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- 摘要
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- 实验方案
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Controllable Core–Shell BaTiO <sub/>3</sub> @Carbon Nanoparticle-Enabled P(VDF-TrFE) Composites: A Cost-Effective Approach to High-Performance Piezoelectric Nanogenerators
摘要： Piezoelectric nanogenerators (PENGs), as a promising solution to harvest mechanical energy from ambient environment, have attracted much attention over the past decade. Here, the core-shell structured BaTiO3@Carbon (BT@C) nanoparticles (NPs) were synthesized by simple surface-modifying method and then used to fabricate the efficient PENGs with poly [(vinylidene fluoride)-co-trifluoroethylene] (P(VDF-TrFE)). The carbon shell with the uniform thickness of 10-15nm can increase the content of polar β phase in P(VDF-TrFE), and significantly enhance the interfacial polarization between BT NPs and polymer matrix during poling process. Out of all compositions, 15wt% BT@C/ P(VDF-TrFE) PENG exhibited the optimal piezoelectric performance with an output voltage of ~17V and the maximum power of 14.3μW under bending-releasing mode. More importantly, the PENG can also efficiently harvest other types of mechanical energy from human activities and exhibits stable output after 1500 bending-releasing cycles. When the PENG was bent and beat by bicycle spokes, a peak voltage of 16V was generated, which can light up 12 white LEDs directly and charge the commercial capacitors. Our research provides a new strategy to fabricate flexible and efficient PENGs from nanoscale viewpoint, it can be hopefully applied in energy harvesting system and wearable electric sensors.
关键词： Core-shell structure,energy harvesting,Interfacial polarization,composite material,piezoelectric nanogenerator
更新于2025-09-12 10:27:22
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Electronic coupling in colloidal quantum dot molecules; the case of CdSe/CdS core/shell homodimers
摘要： Coupled colloidal quantum dot molecules composed of two fused CdSe/CdS core/shell sphere monomers were recently presented. Upon fusion, the potential energy landscape changes into two quantum dots separated by a pretuned potential barrier with energetics dictated by the conduction and valence band offsets of the core/shell semiconductors and the width controlled by the shell thickness and the fusion reaction conditions. In close proximity of the two nanocrystals, orbital hybridization occurs, forming bonding and antibonding states in analogy to the hydrogen molecule. In this study, we examine theoretically the electronic and optical signatures of such a quantum dot dimer compared to its monomer core/shell building-blocks. We examine the effects of different core sizes, barrier widths, different band offsets, and neck sizes at the interface of the fused facets on the system wave-functions and energetics. Due to the higher effective mass of the hole and the large valence band offset, the hole still essentially resides in either of the cores, breaking the symmetry of the potential for the electron as well. We found that the dimer signature is well expressed in a red shift of the band gap both in absorption and emission, in slower radiative lifetimes and in an absorption cross section which is significantly enhanced relative to the monomers at energies above the shell absorption onset, while remains essentially at the same level near the band-edge. This study provides essential guidance to predesign of coupled quantum dot molecules with specific attributes which can be utilized for various new opto-electronic applications.
关键词： optical signatures,CdSe/CdS core/shell,electronic coupling,colloidal quantum dot molecules,quantum dot dimer
更新于2025-09-12 10:27:22
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Core–Shell‐Heterostructured Magnetic–Plasmonic Nanoassemblies with Highly Retained Magnetic–Plasmonic Activities for Ultrasensitive Bioanalysis in Complex Matrix
摘要： Herein, a facile self-assembly strategy for coassembling oleic acid-coated iron oxide nanoparticles (OC-IONPs) with oleylamine-coated gold nanoparticles (OA-AuNPs) to form colloidal magnetic–plasmonic nanoassemblies (MPNAs) is reported. The resultant MPNAs exhibit a typical core–shell heterostructure comprising aggregated OA-AuNPs as a plasmonic core surrounded by an assembled magnetic shell of OC-IONPs. Owing to the high loading of OA-AuNPs and reasonable spatial distribution of OC-IONPs, the resultant MPNAs exhibit highly retained magnetic–plasmonic activities simultaneously. Using the intrinsic dual functionality of MPNAs as a magnetic separator and a plasmonic signal transducer, it is demonstrated that the assembled MPNAs can achieve the simultaneous magnetic manipulation and optical detection on the lateral flow immunoassay platform after surface functionalization with recognition molecules. In conclusion, the core–shell-heterostructured MPNAs can serve as a nanoanalytical platform for the separation and concentration of target compounds from complex biological samples using magnetic properties and simultaneous optical sensing using plasmonic properties.
