Boron doped diamond synthesized at high pressure was studied using Raman scattering. Shift and broadening of the diamond phonon line was observed and attributed to disorder produced by boron doping. Electronic transitions within boron acceptor states and Fano-type interference between phonons and the electronic continuum have also been observed in the spectra.

Degenerate four-wave mixing experiments have been performed for Au colloid-doped glasses prepared by melting and sputtering methods. The nonlinear optical properties of the glasses are discussed from viewpoint of the concentration of the Au colloid particles and the thickness of the glasses. We also discuss the dependence of the nonlinear properties on the pulse duration of laser for the measurements, and a very slow relaxation.

We report measurements and analysis of the optical transmission spectra of colloidal 2H-M0S2. prepared by ultrasonic shattering of synthetic crystals in N-Methyl Formamide. We used a combination of TEM, X-ray diffraction and dynamic light scattering to characterize particle shape and size. For a typical sample, the particles are platelets which have an average thickness of 50 Å and a diameter of 500 Å. Particle dielectric functions, deduced from both dilute colloids and thin films prepared by flocculaUon, differ significantly from bulk values. Calculations show that the average extinction coefficient is affected by particle aspect ratio, but this can not explain all the features of the data. Specifically, we observe a suppression of the absorbance peaks in the band edge exciton region between 1.7 and 2.1 eV, and increased absorbance below 1.7 eV. We suggest that the particles do not possess bulk-like dielectric properties and that tins is due to defects.

Structural, electrical and optical characterisations were performed on tellurium film deposited under high vacuum conditions on ultrasonically cleaned Corning glass 7059 substrates. SEM and TEM studies reveal the polycrystalline nature of deposited tellurium films. At steady state high field conditions, space charge limited conduction is believed to have occurred due to the existence of a fast decaying density of trapping states in the energy gap. The DC conductivity is believed to exhibit a T-1/ law dependence below room temperature, giving a value of 2×10-l6eV/m3 for conduction states close to the Fermi level. From the power law dependence on frequency of AC conductivity, the barrier for bipolaron hopping is estimated to 0.33eV.Optical absorption in 9nm thick tellurium samples is due to direct transitions both allowed and forbidden producing two edges, the first one at 4eV and the other at about 0.5eV, respectively.

For the first time the Scanning Electron Microscopy (SEM) Dark Voltage Contrast (DVC) technique was used to examine the field distribution in a solar cell made of polycrystalline silicon.

The samples were cut off solar cells made of Edge-defined Film-fed Grown (EFG) Silicon and lapped at 2 and 5 degree angles. The DVC measurements were performed at forward, reverse, and zero bias conditions using a Hitachi S-570 SEM and a Kevex-8000 microanalyzer.

The I-V curves were recorded to test the electric performance of the samples. We examined two groups of solar cells. One group of cells demonstrated, after regular processing, reasonable electrical performance and abrupt DVC profile. The other group was intentionally doped with titanium, which presumably was agglomerated in the p-n junction area thus degrading completely the electrical performance of the cells and weakening the electric field by a factor of 4–6.

Thin films of CuInSe2, grown by coevaporation or by selenization of a Cu-In precursor, were analyzed in a scanning transmission electron microscope. While the coevaporated film shows clear evidence of second phases (Cu2Se) around the individual grains, no second phases could be found in the selenized material. Structural characterization also showed the presence of two ordered phases in the coevaporated films, the ordered-vacancy compound CuIn2Se3.5, and a CuPt-ordered phase of CuInSe2.

Polycrystalline fluorine doped tungsten oxide thin films were deposited onto glass substrates by reacting tungsten hexafluoride, difluoroethane, and isopropanol. The reaction was performed in an atmospheric pressure chemical vapor deposition reactor at a temperature of approximately 400 °C. The electrical conductivity and spectral properties were suggestive of n-type substitutional doping in which oxygen is partially replaced by fluorine. Temperature dependent resistivity measurements were consistent with the presence of polarons. The films were blue in color with enhanced reflectance and absorbance in the IR. These optical characteristics are potentially useful in improving the solar control properties of glass. Scanning electron microscopy revealed a faceted surface morphology. The fluorine atom concentration decreased when the films were annealed in air.

In this paper we report the synthesis of Au2S nanoparticles with a gold coating on the surface; the particles are characterized by transmission electron microscopy (TEM), electron diffraction and absorption data. The absorption spectrum is recorded during the gold coating growth process; this data demonstrates a large resonance shift during the growth process. The results are consistent with the growth of a metal shell around the particles; the theoretical model includes electron quantum confinement in the metal shell. The size dependence of the frequency shift, as well as the width of the resonance are consistent with the model.