- 标题
- 摘要
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- 实验方案
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Ambient-Processed, Additive-Assisted CsPbBr3 Perovskite Light-Emitting Diodes with Colloidal NiOx Nanoparticles for Efficient Hole Transporting
摘要： In this study, the electrically driven perovskite light-emitting diodes (PeLEDs) were investigated by hybridizing the organic polyethylene oxide, 1,3,5-tris (N-phenylbenzimiazole-2-yl) benzene (TPBi), and bis(3,5-di?uoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium III (FIrpic) with CsPbBr3 in the emission layer and adopting the colloidal NiOx nanoparticle (NP) hole transport layer. The synthesized NiOx NPs, having an average size of ~5 nm, can be spin-coated to become a smooth and close-packed ?lm on the indium–tin–oxide anode. The NiOx NP layer possesses an overall transmittance of ~80% at 520 nm, which is about the peak position of electroluminescence (EL) spectra of CsPbBr3 emission layer. The coating procedures of NiOx NP and CsPbBr3 layers were carried out in ambient air. The novel PeLED turned on at 2.4 V and emitted bright EL of 4456 cd/m2 at 7 V, indicating the remarkable nonradiative-related defect elimination by organic additive addition and signi?cant charge balance achieved by the NiOx NP layer.
关键词： colloidal NiOx nanoparticles,organic additives,ambient-process,perovskite light-emitting diodes (PeLEDs),inorganic lead halide perovskites
更新于2025-09-23 15:19:57
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Excess Random Laser Action in Memories for Hybrid Optical/Electric Logic
摘要： To surmount the scalability limitations of the nano-electronics industry, the invention of resistance random access memory (RRAM) has drawn considerable attention in recent years for being a new-era memory. Nevertheless, the data transmission speed of RRAM is confined by virtue of its sequential reading nature. To improve upon this weakness, a hybrid optical/electric memory with ION/IOFF ratio up to 105 and laser-level optical signal is proposed. The device was engineered through an adroit design of integrating a random laser (RL) into the conducting bridge random access memory (CBRAM). According to the electrochemical metallization (ECM) effect of CBRAM, agglomerative silver nanoparticles form in the insulating layer during the ON/OFF switching process, which can serve as scattering centers. By adding CdSe/ZnS quantum dots (QDs) as gain medium, a random laser system is obtained. Due to the quantum confinement effect, the device also features spectral tunable signal feedback by modulating the size of the QDs. In this study, devices with two different sizes of QDs are demonstrated such that a multiple-bits AND gate logic can be achieved. The innovation behind this RL-ECM memory might facilitate a key step toward the development of ultrahigh speed information technology.
关键词： RRAM,AND gate logic,random laser,electrochemical metallization effect,CdSe/ZnS colloidal quantum dots
更新于2025-09-23 15:19:57
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Nanoshell quantum dots: Quantum confinement beyond the exciton Bohr radius
摘要： Nanoshell quantum dots (QDs) represent a novel class of colloidal semiconductor nanocrystals (NCs), which supports tunable optoelectronic properties over the extended range of particle sizes. Traditionally, the ability to control the bandgap of colloidal semiconductor NCs is limited to small-size nanostructures, where photoinduced charges are confined by Coulomb interactions. A notorious drawback of such a restricted size range concerns the fact that assemblies of smaller nanoparticles tend to exhibit a greater density of interfacial and surface defects. This presents a potential problem for device applications of semiconductor NCs where the charge transport across nanoparticle films is important, as in the case of solar cells, field-effect transistors, and photoelectrochemical devices. The morphology of nanoshell QDs addresses this issue by enabling the quantum-confinement in the shell layer, where two-dimensional excitons can exist, regardless of the total particle size. Such a geometry exhibits one of the lowest surface-to-volume ratios among existing QD architectures and, therefore, could potentially lead to improved charge-transport and multi-exciton characteristics. The expected benefits of the nanoshell architecture were recently demonstrated by a number of reports on the CdSbulk/CdSe nanoshell model system, showing an improved photoconductivity of solids and increased lifetime of multi-exciton populations. Along these lines, this perspective will summarize the recent work on CdSbulk/CdSe nanoshell colloids and discuss the possibility of employing other nanoshell semiconductor combinations in light-harvesting and lasing applications.
