Abstract: In a method for forming a light absorber layer (4) of a thin film solar cell, the absorber layer is formed from a plurality of sub-layers each of which is formed by preparing a plurality of mixtures containing Cu, Se, In and Ga in a liquid medium, a composition ratio of In to Ga being progressively increased from one mixture to another, the mixtures optionally including a mixture containing no In or Ga; applying a layer of one of the mixtures onto a back electrode layer (3) formed on a substrate (2); drying the applied layer of the mixture; and rapidly baking the dried layer of the mixture. By forming the absorber layer with a plurality of thin absorber sub-layers each having a controlled band gap, a solar cell having a large surface area can be fabricated at low cost and the efficiency of the solar cell can be improved by forming a favorable band gap gradient structure.

Abstract: In a method for forming a light absorber layer (4) of a thin film solar cell, the absorber layer is formed from a plurality of sub-layers each of which is formed by preparing a plurality of mixtures containing Cu, Se, In and Ga in a liquid medium, a composition ratio of In to Ga being progressively increased from one mixture to another, the mixtures optionally including a mixture containing no In or Ga; applying a layer of one of the mixtures onto a back electrode layer (3) formed on a substrate (2); drying the applied layer of the mixture; and rapidly baking the dried layer of the mixture. By forming the absorber layer with a plurality of thin absorber sub-layers each having a controlled band gap, a solar cell having a large surface area can be fabricated at low cost and the efficiency of the solar cell can be improved by forming a favorable band gap gradient structure.