Fabrication and characterization of transparent, self-cleaning glass covers for solar photovoltaic cells

Solar photovoltaic (SPV) cells have become ubiquitous in meeting the increasing global energy demand, but they face major challenge of performance degradation due to dust on the SPV panels. The traditional mechanical methods of cleaning are costly and time consuming. To ameliorate this problem, a ``selfcleaning" superhydrophobic coating is laid on the upper glass cover of SPV array that repels water. This promotes droplet roll-off, enabling a very small amount of water to clean the surface. Herein, such a coating on glass has been developed by depositing 10-20 nm silica nanoparticles via a facile sol-gel method on glass surface and grafting a layer of fluoroalkylsilane above it. Surface roughness, wettability and durability of the fabricated coating are characterized through surface profiling, contact angle measurements and droplet impact test, respectively. The treated surface shows an attenuation of 6 +/- 1.24% of the incident radiation, while the SPV voltage output is only slightly affected. Moreover, the treated surfaces show significantly better recovery in the SPV-cell performance upon cleansing with a measured quantity of water than that observed with the untreated surface. (C) 2020 Elsevier B.V. All rights reserved.