Solar cell module and solar cell

This application claims the priority benefits of U.S. provisional application Ser. No. 61/482,636, filed on May 05, 2011. The entirety of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

1. Technical Field

This disclosure relates to a solar cell module, and a solar cell that can serve as a constituting unit of the solar cell module.

2. Related Art

A solar cell typically includes a bottom electrode, a top electrode and a photoelectric conversion layer between them. A type of solar cell module includes a number of solar cells arranged in a series, wherein the bottom electrode of a solar cell is electrically connected with the top electrode of an adjacent solar cell.

In the manufacturing of a thin-film solar cell, each of the bottom electrode, the photoelectric conversion layer and the top electrode is formed with a deposition process and a subsequent patterning process that patterns the deposited layer. The patterning process takes a certain period of time and has certain issues to care.

Accordingly, this disclosure provides a structure of a solar cell module.

This disclosure also provides a structure of a solar cell as a constituting unit of the solar cell module of this disclosure.

The solar cell module of this disclosure includes a plurality of solar cells arranged in a series on a substrate. Each solar cell includes a bottom electrode, a photoelectric conversion layer, an insulating pattern, a top electrode layer and a passivation layer. The photoelectric conversion layer is on the bottom electrode and also on the substrate at a first side of the bottom electrode. The insulating pattern is on the bottom electrode, covering an edge portion of the photoelectric conversion layer near a second side of the bottom electrode. The top electrode layer is on the photoelectric conversion layer and adjacent to the insulating pattern. The passivation layer is on the top electrode layer and adjacent to the insulating pattern, wherein the top of the passivation layer on the top electrode layer is lower than the top of the insulating pattern. In the solar cell module, the bottom electrode of a solar cell is electrically connected with the top electrode layer of an adjacent solar cell.

By disposing a sufficiently thick insulating pattern on the bottom electrode of each solar cell, the films deposited subsequently, which include the film for forming the top electrodes, are divided by the insulating patterns as deposited and are not needed to pattern, so the manufacture of the solar cell module is simplified.

In order to make the aforementioned and other features of this disclosure comprehensible, a preferred embodiment accompanied with figures is described in detail below.

FIGS. 1A-1C illustrate, in a cross-sectional view, a method for fabricating a solar cell module according to an embodiment of this disclosure, wherein FIG. 1C also illustrates the structures of the solar cell module and the solar cells therein.

This disclosure is further explained with the following embodiment, which is not intended to limit the scope of this disclosure. For example, though the illustrated solar cell module for the embodiment includes two solar cells, the solar cell module of this disclosure may alternatively include more than two solar cells.

FIGS. 1A-1C illustrate, in a cross-sectional view, a method for fabricating a solar cell module according to an embodiment of this disclosure.

Referring to FIG. 1A , the bottom electrodes 102 a of the solar cells in the solar cell module, a contact pad 102 b for electrically connecting the top electrode layer (shown later) of a first terminal solar cell to a conductive wire of the solar cell module, and another contact pad 102 c for electrically connecting the bottom electrode 102 a of a second terminal solar cell to another conductive wire of the solar cell module, are formed on a substrate 100 .

In an embodiment, the contact pad 102 b for electrically connecting with the top electrode layer of the first terminal solar cell is separated from the bottom electrode 102 a of the first terminal solar cell, and the contact pad 102 c for electrically connecting with the bottom electrode 102 a of the second terminal solar cell is contiguous with the bottom electrode 102 a of the second terminal solar cell.

The bottom electrodes 102 a and the contact pads 102 b and 102 c may be formed through a sputtering process and a subsequent patterning process, which may utilize laser scribing or mechanical scribing to pattern the deposited film. The substrate 100 may be a flexible substrate or a non-flexible one. The material of a flexible substrate 100 may be selected from the group consisting of polymers and inorganic materials. Examples of the polymers include polyimide (PI) and polyethylene terephthalate (PET), etc. Examples of the inorganic materials include metal foils such as stainless foil, glass, and flexible glass, etc. The material of the bottom electrodes 102 a and the contact pads 102 b and 102 c may be selected from various conductive materials having sufficiently low resistance, which include metals and conductive materials, etc. Examples of the metals include molybdenum and aluminum, etc. Examples of the conductive materials include transparent conductive oxide materials (TCOs), etc. Examples of the TCOs includes indium tin oxide (ITO), etc.

Referring to FIG. 1A again, a photoelectric conversion layer 104 is formed on each bottom electrode 102 a , exposing a first edge of the bottom electrode 102 a but cover the sidewall of a second edge of the bottom electrode 102 a opposite to the first edge. The photoelectric conversion layer 104 may include silicon, a III-V semiconductor material, copper indium gallium selenide (CIGS), copper indium selenide (CIS), cadmium telluride (CdTe), or an organic photovoltaic (OPV) material. The photoelectric conversion layers 104 may be formed through a deposition process and a subsequent patterning process, which may utilize laser scribing or mechanical scribing to pattern the deposited film.

