by the target tissues, requiring the light waves to have strong tissue penetration ability. Long wavelength (red and near infrared) is known to have strong tissue penetration. However, carbon dots in the long wavelength region give a low quantum yield. Thus, obtaining long wavelength emitting carbon dots with high quantum yield is a big challenge in practical bioimaging and phototherapy. In this paper, recent progress in the development of long wavelength, strongly luminescence emitting carbon dots, the mechanisms and methods to regulate their optical properties and improve their quantum yield are reviewed. Recent applications of carbon dots in biosensing, bioimaging and therapy are described. Finally, the future challenges and prospects of long wavelength carbon based luminescent materials are discussed.

title: Highly efficient solid state emission of diphenylfumaronitriles with full color AIE, and application in explosive sensing, data storage and WLEDs
abstract: Luminescent materials with aggregation induced emission (AIE) have attracted extensive attentions for their strong emission in aggregated states. Although all kinds of AIE luminogens have been recently developed, it is difficult to realize full color AIE which is popular for the various applications in optoelectronic fields. Herein, a class of diphenylfumaronitrile core based dyes emitting in a wide region from near ultraviolet (382 nm) to near infrared (682 nm) have been synthesized and well characterized. It is found that the emission wavelength of the dyes severely depends on the peripheral substituent, including electron withdrawing trifluoromethyl (1) methyl (2) electron pushing methoxyl (3) and bulky aromatic amine (7 9) and that the substituting location imposes great effect on the emission intensity of multiple substituted dyes (4 6) Compound 4 with two methyl substituting at 3,4 position gives a ultrahigh quantum yield of 93% for unique packing structure. 1 3 and 7 can be used in explosive detecting and data storage for their emission sensitive to picric acid and external stimuli, respectively. When 4 and 8 applied in white light emitting diodes (WLEDs) a pure white emission can be obtained with 90 of CRI and (0.32, 0.32) of CIE.

title: Tunable NIR AIE active optical materials for lipid droplet imaging in typical model organisms and photodynamic therapy.
abstract: Near infrared (NIR) luminescent materials with aggregation induced emission (AIE) features have attracted enormous attention in the areas of medical imaging and diagnostic therapeutics because of their low background fluorescence and strong tissue penetration. This study reports a series of easily synthesized AIEgen molecules that feature NIR emission. These molecules have a donor donor p acceptor (D1 D2 p A) structure with intramolecular charge transfer (ICT) character. The nature of charge transfer transition can be modified by different structures of D2, i.e. phenyl, thiophene, and furan ring. These AIEgens have high selectivity towards lipid droplets (LDs) in vitro and in vivo, such as zebrafish, Caenorhabditis elegans, and oil crop tissue. In addition, the effect of photodynamic therapy (PDT) on SMMC 7721 cells was investigated, and the results indicate that these AIEgens have potential application for PDT on cancer cells with white light illumination. This study reveals that these triphenylamine (TPA) based AIEgens have great potential for biological imaging and preclinical applications of PDT.

title: Stacking patterns robust to type I PtSe2/InSe van der Waals heterostructures
abstract: Recently, constructing van der Waals (vdW) heterostructures has been considered as an effective method to extend the application of two dimensional (2D) materials. In this paper, we choose monolayer InSe and PtSe2 to build theoretically the PtSe2/InSe vdW heterostructure, calculating its band structures and optical properties to explore its potential applications. For all possible stacking cases, the PtSe2/InSe heterostructures keep the typical type I band alignment with a quasi direct band structure. Moreover, band gap values of PtSe2/InSe heterostructures are tunable via changing the interlayer coupling. In addition, under diverse stacking patterns, the PtSe2/InSe vdW heterostructures present both a high optical absorption strength ~106 cm 1) and broadband spectrum from near infrared to ultraviolet light region. All these calculated results indicate the 2D PtSe2/InSe vdW heterostructures are potential to be applied to 2D materials based luminescent devices.

title: Advances in engineering near infrared luminescent materials
abstract: Near infrared (NIR) luminescent materials have emerged as a growing field of interest, particularly for imaging and optics applications in biology, chemistry, and physics. However, the development of materials for this and other use cases has been hindered by a range of issues that prevents their widespread use beyond benchtop research. This review explores emerging trends in some of the most promising NIR materials and their applications. In particular, we focus on how a more comprehensive understanding of intrinsic NIR material properties might allow researchers to better leverage these traits for innovative and robust applications in biological and physical sciences.

title: Facilitating Low Energy Activation in the Near Infrared Persistent Luminescent Phosphor Zn1+xGa2 2xSnxO4:Cr3+ via Crystal Field Strength Modulations
abstract: Cr3+ activated persistent luminescent phosphors with the spinel structure are emerging materials in bio imaging applications for their distinctive features of deep bio tissues penetration and recha.