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Polymer spacer tunable Purcell-enhanced spontaneous emission in perovskite quantum dots coupled to plasmonic nanowire networks
摘要： Polymer spacer tunable Purcell-enhanced spontaneous emission in perovskite quantum dots coupled to plasmonic nanowire networks? Lead halide perovskite quantum dots (PQDs) have recently been proposed as a scalable and color-tunable quantum source, but their slow spontaneous emission creates a mismatch with high-speed nanophotonic devices. Here, we demonstrate fast and bright emission in PQD films coupled to silver nanowire networks (NWKs), in which polyvinyl alcohol (PVA) is used as a spacer to regulate the lossy characteristics of the plasmonic cavity. Compared with bare quartz, the PVA substrate shows a considerable enhancement effect on the apparent emission intensity, but a reduction in the emission rate of PQD excitons. The efficient NWK–PQD coupling generates an increase in the emission intensity of a factor of 6.0 (average 3.4) and simultaneously a 2.4-fold (average 1.9) enhancement in the emission rate. However, an opposite PVA spacer thickness dependence for Purcell factor and quantum yield is observed, indicating that the fast and bright emission would be a trade-off between the Purcell-enhanced radiative rate and large metal guidance on plasmonic cavity design for perovskite-based nanophotonic devices.
关键词： plasmonic nanowire networks,spontaneous emission,Polymer spacer,Purcell-enhanced,perovskite quantum dots
更新于2025-11-21 11:24:58
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Ferroelectric Enhanced Performance of a GeSn/Ge Dual-Nanowire Photodetector
摘要： GeSn offers a reduced bandgap than Ge and has been utilized in Si-based infrared photodetectors with extended cutoff wavelength. However, traditional GeSn/Ge heterostructure usually consists defects like misfit dislocations due to the lattice mismatch issue. The defects with the large feature size of photodetector fabricated on bulk GeSn/Ge heterostructure induces considerable dark current. Here, we demonstrate a flexible GeSn/Ge dual-nanowire (NW) structure, in which the strain relaxation is achieved by the elastic deformation without introducing defects and the feature dimension is naturally at nanoscale. Photodetector with low dark current can be built on GeSn/Ge dual-NW, which exhibits an extended detection wavelength beyond 2 μm and the enhanced responsivity compared to Ge NW. Moreover, the dark current can be further suppressed by the depletion effect from ferroelectric polymer side gate. Our work suggests the flexible GeSn/Ge dual-NW may open an avenue for Si-compatible optoelectronic circuits operating in the short-wavelength infrared range.
关键词： Nanowire,Germanium-tin,Molecular beam epitaxy (MBE),Side-gated,Photodetector,Ferroelectrical polymer
更新于2025-11-21 11:01:37
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Robust Janus fibrous membrane switchable infrared radiation properties for potential building thermal management application
摘要： Buildings heating and cooling consumes a large part of global energy, contributing to aggravating the global warming and energy crisis. It is strongly desired but still lacking in realizing heating and cooling functions within the same material without intensive energy input. Herein, a Janus thermal management membrane with trilayer structure has been prepared by using the ZnO nanorods array-coated cellulose (ZnO-NRs@cellulose), ultralong MnO2 nanowires (UL-MnO2-NWs) and silver nanowires (Ag-NWs) as building blocks. The ZnO-NRs@cellulose fiber layer with rough surface was fabricated by a hydrothermal progress based on the controlled growth of ZnO nanorods on cellulose surfaces. Subsequently, the hydrothermally synthesized UL-MnO2-NWs and Ag-NWs were filtered onto the ZnO-NRs@cellulose layer in turn, forming laminated Janus membrane. The Janus membrane exhibited asymmetric radiation properties on each side: the ZnO-NRs@cellulose side of the Janus membrane shows high solar radiation reflectivity and high infrared emissivity to minimize heat input from sun and enhance the heat dissipation in hot environment, while Ag-NWs side of that exhibits relatively high solar radiation absorption rate and low infrared emissivity for enhancing heat input from sun and reducing the heat radiation loss in cold environment. The introduction of UL-MnO2-NWs and Ag-NWs into the laminated Janus membrane endows the membrane with high tensile stress of 61.4 MPa. Moreover, the strong compatible entanglement among three layers of the Janus membrane causes the satisfactory interface stability. Due to the special asymmetric radiation performance, excellent interfacial compatibility, and high mechanical stability, such Janus membrane might be potential useful in building energy saving, personal thermal management and other facilities.
