JPH10270727A - Amorphous silicon solar battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lightweight and thin amorphous silicon solar battery whose appearance and reliability are excellent and whose production process is simplified by forming an amorphous power generating layer, an electrode part and a protection layer on a substrate and using the substrate or protection layer in common with a clock dial plate. SOLUTION: An electrode group formed of Al metallic electrode 4 and transparent conductive film 2 and an amorphous silicon power generating layer 3 are formed on an SUS substrate 6, constituting an amorphous silicon solar cell structure. Then, a protection layer 7 having a flat and smooth surface is formed and it is used as a dial plate, forming an amorphous silicon solar battery. Thus, the amorphous silicon solar cell structure can be formed directly on the clock dial plate 9 and a light loss due to reflection on the light reception surface can be prevented. Further, the clock can be made to be light in weight and thin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amorphous silicon solar cell, and more particularly to a dial for an amorphous silicon solar cell for a timepiece.

[0002]

2. Description of the Related Art When an amorphous silicon solar cell is used as a battery for a timepiece, the amorphous silicon solar cell is installed at a position different from the timepiece dial. Therefore, light utilization efficiency is poor due to light loss due to reflected light from the timepiece dial and the like, and amorphous silicon solar cell characteristics and the like are poor.

Further, since the timepiece dial and the amorphous silicon solar cell are installed at different positions, it has been difficult to reduce the weight and thickness.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an amorphous silicon solar cell for a timepiece, and it is an object of the present invention to provide an amorphous silicon solar cell which is excellent in appearance and reliability, has a simple manufacturing process, and can be reduced in weight and thickness. .

[0005]

An amorphous silicon solar cell element having a structure including an amorphous silicon power generation layer, an electrode portion comprising a transparent conductive film and a metal electrode on a substrate, and a protective layer for protecting the amorphous silicon power generation layer and the electrode portion. In the structure, the substrate also serves as a timepiece dial.

Further, in the amorphous silicon solar cell element structure having a structure including an amorphous silicon power generation layer, an electrode portion composed of a transparent conductive film and a metal electrode on a substrate, and a protective layer for protecting the amorphous silicon power generation layer and the electrode portion, The protective layer also serves as a clock dial.

[0007]

DETAILED DESCRIPTION OF THE INVENTION An amorphous silicon solar cell having a structure including an amorphous silicon power generation layer, an electrode portion composed of a transparent conductive film and a metal electrode on a substrate, and a protective layer for protecting the amorphous silicon power generation layer and the electrode portion. An amorphous silicon solar cell, wherein the substrate also serves as a clock dial.

[0008]

【Example】

(Embodiment 1) An embodiment of the present invention will be described with reference to FIG.
FIG. 1 shows a method in which a transparent conductive film (ITO film) 2 is formed on a glass substrate 1 by a sputtering method or the like, patterning is performed on an element shape, and SiH4 gas is decomposed by high-frequency glow discharge to form a thin film on the substrate. After forming a pin-junction type amorphous silicon power generation layer 3 by a method of growing (hereinafter, plasma CVD method), an Al metal electrode 4 is deposited by a sputtering method to form an amorphous silicon solar cell element structure. The protective layer 5 was formed by screen printing.

In the present invention, a glass substrate 1 is used as a substrate for forming an amorphous silicon solar cell element structure and the like. However, the substrate is transparent, chemically and physically stable, has corrosion resistance, strength, heat resistance, weather resistance, and the like. Any material that is excellent in durability and the like, has good adhesiveness to the amorphous silicon film, and can obtain an electrically low resistance contact can be used. Further, a film or plate of a polymer organic film or an inorganic film such as an epoxy resin having a light-transmitting property may be used, and a lighter and thinner amorphous silicon solar cell having excellent adhesion to an amorphous silicon film or the like can be manufactured.

Inorganic oxides such as ceramics become transparent as the firing temperature increases and can transmit light. Therefore, they can be used for the substrate, and can be used as an insulating, amorphous silicon film or the like. It has excellent properties such as adhesion, contact resistance with amorphous silicon film, and sheet resistance, and is chemically and physically stable such as corrosion resistance and weather resistance. An amorphous silicon solar cell can be manufactured.