关键词： magnetic–plasmonic nanoassemblies,highly retained magnetic-plasmonic activities,core–shell heterostructures,lateral flow,self-assembly,immunoassays
更新于2025-09-12 10:27:22
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Signature of plasmonic nanoparticles in multi-wavelength low power random lasing
摘要： A multi-wavelength plasmonic random lasing is attained by core-shell nanoparticles and the mixture of metallic nanoparticles in the host dye medium. The plasmonic nanoparticles, fabricated using laser ablation in liquid, were mixed in the corresponding dye medium and pumped with green nano-second pulsed laser. Due to this optical pumping process of plasmonic nanoparticles, amplification of the fluorescence and the lasing activity took place due to the localized surface plasmon resonance and scattering of each nanoparticle, core-shell and mixture nanoparticles. Our results show efficient coherent random lasing due to the interface between two different metallic nanoparticles in the middle part of the visible spectral region considering its applicability in the design and fabrication of compact and miniaturized random laser sources.
关键词： Plasmonic nanoparticles,Dye,Random laser,Core shell,Coherent laser
更新于2025-09-12 10:27:22
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Detection of lead Using Thioglycolic Acid Capped ZnSe and ZnSe@ZnS core-shell Quantum Dots
摘要： Herein, we proffer a sensitive and selective sensor using ZnSe and ZnSe@ZnS quantum dots (QDs), for detection of toxic metal ions at nm level. It has been found that the TGA capped ZnSe and ZnSe@ZnS QDs were apparently sensitive to Pb2+ ions as perceptible from their fluorescence quenching measurements. However, in case of few common heavy metal ions such as Zn2+, Co2+, Fe2+, , Mg2+, Cu2+, Ni2+ and Cd2+ ions, negligible quenching compared to Pb2+ ions was noted. Hence, we have successfully detected Pb2+ ions in aqueous solutions based on the photoluminescence (PL) spectroscopy. The observed linearity range was from 10 NM to 100 nM for both Pb2+ ions. An alternative QD based sensor for the spectroscopic detection, and concentration quantification of Pb2+ ions is proposed.
关键词： Metal ions,Photoluminescence,Thioglycolic acid,Quantum dots,Core-shell QDs
更新于2025-09-12 10:27:22
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Nanoparticle-Mediated Cavitation via CO2 Laser Impacting on Water: Concentration Effect, Temperature Visualization, and Core-Shell Structures
摘要： By taking advantage of seeded polymer nanoparticles and strong photo energy absorption, we report co2 laser impacting on water to produce cavitation at the air/water interface. Using a high-speed camera, three regimes (no cavitation, cavitation, and pseudo-cavitation) are identified within a broad range of nanoparticles concentration and size. The underlying correlation among cavitation, nanoparticles and temperature is revealed by the direct observation of spatiotemporal evolution of temperature using a thermal cameral. These findings indicate that nanoparticles not only act as preexisted nuclei to promote nucleation for cavitation, but also likely affect temperature to change the nucleation rate as well. Moreover, by exploiting a compound hexane/water interface, a novel core-shell cavitation is demonstrated. This approach might be utilized to attain and control cavitations by choosing nanoparticles and designing interfaces while operating at a lower laser intensity, for versatile technological applications in material science and medical surgery.
关键词： temperature visualization,nanoparticle,CO2 laser,cavitation,core-shell structures
更新于2025-09-12 10:27:22
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Dielectric environment effect on linear and nonlinear optical properties for CdS/ZnS core/shell quantum dots
摘要： The eigenvalues, transition energy, the linear and nonlinear dielectric functions have been numerically investigated for CdS/ZnS spherical core/shell quantum dots embedded in various dielectric matrices. The evaluation was carried out for three commonly used matrices, such as PVA, PMMA and SiO2. Calculations were done under the effective mass approximation and compact density matrix approach. Results revealed that the nonlinear optical property is strongly affected by the nature of the matrix material. By increasing core/shell radii ratio the energy states as well as the transition energy are decreasing. It is also indicated that the presence of the dielectric mismatch in the QD-matrix system can cause significant enhancement on the linear and third order nonlinear dielectric function.
