Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.2.1.1 (ACS)
 78,556 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A high molar extinction coefficient heteroleptic ruthenium complex, incorporating an electron-rich hexylthio-terminal chain, has been synthesized and demonstrated as an efficient sensitizer for dye-sensitized solar cells. With this new sensitizer excellent power conversion efficiency is 11.5% and 4.7% obtained under an irradiation of full sunlight (air mass 1.5 global) in combination with a volatility electrolyte and solid state hole transporting material, respectively. The devices with low volatility electrolyte showed good stability under visible-light soaking at 60 degrees C during 1000 h of accelerated tests.
ACS Nano 2009 Oct 27
PMID:Highly efficient light-harvesting ruthenium sensitizer for thin-film dye-sensitized solar cells. 1974 29

We investigate the effect of the electronic energy level positioning, conductivity, and morphology of metal oxide charge transport layers on the performance of light emitting devices (LEDs) that consist of a colloidally synthesized quantum dot (QD) luminescent film embedded between electron and hole injecting ceramic layers. We demonstrate that understanding of these material properties and their effect on charging processes in QDs enables the systematic design of higher efficiency QD-LEDs and excitation of QDs with different emission colors using the same device structure.
ACS Nano 2009 Nov 24
PMID:Selection of metal oxide charge transport layers for colloidal quantum dot LEDs. 1988 43

Computational modeling is used to describe the mechanisms governing energy level alignment between an organic semiconductor (OSC) and a metal covered by various self-assembled monolayers (SAMs). In particular, we address the question to what extent and under what circumstances SAM-induced work-function modifications lead to an actual change of the barriers for electron and hole injection from the metal into the OSC layer. Depending on the nature of the SAM, we observe clear transitions between Fermi level pinning and vacuum-level alignment regimes. Surprisingly, although in most cases the pinning occurs only when the metal is present, it is not related to charge transfer between the electrode and the organic layer. Instead, charge rearrangements at the interface between the SAM and the OSC are observed, accompanied by a polarization of the SAM.
ACS Nano 2009 Nov 24
PMID:Understanding the electronic structure of metal/SAM/organic-semiconductor heterojunctions. 1989 41

We study surface plasmon polariton lifetimes in two-dimensional arrays of blind holes on gold surfaces. The lifetimes are determined from the line widths of the resonant dips appearing in the specular reflection spectra. We find a strong dependence of lifetimes on the resonant wavelength and the hole geometry. Through both experiments and numerical simulations, we analyze the validity of the Rayleigh approximation and also explore the range of wavelengths and geometric parameters where it fails. Finally, we show that, within the range of geometries and wavelengths considered in our experiments, the behavior of surface plasmon polariton lifetimes can be understood as resulting from the interplay between the intrinsic metal absorption and the scattering of surface waves by single isolated holes.
ACS Nano 2010 Jan 26
PMID:Geometry dependence of surface plasmon polariton lifetimes in nanohole arrays. 2002 1

The electronic structures of the CdSe/CdS core-shell nanorods are systemically investigated by large-scale first-principles quality calculations. The effects of band alignment, quantum confinement, piezoelectric field, and dipole moments are analyzed and delineated by comparing the results of systems with or without some of these attributes. We found complicated interplays between these effects in determining the nanorod band gap and electron hole wave function localizations. The hole wave function is found to be localized inside the CdSe core, while the electron wave function is localized in the CdS shell, with its distance to the CdSe core depending on the surface passivation. The permanent dipole moment induced by different surface passivations can change the electron hole separation, while the piezoelectric effect plays a relatively minor role. Finally, we demonstrate that it is straightforward to manipulate the nanorod electronic structure by changing its CdSe core position.
ACS Nano 2010 Jan 26
PMID:Electronic structures of the CdSe/CdS core-shell nanorods. 2004 92

Branched SnO(2)/alpha-Fe(2)O(3) semiconductor nanoheterostructures (SNHs) of high purity were synthesized by a low-cost and environmentally friendly hydrothermal strategy, through crystallographic-oriented epitaxial growth of the SnO(2) nanorods onto the alpha-Fe(2)O(3) nanospindles and nanocubes, respectively. It was demonstrated that the SnO(2) nanorods would change their preferential growth direction on the varied alpha-Fe(2)O(3) precursors with distinct crystallographic surface, driven by decrease in the distortion energy induced by lattice mismatch at the interfaces. All of the prepared SNHs were of high purity, ascribing to the successful preinhibition of the SnO(2) homonucleation in the reaction system. Significantly, some of the SnO(2)/alpha-Fe(2)O(3) SNHs exhibited excellent visible light or UV photocatalytic abilities, remarkably superior to their alpha-Fe(2)O(3) precursors, mainly owing to the effective electron-hole separation at the SnO(2)/alpha-Fe(2)O(3) interfaces.
ACS Nano 2010 Feb 23
PMID:Hydrothermal synthesis, structural characteristics, and enhanced photocatalysis of SnO(2)/alpha-Fe(2)O(3) semiconductor nanoheterostructures. 2007 69