关键词： Optoelectronic properties,Nanoshell quantum dots,CdSbulk/CdSe nanoshell,Colloidal semiconductor nanocrystals,Quantum confinement
更新于2025-09-23 15:19:57
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Nonlinear optical properties of colloidal CdSe/ZnS quantum dots in PMMA
摘要： The colloidal CdSe/ZnS quantum dots (QDs) in the PMMA polymer film with different QDs concentrations were fabricated. The influence of QDs concentration and excitation pump energy on nonlinear optical (NLO) properties of PMMA capped CdSe/ZnS QDs was investigated by the Z-scan technique with nanosecond laser pulses in the near-infrared spectral band. A large effective nonlinear absorption coefficient (βeff～?10?13 esu) due to the saturable absorption was observed. It was found that the appropriate concentration could lead to the reinforcement of NLO effect. In addition, the impact of the excitation energy on the nonlinear refractive index n2, real and imaginary parts of the third-order nonlinear optical susceptibility was also performed. This study involving the light–matter interactions in the colloidal quantum dots will benefit potential NLO-based applications of optoelectronics, optical modulation and photonics.
关键词： nanophotonics,semiconductor colloidal quantum dots,impact behavior,Z-scan technique,nonlinear optical (NLO) properties
更新于2025-09-23 15:19:57
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Prolonged Lifetime in Nanocrystal Light-Emitting Diodes Incorporating MoS <sub/>2</sub> -Based Conjugated Polyelectrolyte Interfacial Layer as an Alternative to PEDOT:PSS
摘要： Colloidal semiconductor nanocrystals (NCs), and recently nanoplatelets (NPLs), owing to their efficient and narrowband luminescence, are considered as frontier materials for the light-emitting diode (LED) technology. NC-LEDs typically incorporate interfacial layers as charge regulators to ensure charge balancing and high performance. In this communication, we show the prolongation of the lifetime of multilayer solution-processed NC-LEDs by combining a self-doped conductive conjugated polyelectrolyte and exfoliated molybdenum disulfide (MoS2) flakes as an alternative to PEDOT:PSS. The ink features a neutral pH and a tunable hydrophobicity that mainly results in a remarkable stability of LEDs, using CdSe/CdZnS NPLs.
关键词： di-chalcogenides,colloidal nanoplatelets,interfacial layers,light-emitting devices,conjugated polyelectrolytes
更新于2025-09-23 15:19:57
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Top-down Fabrication of Colloidal Plasmonic MoO <sub/>3-x</sub> Nanocrystals via Solution Chemistry Hydrogenation
摘要： A high-efficiency top-down approach was used to fabricate orthorhombic MoO3-x nanocrystals through the synergic effect of oleic acid (OA) and oleylamine (OAm), in which OA providing H+ ions and OAm contributing free electrons. This investigation might provide new guidance for manipulating the optical properties of metal oxide semiconductors.
关键词： top-down fabrication,solution chemistry hydrogenation,oleic acid,oleylamine,colloidal plasmonic MoO3-x nanocrystals
更新于2025-09-23 15:19:57
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Laser ablation of Ni in the presence of external magnetic field: Selection of microsized particles
摘要： The study presents results of nanosecond laser ablation of a Ni target in a liquid as a method of producing contamination-free micro- and nanosized colloidal structures. The ablation was performed in two liquids – double distilled water and ethanol, as their role on the characteristics of the ablated material is clarified. The laser ablation method in liquid was extended by applying an external magnetic field during the ablation process. A separation of micron and submicron particles from the nanoparticles in the colloidal solution is achieved by placing a substrate in the liquid, where the micron size structures are deposited under the action of the external magnetic field. At certain experimental conditions, the deposition of ordered one-dimensional microstructures on the substrate can be realized. The influence of different laser wavelengths on the features of the nanostructures dispersed in the liquid and microstructures deposited on the substrate was also investigated. On the basis of detailed analyses using Optical Microscopy, Scanning Electron Microscopy, Selected area electron diffraction, and Transmission Electron Microscopy the morphology, composition, and size distribution of the fabricated structures were studied. The presented method allows the fabrication of contamination-free micro- and nanostructures with potential applications in biotechnology, catalysis, and magneto-optics devices.
