Recent theoretical studies on linear absorption spectra of dye-semiconductor systems [perylene attached to nanostructured TiO2, L. Wang et al., J. Phys. Chem. B 109, 9589 (2005)] are extended here in different respects. Since the systems show ultrafast photoinduced heterogeneous electron transfer the time-dependent formulation used to compute the absorbance is also applied to calculate the temp...

Only a handful of late-T brown dwarfs have been monitored for spectro-photometric variability, leaving incomplete the study atmospheric cloud structures coldest dwarfs, that share temperatures with some cold, directly-imaged exoplanets. 2MASSJ00501994-332240 is T7.0 rapidly rotating, field dwarf showed low-level photometric variability in data obtained Spitzer Space telescope. We during ~2.6 hr...

The reaction between the FAD-containing enzyme, mercuric reductase, and its reducing substrate, NADPH, has been studied at 5 degrees C, pH 7.3, by rapid-scan and fixed-wavelength stopped-flow techniques with the aim to characterize reaction intermediates. With an excess of NADPH the spectral changes observed in rapid-scan experiments can be described by a simple kinetic model, A----B----C----D,...

Some strategies toward the realization of molecular control of photo-induced charge-transfer processes at nanocrystalline semiconductor interfaces are discussed. Supramolecular compounds that efficiently absorb light, promote interfacial electron transfer, and feature additional functions such as intramolecular electron transfer when bound to semiconductor surfaces are of specific interest. Tun...

By m eans o f an electron m icroprobe the lith iu m -K and a lu m in iu m -K X -ray em ission lines o f A l-L i alloys were studied. The L i-line can be well described by the calculated emission line. The evaluation yields the transfer o f electrons from the Li-sto the A l-p-band during alloying. T he charge transfer is enhanced by heat treatm ent. The dependence o f the elastic m odulus on the...

An investigation is reported of the photoluminescence (PL) properties of Al3GdB4O12:Eu phosphors. Under vacuum ultraviolet excitation, Al3GdB4O12:Eu exhibited a bright red luminescence with CIE chromaticity coordinates of (0.643, 0.356) with a PL intensity of 60% of the sodium salicylate standard. The PL spectrum showed a ground state splitting pattern consistent with D3 symmetry. The PL excita...

Here, we report multilayer stacking of films of quantum dots (QDs) for the purpose of tailoring the energy band alignment between charge transport layers and light emitting layers of different color in quantum dot light-emitting diodes (QD LED) for maximum efficiency in full color operation. The performance of QD LEDs formed by transfer printing compares favorably to that of conventional device...

Functionalization of semiconductor nanocrystals can be achieved by anchoring organic ligands to the surface dangling bonds. The resulting surface complexes often introduce electronic states in the semiconductor band gap. These interband states sensitize the host material for photoabsorption at frequencies characteristic of the molecular adsorbates, leading to the well-known process of photoexci...

The electronic structures of the highest occupied molecular orbital (HOMO) or the HOMO-derived valence bands dominate the transport nature of positive charge carriers (holes) in organic semiconductors. In the present study, the valence-band structures of single-crystal pentacene and the temperature dependence of their energy-momentum dispersion relations are successfully demonstrated using angl...

An important issue regarding DNA electrical conductivity is the electron (hole) transfer rate. Experiments have found that this transfer rate involves quantum mechanical tunneling for short distances and thermally activated hopping over large distances. The electron (or hole) tunneling probability through a molecule depends on the length of molecule L, as e(-beta(E)L), where the tunneling betaE...