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Electron-transfer dynamics from single CdSe/ZnS (core/shell) QDs to TiO(2) nanoparticles were studied. Single QDs on TiO(2) showed pronounced and correlated fluctuations of fluorescence intensity and lifetime. Compared to QDs on glass, the presence of the interparticle ET pathway on TiO(2) led to smaller on-state and larger off-state probability densities,(More)
The electron transfer (ET) dynamics from core/multi-shell (CdSe/CdS(3ML)ZnCdS(2ML)ZnS(2ML)) quantum dots (QDs) to adsorbed Fluorescein (F27) molecules have been studied by single particle spectroscopy to probe the relationship between single QD interfacial electron transfer and blinking dynamics. Electron transfer from the QD to F27 and the subsequent(More)
The exciton quenching dynamics of single CdSe/CdS(3ML)ZnCdS(2ML)ZnS(2ML) core/multishell QDs adsorbed on glass, In2O3, and ITO have been compared. Single QDs on In2O3 show shorter fluorescence lifetimes and higher blinking frequencies than those on glass because of interfacial electron transfer from QDs to In2O3. Compared to glass and In2O3, single QDs on(More)
Functional quantum dot (QD)-based nanostructures are often constructed through the self-assembly of QDs with binding partners (molecules or other nanoparticles), a process that leads to a statistical distribution of the number of binding partners. Using single QD fluorescence spectroscopy, we probe this distribution and its effect on the function(More)
We report the synthesis and characterization of two thin films (DA-MOF and L2-MOF) of porphyrin-based MOFs on functionalized surfaces using a layer-by-layer (LbL) approach. Profilometry measurements confirm that the film thickness increases systematically with number of growth cycles. Polarization excitation and fluorescence measurements indicate that the(More)
Given that energy (exciton) migration in natural photosynthesis primarily occurs in highly ordered porphyrin-like pigments (chlorophylls), equally highly ordered porphyrin-based metal-organic frameworks (MOFs) might be expected to exhibit similar behavior, thereby facilitating antenna-like light-harvesting and positioning such materials for use in solar(More)
Electron transfer activity from excited single CdSe/ZnS core/shell quantum dots (QDs) to adsorbed Fluorescein 27 was studied by single QD fluorescence spectroscopy. In comparison with QDs, the QD-acceptor complexes showed a shorter average and broader distribution of QD emission lifetimes due to electron transfer to adsorbates. Large fluctuation of(More)
High-quality ultrathin single-crystalline SnSe2 flakes are synthesized under atmospheric-pressure chemical vapor deposition for the first time. A high-performance photodetector based on the individual SnSe2 flake demonstrates a high photoresponsivity of 1.1 × 10(3) A W(-1), a high EQE of 2.61 × 10(5)%, and superb detectivity of 1.01 × 10(10) Jones, combined(More)
Because of their efficient energy-transport properties, porphyrin-based metal-organic frameworks (MOFs) are attractive compounds for solar photochemistry applications. However, their absorption bands provide limited coverage in the visible spectral range for light-harvesting applications. We report here the functionalization of porphyrin-based MOFs with(More)
Single-crystal CH3NH3PbX3 (X = I(-), Cl(-), Br(-)) perovskite nanowires (NWs) and nanoplates (NPs), which demonstrate ultracompact sizes and exceptional photophysical properties, offer promises for applications in nanoscale photonics and optoelectronics. However, traditional electronic and transient techniques are limited by the dimensions of the samples,(More)