We present a mesoporous hole-conducting polymer film resulting from spontaneous block copolymer self-assembly based on a simple spin-coating protocol. A diblock copolymer consisting of a triphenylamine side group polymer and a poly(d,l-lactide) block (PSTPA-b-PLA) is shown to microphase separate to form ordered 13 nm cylindrical PLA microdomains embedded in the semiconducting PSTPA matrix. Partially ordered and film-spanning PLA domains could be identified in films immediately after spin coating from toluene solutions on conducting substrates. Selective mild etching of the minority PLA domains (in weak aqueous base) leads to a mesoporous hole-conducting polymer matrix. The pore structure is replicated electrochemically in platinum, demonstrating the viability of this approach to producing nano-organized heterojunction structures in thin films.
ACS Nano 2010 Feb 23
PMID:Soft-etch mesoporous hole-conducting block copolymer templates. 2009 66

A proof of concept of the electronic detection of two anabolic steroids, stanozolol (Stz) and methylboldenone (MB), was carried out using two specific antibodies and arrays of carbon nanotube field-effect transistors (CNTFETs). Antibodies specific for Stz and MB were prepared and immobilized on the carbon nanotubes (CNTs) using two different approaches: direct noncovalent bonding of antibodies to the devices and bonding the antibodies covalently to a polymer previously attached to the CNTFETs. The results indicated that CNTFETs bonded to specific antibodies covalently or noncovalently are able to detect the presence of steroids. Statistically significant changes in the threshold voltage and drain current were registered in the transistors, allowing the steroids to be recognized. On the other hand, it was determined that the specific antibodies do not detect other steroids other than Stz and MB, such as nandrolone (ND) because, in this case, statistically significant changes in the transistors were not detected. The polymer prevents the aggregation of antibodies on the electrodes and decreases the transistor hysteresis. Nevertheless, it is not able to avoid the nonspecific adsorption of streptavidin, meaning that nonspecific adsorption on CNTs remains a problem and that this methodology is only useful for purified samples. Regarding the detection mechanism, in addition to charge transfer, Schottky barrier, SB, modification, and scattering potential reported by other authors, an electron/hole trapping mechanism leading to hysteresis modification has been determined. The presence of polymer seems to hinder the modulation of the electrode-CNT contact.
ACS Nano 2010 Mar 23
PMID:Electronic anabolic steroid recognition with carbon nanotube field-effect transistors. 2014 39

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 ITO show suppressed blinking activity as well as reduced fluorescence lifetimes. For QDs in contact with the n-doped ITO, the equilibration of their Fermi levels leads to the formation of negatively charged QDs. In these negatively charged QDs, the off states are suppressed because of the effective removal of the valence band holes, and their fluorescence lifetimes are shortened because of exciton Auger recombination and hole transfer processes involving the additional electrons. This study shows that the blinking of single QDs can be effectively suppressed on the surface of ITO. This phenomenon may also be observable for other QDs and on different n-doped semiconductors.
ACS Nano 2010 Mar 23
PMID:Suppressed blinking dynamics of single QDs on ITO. 2017 Jan

In this study, we prepared carbon nanotube (CNT) forests exhibiting two types of optical properties: so-called "darkest materials" and films displaying iridescence phenomena. The darkest materials, comprising vertically aligned CNT (VA-CNT) forests, displayed extremely low reflections as a result of the rough surface and the trapping of light in the CNT forests. The lengths of the CNTs in the CNT forests had a strong influence on whether the light transmitted through the CNT forest or reflected from the substrate. From an investigation of the limitations of the darkest materials of CNT forests, we prepared CNT surfaces running the gamut from dark materials to iridescent. To study iridescence phenomena, we prepared two kinds of patterns of CNT forests on flexible polycarbonate substrates: CNTs arrayed in hexagonal-hole patterns and broccoli-like CNTs, the latter formed through a combination of inverse nanosphere lithography (INSL) and a poisoned-catalyst mechanism. In the patterned CNT forests, even though the refractive index difference between the CNT film and air was extremely low and even though the CNTs could trap the incident light, the iridescence phenomenon remained, inducing colorful images from the CNT films.
ACS Nano 2010 Mar 23
PMID:Iridescence of patterned carbon nanotube forests on flexible substrates: from darkest materials to colorful films. 2018 84


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>