Photoelectric Properties of Screen-Printed Al-Doped ZnO Films
The potential of cheap semiconductor materials in the area of solar energy use is illustrated by the example of zinc oxide (pure and Al-doped in various concentrations). Under investigation was the electric conductivity and photoelectric properties of ZnO thin films. The samples were prepared using screen-printing technique. The results of measurements point to non-linear relationships between Al concentration, photosensitivity and electrical conductivity of thin ZnO films. Optimal Al concentration for practical use of ZnO in photovoltaic devices is found to be ~ 1%. The experimental methods, technologies and results described in the paper could be used for further investigations in this area.
Well-structured ZnO nanotubes are obtained by a self-selective etching method with lowering temperatures of growth during the hydrothermal process.
The structural and optical properties of the obtained nanostructures are investigated by various conventional methods.
The goal of the research is to compare the efficiency of ZnO nanotubes to that of ZnO nanorods during lead adsorption process from aqueous solution and demonstrate that hollow nanostructures are more effective than solid nanostructures of the same morphology due to their larger effective surface.
Both nanotubes and nanorods are obtained under similar growth conditions: neither growth solution composition, nor concentration is changed. ZnO morphology is switched only by changing temperature during the growth process.
The measurements are carried out to assess the efficiency of the adsorption per unit weight of ZnO nanorod and nanotube capacity of static adsorption.
A new concept is proposed for digital hologram production along with the relevant techniques developed in our laboratory. The main idea of the concept is to maximally separate the calculation of hologram from its optical recording on the light-sensitive media. A special file format containing information on each holographic pixel is created at the stage of calculation. The file is a device-independent by structure, and can be employed for recording a hologram using any of the existing techniques (dot-matrix, optical matrix lithography, e-beam lithography). An optical lithography device is applied to calculate the images for a spatial light modulator at the stage of hologram recording in accordance with the data from the file and in conformity with the hardware features of the device. The proposed method was tested and successfully used to record security holograms. For commercial use a software package and an optical recording system have been developed.