Patent ID: 8058548

Claim:
A solar cell apparatus comprising: a solar cell element; a pair of electrodes connected to the solar cell element; a variable light condensing apparatus comprising a translucent support having a hydrophilic photocatalyst on a surface thereof and a first translucent liquid supported on the surface of the translucent support in contact therewith, and disposed opposed to the solar cell element, wherein the hydrophilic photocatalyst is TiO 2 , BaTiO 3 , SrTiO 3 , BaZrO 3 , SrZrO 3 or Ge 3 N 4 doped or not doped with N, S or C and hydrophilicity thereof increases when irradiated with light having a predetermined wavelength compared to when not irradiated with such light, and the first translucent liquid is water or an aqueous solution and does not form any condensing lens when the hydrophilic photocatalyst is irradiated with light at a predetermined luminous flux density or higher, whereas the first translucent liquid forms a condensing lens when the hydrophilic photocatalyst is irradiated with light at less than the predetermined luminous flux density.