A5072725184- Quantum Dots Synthesis And Properties
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Perovskite Materials and Applications
- Nanocluster Synthesis and Applications
- Theoretical and Computational Physics
- Solid-state spectroscopy and crystallography
- Neuroscience and Neural Engineering
- Quantum, superfluid, helium dynamics
- Seismology and Earthquake Studies
- Rare-earth and actinide compounds
- Material Dynamics and Properties
- High-pressure geophysics and materials
- Molecular Junctions and Nanostructures
- Semiconductor materials and devices
- Photoreceptor and optogenetics research
- Seismic Waves and Analysis
- Copper-based nanomaterials and applications
- Electronic and Structural Properties of Oxides
- Surface and Thin Film Phenomena
- Iron-based superconductors research
- Optical properties and cooling technologies in crystalline materials
- Advancements in Semiconductor Devices and Circuit Design
- Atomic and Subatomic Physics Research
- Methane Hydrates and Related Phenomena
Brown University
2017-2025
John Brown University
2017-2025
University of Florida
2010-2022
Providence College
2017
Nagoya University
1974-2016
Toyoda Gosei (Japan)
2014
Kyoto University
1978-2013
Instituto de Física Teórica
1992-2013
The University of Tokyo
2010
Association for the Development of Earthquake Prediction
2010
Effect of the spin-orbit interaction is studied for random potential scattering in two dimensions by renormalization group method. It shown that localization behaviors are classified three different types depending on symmetry. The recent observation negative magnetoresistance MOSFET discussed.
Lead halide perovskites are promising materials for a range of applications owing to their unique crystal structure and optoelectronic properties. Understanding the relationship between atomic/mesostructures associated properties perovskite is crucial application performances. Herein, detailed pressure processing CsPbBr3 nanocube superlattices (NC-SLs) reported first time. By using in situ synchrotron-based small/wide angle X-ray scattering photoluminescence (PL) probes, NC-SL structural...
Lead-free double perovskite nanocrystals (NCs) have emerged as a new category of materials that hold the potential for overcoming instability and toxicity issues lead-based counterparts. Doping chemistry represents unique avenue toward tuning optimizing intrinsic optical electronic properties semiconductor materials. In this study, we report first example doping Yb3+ ions into lead-free Cs2AgBiX6 (X = Cl-, Br-) NCs via hot injection method. The endows with newly near-infrared emission band...
Concerns about the toxicity of lead-based perovskites have aroused great interest for development alternative lead-free perovskite-type materials. Recently, theoretical calculations predict that Pb2+ cations can be substituted by a combination Cu2+ and Sb3+ to form vacancy-ordered layered double perovskite structure with superior optoelectronic properties. However, accessibilities this class materials remain inadequate, hindering their practical implementations in various applications. Here,...
Abstract Doping metal ions into lead halide perovskite nanocrystals (NCs) has attracted great attention over the past few years due to emergence of novel properties relevant optoelectronic applications. Here, synthesis Mn 2+ /Yb 3+ codoped CsPbCl 3 NCs through a hot‐injection technique is reported. The resulting show unique triple‐wavelength emission covering ultraviolet/blue, visible, and near‐infrared regions. By optimizing dopant concentrations, total photoluminescence quantum yield (PL...
Developing Type-I core/shell quantum dots is of great importance toward fabricating stable and sustainable photocatalysts. However, the application systems has been limited due to strongly confined photogenerated charges by energy barrier originating from wide-bandgap shell material. In this project, we found that through decoration Au satellite-type domains on surface CdS/ZnS dots, such an can be effectively overcome over 400-fold enhancement photocatalytic H2 evolution rate was achieved...
Two-dimensional single-crystal PbS nanosheets were synthesized by deviatoric stress-driven orientation and attachment of nanoparticles (NPs). In situ small- wide-angle synchrotron X-ray scattering measurements on the same spot sample under pressure coupled with transmission electron microscopy enable reconstruction nucleation route showing how enhanced stress causes ordering NPs into a lamellar mesostructure. At time that drives SC(110) in face-centered-cubic supercrystal (SC), rocksalt (RS)...
Hybrid organic–inorganic formamidinium lead halide perovskite nanocrystals can be synthesized through a solid–liquid–solid cation exchange reaction.
Quasicrystalline superlattices (QC-SLs) generated from single-component colloidal building blocks have been predicted by computer simulations but are challenging to reproduce experimentally. We discovered that 10-fold QC-SLs could self-organize truncated tetrahedral quantum dots with anisotropic patchiness. Transmission electron microscopy and tomography measurements allow structural reconstruction of the QC-SL nanoscale packing atomic-scale orientation alignments. The unique QC order leads...
