In conclusion, a multifunctional film composed of silica nanoparticles
was prepared. The combination of hydrophilic SiOH groups and
nanoporous topography endows the silica film with superhydrophilicity
and thereby antifogging property. The nanoporous morphology
also effectively reduces the refractive index of the film, thus antireflectivity
can be obtained with a suitable film thickness. Application
of such a multifunctional film on a full sized crystalline silicon solar
cell demonstrates that 2% increase in power output can be obtained
at 0° irritation and it increases to 5% and 8% at incidence angles of
30° and 60°, respectively. In terms with the self-cleaning property
resulted from the ultra hydrophilicity of the antireflective silica
coating, this multifunctional film promises an important application
in the solar modules.
Acknowledgments
This work was supported by the NSFC (No. 50803072, 50903088), 863
project (2009AA03Z336), CAS-TJ project and ICCAS (CMS-CX200805).