Effects of Solar-Glass Coatings on the Adhesion Forces Related to Soiling

We report on the impact that different coatings on solar glass have on the adhesion forces with SiO
₂
spheres, which are used to emulate real dust particles. We measured the forces in an atomic force microscope, using force versus distance measurements, and performed the investigation at different values of relative humidity, from 15% to 80%. We will show that, in general, bare solar glass has the largest adhesive forces, with a strong influence of RH. In contrast, some coatings result in much lower adhesion forces and little influence of humidity, which suggests that these coatings may help reduce soiling, and have an impact on soiling associated with dew formation and some cementation processes.