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Additive-controlled synthesis of monodisperse single crystalline gold nanoparticles: interplay of shape and surface plasmon resonance
摘要： We introduce a three-step seed-mediated synthesis for single crystalline gold nanoparticles (Au NPs) stabilized by hexadecylpyridinium chloride (CPC) in variable sizes with an adjustable ratio of the cubic and octahedral facets. The effect of KBr and ascorbic acid (AA) on shape and growth kinetics is systematically investigated. The kinetic data were evaluated using the minimalistic Finke-Watzky autocatalytic two-step mechanism, which allows to estimate the rate constants of the “pseudoelementary” reactions. The proposed surface-mediated mechanism of reduction of gold ions and Au NPs growth allows to explain the effect of gradual increase of bromide ion concentration on switching the Au NPs morphology from cubic to octahedral. The plasmonic properties of single particles of different facetings and their assemblies are investigated.
关键词： gold nanoparticles,Finke-Watzky mechanism,plasmonic properties,seed-mediated synthesis,surface plasmon resonance
更新于2025-09-23 15:21:01
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Enhancing Galvanic Replacement in Plasmonic Hollow Nanoparticles: Understanding the Role of the Speciation of Metal Ion Precursors
摘要： Hollow nanostructures offer great potential for plasmonic applications due to their strong and highly tunable localized surface plasmon resonance. The relationship between the plasmonic properties and geometry of hollow nanoparticles, such as core-shell size ratio, concentricity of the cavity and porosity of the wall, is well documented. Nanoscale galvanic replacement provides a simple, versatile and powerful route for the preparation of such hollow structures. Here we demonstrate how the efficiency of reductant-assisted galvanic replacement processes can be enhanced by controlling the degree of hydration and hydrolysis of the metal ion precursor using pH and pL as key control parameters (by analogy to pH, the letter p in the expression pL is used to indicate the decimal cologarithm associated with the concentration of the ligand L). Adjusting precursor speciation prior to the sacrificial template’s hollowing process offers a new strategy to tune the morphology and optical properties of plasmonic hollow nanostructures.
关键词： co-reduction,localized surface plasmon resonance,nanoscale galvanic replacement,hollow nanoparticle synthesis,Ag-Au, Ag-Pd and Ag-Pt alloys,aqueous metal ion speciation
更新于2025-09-23 15:21:01
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Direct carbonization of organic solvent toward graphene quantum dots
摘要： The bottom-up synthesis of graphene quantum dots (GQDs) using solvothermal method has attracted considerable attention because of their fewer defects and controllable size/ morphology. However, the influence of organic solvent on the preparation of GQDs is still unknown. Herein, a systematic study about carbonization of organic solvents toward GQDs is reported. Results show that organic solvent with the double bond or benzene ring or double hydrophilic groups could be directly decomposed into GQDs without the addition of catalysts or molecule precursors. The as-synthesized GQDs demonstrate ultra-small size distribution, high stability, and excitation wavelength-tunable and upconverted fluorescence. Both hematological and histopathological analyses studies show that the as-synthesized GQDs demonstrate a much good safety profile and excellent biocompatibility. The versatility of this synthetic strategy allows easy control of the surface group, composition, and optical properties of GQDs at the molecular level.
关键词： organic solvents,biocompatibility,fluorescence,graphene quantum dots,solvothermal synthesis
更新于2025-09-23 15:21:01
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Synthesis and Property of Tellurium-Containing Polymer for Extreme Ultraviolet Resist Material
摘要： Synthesis, physical properties, and resist properties of tellurium containing polymer with pendant adamantyl ester groups poly(Re-co-Te)-AD were examined, relevant to the application of resist material for extreme ultraviolet laser photolithography (EUVL) system. A tellurium containing polymer with pendant hydroxyl groups poly(Re-co-Te) was synthesized by the condensation reaction of resorcinol (Re) and tellurium tetrachloride (TeCl4), followed by the condensation reaction with adamantyl bromo acetate to give a corresponding polymer poly(Re-co-Te)-AD. Their physical properties (solubility, film-forming ability, thermal stability) and resist properties (thickness loss property after soaking in 2.38 wt% TMAH aq. solution, out-gassing on EUV exposure tool, and resist sensitivity under EUV exposure tool) were also examined.
