Self-Cleaning Performance of Super-Hydrophilic Coatings for Dust Deposition Reduction on Solar Photovoltaic Cells

Abstract

Dust deposition on solar photovoltaic (PV) cell surface will significantly decrease the PV power efficiency, as the transmittance of the solar cells would be greatly decreased by the deposited dust particles. This paper aims to study the anti-dust performance of super-hydrophilic coatings for the solar PV cells with water spraying condition. The solar cell covering glass was treated to be super-hydrophilic and compared with the bare glass sample. It was found that many dust particles adhere and aggregate on the uncoated glass while the particles deposited on the super-hydrophilic glass surface are densely distributed. When the water spraying process was conducted, the dust deposition mass for the bare and the coated glass samples are both reduced obviously with the increase time of water spraying. In addtion, dust deposition mass is significantly reduced with the increase of deposition and spraying tilt angles. The self-cleaning efficiency of super-hydrophilic coating on dust deposition is 92% higher than the bare glass cases. The spectral transmittance of glass samples for all the coated cases are significantly higher than that for all the bare cases. The maximum transmittance improvement can reach 26.5% when the deposition tilt angle is 30° and the spraying tilt angle is 60°.

Progress in Studies of Surface Nanotextures and Coatings with Nanomaterials on Glass for Anti-Dust Functionality

“…Like superhydrophobic surfaces, superhydrophilic surfaces are also easy to clean, as they remove dust particles from the entire surface by forming a uniform water film on the solid surface [ 32 ]. Nature’s fish scales, shark skin, and forest frogs have superhydrophilic properties [ 154 , 155 ].…”

“…The main methods for producing dust-proof and easy-cleaning surfaces are: (a) preparing micro-/nanotextures on the substrate surface to reduce the contact area with dust particles [ 20 , 21 , 22 ]; (b) lowering the electrical resistance of the material surface to enhance its anti-static properties and reduce electrostatic attraction to charged dust particles [ 23 , 24 , 25 ]; (c) adding nano-sized active agents to the material surface to reduce the surface free energy and reduce the adhesion between the substrate and the dust particles [ 26 , 27 , 28 ]; (d) creating a superhydrophobic surface, which enables water droplets rolling across the surface to carry away dust particles [ 29 , 30 , 31 ]; (e) creating a superhydrophilic surface, which removes dust particles from the entire surface by generating a uniform water film on the substrate [ 32 , 33 , 34 ]; and (f) creating a photocatalytic surface, which decomposes organic dust particles on the surface by adding a photocatalyst to the coating [ 35 , 36 , 37 ]. Figure 1 shows an illustration of the strategies used to prevent dust accumulation and adhesion.…”

Optically Transparent TiO2 and ZnO Photocatalytic Thin Films via Salicylate-Based Sol Formulations

“…Typically, highly efficient TiO 2 and ZnO coatings are in the form of thick mesoporous layers to maximize their specific surface area [14]. However, these mesoporous coatings may not be practical for applications requiring functional photocatalytic layers with intrinsic optical transparency, such as selfcleaning and antifogging coatings on windowpanes or photovoltaics [15][16][17].…”

“…Vacuum-based physical vapor deposition (PVD) techniques, such as reactive magnetron sputtering [15,[17][18][19], are commonly favored, however, they can be cost-prohibitive and require specialized equipment and expertise, making them less suitable for smallscale applications. As a result, wet-chemical methods, particularly the sol-gel-based techniques, are preferred, especially in research-scale applications, due to their simplicity, cost-effectiveness, and ability to deposit films without the need for high-vacuum conditions [16,20,21]. In sol-gel deposition, the coating is initially formed from a liquid sol formulation, applied to the substrate using techniques like dip-coating or spin coating, and subsequently converted to the desired metal oxide via post-deposition heat-treatment step [22].…”

Incorporating Hydrophobic Moieties into Self-Assembled Monolayers to Enable Electrochemical Aptamer-Based Sensors Deployed Directly in a Complex Matrix

“…Other studies have also reported the use of hydrophilic SAMs for electrochemical biosensors . In contrast to hydrophilic monolayers, hydrophobic SAMs are rarely explored in electrochemical biosensors, while such monolayers have been employed for applications in solar panels, window glass, fabric, metal, wood, sponge, plastic, and marble as antifouling coatings. − …”