Cooper pair formation in the heavy fermion system is discussed on basis of a tight-binding model for Kondo lattice system. The attractive interaction between fermions stems from coupling with phonons, which arises through modulations transfer to nearest neighbor site and single-particle level owing vibrations. relevant written form superposition separable forms s-, d- p-like symmetries. A comparison among transition temperatures various types pairing shows that singlet always favorable...
We report a host–guest chemistry approach to controlling the structures of nanocrystal superlattices through molecular inclusion process. Upon addition an appropriate amount guest molecules such as squalane, polyisoprene, and 4-cyano-4′-pentylbiphenyl into suspension, resulting adopted non-close-packed (e.g., from face-centered cubic body-centered cubic) changed their morphologies form superparticles. Our mechanistic studies revealed that these can strongly tailor kinetic process in...
Heterostructural core–shell quantum dots (hetero-QDs) have garnered a copious amount of research effort for not only scientific advances but also range technological applications. Particularly, controlling the heteroshell deposition, which in turn determines particle morphology, is vital regulating photophysical properties and application potential hetero-QDs. In this work, we present first report on synthesis pyramidal shaped (i.e., hexagonal pyramid, HP, bipyramid, HBP) CdSe-CdS hetero-QDs...
This report presents the fabrication and pressure-driven processing of heterostructural nanocrystal superlattices (HNC-SLs) self-assembled from quantum-dot-Au (QD-Au) satellite-type HNCs. In situ small/wide-angle X-ray scattering electron microscopic measurements showed that HNC-SLs underwent structural transformation at both atomic- mesoscales during pressure processing. Upon deviatoric stress-driven orientational migration, intraparticle coalescence Au satellites QD surfaces transforms...
Manganese-doped cesium lead chloride (CsPbCl3) perovskite nanocrystals (NCs) have recently garnered attention because of their unique magneto-optical properties, giving them potential in a variety optoelectronic applications. One common method to dope Mn2+ into host CsPbCl3 NCs is through postsynthetic ion exchange reaction. However, most strategies utilize Mn2+-containing precursor solution, which adds limitations the reaction due compatibility and stability issues. Here, we report new...
Self-assembly of nanocrystals is a promising route for creating macroscale materials that derive function from the properties their nanoscale building blocks. While much progress has been made assembling into different superlattices, controlling relative orientations in those lattices remains challenge. Here, we combine experiments with computer simulations to study self-assembly patchy heterostructural (HNCs), consisting near-spherical quantum dots decorated regular arrangements small gold...
The ambient metastability of the rock-salt phase in well-defined model systems comprising nanospheres or nanorods cadmium selenide, sulfide, both was investigated as a function composition, initial crystal phase, particle structure, shape, surface functionalization, and ordering level their assemblies. Our experiments show that these nanocrystal exhibit ligand-tailorable reversibility rock salt-to-zinc blende solid-phase transformation. Interparticle sintering used to engineer kinetic...
An approximation is proposed for the magnetic-impurity effect on superconductivity, where many-body of impurities, i.e., Kondo effect, fully taken into account. It an interpolation between behavior in two limiting cases; pair-breaking due to magnetic scattering electrons high-temperature and energy region, effective repulsive interaction Cooper-pair mediated by virtual polarization impurities low-temperature region. Using this approximation, superconducting transition temperature upper...
This Article reports a mechanistic study on the formation of colloidal UO(2)/In(2)O(3) and FePt/In(2)O(3) heterodimer nanocrystals. These dimer nanocrystals were synthesized via growth In(2)O(3) as epitaxial material onto seed UO(2) or FePt. The resulting characterized using X-ray powder diffraction (XRD), energy dispersion spectroscopy, transmission electron microscopy (TEM), scanning microscopy, high-resolution TEM (HRTEM). results from XRD HRTEM clearly show that lattice strains exist in...
Transition metal doping in semiconductor quantum dots (QDs) significantly impacts their optical properties, thus expanding the range of potential optoelectronic applications. This study investigates pressure-dependent energy transfer dynamics Mn2+-doped CdS/ZnS core/shell QDs, focusing on how external hydrostatic pressure modulates these and properties. By synthesizing QDs with varying Mn2+ concentrations, we explore effects photoluminescence (PL) spectra efficiency. Our reveals that...
We investigate the superfluid transition of 4He then film adsorbed on porous materials with emphasis role vortices. Considering multi-connectivity film, we show that interaction among vortices excited in is essentially one dimensional due to quantum behavior flow. As a result, it generally shown do not dissociate at Tλ where long range order (LRO) vanishes contrast two case.
Nanocrystals (NCs) can self-assemble into ordered superlattices with collective properties, but the ability for controlling NC assembly remains poorly understandable toward achievement of desired superlattice. This work regulates several key variables PbS (e.g., concentration and solubility, solvent type, evaporation rate, seed mediation thermal treatment), thoroughly exploits nucleation growth as well subsequent superlattice transformation assembles underneath mechanisms. NCs in toluene a...