Method for forming an absorber layer of a thin film solar cell

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. As these sub-layers can be applied simply by any known processes, the method of the present invention is highly suited to be used for mass producing solar cells.

Dependencies are inferred from the claim text.