The creation of a single electron-hole pair (i.e., exciton) per incident photon is fundamental limitation for current optoelectronic devices including photodetectors and photovoltaic cells. prospect multiple exciton generation great interest to science the improvement solar cell technology. Multiple known occur in semiconductor nanostructures with increased efficiency reduced threshold energy compared their bulk counterparts. Here we report significant enhancement PbSe quasi-one-dimensional...

Nanocrystal quantum dots (QD) show great promise toward improving solar cell efficiencies through the use of confinement to tune absorbance across spectrum and enable multi-exciton generation. Despite this remarkable potential for high photocurrent generation, achievable open-circuit voltage (Voc) is fundamentally limited due non-radiative recombination processes in QD cells. Here we report highest voltages date colloidal based cells under one sun illumination. This Voc 692 ± 7 mV 1.4 eV PbS...

A series of gold nanoclusters stabilized by ligands containing short ethylene oxide oligomers fixed length were prepared and characterized. The thiols CH3(OCH2CH2)nSH (where n = 2, 3, 4) substituted onto the surface 1.8-nm hexanethiol-capped clusters a thiol-exchange reaction, resulting characterized NMR, FTIR, UV/vis spectroscopies; TGA; TEM analysis. degree ligand exchange greater than 99% was achieved, core diameter remained unchanged in final material. Of particular interest, cluster...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis of Nanocrystalline Bismuth in Reverse MicellesEdward E. Foos, Rhonda M. Stroud, Alan D. Berry, Arthur W. Snow, and J. Paul ArmisteadView Author Information Chemistry Division, Code 6174 Naval Research Laboratory, Washington, D.C. 20375 Cite this: Am. Chem. Soc. 2000, 122, 29, 7114–7115Publication Date (Web):July 8, 2000Publication History Received30 March 2000Published online8 July inissue 26...

A series of primary, secondary, and tertiary amines have been examined as cosolvents with trioctylphosphine oxide (TOPO) for the synthesis CdSe nanoclusters. Syntheses were conducted in 66 mol % hexadecylamine (HDA), dodecylamine (DDA), dioctylamine (DOA), or trioctylamine (TOA) TOPO growth rates size distributions resulting products compared those obtained from same reaction pure TOPO. DOA was found to advantageously slow rate nanoclusters produce material a narrow distribution moderate...

High yielding syntheses of mercapto terminated monodisperse dimer, trimer, and tetramer ethyleneoxide oligomers p-hydroxyphenethyl thiol via an alcohol-tosylate-thiol route are reported. Comparisons made with the more conventional alcohol-bromide-thiol route.

We report the first synthesis and characterization of nanocrystalline Bi2Te3 with particle sizes less than 10 nm. The reaction BiOClO4·xH2O (Me3Si)2Te in a reverse micelle formed by sodium dioctylsulfosuccinate water hexane has produced good yields (71%) black powder that been characterized elemental analysis, X-ray diffraction, transmission electron microscopy.

A shadow mask technique employing V2O5 nanowires and ion-beam milling is used to define narrow lines of monolayer-encapsulated Au nanoclusters. When positioned between electrodes these are shown be conducting have nonlinear I−V characteristics with nonzero threshold voltages consistent Coulomb blockade.

We investigate the fine structure of band-edge excitons in PbSe nanocrystals and nanorods using circularly polarized magnetophotoluminescence optically detected magnetic resonance and, based on results, propose a singlet-triplet model exciton photoluminescence from nondegenerate conduction valence bands. From data we extract $g$-factors for electrons holes $+1.2$ $+0.8$, respectively. The splitting triplet ground state, which is responsible low-temperature photoluminescence, $88\text{...

Layer-by-layer self-assembly of hexanethiol stabilized gold nanoclusters by a series alkanedithiol coupling agents [HS(CH2)nSH, n = 6, 8, 9, 12] onto SiO2/Si substrates with micron- and nanometre-scale Au electrodes is investigated electron transport XPS measurements. The process for each layer consists two-step cycle treatment cluster deposition. For maximized transport, critical features to optimize are the chain length extent dithiol agent displacement ligand. Substitution phenethyl hexyl...

The aspect ratio and yield of PbSe nanorods synthesized by the reaction Pb-oleate with tris(diethylamino)phosphine selenide are highly sensitive to presence water, making it critical control amount water present in reaction. By carefully drying precursors then intentionally adding back into reaction, nanorod can be controlled from 1.1 10 1 14% varying concentration 0 204 mM. (31)P{(1)H} (1)H NMR show that reacts create bis(diethylamido)phosphorous acid. It was determined acid is responsible...

The independent 1:1 reactions of Et3Ga and (Me3SiCH2)3In with Sb(SiMe3)3 yield the simple Lewis acid−base adducts Et3Ga·Sb(SiMe3)3 (1) (Me3SiCH2)3In·Sb(SiMe3)3 (2), respectively. Reaction (Me3CCH2)2GaCl or (Me3SiCH2)2InCl in a mole ratio affords dehalosilylation products [(Me3CCH2)2GaSb(SiMe3)2]x (3) [(Me3SiCH2)2InSb(SiMe3)2]2 (4), These new compounds were characterized by multinuclear solution NMR (1H 13C), partial elemental analysis, and, for 1, 2, 4, single crystal X-ray analysis.

