Bi2Te3-based materials have been reported to be one of the best room-temperature thermoelectric materials, and it is a challenge to substantially improve their thermoelectric properties. Here novel Bi2Te3 core fibers with borosilicate glass cladding were fabricated utilizing a modified molten core drawing method. The Bi2Te3 core of the fiber was found to consist of hexagonal polycrystalline nanosheets, and polycrystalline nanosheets had a preferential orientation; in other words, the hexagonal Bi2Te3 lamellar cleavage more tended to be parallel to the symmetry axis of the fibers. Compared with a homemade 3-mm-diameter Bi2Te3 rod, the polycrystalline nanosheets’ preferential orientation in the 89-μm-diameter Bi2Te3 core increased its electrical conductivity, but deduced its Seebeck coefficient. The Bi2Te3 core exhibits an ultrahigh ZT of 0.73 at 300 K, which is 232% higher than that of the Bi2Te3 rod. The demonstration of fibers with oriented nano-polycrystalline core and the integration with an efficient fabrication technique will pave the way for the fabrication of high-performance thermoelectric fibers.
Organic microlasers have attracted much attention due to their unique features such as high mechanical flexibility, facile doping of gain materials, high optical quality, simplicity and low‐cost fabrication. However, organic gain materials usually suffer from aggregation‐caused quenching (ACQ), preventing further advances of organic microlasers. Here, a new type of microlaser from aggregation‐induced emission (AIE) material is successfully demonstrated. By introducing a typical noncrystalline AIE material, a high quality microlaser is obtained via a surface tension‐induced self‐assembly approach. Distinct from conventional organic microlasers, the organic luminescent material used here is initially nonluminescent but can shine after aggregation under optical pumping. Further investigations demonstrate that AIE‐based microlasers exhibit advantages to enable much higher doping concentrations, which provides an alternative way to improved lasing performance including dramatically reduced threshold and favorable lasing stability. It is believed that these results could provide a promising way to extend the content of microlasers and open a new avenue to enable applications ranging from chemical sensing to biology.
Phosphate glass-clad optical fibers comprising amorphous Se(0.8)Te(0.2) semiconductor core were fabricated by a reactive molten core approach. The Se(0.8)Te(0.2) crystals were precipitated in core region by a postdrawing annealing process, which were confirmed by X-ray diffraction, micro-Raman spectra, electron probe X-ray micro-analyzer, and transmission electron microscope measurement results. A two-cm-long crystalline Se(0.8)Te(0.2) semiconductor core optical fiber, electrically contacted to external circuitry through the fiber end facets, exhibits a two-orders-of-magnitude change in conductivity between dark and illuminated states. The great discrepancy in light and dark conductivity suggests that such crystalline Se(0.8)Te(0.2) semiconductor core optical fibers have promising applications in optical switch and photoconductivity of optical fiber array.
Diabetic nephropathy (DN) is characterized by unclear pathogenesis. Recent medical data shows that the incidence of DN rises year by year. Rhein is the main compositions of rhubarb, a traditional Chinese medicinal plant, which plays an active role in kidney protection. The prophylaxis and phytotherapeutic effects of rhein are due to its anti-inflammatory and antifibrosis properties. Here, we shed light on the renal protective role of rhein in diabetes mellitus (DM) with a particular focus on the molecular basis of this effect.
Continuous monitoring of volatile organic compounds (VOCs) is an important challenge for human beings. Allinorganic halide perovskites (AIHPs) have attracted extensive attention because of their excellent semiconductor properties. Perovskite interfacial modulation engineering is considered as a key factor in the preparation of stable and high-performance AIHP devices. In this work, organic hydrophilic ligand 3-mercaptopropionic acid (MPA) is creatively introduced to regulate the nanostructure of CsPbBr 3 and construct the ambient stable binary heterojunction of CsPbBr 3 nanoparticles (NPs)/ZnO NPs. The microscopic morphology design shows that CsPbBr 3 NPs with the optimal nano size have abundant sensitive gas adsorption sites and large specific surface area, which can effectively improve the sensitivity of the CsPbBr 3 -based sensor to ethanolamine (EA). Moreover, hydrophilic groups in MPA are good for the formation of hydrogen bonds and MPA network structures, which effectively improve the binding affinity of metal oxides on MPA surfaces, enhancing the stable anchoring of ZnO to halide perovskite CsPbBr 3 and the heterojunction construction of CsPbBr 3 /ZnO. The CsPbBr 3 -2MPA/ZnO sensor displays the advantages of the lowest theoretical detection limit (DL, 31 ppb), excellent selectivity, a much shorter response time (50 s) than CsPbBr 3 , and significantly enhanced EA response (13.25, 100 ppm) at room temperature, besides the stable repeatability in more than 1 month. In addition, we propose a feasible sensing mechanism. The gas sensor based on CsPbBr 3 /ZnO nano-heterojunctions with efficient hydrophilic MPA modulation may provide constructive idea for the detection of VOCs.
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