Search

The thermodynamic behavior of mixed monolayers of cardiolipin-dipalmitoylphosphatidylcholine (CLP-DPPC) and cardiolipin-dipalmitoylphosphatidylethanolamine (CLP-DPPE) is investigated by studying their Langmuir surface pressure and surface potential isotherms at different cardiolipin molar fractions. The overall thermodynamic behavior is independent of mole fraction for the mixed CLP-DPPC monolayers while a critical fraction exists for the CLP-DPPE monolayers.

Moderate heating effects in vacuum on photoemissions from hydrogen terminated chemical vapor deposited diamond films were investigated.

The Au/n-GaAs(100) Schottky barrier height has been altered by thin silicon nitride intralayers. Thin intralayers were produced by nitridation of evaporated Si films on decapped GaAs substrates in an argon-nitrogen mixture plasma. The nitridation was achieved at a beam energy of less than 40 eV at 573 degrees K sample temperature. Gold was deposited to examine in situ the Schottky barrier formation process with x-ray photoelectron spectroscopy.

Shifting of energy from place to place by the core-level photoemission peaks of several insulators influences the general lineshape and linewidth of traditional, spatially unified spectra. The shifting occurs due to the presence of local charging effects. The use of the flood gun has no influence on the variations in linewidth and lineshape.

Space-resolved version of electron spectroscopy for chemical analysis (ESCA) enables the analysis of microchemical composition and electronic structure of two HgBaCaCuO high-temperature superconductors. One impurity phase is present in both superconductors, which changes its concentration from place to place. Oxygenation increases transition temperatures but decreases Cu(super 1+)/Cu(super 2+) concentration ratio.

The behavioral characteristics of the active region of SnOx thin films grown by dc sputtering was investigated using photoemission spectromicroscopy. The results showed that the degree of oxidation and the homegeneity of the samples indicated an unusually high amount of tin monoxide on the surface of the film. The surface of the sample was composed of three layers: Sn, SnO2 and SnO. The oxygen concentration during sputtering determined the eventual arrangement of these layers.

Photoluminescence experiments were used to investigate hydrogen activated radiative states in GaAs/GaAlAs heterostructures and InGaAs/GaAs multiquantum wells. The results showed that the density of impurities and defects determined the level of volume incorporation of hydrogen. At moderate hydrogen treatment, novel emission bands and passivation of shallow acceptors were observed. Heavy hydrogen treatment produced a deep structure.

The effect of ohmic contact conductance on the distribution of surface and bulk currents in semiconductor planar devices was investigated. The results showed that current distribution was significantly affected by the contact conductance and the ratio between the shunt currents from probes one to two, and from one to three were mainly dominated by the contact and surface conductivities in the sample.

A unique negative-conductance device composed of a series of N laterally indented barriers which has shows resonant tunneling under one bias polarity and simple tunneling under the opposite one and therefore functioning as a rectifier, is presented. Electrons undergo resonant tunneling when the bias forms a band profile with N triangular wells which can each have a resonant state. From 1 to N the addition of each indentation can be utilized to raise the current density and the rectification ratio.

Microscopic manipulation was used to prove that homojunction band lineups can be artificially relocated in energy by means of double intralayers of atomiclike thickness. The results showed that a II-V intralayer at a group-IV homojunction results in an artificial valence-band discontinuity when the anion is deposited first. Artificial band structure misalignments between the sides of a homojunction can be artificially induced.

Focuses on a study which investigated the effect of scattering in the well on resonant tunneling in double-barrier heterostructures using the transfer matrix approach. Methodology of the study; Description of the perturbation potential of the scattering centers; Findings from the calculations of the transmission probability of the system; Discussion on the effect of scattering.

Studies the effect of the ohmic contact conductance on the current distribution in the surface and bulk layers in semiconductor planar devices. Information on the contact configurations that are considered in the study; Required approximations for the reduction of the current density distribution problem; Results of the study.

Presents information on a study which investigated the mechanism of electron tunneling in thin silicon dioxide films by using transfer matrix and Airy function. Analysis of the problems associated with the carrier transport within thin silicon dioxide films of metal-oxide-semiconductor structures; Methodology of the study; Results and discussion.

Presents a study that measured by internal photoemission the conduction-band discontinuity ΔE[subc] in p-indium-gallium-arsenic/n-indium-phosphorus heterojunctions with a silicon δ layer inserted in indium-phosphorus at certain Å from the interface. Inducement of an inhomogeneous and temperature-dependent conduction-band offset reduction; Measured value of the modification; Temperature of the modification of the transport parameters of the heterojunction.