Turkey and Albania are located in an advantageous position in the southern part of Europe in terms of the solar energy. Both countries can receive the solar light with a high intensity (~1500 kWh/m²) when compared with the most of the European countries. However, the installed PV capacity of Turkey (5 GW) and Albania (10 MW) is low compared to the European countries. Although Germany can receive the solar light with a low intensity of around 900 kWh/m², the installed PV capacity has reached to about 49 GW in 2019. The installed PV capacities of both countries can only cover 2.5% of Turkey’s electricity need and 1% of Albania’s electricity need. In addition, both countries meet the majority of their energy needs from foreign countries, which means that both countries need to increase the installed capacity of the PV systems and maintain the efficiency of the existing PV systems to able to benefit more from the sunlight.

With the proposed project, it is planned to develop self-cleaning coatings for the PV systems. If the project is accepted and completed successfully, the contamination-induced efficiency loss of the existing PV systems and the PV systems to be produced can be prevented or the contamination effect on the efficiency loss can be reduced. The acceptance and successful completion of the project will bring a lot of economic benefits to both countries. The research groups from both countries have a deep knowledge on the materials science and its application. The success of their previous studies in the field of materials science shows the potential for successful completion of this project. The majority of the works planned within the scope of the project will be carried out in both countries in partnership. Task 1 will be carried out jointly in coordination. A certain part of Task 2 will be carried out by the research group in Turkey and another part by the other research group in Albania.

The accumulation of pollution and any kinds of contamination on the glass cover of the solar cell affects the efficiency of the photovoltaic (PV) systems. The contamination of the glass cover can absorb and reflect a certain part of the sunlight irradiation, which can decrease the intensity of the light coming in through the glass cover. The contamination on the cover glass of the PV panel has a negative effect on the economic return of the PV systems. The conversion efficiency from the solar energy to the electrical energy reduces and the contamination causes additional maintenance and cleaning costs. Depending on the intensity and the thickness of the contamination on the cover glass, there might be a 10-20% efficiency loss due the contamination.

In the scope of the project, SiO₂/WO₃ and SiO₂/WO₃/ZnO composites will be coated from their solutions on the glass substrates. The boron doping will be applied to WO₃ to produce the SiO₂/WO₃-B and SiO₂/WO₃-B/ZnO composites. SiO₂ has been selected as the composite constituent owing to its low refractive index and low surface scattering, which is important in terms of the light transmittance through the cover glass of the solar cell. SiO₂ is also a hydrophilic semiconductor, which can contribute to the photoinduced hydrophilicity of the photocatalyst semiconductor. On the other hand, WO₃ has been selected as a photocatalyst semiconductor. Under the UV light irradiation, WO₃ can absorb the photons of the UV light, generating the photoinduced charge carriers. The photoexcited charge carriers provide both the photoinduced hydrophilicity on the surface of the coating and the photocatalytic degradation of the organic contaminants accumulated on the surface of the coating, which allows water droplets to spread and flow on the surface of the cover glass to remove the contaminations. However, the recombination rate of the photoexcited charge carriers on the photocatalyst semiconductor is mostly high. In order to suppress the recombination of the photoinduced charge carriers, WO₃ will be combined with SiO₂ or doped with boron atoms. Both effects are expected to reduce the recombination rate of WO₃. Although SiO₂ has superior features in terms of the light transmission, it is not very effective under UV light as a photocatalyst. The widely preferred photocatalyst ZnO will also be added to the SiO₂/WO₃ composite structure to reduce the recombination rate of WO₃ and support its photocatalytic activity.