Copper oxide-titanium dioxide (TiO₂) p–n junctions are promising materials for photovoltaic devices and may reduce production costs due to their low cost and inexpensive production methods compared with silicon solar cells. The present review compares solar cells made with copper oxides combined with TiO₂–TiO₂/Cu₂O and TiO₂/CuO heterojunctions, and “cascade heterojunction systems.” First, we describe the main properties of titanium (iv) dioxide (TiO₂), cuprous oxide (Cu₂O), and cupric oxide (CuO), and their potential applications. Next, we explain the concept of copper oxide and TiO₂ heterojunctions. We summarize and present the photovoltaic characteristics (efficiency, fill factor, circuit current density, and open circuit voltage), thickness, preparation method, and electrode type for solar cells comprising copper oxide and TiO₂. The efficiency of the solar cells ranged from 0.0005% to 1.62%. The thickness of the TiO₂ and cupric oxide layers ranged from 0.06 to 16 µm, and from 0.18 to 1.5 µm, respectively, depending on the fabrication method. Additionally, we review and discuss the available combinations of copper oxide with other materials (Cu₂O with ZnO, CuO with ZnO, and CuO with Si), as well as the effect of the thickness of the copper (i) oxide and copper (ii) oxide on the solar cell performance. Finally, we present aspects to improve the conversion efficiency of heterojunction solar cells with copper oxides combined with TiO₂. This review will be useful for the construction and further development of thin-film solar cells.

Here authors present a numerical study of a thin-film TiO₂/Cu₂O solar cell using the Solar Cell Capacitance Program. Authors simulated the current density and voltage (J–V) characteristics of an n-TiO₂ /p-Cu₂O solar cell without defects under standard test conditions for a 400-nm thick Cu₂O absorber layer and a 200-nm thick TiO₂ buffer layer. The simulation confirmed the high potential of the n-TiO₂/p-Cu₂O structure. The cell efficiency (η) of the n-TiO₂/p-Cu₂O solar cell was 7.71% with: J _SC ≈ J _MPP ∼ 9.6 mA/cm² and V _MPP = 0.8 V. Additionally, authors produced a n-TiO₂/p-Cu₂O thin-film heterojunction solar cell using a direct current magnetron-sputtering technique and analyzed the basic material properties, e.g., composition, optical characteristics, morphologic characteristics, and I–V measurement of TiO₂/Cu₂O. Our findings revealed the high potential of the TiO₂/Cu₂O structure as a future-oriented solution for photovoltaic applications.

Nowadays, much attention is paid to the elimination of heat sources poisoning our environment. Air pollution is the most dangerous form of pollution of the environment due to its direct impact on all living organisms, coverage of large areas and easy movement of pollutants. Therefore, air...

TiO₂ thin films deposited on glass and silicon were obtained using a direct current magnetron sputtering technique and pulsed laser deposition using a modular deposition platform. The sample properties were determined by scanning electron microscopy (SEM) and X-ray diffraction analysis. Basic material properties, such as thickness, layer structure, and optical properties, were also examined. The obtained films had a nanocrystalline structure with a mean grain diameter ranging from 0.2 to 0.4 m. This article presents a detailed discussion of the influence of the manufacturing technique on TiO₂ thin film morphology and optical properties for possible photovoltaic applications for polycrystalline heterostructures.

Here, we evaluated the efficiency of a solar domestic hot water system in a dormitory in Rzeszow. Radiance exposure was analyzed based on information obtained from an online database (the meteorological station in Rzeszow-Jasionka). The mean seasonal and annual solar irradiation of a flat surface and surfaces inclined at 30°, 45°, and 60° from the horizontal plane in Rzeszow were determined. The mean monthly irradiation was compared with that in selected European cities based on the Photovoltaic Geographical Information System meteorological database. The thermal solar panel area and final consumption of solar energy in Poland from 2005 to 2014 are also presented. The characteristics of the analyzed building, distribution of the inhabitants, and consumption of hot water from 2009 to 2014 are described. The heat demand was determined by hot water consumption per day per person based on hot water consumption metering and heat metering. The solar energy conversion efficiency was determined after the solar thermal collectors were installed in the building. The relation of the heat demand calculated based on the thermal energy utilized to heat water per person and heat metering for heating water was also analyzed. We also present a method of calculating the annual (stratified by month) ratio of solar energy utilization. Energy savings for the building were calculated. Improvements that could further increase the solar energy efficiency and shorten the investment payback period are proposed.