The effect of geometric scaling on the performance metal-insulator metal-ensemble (MIME) chemiresistors based gold nanoclusters is investigated. ultrasmall size shown to enable extreme sensors with reductions in area at least a factor 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> over conventional MIME devices. If operating voltage held constant, absolute sensitivity devices found remain essentially unchanged by scaling....

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation S. M. Prokes, O. J. Glembocki, Erin Cleveland, Josh D. Caldwell, Edward Foos, Jaakko Niinistö, Mikko Ritala; Spoof-like plasmonic behavior of plasma enhanced atomic layer deposition grown Ag thin films. Appl. Phys. Lett. 30 January 2012; 100 (5): 053106. https://doi.org/10.1063/1.3679106 Download citation file:...

We report the attenuance and temperature-dependent photoluminescence spectra of PbSe nanowires with diameters between 5.6 26.4 nm (12−23% relative standard deviation) lengths greater than 1 μm. The nanowire first exciton energy varies 0.3 0.6 eV as diameter decreases from to nm, respectively. Compared spherical nanocrystals, show less quantum confinement larger Stokes shifts. band gap temperature coefficient (dEg/dT) decreases, consistent previous results for nanocrystals.

Solution-synthesized inorganic cadmium telluride nanocrystals (∼4 nm; 1.45 eV band gap) are attractive elements for the fabrication of thin-film-based low-cost photovoltaic (PV) devices. Their encapsulating organic ligand shell enables them to be easily dissolved in solvents, and resulting solutions can spray-cast onto indium-tin oxide (ITO)-coated glass under ambient conditions produce photoactive thin films CdTe. Following annealing at 380 °C presence CdCl2(s) evaporation metal electrode...

In this paper, we report a novel heterojunction solar cell based on sintered CdTe and CdSe nanocrystal thin films using solution-based deposition. For the absorber layer, were made layer-by-layer deposition process consisting of spin coating colloidal nanocrystals followed by sintering step. The optical constants for these accurately determined through combination modeling measurements. all-solution processed p-n heterojunction, focus due to their excellent compatibility with solution...

The 1:1 mol ratio reaction of t-Bu3Ga with Sb(SiMe3)3 in hexane yields the expected Lewis acid−base adduct t-Bu3Ga·Sb(SiMe3)3 (1). dehalosilylation t-Bu2GaCl dimeric compound [t-Bu2GaSb(SiMe3)2]2 (2). mixed-bridge was isolated from both 2:1 and equilibration 2. These new gallium−antimony compounds have been characterized through multinuclear solution NMR spectroscopy, partial elemental analysis, single-crystal X-ray structural analysis. In addition, 2 found to produce nanocrystalline GaSb an...

Films of nanocrystalline PbSe were fabricated with a set structurally varied short-chain dicarboxylic acids. Oxidation rates studied via NIR spectroscopy to determine the effect structure diacid ligands on film stability under ambient conditions. Ligands favoring non-bridging bonding mode found provide best protection against oxidation, while among expected bridge between adjacent nanocrystals in films, those shorter chain lengths conferred better oxidative stability. Electronic coupling was...

Absorption spectroscopy has traditionally served as a powerful technique for the study of solution synthesized semiconductor nanocrystals, enabling information on size, dispersity, concentration, and overall quality sample to be obtained quickly easily. When thin, densely packed films these materials are produced through ligand exchange, spectroscopic shifts both higher lower energy observed. Reduction internanocrystal distance can result in change dielectric constant film well increased...

Robust all inorganic solar cells showing 1.7% efficiency were fabricated entirely from solution in air onto non-conductive glass using soluble nanocrystal inks.

A scalable means of isolating significant quantities trioxyethylene-encapsulated gold nanoclusters (GNCs) labeled with a single DNA strand is demonstrated. Quantitative characterization the product obtained using UV−vis absorbance spectroscopy. These methods isolation and singly functionalized GNC−ssDNA conjugates are expected to aid development nanoscience applications that use molecular recognition for guiding self-assembly.

An omega-fluorine-labeled oxyethylene thiol ligand, F(CH2CH2O)2CH2CH2SH, was synthesized, characterized and incorporated into mixed self-assembled monolayers with CH3(OCH2CH2)3SH onto a planar gold substrate 2 nm nanoclusters. The fluorine-labeled nanocluster substrates using alkane dithiol (HS(CH2)nSH; n = 5, 8, 11) (HS(CH2CH2O)nCH2CH2SH; 1, 2, 3) linking agents equivalent chain lengths for comparative purposes. X-ray photoelectron spectroscopy (XPS) used to track the fluorine-label in...