Conformational completion of Lorentz symmetric spaces

Every simply connected Lorentz symmetric space of dimensionn3 has a symmetric quotient which can be conformally imbedded in a quadric of the projective space ⁿ⁺¹ (R).     

The stability of K2[Pt(CN)4]Cl0·3·x.H2O in wet and dry atmosphere

The behavior of the one-dimensional electrical conductor K₂[Pt(CN)₄Cl_0·3·x.H₂O is studied at several temperatures in both wet and dry atmospheres using chemical analysis, X-ray diffraction and magnetic susceptibility data. It is concluded that the material is a series of hydrates with x between 2.5 and 3, and that a variation in x might influence its physical properties.     

Molecular adjustment of the electronic properties of nanoporous electrodes in dye-sensitized solar cells

Molecular modification of dye-sensitized, mesoporous TiO2 electrodes changes their electronic properties. We show that the open-circuit voltage (V(oc)) of dye-sensitized solar cells varies linearly with the dipole moment of coadsorbed phosphonic, benzoic, and dicarboxylic acid derivatives. A similar dependence is observed for the short-circuit current density (I(sc)). Photovoltage spectroscopy measurements show a shift of the signal onset as a function of dipole moment. We explain the dipole dependence of the V(oc) in terms of a TiO2 conduction band shift with respect to the redox potential of the electrolyte, which is partially followed by the energy level of the dye. The I(sc) shift is explained by a dipole-dependent driving force for the electron current and a dipole-dependent recombination current.     

Molecular monolayer-mediated control over semiconductor surfaces: evidence for molecular depolarization of silane monolayers on Si/SiO(x)

We show that, for molecules with particularly strong dipoles, their organization into a monomolecular layer can lead to depolarization, something that limits the range over which the substrate's work function can be changed. It appears that, with molecules, depolarization is achieved by changes in orientation and conformation, rather than by charge transfer to the substrate as is common for atomic layers.     

Deformation program for principal series representations

We suggest a realization of the deformation program for principal series representation of a semisimple Lie group by use of a generalized Weyl correspondence.     

Energy level and band alignment for GaAs-alkylthiol monolayer-Hg junctions from electrical transport and photoemission experiments

A series of p- and n-GaAs-S-C(n)H(2n+1) || Hg junctions are prepared, and the electronic transport through them is measured. From current-voltage measurements, we find that, for n-GaAs, transport occurs by both thermionic emission and tunneling, with the former dominating at low forward bias and the latter dominating at higher forward bias. For p-GaAs, tunneling dominates at all bias voltages. By combining the analysis of the transport data with results from direct and inverse photoemission spectroscopy, we deduce an energy band diagram of the system, including the tunnel barrier and, with this barrier and within the Simmons tunneling model, extract an effective mass value of 1.5-1.6m(e) for the electronic carriers that cross the junctions. We find that transport is well-described by lowest unoccupied and highest occupied states at 1.3-1.4 eV above and 2.0-2.2 eV below the Fermi level. At the same time, the photoemission data indicate that there are continua of states from the conduction band minimum and the valence band maximum, the density of which varies with energy. On the basis of our results, it appears likely that, for both types of junctions, electrons are the main carrier type, although holes may contribute significantly to the transport in the p-GaAs system.