关键词： Adamantyl ester,Synthesis,Resist,Extreme ultraviolet,Tellurium
更新于2025-09-23 15:21:01
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Synthesis of Tungsten Disulfide and Molybdenum Disulfide Quantum Dots and their Applications
摘要： With fascinating optical, electronic, and mechanical properties, tungsten disulfide (WS2) and molybdenum disulfide (MoS2) quantum dots (QDs) are promising for related applications. Their bandgap energy, photoluminescence and electrochemical properties are closely related to their size, morphology, dimensionality, crystal phase and structure. In this review, we introduce the crystal phases and structures of WS2 and MoS2 QDs followed by a summary of their physical and chemical synthetic methods and their applications in light-emitting devices (LEDs), supercapacitors and others. Additionally, the advantages and limitations of different synthetic strategies and challenges in these promising fields are discussed on the basis of current development.
关键词： Synthesis methods,Applications,Quantum dots,Molybdenum disulfide,Tungsten disulfide
更新于2025-09-23 15:21:01
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A hydrothermally synthesized MoS <sub/>2(1a??x)</sub> Se <sub/>2x</sub> alloy with deep-shallow level conversion for enhanced performance of photodetectors
摘要： Photoelectric detectors based on binary transition metal chalcogenides have attracted widespread attention in recent years. However, due to the high-temperature synthesis of binary TMD, high-density deep-level defect states may be generated, leading to poor responsiveness or a long response time. Besides, the addition of an alloy will change the DLDSs from deep to shallow energy levels caused by S vacancies. In this paper, MoS2(1?x)Se2x nanostructures were synthesized by a hydrothermal method, and a novel type of photodetector was fabricated by using the synthesized material as a light sensitive material. The MoSSe-based photodetector not only has a high photocurrent, but also exhibits a wide spectral response in the range of 405 nm to 808 nm. At the same time, it can achieve a responsivity of 1.753 mA W?1 under 660 nm laser irradiation of 1.75 mW mm?2. Therefore, this work can be considered as a method of constructing a new type of photodetector with a simple process and low cost.
关键词： MoS2(1?x)Se2x,photoelectric detectors,photodetector,transition metal chalcogenides,hydrothermal synthesis
更新于2025-09-23 15:21:01
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Potential and limitations of CsBi3I10 as photovoltaic material
摘要： Herein we demonstrate the dry synthesis of CsBi3I10 both as free-standing material as well as in the form of homogeneous thin films, deposited by thermal vacuum deposition. Chemical and optical characterization shows high thermal stability, phase purity, and photoluminescence centered at 700 nm, corresponding to a bandgap of 1.77 eV. These characteristics make CsBi3I10 a promising low-toxicity material for wide bandgap photovoltaics. Nevertheless, the performance of this material as a semiconductor in solar cells remains rather limited, which can be at least partially ascribed to a low charge carrier mobility, as determined from pulsed-radiolysis, time-resolved microwave conductivity. Further developments should focus on understanding and overcoming the current limitations in charge mobility, possibly by compositional tuning through doping and/or alloying, as well as optimizing thin film morphology which may be another limiting factor.
