Patent ID: 7833821

Claim:
A method of producing a thin film absorber layer for solar cell fabrication comprising: providing a single compositionally uniform Cu—In—Ga target, wherein the single compositionally uniform Cu—In—Ga target is formed solely of a plurality of different solid particles that were each separately formed, intermixed to be compositionally uniformly distributed, and then compressed together, wherein the plurality of different solid particles include at least a plurality of alloy particles, with each of said plurality of alloy particles including at least two of Cu, In and Ga therein, wherein said plurality of different solid particles have a pre-determined stoichiometry, and wherein no Group VIA material is within the compositionally uniform Cu—In—Ga target; sputter depositing a precursor film with a first composition and comprising Cu, In and Ga using, as an only target, the single compositionally uniform Cu—In—Ga target, wherein the step of sputter depositing occurs in the absence of a Group VIA material, and wherein the step of sputter depositing further occurs with the single compositionally uniform Cu—In—Ga target being cooled below about 10° C. during the step of sputter depositing; and after completion of the sputter depositing, reacting the precursor film with at least one Group VIA material thereby forming a Cu(In,Ga)(VIA) 2 compound on the solar cell to produce said absorber layer.