A5105457901- Quantum Dots Synthesis And Properties
- Gold and Silver Nanoparticles Synthesis and Applications
- Advanced Photocatalysis Techniques
- Copper-based nanomaterials and applications
- Chalcogenide Semiconductor Thin Films
- Laser-Ablation Synthesis of Nanoparticles
- Nanocluster Synthesis and Applications
- Nanomaterials for catalytic reactions
- Perovskite Materials and Applications
- ZnO doping and properties
- TiO2 Photocatalysis and Solar Cells
- Organic Light-Emitting Diodes Research
- Nonlinear Optical Materials Studies
- Spectroscopy and Quantum Chemical Studies
- Organic Electronics and Photovoltaics
- Advanced biosensing and bioanalysis techniques
- Luminescence and Fluorescent Materials
- Photochemistry and Electron Transfer Studies
- Molecular Junctions and Nanostructures
- Plasmonic and Surface Plasmon Research
- Electrochemical Analysis and Applications
- Photoreceptor and optogenetics research
- Conducting polymers and applications
- nanoparticles nucleation surface interactions
- Catalytic Processes in Materials Science
Seoul National University
2013-2022
Government of the Republic of Korea
2017-2020
Seoul Institute
2015-2019
University of Seoul
2018
IMDEA Nanoscience
2009
Universitat de València
2009
Universidad Autónoma de Madrid
2009
Yonsei University
2004
Korea Research Institute of Standards and Science
1990-1991
University of California, Los Angeles
1986-1991
White-light-emitting single molecules are promising materials for use in a new generation of displays and light sources because they offer the possibility simple fabrication with perfect color reproducibility stability. To realize white-light emission at molecular scale, thereby eliminating detrimental concentration- or environment-dependent energy transfer problem conventional fluorescent phosphorescent systems, between larger band-gap donor smaller acceptor must be fundamentally blocked....
According to relative energy band positions between TiO2 and visible-light-absorbing semiconductors, three different types of heterojunction were designed, their visible-light photocatalytic efficiencies analyzed. In Type-A heterojunction, the conduction (CB) level sensitizer is positioned at a more negative side than that TiO2, whereas in Type-B system its valence (VB) positive Type-C located CB VB TiO2. evolving CO2 from gaseous 2-propanol (IP) under irradiation, systems such as...
A high‐quality ZnO nanorod array (NRA) has been successfully grown on a Si wafer by wet‐chemical process, where the was dip‐coated with 4 nm sized nanoparticles as buffer and seed layer prior to crystal growth. It is found that as‐prepared NRA threshold power density of ∼ 70 kW cm –2 , which comparable lowest one determined for NRAs Al 2 O 3 substrates (40 ). The ultraviolet lasing efficiency thus similar both substrates.
Barbell-shaped porous and hollow ZnS nanoplates with a controlled amount of S vacancies have been fabricated facilely for enhanced photocatalytic performances.
The surface of gold nanorods is coated with thickness-controlled silver by reducing AgCl43- exclusively on the metallic to form AucoreAgshell and then restored selectively removing coating. show much sharper, stronger, shorter-wavelengthed plasmon absorption than nanorods. However, wavelength longer one calculated for pure Ag This means that core−shell structure must be explicitly taken into account in these calculations.
The Mn2+ impurity luminescence decay of Mn2+-doped ZnS nanoparticles has been clearly distinguished from host emission by measuring transient absorption and kinetic profiles in the picosecond−millisecond time domain. for doped sample shows two components 0.18 2 ms. fast one is attributed to surface-bound impurities slow lattice-bound impurities. In comparison, slowest component decays within 20 ns. Moreover, excitation-energy transfer also measured occur on scale 700 ps.
Abstract Ultraviolet (UV) light photodetectors constructed from solely inorganic semiconductors still remain unsatisfactory because of their low electrical performances. To overcome this limitation, the hybridization is one key approaches that have been recently adopted to enhance photocurrent. High-performance UV showing stable on-off switching and excellent spectral selectivity fabricated based on hybrid structure solution-grown ZnS nanobelts CVD-grown graphene. Sandwiched structures...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRaman Spectroscopic Study of 1,4-Benzenedithiol Adsorbed on SilverSeong Ho Cho, Hyouk Soo Han, Du-Jeon Jang, Kwan Kim, and Myung KimCite this: J. Phys. Chem. 1995, 99, 26, 10594–10599Publication Date (Print):June 1, 1995Publication History Published online1 May 2002Published inissue 1 June 1995https://doi.org/10.1021/j100026a024RIGHTS & PERMISSIONSArticle Views1310Altmetric-Citations103LEARN ABOUT THESE METRICSArticle Views are the...
