JPH0536280Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a photovoltaic device that allows part of incident light to pass through.

(b) Conventional technology Regarding photovoltaic devices that convert light energy into electrical energy, so-called solar cells, amorphous solar cells mainly made of amorphous silicon can easily be made larger in area and can be lowered in cost. Because of these characteristics, it is considered very promising as a future power solar cell. Currently, attempts are being made to use it as an independent power source as an extension of its application to consumer devices, and applications are beginning to be made to power sources for automobiles and for charging batteries (Japanese Patent Laid-Open No. 58 -50782 publication and/or JP-A-58-52884
(see publication). When using solar cells for automobiles, it is normal to attach the solar cells to the window glass or sunroof of the car body, but with this method, the windows and sunroof become opaque.
Visibility may be poor and driving may be impaired. Therefore, in order to eliminate such drawbacks, the applicant of the present application devised a see-through type solar cell in which many holes are formed in the solar cell, and filed the application as Utility Model Application No. 87352/1983.

Not only in the see-through solar cells mentioned above, but also in conventional photovoltaic devices, the back electrode provided on the back side of the semiconductor film when viewed from the light incident side is completely transparent like the electrode on the light receiving side. Since optical properties are not required, Al, Ag, TiAg, Ni, Au, etc. have lower sheet resistance and can reduce the series resistance component compared to TCO such as SnO ₂ , In ₂ O ₃ , ITO, etc. that make up the light-receiving surface electrode. Cr
It has a single layer or laminated structure including at least one metal film such as.

When a back electrode including at least one layer of metal film is applied to a see-through type solar cell, the metal film has a large number of holes, allowing a portion of incident light to pass through.

However, in a photovoltaic device that transmits a portion of incident light through through holes distributed in the metal film of the back electrode, when the light-receiving surface side is viewed from the back side, the gloss of the metal film of the back electrode The disadvantage is that it stands out and spoils the appearance. Although coating with colored resin is effective in reducing the gloss of such metal films, if the coating is uneven, it not only causes color spots but also penetrates into the pores and reduces the transmittance of incident light. .

(c) Problems to be solved by the invention The photovoltaic device of the invention is intended to solve the problem of deterioration in appearance due to the gloss of the metal film.

(d) Means for solving the problem The present invention includes a light-transmitting light-receiving surface electrode, a semiconductor film including a semiconductor photoactive layer, and a back electrode including a metal film in the light-receiving region of a light-transmitting insulating substrate. The photovoltaic device is a stacked photovoltaic device, and the light-receiving region includes a plurality of dispersed transmitting portions that transmit at least a part of the incident light and that do not have a metal film on the back electrode, and
It has the same shape as the etching pattern of the metal film above,
Further, when viewed from the film-forming surface side of the substrate, a colored resist film capable of suppressing the gloss of the metal film is disposed.

(e) Effect As mentioned above, when the resist film that defines the etching pattern of the metal film has the same shape as the etching pattern of the metal film, and when viewed from the film formation side of the substrate, the gloss of the metal film is suppressed. By arranging the colored resist film in such a way that it can be used, the resist film suppresses the gloss of the metal film of the back electrode without penetrating into the pores of the metal film.

(F) Embodiment The figures show an embodiment of the photovoltaic device of the present invention, in which FIG. 1 is an enlarged vertical cross-sectional view of the main parts, and FIG. 2 is a top view viewed from the direction of light irradiation. A light-transmitting insulating substrate 2 made of glass, transparent plastic, etc. is a photoelectric film provided in a light receiving region (PR) on the other main surface 1b when one main surface 1a of the insulating substrate 1 is a light incident surface. The conversion element is described as a single element in this embodiment, but normally such elements are connected in series as in US Pat. No. 4,281,208. The photoelectric conversion element 2 has SnO ₂ ,
A light-receiving surface electrode 3 made of TCO such as In ₂ O ₃ or ITO;
An amorphous silicon-based semiconductor film 4 such as amorphous silicon, amorphous silicon carbide, amorphous silicon germanium, etc., which has a semiconductor junction including a semiconductor photoactive layer such as a pin or pn junction parallel to the film surface therein; Al, Ag, Ti,
TiAg, Au, TCO/Ag, TCO/Al, TCO/
Au, Al/Ti, Al/TiAg, TCO/Al/Ti,
The back electrode 5 includes at least one layer of metal film such as TCO/Al/TiAg, Al/Ti/Al/Ti, etc., which contributes to reducing the series resistance component.

6, 6, 6... are one main surface 1 of the insulating substrate 1 in the light receiving region (PR) of the insulating substrate 1.
A plurality of transmitting parts are separately arranged to transmit a part of the incident light emitted from the side a to the back side, and the stacked body of the semiconductor film 4 and the back electrode 5 is spread over the light receiving surface electrode 3 in the light receiving area. Resist film 7 after formation
Micro-diameter (0.1 to several mm) that is selectively etched away using photolithography using a mask.
It is formed by a through hole. In this embodiment, the shape of the transmitting portions 6, 6, 6, etc. formed by such through holes is the second shape.
Although the shape is circular as shown in the figure, the shape is not limited to such a circle and can be any shape. Furthermore, the ratio of the transmitting portions 6, 6, 6, .
It is sufficient to increase the area of the individual transmitting parts 6,
Rather than increasing the area of 6, 6, etc., it is better to provide a large number of small-area transmitting parts 6, 6, 6, etc., so that the lighting parts can be dispersed, and a uniform lighting state can be realized.

