Disclosed are methods for forming nanoparticle films using electrophoretic deposition. The methods comprise exposing a substrate to a solution, the solution comprising substantially dispersed nanoparticles, an organic solvent, and a polymer characterized by a backbone comprising Si—O groups. The methods further comprise applying an electric field to the solution, whereby a nanoparticle film is deposited on the substrate. Suitable polymers include polysiloxanes, polysilsesquioxanes and polysilicates. Coated glass windows and methods of forming the coated glass windows using the solutions are also disclosed. The methods may be adapted to form nanoparticle films suitable for use as back reflectors in solar cells, where such nanoparticle-based back reflectors exhibit high reflection and light scattering properties, including use of such back reflectors to fabricate solar cells and other photovoltaic-based and light dependent devices such as television screens, computer monitors, portable systems such as mobile phones, handheld games consoles and PDAs.