LAMINATED STRUCTURE FOR CIS BASED SOLAR CELL, AND INTEGRATED STRUCTURE AND MANUFACTURING METHOD FOR CIS BASED THIN-FILM SOLAR CELL

• US 20100267190A1
• Filed: 11/25/2008
• Published: 10/21/2010
• Est. Priority Date: 11/30/2007
• Status: Active Grant

• Current Assignee: Solar Frontier K.K. (Idemitsu Kosan Company Limited)
• Original Assignee: Solar Frontier K.K. (Idemitsu Kosan Company Limited)
• Inventors: Fujiwara, Yosuke, Hakuma, Hideki, Kushiya, Katsumi, Tabuchi, Katsuya
• Granted Patent: US 8,691,619 B2
• Time in Patent Office: Days
• US Class Current: 438/95
• CPC Class Codes: H01L 31/0296 including, apart from doping material or other impurities, only AIIBVI compounds, e.g. CdS, ZnS, HgCdTe
• CPC Class Codes: H01L 31/0749 including a AIBIIICVI compound, e.g. CdS/CulnSe2 [CIS] heterojunction solar cells
• CPC Class Codes: H01L 31/1836 comprising a growth substrate not being an AIIBVI compound
• CPC Class Codes: Y02E 10/541 CuInSe2 material PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

This invention aims to provide a laminated structure and an integrated structure of a high production efficiency for a CIS based thin-film solar cell, which can produce a high-resistance buffer layer of the CIS based thin-film solar cell efficiently on a series of production lines and which needs no treatment of wastes or the like, and a manufacturing method for the structures. The CIS based thin-film solar cell includes a back electrode, a p-type CIS based light absorbing layer, a high-resistance buffer layer and an n-type transparent conductive film laminated in this order. The high-resistance buffer layer and the n-type transparent conductive film are formed of thin films of a zinc oxide group. The buffer layer contacts the p-type CIS based light absorbing layer directly, and has a resistivity of 500 Ω·cm or higher.

Claims

1-22. -22. (canceled)

23. A method for manufacturing a CIS based thin-film solar cell, comprising the steps of:

making a back electrode on a substrate;

forming a p-type CIS based light absorbing layer on the back electrode;

forming a buffer layer formed of a thin film of a zinc oxide group directly on the p-type CIS based light absorbing layer; and

forming an n-type transparent conductive film formed of the thin film of a zinc oxide group on the buffer layer,

wherein the buffer layer forming step is performed by an MOCVD method, and

a substrate temperature of the buffer layer forming step is made higher than the substrate temperature at the time of forming the n-type transparent conductive film.

24. The method for manufacturing a CIS based thin-film solar cell according to claim 23, wherein the substrate temperature at the time of forming the buffer layer is 190 to 300°

C.

25. The method for manufacturing a CIS based thin-film solar cell according to claim 23, wherein the n-type transparent conductive film is formed by the MOCVD method.

28. The method for manufacturing a CIS based thin-film solar cell according to claim 23, wherein a film forming rate of the buffer layer is 15 nm per minute or higher.

26. A method for manufacturing a CIS based thin-film solar cell, comprising the steps of:

making a back electrode on a substrate;

forming a p-type CIS based light absorbing layer on the back electrode;

forming a buffer layer formed of a thin film of a zinc oxide group directly on the p-type CIS based light absorbing layer; and

forming an n-type transparent conductive film formed of the thin film of a zinc oxide group on the buffer layer,

wherein the buffer layer forming step and the n-type transparent conductive film forming step are performed by an MOCVD method, and

a material molar ratio ([O]/[Zn]) of the buffer layer forming step is made higher than the material molar ratio ([O]/[Zn]) of the n-type transparent conductive film forming step.

27. The method for manufacturing a CIS based thin-film solar cell according to claim 26, wherein the material molar ratio ([O]/[Zn]) of the buffer layer forming step is 2 or higher.

29. The method for manufacturing a CIS based thin-film solar cell according to claim 26, wherein a film forming rate of the buffer layer is 15 nm per minute or higher.