NOVELTY - An optoelectronic device, comprises a surfactant-templated film having interconnected pores distributed in a uniform fashion with neighboring pores separated by a distance of 1-100 nm; and a pore-filling material that fills the pores in porous film. The surfactant-templated porous film and pore-filling material have complementary charge-transfer properties with respect to each other.    USE - As an optoelectronic device, i.e. photovoltaic devices, and power generation systems.    ADVANTAGE - The inventive optoelectronic device has charge-splitting networks. It may be formed relatively inexpensively and on a large scale.    DETAILED DESCRIPTION - An optoelectronic device, comprises a surfactant-templated film having interconnected pores (diameter of 1-100 nm) that are distributed in a substantially uniform fashion with neighboring pores separated by a distance of 1-100 nm; and a pore-filling material that substantially fills the pores in the porous film. The surfactant-templated porous film (206) and the pore-filling material (208) have complementary charge-transfer properties with respect to each other. The interconnected pores in the surfactant-templated film are accessible from an underlying layer and/or overlying layer.    INDEPENDENT CLAIMS are also included for the following:    (a) a method for making an optoelectronic device as above, comprising forming a porous film on a substrate by a surfactant temptation technique; and substantially filling the pores in the porous film with a pore-filling material, where the porous film and the pore-filling material have complementary charge transfer properties with respect to each other;    (b) a solar power generation system, comprising an array of photovoltaic cells, where the cell(s) in the array includes porous nano-architected charge-splitting network(s) (205) between a first electrode (202) and a second electrode (210); and    (c) a method for making a charge-splitting network, comprising forming a porous nano-architected film on a substrate by, and substantially filling the pores in the porous nano-architected film with a pore-filling material.    The porous nano-architected film includes interconnected pores that are substantially uniformly distributed. The pores have diameters of 1-100 nm. The neighboring pores are separated by 1-100 nm. The interconnected pores in the surfactant-templated film are accessible from an underlying layer and/or overlying layer. The porous film and the pore-filling material have complementary charge transfer properties with respect to each other.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic of a device structure for a photovoltaic cell.    First electrode (202)    Charge-transport film (204)    Charge-splitting network (205)    Surfactant-templated porous film (206)    Pore-filling material (208)    Second electrode (210)