关键词： solar radiation,infrared radiation,laminated structure,MnO2 nanowire,Ag nanowire,Janus membrane
更新于2025-11-19 16:56:35
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Dual-Signal Amplification Strategy for miRNA Sensing with High Sensitivity and Selectivity by Use of Single Au Nanowire Electrodes
摘要： MicroRNAs (miRNAs) have been applied as biomarkers and better detection of their expression profiles plays important roles in early diagnosis of cancers. In this work, a simple dual-signal amplification strategy has been used to construct a novel nanosensor on single Au nanowire electrodes (SAuNWEs) for miRNA-16 detection based on the “signal-on” and “signal-off” features during hybridization/de-hybridization process. The ferrocene-labeled aptamer capture probe (Fc-CP-16) is designed to hybridize with thiolated methylene blue-labeled DNA probe (MB-CP) on SAuNWE to form duplex DNA, and the addition of miRNA-16 can lead to the dissociation of duplex structure due to the highly matched sequences between miRNA-16 and Fc-CP-16. The remaining MB-CP can thus tend to recover its hairpin structure at the presence of Mg2+ through the hybridization of its complementary sequences. During this hybridization/de-hybridization process, the changes of Fc and MB oxidation peaks can be recorded, and there has a linear relationship between the sum of dual-signal changes (ΔI = ΔIMB + |ΔIFc|) and the logarithm of miRNA-16 concentrations, which can be used to detect miRNA-16. Including miRNA extraction, the dual-signal amplification strategy for miRNA sensing assay was carried out about 2 hours for the detection in real samples. This novel nanosensor has small dimension, good selectivity, rapid response and regeneration ability, which can satisfy the need for early cancer marker detection in cells/organelles.
关键词： nanosensors,single Au nanowire electrodes,dual-Signal Amplification Strategy,micro RNA
更新于2025-11-14 17:03:37
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TiO2-Coated Core-Shell Ag Nanowire Networks for Robust and Washable Flexible Transparent Electrodes
摘要： Silver nanowires (AgNWs) are the most promising materials to fabricate flexible transparent electrodes (FTEs) used in next-generation electronics. However, there are several bottlenecks for AgNWs-based FTEs to achieve large-scale applications, which are the thermal instability and rough surface topography of AgNWs and the poor interfacial adhesion between AgNWs and used substrate. To simultaneously address these aforementioned issues, a robust and washable FTE is prepared based on AgNW@TiO2 core-shell network embedding in polyimide (PI) substrate through a facile and scalable solution-based process. After treating with TiO2 sol, an ultra-thin, conformal, and continuous TiO2 shell is coated on AgNWs, which can effectively suppress the atomic surface diffusion. In comparison with pristine AgNW network that breaks into nanorods and nanospheres at 250 °C for 10 min, the AgNW@TiO2 core-shell network is stable at 300 °C, and its resistance just increases by a factor of 11 after annealing at 400 °C for 1 h. Furthermore, the TiO2 shell simultaneously increases the electrical and optical properties of AgNW network. After flowing PI precursors, drying, and thermally curing, the AgNW@TiO2 core-shell network is embedded on the surface of PI substrate with surface roughness of 1.9 nm. In addition to high thermal stability, the conductivity of the AgNWs@TiO2-PI composite FTE remains almost unchanged after repeated 3M tape peeling off cycles and mechanical bending cycles. It is also demonstrated that the AgNWs@TiO2-PI composite FTE is washable, and the relative change in resistance (?R/R0) is ~12% after 100 washing cycles in which a variety of stress situations occurring in combination.
关键词： flexible transparent electrodes,peeling off and mechanical stabilities,TiO2 sol,silver nanowire@TiO2 core-shell network,thermal and washing stabilities
更新于2025-11-14 14:32:36
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Simulation of GaAs Nanowire Growth and Crystal Structure
摘要： Growing GaAs nanowires with well defined crystal structures is a challenging task, but may be required for the fabrication of future devices. In terms of crystal phase selection, the connection between theory and experiment is limited, leaving experimentalists with a trial and error approach to achieve the desired crystal structures. In this work, we present a modelling approach designed to provide the missing connection, combining classical nucleation theory, stochastic simulation and mass transport through the seed particle. The main input parameters for the model are the flows of the growth species and the temperature of the process, giving the simulations the same flexibility as experimental growth. The output of the model can also be directly compared to experimental observables, such as crystal structure of each bilayer throughout the length of the nanowire and the composition of the seed particle. The model thus enables for observed experimental trends to be directly explored theoretically. Here, we use the model to simulate nanowire growth with varying As flows, and our results match experimental trends with good agreement. By analysing the data from our simulation, we find theoretical explanations for these experimental results, providing new insights into how the crystal structure is affected by the experimental parameters available for growth.
