Durable Hydrophobic Microcavity Surfaces for Self-Cleaning of Photovoltaic Panels

Abstract In solar power generation, as solar panels are installed outdoors, dust particles accumulate on the solar cell surface, causing attenuation of light and reducing the power output. To maintain the output performance of solar panels, foreign substances on the surface must be cleaned. In general, cleaning the solar panel surface directly or using a drone or automated device causes scratches on the surface, results in the consumption of resources, and increases the costs. To solve this problem, in this study, we aimed to remove foreign substances from the solar panel through the self-cleaning function of the superhydrophobic surface. To produce the superhydrophobic surface, a hexagonal wall pattern was transferred to a solar cell through nanoimprint lithography, and silica nanoparticles were coated on the wall. Fine particles were removed from the surface of the manufactured solar cell as water droplets rolled off with a contact angle of greater than 160° and a rolling angle as low as 5°. Owing to the optical characteristics of the micro silica cavity surface, a lower light reflectance and a 1.3% increase in efficiency were confirmed in the 600–800 nm wavelength range compared with a typical solar cell.