NOVELTY - Depositing buffer layer to solar cell absorber layer to form solar cell involves: advancing flat section of workpiece with solar cell absorber layer (34) on heated plate (48) with cavity to elastically alter section into curved shape conforming cavity; flowing supply solution of buffer layer material (41) over exposed curved surface of workpiece (21A); heating at higher temperature workpiece and absorber layer with heated plate to transfer heat from layer to solution to deposit material on exposed surface of solar cell absorber layer; and moving workpiece away from cavity to flatten.    USE - For depositing a buffer layer from solution to surface of solar cell absorber layer on continuous flexible workpiece for manufacturing solar cells as continuous flexible workpiece (claimed).    ADVANTAGE - The method provides deposition of buffer layer (preferably CdS buffer layer) on surface of solar cell from process solution including all chemical components of CdS buffer layer material; where CdS is deposited directly on absorber layer disposed on flexible workpiece that is conformed to a curve shape to hold process solution in it and prevent spillage of process solution onto backside of continuous workpiece, such that buffer layer of CdS is deposited from deposition solution while flexible workpiece is heated and elastically shaped by heated shaping plate to retain process solution on solar cell absorber layer, and allow for manufacturing solar cells as continuous flexible workpiece; as compared to prior art processes of chemical bath deposited (CBD) of buffer layer, in which pre-measured amount of bath or solution is used to form buffer layer on pre-selected surface area of solar cell structure, used bath is discarded along with particles formed within bath, and generate large amounts of chemical waste and increase cost since actual materials utilization to form buffer layer on surface of structure is very low (lower than 20%), such that most of buffer layer material is wasted on forming film on walls of reactor holding CBD solution, and on forming particles of buffer layer material within solution. The method forms solar cells as continuous flexible workpiece, increases materials utilization of CBD processes, reduces waste, and allows continuous deposition of materials on substrates in form of rolled foils. The solution is heated when is in contact with surface to be coated and cooled when not in contact with surface, and can then be re-circulated again over surface to be coated. Thus film formation reaction is accelerated on surface to be coated and homogeneous nucleation within solution and on surfaces other than the surface to be coated is minimized and materials utilization is improved. Further, substantially all surfaces of reactor walls are covered with substrates to be coated and hence deposition and waste of material on reactor walls is eliminated or reduced in zone where heat is applied to solution. The solution is further continually monitored with a monitoring unit for chemical composition and filtered, and involves further dosing to keep composition substantially same for long periods. Thus waste is minimized, materials utilization is further enhanced and continuous deposition of materials on large number of substrates or long sheets of flexible substrates can be achieved.    DETAILED DESCRIPTION - Method for depositing a buffer layer material from solution to exposed surface of solar cell absorber layer disposed on continuous flexible workpiece for manufacturing solar cells as continuous flexible workpiece, by advancing through a roll-to-roll system, involves: advancing section of continuous flexible workpiece with solar cell absorber layer (34) having flat shape from supply roll (35) onto heated plate (48) including cavity area, where cavity area of heated plate is configured to elastically alter section of continuous flexible workpiece into curved shape that conforms to cavity area of continuous flexible workpiece; flowing supply solution (41) including all chemical components of buffer layer material, over exposed surface (21A) of solar cell absorber layer that is curved-shape section of continuous flexible workpiece, where supply solution is maintained at first temperature before flowing into section of continuous flexible workpiece and conforms to cavity area of heated plate with curved shape; heating, to a second temperature which is higher than first temperature, continuous flexible workpiece and solar cell absorber layer using heated plate when section of continuous flexible workpiece is within cavity area and conforming to cavity area with curved shape, where heating of continuous flexible workpiece and absorber layer causes transfer of heat from solar cell absorber layer to at least a portion of solution that is in contact with exposed surface of solar cell absorber layer, to cause depositing of buffer layer material within solution onto exposed surface of solar cell absorber layer; and moving section of continuous flexible workpiece away from cavity areas of heated plate so that section of continuous flexible workpiece flattens. The method further involves wrapping up flattened continuous flexible workpiece around receiving roll after moving step. The first temperature is 15-40 degrees C and second temperature is 50-90 degrees C. The heated plate further comprises a transition area between supply roll and cavity area of heated plate; and the step of advancing section of continuous flexible workpiece includes advancing section over transition area to aid in conforming flexible workpiece into curved shape. The heated plate is configured to elastically alter section of continuous flexible workpiece into curved shape that conforms to cavity area using attractive force induced by magnetic field or vacuum. An INDEPENDENT CLAIM is included for a system for depositing buffer layer material from solution onto exposed surface of solar cell absorber layer formed on flexible workpiece to manufacture solar cells, comprising: a heated plate including a cavity area, to heat exposed surface of solar cell absorber layer to a process temperature, where cavity area of heated plate is configured to elastically alter section of flexible workpiece into curved shape that conforms to cavity area of heated plate; and a solution inlet to flow solution onto exposed surface of flexible workpiece maintained in curved shape within cavity area.    DESCRIPTION OF DRAWING(S) - The figure shows side view of deposition chamber for deposition of buffer layer material on solar cell absorber layer on continuous flexible workpiece, by using shaped heated wall.    Exposed wall of deposition section (21A)    Flexible workpiece structure with solar cell absorber layer (34)    Supply spool (35)    Solution of buffer layer material (41)    Used process solution (42)    Container (43)    Transition wall/plate including cavity area (48)