A cost-effective procedure for hydrophobization of commercial silica nanopartides by octadecyltrichlorosilane or trichloro (1H,1H,2H,2H-perfluorooctyl) silane was developed. The functionalized nanoparticle solution could easily be applied on a glass surface by Langmuir-Schaefer deposition or spincoating to create a superhydrophobic surface with the contact angle above 170 degrees. A hydrophobization driven formation of nanoparticle clusters resulted in multiscale hierarchical surface roughness as evidenced by the stylus profilometry and atomic force microscopy. Consequently, optical measurements in the vis-NIR region revealed enhanced forward diffuse scattering and reduced reflectance in a broad interval of the incidence angles. A small sliding angle far below 1 degrees suggests additional coating functionalities such as the self-cleaning and anti-icing. The coating was tested on a front surface of an organic photovoltaic device. A more than 6% enhancement of the photoconversion efficiency comparing with the uncoated device was achieved which may be even larger in real operation conditions considering the air pollution and humidity. (C) 2014 Elsevier B.V. All rights reserved.