Search

In the first part of this paper we present an overview of photovoltaic devices installed in Poland in the years 1960-2015. In the years 2009-2016, approximately 199 MW in total power of photovoltaic devices were installed. The second part of the paper we focus on presenting the research results on the usage of tracking photovoltaic installations in 2010-2016 collected in various periods of their work. PV panels were installed on the building of the Institute of Electrical Power Engineering of the Lodz University of Technology. In this paper we considered PV installations as an additional source of energy improving the total energetic efficiency of the building via the reduction of energy consumed from public electric and power networks. The installation satisfies up to 30% of annual energy demand of laboratories. However, the break-even period of the system was estimated to be about 30 years because of the high cost of installation.

According to increasing demand for energy, PV cells seem to be one of the best answers for human needs. Considering features such as availability, low production costs, high stability, etc., metal oxide semiconductors (MOS) are a focus of attention for many scientists. Amongst MOS, TiO2 and CuxO seem to be promising materials for obtaining an effective photoconversion effect. In this paper, specific investigation, aimed at the manufacturing of the complete photovoltaic structure based on this concept is described in detail. A set of samples manufactured by DC magnetron sputtering, with various process parameters, is characterized by morphology comparison, layer structure and material composition investigation, and finally by the obtained photovoltaic parameters. Based on SEM studies, it was established that the films are deposited uniformly and complete their formation; without clearly defined faces, the conglomerates of the film grow individually. These are areas with a uniform structure and orientation of atoms. The sizes of conglomerates are in a normal direction range from 20 to 530 nm and increase with film thickness. The film thickness was in the range from 318 to 1654 nm, respectively. The I-V study confirms the photovoltaic behavior of thin film solar cells. The open-circuit voltage (Voc) and short-circuit current density (Jsc) values of the photovoltaic devices ranged from 1.5 to 300 mV and from 0.45 to 7.26 µA/cm3, respectively, which corresponds to the maximum efficiency at the level of 0.01%. Specific analysis of the junction operation on the basis of characteristics flow, Rs, and Rsh values is delivered. [ABSTRACT FROM AUTHOR]

The problem of copper diffusion in semiconductor devices has been known for several decades as copper has been used as an interconnecting (bonding) metal and has been intensively studied due to its high diffusion coefficient. The influence of the intensive diffusion of copper, depending on the technology of the deposition regimes, has been investigated in thin-film solar cells based on copper, zinc, and titanium oxides obtained by DC-reactive magnetron sputtering. The observed effect significantly changes the structure of the CuO films and affects the properties of the TiO2:ZnO/CuO photocell. The composition of the layers and the copper diffusion in the photocells were studied using a cross-section obtained by scanning electron microscopy (SEM). The influence of the copper diffusion in the layers on the current–voltage (I-V) and power–voltage (P-V) characteristics and optical properties was investigated. The photoelectric behavior of two structures of thin-film solar cells was confirmed through -V research. The values of the open-circuit voltage (VOC) and short-circuit current density (JSC) of photovoltaic devices reached (11 ÷ 15) mV and (6.1 ÷ 6.8) μA, respectively. Furthermore, the Pmax, FF, RS, and RSH values were calculated and analyzed. The difference in the composition of the upper layer of the structure caused changes in the reflection spectra in the wavelength range of 190–2500 nm and, depending on the wavelength, varies in the range of 0–27%. [ABSTRACT FROM AUTHOR]

The paper describes the research on optical properties of glass/ITO/Ag thin layers obtained on glass/ITO substrates with different properties. The authors will discuss the influence of silver particles and silver layer thickness on the transmission and reflection spectra of the layers and parameters, such as the width of the optical band gap, refractive index, and dieelectric function. For example, the presence of silver leads to a decrease in the transmission of the layers (compared to ITO/glass) regardless of the thickness of the silver layer, and in the case of reflection, both its increase and decrease were observed, depending on the thickness of the silver layer and the type of glass/ITO substrate used. The average transmission value in the visible region depends on the thickness of the silver nanoparticle layer and varies from ~50% to ~90%. The average refractive index takes values from the range ~1.4 to ~1.65 and does not depend on the presence and thickness of the silver layer. [ABSTRACT FROM AUTHOR]

In this study, titanium dioxide/copper oxide thin-film solar cells were prepared using the reactive direct-current magnetron sputtering technique. The influence of the deposition time of the top Cu contact layer on the structural and electrical properties of photovoltaic devices was analyzed. The structural and morphological characterization of the TiO2/CuO/Cu2O solar cells was fully studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and current–voltage (I-V) characteristics. Additionally, using van der Pauw sample geometries, the electrical properties of the titanium dioxide and copper oxide layers were investigated. From the XRD study, solar cells were observed in cubic (Cu2O), monoclinic (CuO), and Ti3O5 phases. In addition, the crystallite size and dislocation density for copper oxide layers were calculated. Basic morphological parameters (thickness, mechanism of growth, and composition of elements) were analyzed via scanning electron microscopy. The thicknesses of the titanium dioxide and copper oxide layers were in the range of 43–55 nm and 806–1223 nm, respectively. Furthermore, the mechanism of growth and the basic composition of the elements of layers were analyzed. The I-V characteristic curve confirms the photovoltaic behavior of two titanium dioxide/copper oxide thin-film structures. The values of short-circuit current density (Jsc) and open-circuit voltage (Voc) of the solar cells were: 4.0 ± 0.8 µA/cm2, 16.0 ± 4.8 mV and 0.43 ± 0.61 µA/cm2, 0.54 ± 0.31 mV, respectively. In addition, the authors presented the values of Isc, Pmax, FF, and Rsh. Finally, the resistivity, carrier concentration, and mobility are reported for selected layers with values reflecting the current literature. [ABSTRACT FROM AUTHOR]

The optimization of dye-sensitized solar cells (DSSCs) technology towards suppressing charge recombination between the contact and the electron transport layer is a key factor in achieving high conversion efficiency and the successful commercialization of this type of product. An important aspect of the DSSC structure is the front blocking layer (BL): optimizing this component may increase the efficiency of photoelectron transfer from the dye to the semiconductor by reduction charge recombination at the TiO 2 /electrolyte and FTO/electrolyte interfaces. In this paper, a series of blocking layer variants, based on TiO 2 and ZnO:TiO 2 , were obtained using the reactive magnetron sputtering method. Material composition, structure and layer thickness were referred to each process parameters. Complete DSSCs with structure FTO/BL/m-TiO 2 @N719/ EL-HSE/Pt/FTO were obtained on such bases. In the final results, verification of opto-electrical parameters of these cells were tested and used for the conclusions on the optimal blocking layer composition. As the conclusion, application of blocking layer consists of neat TiO 2 resulted in improvement of device efficiency. It should be noted that for TiO 2 :ZnO/Cu x O and TiO 2 /Cu x O cells, higher efficiencies were also achieved when pure TiO 2 was used as window layer. Additionally it was proven that the admixture of ZnO phase inspires V oc and FF growth, but is overall unfavorable compared to pristine TiO 2 blocking layer and the reference cell, according to the final cell efficiency., (© 2024. The Author(s).)