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Electrical properties of discontinuous Pt, Cu and Al films were examined. The temperature dependencies of resistance were measured in vacuo in situ for examined films. Structural examinations of the films were conducted by means of electron microscope. Making use of the micrographs and the measured data the dependencies log(R) versus coverage coefficient are presented for selected temperature. To explain the experimental results, especially in the percolation threshold interval, the resistances of discontinuous Pt, Cu and Al films were calculated using a computer method which includes such mechanisms as a substrate conduction, metal conduction, thermally activated tunnelling and quantum tunnelling. Using the computer method, the relationship between log(R) and coverage coefficient were calculated. It was found the qualitative agreement between measured and calculated data. The conduction mechanisms in discontinuous Pt, Cu and Al films are proposed in the different ranges of coverage coefficient. [Copyright &y& Elsevier]

Determines the influence of size effects on the electrical properties of discontinuous copper films. Measurement of the temperature dependence of resistance; Interaction of conduction electrons with a grain boundary and interaction of conduction electrons with film surfaces; Scattering of conduction electrons at the metal boundary when the coverage coefficients are in the percolation range.

Abstract: The application of an optical method for characterizing surface roughness is presented. This method was used for an examination of porous glass surfaces. The expressions relating the root mean square rms (σ) of a surface to its specular reflectance at normal incidence are used for σ ≪ λ, (λ – wavelength). For light of sufficiently long wavelength the decrease in the measured specular reflectance due to the surface roughness depends only on the root mean square (rms) height of the surface irregularities. On the basis of reflectance spectra, one can determine σ for the porous glass surfaces after technological processes. The measured reflectance spectra were compared with calculated ones for which the scattered component of light was taken into account. The parameters rms determined from the optical method are comparable to those obtained from atomic force microscopy examinations. [Copyright &y& Elsevier]

The ranges of statistical description of the systems may be determined on the basis of the inverse power law of the Mandelbrot. The slope of the straight line representing the power law in a double-logarithmic plot, determined as −1/μ (μ being a critical exponent), characterizes the distribution of elements in the system. In this paper, the inverse power law is used to describe the statistical distribution of discontinuous metal films with higher coverage coefficients (near percolation threshold). For these films the critical exponent μ≈1, both the mean value and the variance are infinite. The objects with such microstructure are described according to the Le´vy distribution; Cauchy, inverse Gauss and inverse gamma distribution, respectively. The experimental histograms are compared with the calculated ones. Inhomogeneous metal films were obtained experimentally, their microstructures were examined by means of electron microscope. On the basis of electron micrographs, the fractal dimensions were determined for the metal films with coverage coefficient ranging from 0.35 to 1.00. [Copyright &y& Elsevier]

In the paper, the photoluminescence (PL) measurements, current-voltage-temperature (I-V-T) measurements, space charge techniques (C-V and deep level transient spectroscopy (DLTS)), and photocurrent spectral characteristics have been applied to investigate defects in p-Si/MgO/ n-Zn1-xMgxO heterojunction (HJ). The HJ structure was grown on p-type Si (111) substrate with resistivity equal to 0.1 Ω cm by the plasma-assisted molecular beam epitaxy technique. A radiofrequency cell was used for the generation of oxygen plasma. PL spectrum let us determine the Mg content ~10%. Besides the excitonic Zn0.9Mg0.1O line, the PL spectrum also contains green and yellow emission bands indicating the presence of defect states in the investigated structures. I-V measurements reveal the rectifying properties of the HJ and the current thermally activated with a trap with the activation energy equal to 0.42 eV. DLTS studies yield the majority trap of the activation energy 0.42 eV, confirming the result obtained from the I-V measurements. It was found that the defects related to this trap have a point like behaviour. A spectral characteristic of the photocurrent shows that the p-Si/MgO/n-Zn1-xMgxO HJ may be applied as a photodiode operating within the wavelength range of 300 nm-1100 nm. The dark current transport and photocurrent spectrum were explained using the Anderson model of a HJ. [ABSTRACT FROM AUTHOR]

Gold nanoparticle array on pretreated glass substrates was fabricated by chemical surface growth from the AuCl3, CH2O and Na2CO3 components in aqueous solutions mixture. Transmission, absorption and reflectivity spectra were measured with an UV-Vis spectrophotometer. A change in plasmon maximum absorption position depending on the growth conditions was investigated. The surface morphology was studied by atomic force microscopy. The statistical analysis of the heights, particles diameter and image cross-sections was carried out by scanning probe microscopy methods and the Au NPs size dependence on the growth time was experimentally determined. The results of this paper will contribute to the optimization of plasmonic CdS/CdTe solar cell. [ABSTRACT FROM AUTHOR]