Thin-film solar battery and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9293618-B2
Application number	US-201113807817-A
Country	US
Kind code	B2
Filing date	Jun 15, 2011
Priority date	Aug 6, 2010
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

Cells including a first electrode layer, a photoelectric conversion layer, and a second electrode layer on a translucent substrate are connected. Between adjacent cells, a first separating groove separates the first electrode layer, a second separating groove separates the second electrode layer, and a connecting groove electrically connects the second electrode layer of a cell and the first electrode layer of the other. A reflective film is provided on the second electrode layer having a transparent conductive film and a metal film stacked in this order on the photoelectric conversion layer and at least the metal film is patterned into lines. The metal film is patterned into lines with a same width within the connecting groove and is connected to the first electrode layer of the adjacent cell. The reflective film is provided in the connecting groove where the metal film is not formed and in the second separating groove.

First claim

The invention claimed is:

1. A thin-film solar battery comprising a plurality of cells, wherein each cell includes a first electrode layer made of a transparent conductive material, a photoelectric conversion layer made of a semiconductor material, and a second electrode layer made of a conductive material is formed on a translucent substrate, and the plurality of the cells are connected in series, wherein
the thin-film solar battery further comprises, between adjacent cells of the plurality of the cells,
a first electrode layer separating groove that separates the first electrode layer between adjacent cells,
a second electrode layer separating groove that separates the second electrode layer between adjacent cells, and
a cell connecting groove that is provided between the first electrode layer separating groove and the second electrode layer separating groove, and electrically connects the second electrode layer of one cell of the adjacent cells and the first electrode layer of the other cell, and
the thin-film solar battery further comprises a reflective film made of a white insulating layer on the second electrode layer,
wherein the second electrode layer has a structure in which a transparent conductive film and a metal film are stacked in this order on the photoelectric conversion layer,
the metal film is patterned into lines which extend into the connecting groove and are connected to the first electrode layer of the adjacent cell, wherein the lines of the metal film have a line width within the connecting groove which is the same as a line width outside the connecting groove, and
the reflective film is provided in an area of the connecting groove where the metal film is not formed and in the second electrode layer separating groove;
wherein the transparent conductive film is patterned into lines along with the metal film and the reflective film is formed directly on the photoelectric conversion layer in an area of the photoelectric conversion layer where the metal film is not formed.

2. The thin-film solar battery according to claim 1 , wherein the transparent conductive film has a thickness of 10 to 1,000 nanometers.

3. The thin-film solar battery according to claim 1 , wherein the transparent conductive film and the metal film of the second electrode layer are patterned to have a width of 10 to 1,000 micrometers.

4. The thin-film solar battery according to claim 1 , wherein
the transparent conductive film has a thickness of 10 to 500 nanometers.

5. The thin-film solar battery according to claim 1 , wherein the metal film is patterned to have a width of 10 to 1,000 micrometers.

6. The thin-film solar battery according to claim 1 , wherein the reflective film is made of white pigment and binder resin.

7. A manufacturing method of a thin-film solar battery, comprising:
a first step of forming a film made of a transparent conductive material on a translucent substrate and forming a first separating groove that separates cells from each other to form a first electrode layer of each of the cells;
a second step of forming a photoelectric conversion layer including a thin-film semiconductor layer on the substrate on which the first electrode layer is formed;
a third step of forming a transparent conductive film on the photoelectric conversion layer;
a fourth step of, in parallel to the first separating groove, forming a second separating groove that separates the transparent conductive film and the photoelectric conversion layer in the respective cells;
a fifth step of forming a metal film with linear structure on the transparent conductive film and within the second separating groove such that, at a position where the second separating grove is formed, the metal film is connected to the first electrode layer at a bottom of the second separating groove;
a sixth step of forming a third separating groove that separates the metal film, the transparent conductive film, and the photoelectric conversion layer in the respective cells in parallel to the first separating groove; and
a seventh step of forming a reflective film made of a white insulating layer on the substrate on which the metal film is formed so as to embed the second and third separating grooves with the reflective film, wherein
at the fifth step, the transparent conductive film is patterned into lines along with the metal film, the lines having a line width within the second separating groove which is the same as a line width outside the second separating groove, and
at the seventh step, the reflective film is formed directly on the photoelectric conversion layer in an area of the photoelectric conversion layer where the metal film is not formed.

8. The manufacturing method of a thin-film solar battery according to claim 7 , wherein
at the third step, the transparent conductive film is formed to extend, with a predetermined pitch in a second direction vertical to the first direction, and
at the fifth step, the metal film is formed so as to embed the second separating groove with the metal film at a position where the metal film and the second separating groove intersect.

9. The manufacturing method of a thin-film solar battery according to claim 7 , wherein
at the third step, the transparent conductive film is formed on an entire surface of the photoelectric conversion layer, and
at the fifth step, the metal film that extends, with a predetermined pitch in a first direction in which the first separating groove extends, in a second direction vertical to the first direction is formed.

10. The manufacturing method of a thin-film solar battery according to claim 9 , wherein at the fifth step, a process of etching the transparent conductive film by using the metal film as a mask is further performed after forming the metal film patterned into lines.

Assignees

• Tsuda Yuki
• Nishikawa Yusuke
• Mitsubishi Electric Corp

Inventors

• Tsuda Yuki
• Nishikawa Yusuke

Classifications

• H10F77/244 Primary

  made of transparent conductive layers, e.g. transparent conductive oxide [TCO] layers · CPC title

• H10F77/48

  Back surface reflectors [BSR] · CPC title

• H10F19/35

  Structures for the connecting of adjacent photovoltaic cells, e.g. interconnections or insulating spacers · CPC title

• H10F19/33

  Patterning processes to connect the photovoltaic cells, e.g. laser cutting of conductive or active layers · CPC title

• H10F19/31

  having multiple laterally adjacent thin-film photovoltaic cells deposited on the same substrate · CPC title