Transparent alumina based superhydrophobic self-cleaning coatings for solar cell cover glass applications

- Transparent, anti-reflective and superhydrophobic aluminium oxide coatings were fabricated by chemical method.
- The coatings were superhydrophobic with static water contact angle of 155°.
- The fabricated superhydrophobic substrates were optically transparent.
- The coated glass recovered the efficiency of contaminated solar panel by 91% and useful for cover glass applications.

Superhydrophobic surfaces based on aluminium oxide coatings had been developed on glass substrates via solution based approach for solar panel cover glass applications. The fabricated surface was amorphous with an interconnected porous network of nanoflakes. The static contact angle of the prepared coatings was 161° and exhibited superior self-cleaning behaviour at a tilting angle less than 10°. The 300 nm thick coating with refractive index value gradually decreased from air (n −1), through the fabricated coating (n −1.35) towards the glass substrate (n - 1.56) enabled it to acquire a high average transmittance of 95% with anti-reflecting property. The photovoltaic performance of commercially available solar cells covered with uncoated glass substrate and aluminium oxide coated glass substrate was measured under various conditions (such as - fabricated, artificially contaminated and self - cleaned conditions) and the results were compared. The uncoated glass substrate and aluminium oxide coated superhydrophobic glass substrate recovered the efficiency of saw dust contaminated solar panel by 67% and 91%, respectively, thereby enabling the fabricated superhydrophobic glass substrate to be effectively useful for self-cleaning cover glass applications.