Picosecond laser pulses are employed to adjoin, hold closely, and weld gold nanoparticles on carbon-coated copper grids. Microscopic images profiles indicate that particles well connected showing single-phased nanocontact. Our results suggest laser-induced nanowelding can be achieved in a programmed manner produce ohmic contact by considering the size-dependent thermodynamic, dynamic, kinetic properties of metallic nanometerials.
Graphene quantum dots-embedded ZnS nanobelts showed 14-times higher photocatalytic activity than commercial ZnS.
ZnO nanocoral reefs and nanofibers are synthesized on the glass substrate dip coated with seed nanoparticles an average size of 5 nm under a hydrothermal reaction. The ratios length to diameter for former latter determined be 100 1000, respectively. In addition, we found that threshold power density UV lasing action could remarkably reduced from 40 kW/cm2 8 by increasing cavity nanowires.
Hollow platinum nanospheres (see figure) have been fabricated by optical excavation of the core silver metal Ag@Pt core/shell nanoparticles. The surface plasmon resonances shell were excited with picosecond laser pulses 1064 nm. Thermalized photon energy induces to melt and effuse rapidly through shell, producing smooth hollow nanospheres.
Highly luminescent CdS-core ZnS-shell nanorods stabilized by mercaptopropionic acid in water were synthesized wet-chemically and characterized measuring photoluminescence spectra kinetic profiles as well absorption spectra, diffraction patterns, electron microscope images. Photoluminescence from CdS 22 nm diameter shifts to the blue much 2.8 increases high 1.8 times with thickness of passivating ZnS shell, whereas luminescence lifetime 1:1 CdS@ZnS core−shell is shorter 1.6 at 550 than that...
A new fabrication method of CdS nanobubbles with high photocatalytic activity has been explored under ambient conditions using SiO2 hard templates and microwave irradiation. The one-step Stöber used to produce core nanospheres, onto which shells have readily efficiently coated by 10 min acid etching the cores produced monodispersive outer diameters 300, 370, 400 nm a uniform shell thickness 11 nm. found photocatalyze degradation rhodamine B Xe-lamp irradiation via simultaneous reaction...
Hedgehog-like hierarchical mesoporous anatase TiO<sub>2</sub>nanostructures show highly efficient photocatalytic and photovoltaic performances.
In this work, a simple but effective molecular design strategy is developed for the generation of intense blue emission in solid state including single crystals through multiple secondary intermolecular interactions such as CF…HC hydrogen bonding. The synthesized novel imidazole‐based excited‐state intramolecular proton transfer (ESIPT) molecule, 2‐(1‐(3,5‐bis(trifluoromethyl)phenyl)‐4,5‐diphenyl‐1H‐imidazol‐2‐yl)phenol (HPI‐CF 3 ), shows significantly enhanced fluorescence crystal (Φ F =...
A highly loaded ZnS nanoparticle (NP) array within mesoporous channels was prepared by repetitive insertion of reverse micelles. Contrary to the NPs in water pool micelles exhibiting blue emission, incorporated organically functionalized showed emission ultraviolet region with a single recombination lifetime 1.3 ± 0.2 ns. Such optical characteristics are considered dominantly originate from potential traps lattice sulfur vacancies existing confined fit size host pore channels.
ZnxCd1−xS (0 ≤ x 1) alloy nanoparticles have been fabricated facilely using ethylenediamine as a solvent-coordinating molecular template in water. (x = 0.5) of single-crystalline wurtzite structures having no staking faults constructed homogeneously to show that they are intermediate between ZnS and CdS d-spacing 2θ values. The photoluminescence shifts largely the blue with composition increase Zn shortest wavelength at 0.9 (λmax 480 nm for CdS, 396 Zn0.9Cd0.1S, 424 ZnS). thermal treatment...
A template-free and one-pot solvothermal process has been developed for the facile synthesis of ZnS·(en)0.5 (en = ethylenediamine) hybrid nanobelts having diverse length-to-width (aspect) ratios. While typical synthesized at 180 °C 6 h have an average width 130 nm, a mean thickness 55 length 16 μm, their aspect ratios varied by adjusting solvent volume hydrazine monohydrate (hm) to en. sufficient amount sulfide from reduction sulfur hm found be essential efficient anisotropic one-dimensional...
The metal-enhanced fluorescence of Au<sub>25</sub>-adsorbed Ag@SiO<sub>2</sub>nanoparticles is due to the increase radiative decay rate constant.