An insulating pattern 106 a is then formed on each bottom electrode 102 a , covering an edge portion of the photoelectric conversion layer 104 and exposing a first edge portion of the bottom electrode 102 a . Two additional insulating patterns 106 b are formed on the contact pads 102 b and 102 c , respectively.

In an embodiment, the insulating patterns 106 a and 106 b are sufficiently thick such that each layer deposited later is divided as deposited and hence is not required to pattern. The thickness of the insulating patterns 106 a and 106 b may range from 1 μm to 30 μm. The insulating patterns 106 a and 106 b may be formed through screen printing, photolithography or any other suitable patterning method, and may include any suitable insulating material, such as, a polymer resin, or an inorganic insulator material.

Referring to FIG. 1B , a top electrode layer 108 a / 108 b is deposited over the substrate 100 , possibly by sputtering. When the insulating patterns 106 a / 106 b are sufficiently thick, the top electrode layer 108 a / 108 b is divided as deposited into the top electrodes 108 a of the solar cells and the top electrode layer 108 b on the insulating patterns 106 a / 106 b . The top electrode 108 a of each solar cell covers the photoelectric conversion layer 104 except for the edge portion thereof covered by the insulating pattern 106 a , covers the sidewall of the second edge portion of the bottom electrode 102 a of the solar cell opposite to the first edge portion of the same exposed by the corresponding insulating pattern 106 a , and is electrically connected with the exposed first edge portion of the bottom electrode 102 a of the adjacent solar cell. The top electrode 108 a of the terminal solar cell neighboring to the contact pad 102 b is connected to the contact pad 102 b so that the solar cells connected in series can be electrically connected to a conductive wire of the solar cell module.

The top electrode layer 108 a / 108 b may include one or more materials selected from various conductive materials with sufficiently low resistance. If the bottom electrodes 102 a include a non-transparent conductive material, the top electrode layer 108 a / 108 b have to be a transparent layer, which may include a single transparent conductive material or a stack of multiple transparent conductive materials, for the requirement of light passing. Examples of the single transparent conductive material include transparent conductive oxide materials (TCO), such as indium tin oxide (ITO), zinc oxide and aluminum zinc oxide, etc. Examples of the stack of multiple transparent conductive materials include a multilayer conductive film (MTCF), which may include one or more TCOs layers and a metal layer of nano-scale thickness between them.

Then, a passivation layer 110 a / 110 b is deposited over the substrate 100 . When the insulating patterns 106 a / 106 b are sufficiently thick, the passivation film 110 a / 110 b is divided as deposited into portions 110 a on the top electrodes 108 a and portions 110 b on the top electrode layer 108 b on the insulating patterns 106 a / 106 b . The passivation layer 110 a of each solar cell covers the sidewall of the second edge portion of the bottom electrode 102 a of the solar cell. The passivation layer may include any suitable insulating material having a passivation effect, such as SiN, SiO 2 or Al 2 O 3 .

Referring to FIG. 1C , the insulating patterns 106 b formed on the contact pads 102 b and 102 c are removed to form two openings 112 and 114 in the top electrode layer 108 a and the passivation layer 110 a exposing the contact pads 102 b and 102 c , possibly by dipping the above-formed structure in a solvent or by spraying a solvent on the same. The passivation layer 110 b and the top electrode layer 108 b on the insulating patterns 106 a may also be removed from the tops of the insulating patterns 106 a.

FIG. 1C also illustrates the structures of the solar cell module according to the above embodiment of this disclosure and the solar cells therein. Each solar cell 10 includes a bottom electrode 102 a , an insulating pattern 106 a on the bottom electrode 102 a , a photoelectric conversion layer 104 on the bottom electrode 102 a and having an edge portion covered by the insulating pattern 106 a , a top electrode 108 a on the photoelectric conversion layer 104 and adjacent to the insulating pattern 106 a , and a passivation layer 110 a on the top electrode 108 a and adjacent to the insulating pattern 106 a , wherein the top of the insulating pattern 106 a is higher than that of the passivation layer 110 a on the top electrode 108 a on the photoelectric conversion layer 104 . The bottom electrode 102 a of a solar cell is electrically connected with the top electrode 108 a of the adjacent solar cell, in the manner mentioned above.

Each insulating pattern 106 a may be sufficiently thick such that each layer deposited later, i.e., the top electrode layer 108 a / 108 b or the passivation layer 110 a / 110 b , is divided by the insulating patterns 106 a / 106 b as deposited. Thus, each insulating pattern 106 a has thereon a top electrode layer 108 b and a passivation layer 110 b not contiguous with the top electrode layer 108 a and the passivation layer 110 a on the photoelectric conversion layer 104 , if the layers 108 b and 110 b are not removed from the tops of the insulating patterns 106 a after the layers 108 a / 108 b and 110 a / 110 b are formed.

By disposing a sufficiently thick insulating pattern on the bottom electrode of each solar cell, the films deposited later, which include the film for forming the top electrodes, are divided by the insulating patterns as deposited and are not needed to pattern. Thus, the manufacture of the solar cell module is simplified.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.