关键词： photovoltaic material,thermal vacuum deposition,CsBi3I10,dry synthesis,charge carrier mobility
更新于2025-09-23 15:21:01
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Integrating Properties Modification in the Synthesis of Metal Halide Perovskites
摘要： Metal halide perovskites have attracted enormous attention and show huge potential as promising building blocks of next-generation optoelectronic devices owing to their unique optical and electrical properties. For further promoting their practical applications in various fields, the synthesis of metal halide perovskites with desired characteristics is essential to satisfy the requirements of their applications. The properties of perovskites are highly related to their crystal structures and chemical compositions. The optoelectronic properties of perovskites can be altered via decreasing their dimensionality owing to the quantum confinement effect, while enlarging the crystal size of perovskite can promote the construction of device arrays with homogenous performance. In addition, modifying the chemical composition of perovskites via alloying, doping, or controlling vacancies also greatly changes their optical and electrical properties. Thus, integrating the properties modification in the synthesis process of metal halide perovskites can not only improve the productivity of the desired perovskites but also provide a great opportunity to prepare designed crystals with predictable features. The exciting progress in the synthesis of metal halide perovskites with controllably tailored properties is summarized herein. It is hoped that these technologies can promote the development of perovskites.
关键词： properties modification,metal halide perovskites,synthesis integrating
更新于2025-09-23 15:21:01
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Controlled synthesis of gold nanoparticles in copolymers nano-molds by x-ray radiolysis
摘要： We show by x-ray and neutron small angle scattering that gold nanoparticles with controlled sizes and morphologies can be obtained by the metallic reduction of AuCl4- ions trapped in 3D organic molds by x-ray radiolysis. The molds are spherical frozen micelles of polystyrene‐b‐poly(dimethylaminoethyl methacrylate) (PS‐b‐PDMAEMA) block copolymer in acidic aqueous solution with a PS spherical core surrounded by a corona of PDMAEMA chains in good solvent. The behavior of micelles is controlled by the [AuCl4-]/[DMAEMA] ratio RAuCl4-/DMAEMA. At low gold concentration, AuCl4- ions condense on the positively charged DMAEMA moieties without changing the behavior of the PDMAEMA chains. At intermediate gold concentration, the ions induce a progressive contraction of the corona’s chains and dehydration of micelles. At large gold concentration, the corona becomes a fully dry phase loaded with gold ions, which induces micelle aggregation. The radiolysis of the solution by an intense x-ray beam produces different types of gold nanoparticles with respect to RAuCl4-/DMAEMA and irradiation time. At RAuCl4-/DMAEMA = 0.033, the irradiation produces in a first step gold clusters in the micelle corona which in a second step merge to form nanoparticles of a similar size to the one of the micelle. Conversely, at RAuCl4-/DMAEMA = 0.33, micelles do not operate as templates but only as nucleation zones and large nanoparticles grow outside the micelles.
关键词： gold nanoparticles,copolymers template,x-ray radiolysis,small angle scattering,synthesis
更新于2025-09-23 15:21:01
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Gas-Phase Formation of Highly Luminescent 2D GaSe Nanoparticle Ensembles in a Nonequilibrium Laser Ablation Process
摘要： Interest in layered two-dimensional (2D) materials has been escalating rapidly over the past few decades due to their promising optoelectronic and photonic properties emerging from their atomically thin 2D structural confinements. When these 2D materials are further confined in lateral dimensions toward zero-dimensional (0D) structures, 2D nanoparticles and quantum dots with new properties can be formed. Here, we report a nonequilibrium gas-phase synthesis method for the stoichiometric formation of gallium selenide (GaSe) nanoparticles ensembles that can potentially serve as quantum dots. We show that the laser ablation of a target in an argon background gas condenses the laser-generated plume, resulting in the formation of metastable nanoparticles in the gas phase. The deposition of these nanoparticles onto the substrate results in the formation of nanoparticle ensembles, which are then post-processed to crystallize or sinter the nanoparticles. The effects of background gas pressures, in addition to crystallization/sintering temperatures, are systematically studied. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, and time-correlated single-photon counting (TCSPC) measurements are used to study the correlations between growth parameters, morphology, and optical properties of the fabricated 2D nanoparticle ensembles.
关键词： laser-based synthesis,2D materials,2D quantum dots,2D nanoparticles,laser ablation
更新于2025-09-23 15:21:01