NOVELTY - Solar cell comprises an electrode (11); and a first porous film (13) formed on the electrode with pores and containing metallic oxide particles (131) having a mean particle diameter of 5 - 14 nm. The pores of the first porous film have a mean pore size of 7.5 - 15 nm. The porous film has a thickness of 10 - 3000 nm. The metallic oxide particles are joined by interparticle necking. The solar cell further comprises an additional porous film formed on the first porous film, containing metallic oxide particles, which have a mean particle diameter greater than that of first porous film.    USE - As a solar cell for generating electrical energy, e.g. dye-sensitized solar cell.    ADVANTAGE - The method provides solar cell with enhanced photoelectric conversion efficiency by improving the collection of electrons. The first porous film containing fine, uniform metallic oxide particles formed on the first electrode, improves the interface contact characteristics between the first electrode and the first porous film. Consequently, current collection is maximized to enhance the photoelectric conversion efficiency. The first porous film serves to enhance the interface contact characteristics between the electrode and the porous film, and the additional porous film serves to increase the porous film thickness without increasing the number of processing steps. The ionic conductivity is enhanced due to the fine and even-sized pores. Consequently, the excited electrons from the porous film are easily collected at the first electrode and hence the photoelectric conversion efficiency is enhanced. Several porous films with different characteristics can be formed to enhance the characteristics of each film simultaneously.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for manufacturing a solar cell involving forming a first porous film through self-assembling by using a self-assembling composition.    DESCRIPTION OF DRAWING(S) - The figure shows a sectional view of a solar cell.    first substrate (10)    electrode (11)    first porous film (13)    dye (15)    second substrate (20)    metallic oxide particles. (131)