关键词： Complex dielectric function,Core/shell,Density matrix approach,Effective mass approximation,Nonlinear optic
更新于2025-09-12 10:27:22
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Interband optical absorption in wurtzite GaN/InxGa1?xN/GaN spherical quantum dots with built-in electric field
摘要： Based on the principle of density matrix and the finite element method, the interband optical absorption between the electron and hole has been investigated in a wurtzite GaN/InxGa1?xN/GaN spherical core–shell quantum dot (CSQD) including a strong built-in electric field (BEF). We have studied the effects of the size and the ternary mixed crystal on the optical absorption coefficients (ACs) and refraction index changes (RICs). The results indicate that the absorption peaks of ACs and RICs decrease rapidly, and show a redshift with the increase of the component x. It is also found that the absorption peaks of ACs and RICs reduce obviously and depend on the core radius and the well width. When the core radius increases, the positions of the maximum ACs and RICs show a blueshift. At the same time, it presents a redshift when the well width increases. Particularly, the influence of the well width is much stronger than the core radius in the wurtzite GaN/InxGa1?xN/GaN spherical CSQDs. We hope that these results could provide guidance on both theoretical and experimental study related to the optical properties of spherical CSQDs.
关键词： Core–shell quantum dot,built-in electric field,optical property,ternary mixed crystal effect
更新于2025-09-12 10:27:22
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Wet non-thermal integration of nano binary silicon-gold system with strong plasmonic and luminescent characteristics
摘要： We report on a wet none thermal integration of the binary silicon-gold nano system. Instead of thermally based gas-solid procedures, we use charge exchange/injection-based procedures in a chemical wet environment. SEM and TEM imaging and EDX show 0-D gold-silicon core-shell structures with diameters ranging from 6 to 500 nm in addition to a variety of silicon and gold nano structures. Optical and florescence spectroscopy show that colloids exhibit strong red luminescence and plasmonic resonance in the visible. Mie theory analysis of light scattering is in agreement with the optical observation. The results and procedures are discussed in terms of the relative electron/hole affinity, Schottky potential barrier, strength of the metal-silicon bond, as well as the surface diffusion of metal atoms or clusters on the interface of the constituent materials. Integration of gold and silicon, at the nanoscale in the form core-shell architecture affords the functionalities and attributes of plasmonic light scattering imaging and fluorescence imaging that would be useful for a wide variety of applications, including optical filters, sensing, therapeutics and tracking, and cancer therapy.
关键词： plasmonic,silicon-gold nano system,luminescent,Mie theory,core-shell structures
更新于2025-09-12 10:27:22
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Core/Shell Nanocrystal Tailored Carrier Dynamics in Hysteresis-Less Perovskite Solar Cell with ~20% Efficiency and Long Operational Stability
摘要： The ambient stability, hysteresis and trap states in organo-halide perovskite solar cells (PSCs) are correlated to the influence of interlayer interfaces and grain boundaries. Astute incorporation of Cu2ZnSnS4 (CZTS) and Au/CZTS core/shell nanocrystals (NCs) can achieve the goal of simultaneously achieving better performance and ambient stability of the PSCs. With optimized Au/CZTS NC size and concentration in the photoactive layer, power conversion efficiency can be increased up to 19.97±0.6% with ambient air stability ?800 h, as compared to 14.46±1.02% for the unmodified devices. Through efficient carrier generation by CZTS and perovskite, accompanied by the plasmonic effect of Au, carrier density is sufficiently increased as validated from transient absorption spectroscopy. NCs facilitate the interfacial charge transfer by suitable band alignment, and removal of recombination centers such as metallic Pb0, surface defects or impurity sites. NC-embedding also increases the perovskite grain size and assist in pin-hole filling, reducing the trap state density.
关键词： Carrier Dynamics,Perovskite Solar Cells,Plasmonics,Optoelectronics,Energy Conversion and Storage,Operational Stability,Hysteresis-Less,Core/Shell Nanocrystals
更新于2025-09-12 10:27:22