Charge splitting networks for optoelectronic devices may be fabricated using a nanostructured porous film, e.g., of SiO.sub.2, as a template. The porous film may be fabricated using surfactant temptation techniques. Any of a variety of semiconducting materials including semiconducting metals and metal oxides (such as TiO.sub.2, CdSe, CdS, CdTe, or CuO) may be deposited into the pores of the porous template film. After deposition, the template film may be removed by controlled exposure to acid or base without disrupting the semiconducting material leaving behind a nanoscale network grid. Spaces in the network grid can then be filled with complementary semiconducting material, e.g., a semiconducting polymer or dye to create a exciton-splitting and charge transporting network with superior optoelectronic properties for an optoelectronic devices, particularly photovoltaic devices.