关键词： Wurtzite,Zinc Blende,GaAs,Nanowire,Simulation
更新于2025-09-23 15:23:52
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A Low-Power, Inductorless Wideband Cryogenic Amplifier For Supercondcting Nanowire Single Photon Detector
摘要： This paper presents a low-power, inductorless wideband cryogenic amplifier for superconducting nanowire single photon detector (SNSPD). To achieve wide bandwidth, low power consumption and small chip area, a modified Cherry-Hooper amplifier topology is used. With good input and output match, at 4.2 K temperature the measurement results show that the amplifier achieves 23-dB gain with a flat gain response, a 3-dB bandwidth (BW) of over 3.4 GHz, which covers frequencies as low as 130 kHz. Fabricated in a 0.13-μm silicon germanium (SiGe) BiCMOS technology, the amplifier core occupies a silicon area of only 0.075 mm2 and consumes a power of only 4 mW.
关键词： low power,Cryogenic amplifier,wideband,Superconducting Nanowire Single Photon Detectors,SNSPD
更新于2025-09-23 15:23:52
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Seed Free Growth of Aligned ZnO Nanowire Arrays on AZO Substrate
摘要： In the absence of commonly used seed layer, we can still successfully synthesized aligned ZnO nanowire arrays by the hydrothermal method. By using aluminum-doped zinc oxide (AZO) glass as a substrate, high-density and vertically aligned ZnO nanowires were synthesized directly on the substrate in the absence of the ZnO seed layer. The current-voltage curve indicated that the sample grown on AZO glass substrate in the absence of seed layer possesses better conductivity than that synthesized on FTO glass substrate with ZnO seed layer. Thus, a simplified, seed-free and low-cost experimental protocol was reported here for large-scale production of high quality ZnO nanowire arrays with promoted conductivity.
关键词： conductivity,ZnO nanowire arrays,seed layer free,AZO substrate
更新于2025-09-23 15:23:52
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Germanium catalyzed vapor–liquid–solid growth and characterization of amorphous silicon oxide nanotubes: comparison to the growth of its nanowires
摘要： One-dimensional (1D) nanostructures were grown with a simple technique using continuous-wave laser vaporization of a Ge target containing 5 at.% Si in high-pressure (up to 0.9 MPa) Ar gas atmosphere. A maximum amount (~ 30% of all products) of 1D nanostructures was obtained at 0.9 MPa and these nanostructures were identified as amorphous silicon oxide (SiOx) nanotubes (NTs) and attached with crystalline Ge-rich NPs with elongated prolate-like or sphere-like shapes at their tips by transmission electron microscopy (TEM), high-angle annular dark-field-scanning TEM, and energy dispersive X-ray line scan spectrometry. As the Ar pressure decreased from 0.9 to 0.03 MPa, the average diameters, wall thicknesses, and lengths of the NTs decreased from 57.9 to 22.9 nm, 13.2 to 6.7 nm, and 2.1 to 0.2 μm, respectively, and the tip NP size decreased from 139.0 to 41.7 nm. There was a strong correlation among the diameters, wall thicknesses, and lengths of the NTs and tip Ge NP sizes, indicating the role of molten Ge NPs as catalyst seeds for the precipitation of SiOx in a vapor–liquid–solid growth mechanism at high temperature. The SiOx precipitation quantities from the seed NPs for the NTs were compared with those of amorphous SiOx nanowires (NWs) at 0.1–0.9 MPa to clarify the growth mechanism of the NTs. We argue that smaller precipitation quantities of SiOx than those for the NWs play a critical role in the formation of cap structures with different sizes and shapes from the molten Ge NPs and the growth of the NTs.
关键词： Laser vaporization,Germanium catalyst,Silicon oxide,Nanotube,Nanowire
更新于2025-09-23 15:23:52
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Enhanced sensor life using UV treatment of sulphur poisoned Pt-PtOx
摘要： In this work, we report a novel method for recovery of sulphur poisoned platinum/platinum oxide (Pt-PtOx) core-shell nanowire sensor using UV irradiation. The optimum core to shell thickness ratio and the operating conditions are the key factors to achieve a high-performance H2S sensor, described in this report. The fabricated core-shell nanowire sensor demonstrated response of 6.4% at 1 ppm H2S with detection limit of 10 ppb at 150°C operating temperature. The sensor undergoes prominent time-dependent poisoning at H2S exposure of 3 ppm when operated at 150°C due to sensor surface contamination by sulphur, later confirmed by XPS analysis. Ultraviolet light at two wavelengths, 365 nm, and 248 nm is investigated to recover the poisoned Pt-PtOx surface. UV irradiation at 248 nm for 5 minutes results in sensor recovery, confirmed by further H2S sensing characterization and XPS studies on the recovered sensor. To the best of our knowledge, this is one of the first reports on UV irradiation for recovery of sulphur poisoned metal-oxide surfaces.
关键词： sulphidation,recovery,plasma oxidation,UV irradiation,core-shell nanowire
更新于2025-09-23 15:23:52