Patent ID: 8323735

Claim:
A method of forming a thin film solar cell absorber layer, comprising: providing a base having a front surface and a back surface; depositing a precursor layer over the front surface of the base, wherein the precursor layer includes metallic species comprising at least one Group IB material and at least one Group IIIA material; converting the precursor layer into a planar layer during a planarization period by applying force onto a top surface of the precursor layer by a smooth surface of a planarization apparatus to press down and flatten the precursor layer without removing any material from the precursor layer, wherein a first temperature range is provided within a first process section of a reactor that contains the planarization apparatus; and reacting the planar layer at a second temperature range for a transformation period within a second process section that is different from the first process section of the reactor to transform the planar layer into a planar Group IBIIIAVIA compound layer, the second temperature range being greater than the first temperature range.