Superhydrophobic Silica-based Nano-Coatings for Anti-Reflective and Anti-Soiling Surface: Effect of HMDS and DIPEA

SELF-CLEANING SILICA NANO-COATINGS FOR SOLAR PV CELLS

Abstract

This study presents a novel nano-silica-HMDS (hexamethyldisilazane) surface coating, synthesized through an efficient chemical route, exhibiting anti-reflective, superhydrophobic, and anti-soiling properties suitable for solar panel top covers working in dusty environments. The synthesized surface coating enhances optical transmission, mitigating incident light reflection and performance loss from soiling. The experiment results show a 5.8% average power improvement in the nano-silica-HMDS-coated solar photovoltaic cell compared to a manually cleaned, uncoated solar cell. The cost-effective dip-coating method applied to the substrate surface at room temperature offers a practical alternative to costly surface coatings. The surface coating exhibits a finely tuned refractive index of 1.14 and 96.1% transmittance for wavelengths ranging from 400–800 nm demonstrating exceptional transparency and optical effectiveness. The Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM) results show a highly rough HMDS-modified-nano-silica surface exhibiting anti-soiling and super-hydrophobicity characteristics confirmed by a water contact angle of 156° in test results. The synthesized surface coating also showed excellent stability over two months in a dusty environment consisting of abundant particulate particles pm 2.5 and pm 10 observed in environmental stability tests conducted over 2.5 months with the help of an experimental setup. The test results confirm the nano-silica-HMDS (0.3:1) surface coating as the most optimum concentration for simultaneously achieving superhydrophobicity, anti-soiling, and antireflection properties.