A5018691915- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- MXene and MAX Phase Materials
- 2D Materials and Applications
- nanoparticles nucleation surface interactions
- Nanowire Synthesis and Applications
- Graphene research and applications
- Advanced Materials Characterization Techniques
- Aluminum Alloys Composites Properties
- Ionic liquids properties and applications
- Extraction and Separation Processes
- Gold and Silver Nanoparticles Synthesis and Applications
- Electronic and Structural Properties of Oxides
- Catalytic Processes in Materials Science
- Copper-based nanomaterials and applications
- Semiconductor Quantum Structures and Devices
- Thermal properties of materials
- Advanced Memory and Neural Computing
- Electromagnetic wave absorption materials
- Surface and Thin Film Phenomena
- Additive Manufacturing and 3D Printing Technologies
- Nanocluster Synthesis and Applications
- Electron and X-Ray Spectroscopy Techniques
- Perovskite Materials and Applications
- Advanced Thermoelectric Materials and Devices
University of Chicago
2017-2023
Nanyang Technological University
2017
Modifying MXene surfaces Unlike graphene and transition-metal dichalcogenides, two-dimensional carbides (MXenes) have many surface sites that can be chemically modified. Etching of the aluminum layer a parent MAX phase Ti 3 AlC 2 layered material with hydrofluoric acid leads to C various terminations. Molten salts achieve uniform chloride terminations, but these are difficult further modify. Kamysbayev et al. show etching phases in molten cadmium bromide bromide-terminated MXenes then...
MXenes have the potential for efficient light-to-heat conversion in photothermal applications. To effectively utilize such applications, it is important to understand underlying nonequilibrium processes, including electron-phonon and phonon-phonon couplings. Here, we use transient electron X-ray diffraction investigate heating cooling of photoexcited at femtosecond nanosecond time scales. Our results show extremely strong coupling Ti3C2-based MXenes, resulting lattice within a few hundred...
Control of composition, stoichiometry, and defects in colloidal quantum dots (QDs) III-V semiconductors has proven to be difficult due their covalent character. Whereas the synthesis indium pnictides such as InP, InAs, InSb made significant progress, gallium-containing QDs still remain largely elusive. Gallium represent an important class excellent optoelectronic properties bulk; however, difficulty with prohibited exploration solution-processed semiconductors. Here we introduce molten...
HgTe colloidal quantum dots (QDs) are of interest because confinement semimetallic bulk allows one to synthetically control the bandgap throughout infrared. Here, we synthesize highly monodisperse QDs and tune their doping both chemically electrochemically. The monodispersity was evaluated using small-angle X-ray scattering (SAXS) suggests a diameter distribution ∼10% across multiple batches different sizes. Electron-doped display an intraband absorbance bleaching first two excitonic...
The nature of the interface between solute and solvent in a colloidal solution has attracted attention for long time. For example, surface nanocrystals (NCs) is specially designed to impart stability variety polar nonpolar solvents. This work focuses on special type colloids where molten inorganic salt or organic ionic liquid. such hard rationalize because solvents with high density mobile charges efficiently screen electrostatic double-layer repulsion, purely salts represent an extreme case...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTMonodisperse InAs Quantum Dots from Aminoarsine Precursors: Understanding the Role of Reducing AgentVishwas SrivastavaVishwas SrivastavaDepartment Chemistry and James Franck Institute, University Chicago, Illinois 60637, United StatesMore by Vishwas Srivastava, Eleanor DunietzEleanor DunietzDepartment Dunietz, Vladislav KamysbayevVladislav KamysbayevDepartment Kamysbayev, John S. AndersonJohn AndersonDepartment...
Nanomaterials dispersed in different media, such as liquids or polymers, generate a variety of functional composites with synergistic properties. In this work, we discuss liquid metals the nanomaterials' dispersion media. For example, 2D transition-metal carbides and nitrides (MXenes) can be efficiently Ga lightweight alloys Al, Mg, Li. We show that Lifshitz theory predicts strong van der Waals attraction between nanoscale objects interacting through metals. However, uniform distribution...
GaAs is one of the most important semiconductors. However, colloidal nanocrystals remain largely unexplored because difficulties with their synthesis. Traditional synthetic routes either fail to produce pure phase or result in materials whose optical properties are very different from behavior expected for quantum dots direct-gap In this work, we demonstrate a variety toward crystalline NCs. By using combination Raman, EXAFS, transient absorption, and EPR spectroscopies, conclude that...
Metal nanocrystals exhibit important optoelectronic and photocatalytic functionalities in response to light. These dynamic energy conversion processes have been commonly studied by transient optical probes date, but an understanding of the atomistic following photoexcitation has remained elusive. Here, we use femtosecond resolution electron diffraction investigate lattice responses optically excited colloidal gold nanocrystals, revealing effects nanocrystal size surface ligands on...
Abstract Nonradiative processes limit optoelectronic functionality of nanocrystals and curb their device performance. Nevertheless, the dynamic structural origins nonradiative relaxations in such materials are not understood. Here, femtosecond electron diffraction measurements corroborated by atomistic simulations uncover transient lattice deformations accompanying radiationless electronic colloidal semiconductor nanocrystals. Investigation excitation energy dependence a core/shell system...
Colloidal CdSe nanoplatelets, with the electronic structure of quantum wells, self-assemble into lamellar stacks due to large co-facial van der Waals attractions. These are shown display coherent acoustic phonons that detected from oscillatory changes in absorption spectrum observed infrared pump, probe measurements. Rather than direct excitation nanocrystals using a femtosecond laser, impulsive transfer heat organic ligand shell, excited at C-H stretching vibrational resonances, inorganic...
CdSe and CdS nanoparticles (NPs) are type I II–VI semiconductor materials with excellent optical properties. Usually various shapes of these NPs show a strong emission only from or single domain, while the core combined shell is effectively suppressed due to ultrafast hole relaxation into core. Therefore, design synthesis heteronanostructures based on paramount importance in designing ways integrating useful complex hybrid structures. Here we demonstrate ligand-combination inducing growth...
MXenes are a large and fast-growing family of two-dimensional materials.Their name highlights their sheet-like nature (as is often associated with graphene) synthesis from parent MAX phase material.MXenes -Mn+1XnTx , where M transition metal, X carbon or nitrogen T the surface functional group -are typically synthesized bulk material though etching main element (A) aqueous HF solutions more recently Lewis acidic molten salts 1.With over 80 experimentally phases, MXene has potential to become...