Of the incident light irradiated onto the light-receiving region (PR) from the one main surface 1a side of the light-transmitting insulating substrate 1, light from the laminate of the light-receiving surface electrode 3, the semiconductor film 4, and the back electrode 5 is transmitted. The incident light that entered the photoelectric conversion element 2 is absorbed for the photoelectric conversion operation, is led out as an electrical output, and is also incident on the transparent parts 6, 6, 6, . . . which have no semiconductor film 4 and back electrode 5. The incident light passes through and enters the room (or inside the car) as natural light without coloring. When looking at the light source of natural light obtained in this way from inside the room (or inside the car), the back side of the photovoltaic device will naturally stand out to the eye. Regarding the photovoltaic device of the present invention,
On the back side, there is not only a back electrode 5 containing a metal film, but also a colored resist film 7 that acts as a mask in the etching process of making a through hole for lighting in the metal film of the back electrode 5 and defines the etching pattern of the metal film. As a result, the luster of the metal film is suppressed without blocking the transmission of a portion of the incident light.
The resist film 7 is a liquid photoresist used in photolithography, or a base film on which a photosensitive film is preliminarily coated, such as "Neotrock-E", a product manufactured by Nitto Electric Industries, Ltd., or a product manufactured by Asahi Kasei Corporation. A dry film resist such as "DFR-E15" is used, and various colors are selected depending on the application. The etching process using the dry film resist described above is detailed in Japanese Patent Application Laid-open No. 161883/1983, filed by the applicant of the present application.

The photovoltaic device that will be put to practical use will not have a single element structure as in the above embodiment, but will have a structure similar to that of the U.S. Patent No.
It was previously explained that the device has an integrated structure in which multiple elements are connected in series on the same substrate, as in No. 4281208. Figures 3 and 4 show an embodiment of such an integrated type, with Figure 3 being a perspective view viewed from the back side, and Figure 4
The figure is an enlarged perspective view of the circled part in FIG. 3. In such an embodiment, five unit photoelectric conversion elements 2, 2... shown in FIG. The light-receiving surface electrodes 3 and back electrodes 5 of the matching elements 2, 2, . . . come into contact to complete electrical series connection. Components that are the same as those in the embodiment shown in FIGS. 1 and 2 are given the same numbers.

In this way, even in the conventional integrated structure without the transmitting parts 6, 6, etc. that transmit a part of the incident light like the photovoltaic device of the present invention, the resist film is used to divide the back electrode into each terminal. Patterning is carried out using a photolithographic technique. Therefore, in the present invention, it is only necessary to provide apertures for making a large number of holes in the resist film used for conventional patterning of the back electrode, in other words, it is only necessary to change the pattern of the resist film. It can be manufactured without going through a dedicated manufacturing process. Furthermore, by allowing the resist film 7 to remain, the peeling process for the resist film 7 can be omitted, and the manufacturing process can be simplified.

(G) Effects of the invention As is clear from the above description, the photovoltaic device of the invention has at least a resist film that defines the etching pattern of the metal film of the back electrode in the same shape as the etching pattern of the metal film and a substrate. Since the colored resist film is arranged in such a way that the gloss of the metal film can be suppressed when viewed from the film formation side, the resist film enters the through hole forming the transmission part of the metal film and transmits the transmitted light. It is possible to suppress the luster of the metal film without blocking it. Further, by selecting the type of resist film, any color can be obtained as the back color, and the appearance can be improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the photovoltaic device of the present invention, FIG. 2 is a top view of one embodiment viewed from the light irradiation direction, and FIG. 3 is a rear perspective view of another embodiment.
FIG. 4 shows an enlarged rear perspective view of the main parts of FIG. 3. 1... Insulating substrate, 2... Photoelectric conversion element, 3...
Light-receiving surface electrode, 4... semiconductor film, 5... back electrode,
6...transmissive part, 7...resist film.

Claims (1)

[Scope of utility model registration request] A photovoltaic device in which a light-transmitting light-receiving surface electrode, a semiconductor film including a semiconductor photoactive layer, and a back electrode including a metal film are laminated on a light-receiving region of a light-transmitting insulating substrate, the light-receiving region comprising: A plurality of transmitting parts without a metal film of at least the back electrode, which transmit a part of the incident light, are arranged in a dispersed manner, have the same shape as the etching pattern of the metal film, and are arranged from the film formation side of the substrate. A photovoltaic device characterized in that a colored resist film is disposed that can suppress the gloss of the metal film when viewed.