Patent ID: 8268270

Claim:
A method of producing a coating solution for forming a light-absorbing layer of a chalcopyrite solar cell, comprising: dissolving Cu or Cu 2 Se and a chalcogen in a solvent comprising dimethylsulfoxide and hydrazine to obtain a solution; adding an alcohol solvent to the resulting solution to crystallize a hydrazine-coordinated Cu chalcogenide complex; re-dissolving the crystallized hydrazine-coordinated Cu chalcogenide complex in dimethylsulfoxide to obtain a solution (I); dissolving a hydrazine-coordinated In chalcogenide complex in dimethylsulfoxide to obtain a solution (II); dissolving a hydrazine-coordinated Ga chalcogenide complex in dimethylsulfoxide to obtain a solution (III); and mixing together the solution (I), the solution (II) and the solution (III).