Method for manufacturing thin film compound solar cell

Abstract

To manufacture a thin film compound solar cell which can improve the adhesive property of electrodes even when being provided with a base material, and which prevents the base material from being separated. A cell main body configured by laminating a plurality of compound semiconductor layers is formed on a substrate. A rear surface electrode 7 is formed on the cell main body, and a rear surface film 8 as the base material is formed on the rear surface electrode 7 . A reinforcing material 9 is attached on the rear surface film 8 . The substrate is separated from the cell main body, and the cell main body is mesa-etched. A surface electrode 13 is formed on a contact layer 3 after the etching. The reinforcing material 9 is separated, and the surface electrode 13 is annealed. The formed thin film compound solar cell is separated into a plurality of solar cell elements.

1 - 11 . (canceled) 
     
     
         12 . A method for manufacturing a thin film compound solar cell having a cell main body in which at least one PN junction is formed by a plurality of compound semiconductor layers, each having a different chemical composition, the method comprising: a process of forming an etching-stop layer for suppressing infiltration of an etching solution from the side of a substrate, a contact layer, an emitter layer made of a first conductivity type compound semiconductor, a base layer forming a PN junction with the emitter layer, and a buffer layer; a process of forming a rear surface electrode on the surface on the compound semiconductor layer; a process of annealing the rear surface electrode; a process of forming a base material made of a polyimide film by applying and annealing polyimide on the rear surface electrode; a process of attaching a reinforcing material on the base material; a process of separating and removing the substrate from the cell main body; a process of forming a surface electrode; a process of removing the etching stop layer exposed by separating and removing, a process of etching the contact layer in a predetermined pattern, a process of mesa-etching, a process of forming a surface electrode on the mesa-etched contact layer; a process of separating the reinforcing material; and a process of annealing the surface electrode. 
     
     
         13 . A method for manufacturing a thin film compound solar cell having a cell main body in which at least one PN junction is formed by a plurality of compound semiconductor layers, each having a different chemical composition, the method comprising: a process of forming an etching-stop layer for suppressing infiltration of an etching solution from the side of a substrate, a contact layer, an emitter layer made of a first conductivity type compound semiconductor, a base layer forming a PN junction with the emitter layer, and a buffer layer; a process of forming a rear surface electrode on the surface on the compound semiconductor layer; a process of annealing the rear surface electrode; a process of forming a base material made of a polyimide film by applying and annealing polyimide on the rear surface electrode; a process of attaching a reinforcing material on the base material; a process of separating and removing the substrate from the cell main body; a process of forming a surface electrode; a process of removing the etching stop layer exposed by separating and removing, a process of etching the contact layer in a predetermined pattern, a process of mesa-etching, a process of, after forming the surface electrode on the contact layer, etching the contact layer using the surface electrode as an etching mask, a process of separating the reinforcing material; and a process of annealing the surface electrode. 
     
     
         14 . The method for manufacturing the thin film compound solar cell according to  claim 12 , wherein the polyimide film is formed by applying and sintering a solution of polyamic acid which is a polyimide precursor. 
     
     
         15 . The method for manufacturing the thin film compound solar cell according to  claim 12 , wherein the thickness of the polyimide film is set to 15 μm or less. 
     
     
         16 . A thin film compound solar cell comprising: a compound semiconductor layer in which at least one PN junction is formed; a surface electrode formed on one surface of the compound semiconductor layer; a polyimide film formed on the other surface of the compound semiconductor layer; and a rear surface electrode sandwiched between the compound semiconductor layer and the polyimide film. 
     
     
         17 . The thin film compound solar cell according to  claim 16 , wherein the compound semiconductor layer is made of an epitaxially grown single crystal thin film.