Patent ID: 8225742

Claim:
A system for depositing a buffer layer material from a liquid process solution onto a horizontally disposed flat sheet-shaped exposed top surface of a solar cell absorber layer formed on a continuous flexible workpiece to manufacture solar cells, the system comprising: a horizontal chamber to deposit the buffer layer material onto the horizontally disposed flat sheet-shaped exposed top surface of the solar cell absorber layer, the horizontal chamber comprising: an entrance opening on a side of the horizontal chamber in which to insert the continuous flexible workpiece into the horizontal chamber; a heated wall that supports and heats a part of the continuous flexible workpiece and the horizontally disposed flat sheet-shaped exposed top surface of the solar cell absorber layer corresponding thereto disposed within the chamber to a first temperature that is sufficient to cause deposition of the buffer layer material onto the horizontally disposed flat sheet-shaped exposed top surface of the solar cell absorber layer from a portion of the process solution that is in contact with the horizontally disposed flat sheet-shaped exposed top surface of the solar cell absorber layer; a cooled wall placed substantially across from the heated wall, such that the cooled wall, the horizontally disposed flat sheet-shaped exposed top surface of the solar cell absorber layer, and the heated wall are parallel with each other; a liquid solution inlet to flow the liquid process solution into a gap between the heated wall and the cooled wall and onto the horizontally disposed flat sheet-shaped exposed top surface of the solar cell absorber layer at a predetermined flow rate, wherein the liquid process solution is maintained at a second temperature that is lower than the first temperature; and an exit opening on another side of the horizontal chamber in which to remove the continuous flexible workpiece having the solar cell absorber layer and the buffer layer thereon from the horizontal chamber; a heating mechanism to heat the heated wall and activate the deposition of the buffer layer material onto the horizontally disposed flat sheet-shaped exposed top surface of the solar cell absorber layer; a cooling mechanism associated with the cooled wall, that cools the cooled wall so that the deposition of the buffer layer material cannot occur on the cooled wall due to the solution flowing adjacent the cooled wall being cooled; a liquid solution outlet to flow a used liquid process solution out of the chamber at a flow rate that substantially corresponds to the predetermined flow rate of the liquid process solution; and a moving assembly to hold and linearly move the continuous flexible workpiece through the horizontal chamber, wherein the moving assembly comprises a supply spool to unwrap and feed unprocessed sections of the continuous flexible workpiece into the entry opening of the horizontal chamber and a take-up spool to receive processed portions from the exit opening of the horizontal chamber.