Yung-Jung Hsu

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Various CdS nanostructures, including nanoparticle film, bundles of quasi-aligned and well-aligned nanowires, were fabricated with a non-catalytic and template-free MOCVD process. The well-aligned CdS nanowires exhibit unusually high field emission current densities of 225 mA cm(-2) at the applied electric field of 20 V microm(-1).
Here we demonstrate that the photoactivity of Au-decorated TiO2 electrodes for photoelectrochemical water oxidation can be effectively enhanced in the entire UV-visible region from 300 to 800 nm by manipulating the shape of the decorated Au nanostructures. The samples were prepared by carefully depositing Au nanoparticles (NPs), Au nanorods (NRs), and a(More)
In this study we introduce a new method for the one-pot synthesis of core/shell/shell alloyed Cd1-xZnxSe/ZnSe/ZnS QDs and examine the effect of the shell coating on the optical properties and exciton dynamics of the alloy core. The photoluminescence (PL) quantum yield is greatly enhanced after shell growth, from 9.6% to 63%. The exciton dynamics were(More)
A noncatalytic and template-free vapor transport process was developed to make possible simultaneous growth of single-crystalline tin nanowires, nanosquares, nanodisks, and polycrystalline nanoparticles. The formation of such a rich variety of morphologies in a single growth experiment can be attributed to variations in the growth rate among different(More)
Silver nanoclusters complexed with dihydrolipoic acid (DHLA) exhibit molecular-like excited-state properties with well-defined absorption and emission features. The 1.8 nm diameter Ag nanoparticles capped with Ag8 clusters exhibit fluorescence maximum at 660 nm with a quantum yield of 0.07%. Although the excited state is relatively short-lived (τ 130 ps),(More)
A new approach was developed to prepare coaxial (core-shell) CdS-ZnS nanowires via a one-step metallo-organic chemical vapor deposition (MOCVD) process with co-fed single source precursors of CdS and ZnS. Single source precursors of CdS and ZnS with sufficiently different reactivity were prepared and paired up to form the coaxial heterostructure in a(More)
Conjugated polymer/nanocrystal composites have attracted much attention for use in renewable energy applications because of their versatile and synergistic optical and electronic properties. Upon absorbing photons, charge separation occurs in the nanocrystals, generating electrons and holes for photocurrent flow or reduction/oxidation (redox) reactions(More)
A noncatalytic and template-free vapor transport process has been employed to prepare single-crystalline Sn nanowires with diameters of 10-20 nm. The growth of one-dimensional Sn nanowires follows the mechanism similar to the vapor-solid (V-S) mechanism. Two-dimensional square-shaped nanostructures were also found to form in the region of lower deposition(More)
We developed a single-step hot-injection process to synthesize Cd1-xZnxSe quantum dots (QDs) with tunable emission wavelengths. The multiple emission colors of the Cd1-xZnxSe QDs resulted from the variation in their compositions (x value) with the reaction time. Because of the higher reactivity of the Cd precursor, QDs whose composition was rich in CdSe(More)