Problem Statement Global environmental change and the severe energy crisis are major ecological problems in the world of today. Scientists and engineers are working hard to find sustainable energy solutions that can efficiently convert solar energy into electricity to solve these issues. Solar cells are among the most widely utilized options since they are clean, renewable sources of electricity. Although they are considered to be effective devices in terms of simple maintenance and durability, even the most modern solar cells have limitations in the amount of light utilized and, therefore, their conversion efficiency. Much losses are associated with the inability to use the high-energy UV range of solar light and the use of downconversion luminescent materials was suggested as an alternative solution to increase the efficiency. Another problem that has been identified with the reduced efficiency of photovoltaic devices is the deterioration of solar cells due to their dust pollution and the presence of heavy precipitation, especially snow. Undoubtedly, the level of this problem varies depending on the region and climate. However, since this project is focused on implementing of green research on campus of Nazarbayev University located in Astana, the capital of the great steppe, it is worth noting that the climate of the city is characterized as sharply continental with dry summers and cold, snowy winters, so this problem is significantly pronounced and requires a solution.
Solution Proposal and Methodology
As it was stated above, the use of downconversion luminescent materials is one of the strategies to reflect the problem of inefficient use of the solar light spectrum by solar cells. They are able to convert high-energy ultraviolet photons into lower-energy ones introducing the blue shift of utilized light. In turn, lanthanides possess distinctive optical properties, large Stoke shifts, sharp emissions, and long excited lifetime making their ions a good downconversion material. This project proposes the use of lanthanide-based Y2O3:Eu nanoparticles embedded in PDMS (polydimethylsiloxane) polymer matrix to create a thin film. Additionally, the synthesis strategy included the use of a commercial hydrophobic agent to solve the second problem stated. The nanoparticles were prepared from nitrates of the corresponding lanthanides in the ratio of 97:3 by a facile urea homogeneous precipitation method. The synthesized powder was thoroughly mixed with the commercially available cured PDMS and ultrasonicated until obtaining a monodisperse colloidal suspension. Following this, the solution was diluted with a hydrophobic agent making it even easier to deposit. Speaking of the deposition method, since this material has a potential to be utilized on a large scale in the future, it was decided to implement the spray-coating method as the most approachable and effective way.
To sum up, stable hydrophobic coating for the solar panels has been developed. This coating possesses distinctive properties in terms of its luminescence, screening of destructive UV radiation, and self-cleaning. The operational outcome was tested on the solar panels under real life conditions. As a result, in addition to the hydrophobicity, coating shows the increase in photovoltaic performance of panels. In particular, power of solar panels was increased by 2.48 % compared to the uncoated surface of the device. Another advantage of this work is its simplicity and time-saving. Starting from the synthesis of particles till the deposition of thin film, the process is uncomplicated and does not require expensive equipment and hard work.