关键词： Laser ablation in liquid,Metal nanoparticles,Microstructures,Colloidal solution,External magnetic field
更新于2025-09-23 15:19:57
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Optimizing Solid-State Ligand Exchange for Colloidal Quantum Dot Optoelectronics: How Much Is Enough?
摘要： Progress in chalcogenide and perovskite CQD optoelectronics has relied in significant part on solid-state ligand exchanges (SSEs): the replacement of initial insulating ligands with shorter conducting linkers on CQD surfaces. Herein we develop a mechanistic model of SSE employing 3-mercaptopropionic acid (MPA) and 1,2-ethanedithiol (EDT) as the linkers. The model suggests that optimal linker concentrations lead to efficient exchange resulting in ca. 200 – 300 exchanged ligands per CQD, a 50% thickness reduction of the initial film, decreased interdot spacing, a 15 nm red-shift in the excitonic absorption peak and a 10x reduction in carrier lifetime. It is a combined effect of these physico-chemical changes that have traditionally made 1% MPA and 10-2% EDT (v:v) the concentrations of choice for efficient CQD optoelectronics.
关键词： Colloidal quantum dots,1,2-ethanedithiol,solid-state ligand exchange,3-mercaptopropionic acid,solar cells
更新于2025-09-23 15:19:57
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Self-assembled binary photonic crystals under the active confinement and their light trapping
摘要： The self-assembly of oppositely charged colloidal ellipsoids and spheres under the active con?nement is ?rstly proposed to achieve long-range ordered photonic crystals. Compared with the conventional passive con?nement, a characteristic of the active con?nement is that boundaries are movable. Our Brownian dynamics simulations show that dynamic steady structures, similar to quasi-2D colloidal crystals, can be obtained under the strong con?nement when the two boundaries periodically oscillate together. The in-plane structures can be regulated by changing the charge ratio of the two kinds of particles. These dynamic steady structures are determined by the minimum electrostatic energy with the aid of increased mobility of con?ned particles, which are not available in equilibrium. Numerical simulations verify that light can be perfectly con?ned in this dielectric binary photonic slab without any radiation, which corresponds to a typical optical bound state with divergent lifetime and ultrasharp spectral pro?le. Given the changeable geometry of this photonic slab, the trapped optical ?eld might be applicable to enhanced light-matter interactions. In addition, for thicker layers, layer-by-layer ordered structures occur spontaneously driven by the active con?nement, while no global order in the passive con?nement. Our results show that the boundary motion can become an important factor a?ecting self-assembled structure and function.
关键词： colloidal crystals,light trapping,active con?nement,photonic crystals,self-assembly
更新于2025-09-23 15:19:57
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Two Birds with One Stone: Manipulating Colloids Assembled into Amorphous and Ordered Photonic Crystals and Their Combinations for Coding-Decoding
摘要： Photonic crystals including amorphous and ordered photonic crystals (APCs and OPCs) show wide applications in color displays, sensors, and pigments. The fabrication of APCs and OPCs in one method is highly desired, however, it remains a big challenge due to the lack fine control the of the assemble behavior of the colloids. Herein, an efficient surface charge assisted colloidal assembly (SCACA) is developed to fabricate APCs with noniridescent structural colors and OPCs with iridescent colors by the co-assembly of aminated silica particles and nanosized carbon black (CB) in solution with different pH value. The surface charge of the particle is demonstrated to be the key to manipulate the assembly behavior of the particles, thus, the structure, defect, reflection intensity, and angle in/dependent structural color of the photonic crystals can be precisely controlled. Compared with previous strategies, SCACA is considerable simple and efficient in preparing APCs and OPCs which makes the fabrication more controllable, convenient and scalable. Moreover, through combing the noniridescent and iridescent structural colors of APCs and OPCs, a single color and multicolor based coding-decoding system are developed, in which the structural colors, numbers, positions, and angle in/dependency of codes can be hided and recognized by naked eyes at varied viewing angles. This work provides a new insight for precise manipulating the assembly of the colloids into APCs and OPCs, and extends their combined applications in anti-counterfeiting and information storage.
关键词： Surface charge assisted colloidal assembly,Photonic crystals,Coding-decoding system,Ordered photonic crystals,Amorphous photonic crystals
更新于2025-09-23 15:19:57