Roll-to-roll processing method and tools for electroless deposition of thin layers

A method of depositing a buffer layer material from a solution to an exposed surface of a solar cell absorber layer disposed on a continuous flexible workpiece for manufacturing solar cells as the continuous flexible workpiece is advanced through a roll-to-roll system, comprising:

• advancing a section of the continuous flexible workpiece having a flat shape from a supply roll onto at least one magnetic shaping roller, the at least one magnetic shaping roller including an outer surface with a cavity shape;
• shaping the section of the continuous flexible workpiece into a curved section that conforms to the outer surface with the cavity shape by magnetically attracting the section of the continuous workpiece into the outer surface of the at least one magnetic shaping roller, thereby elastically altering it into the curved section;
• flowing a supply solution over an exposed surface of the solar cell absorber layer of the curved section of the continuous flexible workpiece, wherein the supply solution is maintained at a first temperature before flowing over the curved section of the continuous flexible workpiece, wherein the supply solution includes all the chemical components of the buffer layer material;
• heating the curved section of the continuous flexible workpiece and the solar cell absorber layer to a second temperature, which is higher than the first temperature while the supply solution is flowed thereon, wherein the heating of the curved section of the continuous flexible workpiece and the absorber layer cause the transfer of heat from the solar cell absorber layer to at least a portion of the supply solution that is in contact with the exposed surface of the solar cell absorber layer and thereby causes depositing of the buffer layer material within the supply solution onto the exposed surface of the solar cell absorber layer;
• and
• moving the curved section of the continuous flexible workpiece away from the outer surface with the cavity shape of the at least one shaping roller so that the curved section of the continuous flexible workpiece flattens.