[0011] However, since the surface condition is not good in ceramics which are only fired, there is a problem as a substrate. Therefore, a molten glass coating layer (glaze layer) with less polishing or soda is formed on the order of several tens μm (glaze ceramics). It is necessary to smooth the substrate surface by using the above method.

The transparent conductive film 2 uses an ITO film.
A material having excellent transparency to visible light and excellent electrical conductivity, such as a SnO2 film and an In2O3 film, may be used.

The pin-junction type amorphous silicon power generation layer 3 is formed by laminating an amorphous silicon film in the order of a p layer, an i layer, and an n layer from the glass substrate side, and the amorphous silicon film is formed in the amorphous silicon Si film. A film (hereinafter referred to as hydrogenated amorphous silicon film) is formed by a plasma CVD method so that hydrogen is taken in. In the hydrogenated amorphous silicon film, dangling bonds (hereinafter, dangling bonds) of Si are terminated with H. The effect of (1) has few defects, and the substrate is heated and formed at 200 to 300 ° C., so that the hopping movement of the film-forming radical species is facilitated and the role of the network as a structure relaxation agent is improved. In fact, coupled with the thermal structure relaxation, a film having extremely few dangling bonds is formed.

The hydrogenated amorphous silicon p-layer and n-layer are controlled by valence electrons by adding (hereinafter referred to as doping) impurities by adding B2H6 gas to the p-layer, B2H6 gas to the p-layer, and PH3 gas to the n-layer. , B2H6 gas or PH3 gas at 10-6 to 10-1 (1 to 104
ppm) mixed and decomposed by glow discharge to control electric conductivity and activation energy. In this embodiment, glow discharge decomposition of only SiH4 gas was performed to form an i-layer. Isodope)
Thus, it is also possible to form an i-layer.

Further, in the present embodiment, p-i
Although the hydrogenated amorphous silicon laminated film of the -n junction type is used, a fluorinated amorphous silicon film in which F having a stronger bonding force with Si is incorporated into the amorphous silicon film can be used.

Although not performed in this embodiment, by forming an insulating layer such as a nitride film or an oxide film between the transparent conductive film 2 and the amorphous silicon power generation layer 3, more chemical stability and flatness can be obtained. An amorphous silicon power generation layer can be obtained, in which case the insulating film must be excellent in light transmission.

Further, by forming an insulating film such as a nitride film or an oxide film between the metal electrode 4 and the protective layer 5, the interface of the metal electrode 4 can be made flatter. In this case, screen printability and adhesion can be further improved, and a chemically stable interface state can be obtained.

The metal electrode 4 is made of Al metal.
W, Mo, Ti, Ta, Ni, Cr, Au, Pt, Cu
And so on.

Although the metal electrode 4 is formed by the sputtering method, the metal electrode 4 can be formed by the plasma CVD method, so that the manufacturing process can be made consistent, further improving the mass productivity and simplifying the manufacturing process. Is possible.

Still further, since the metal electrode 4 has no translucency, the light reflected on the metal electrode can be used for the photovoltaic effect, so that the solar cell characteristics such as conversion efficiency are not lost but rather improved. .

In this embodiment, an epoxy resin mixed with a filler and a pigment is used for the protective layer 5. However, even when a nitride film or an oxide film is formed by a plasma CVD method or the like, corrosion of the metal electrode and amorphous Since the deterioration of the performance of the amorphous silicon solar cell such as the deterioration of the silicon layer can be prevented, the protection layer of the amorphous silicon solar cell element having excellent reliability such as environmental resistance and appearance can be provided. .

The protective layer 5 is preferably formed by mixing a black pigment into an epoxy resin and connecting the respective amorphous silicon solar cells in series when viewed from the light receiving surface. That is, it is needless to say that the electrode portion of the amorphous silicon solar cell is not exposed, and the unevenness in brightness can be eliminated, so that an amorphous silicon solar cell excellent in appearance can be manufactured.

However, since the ceramic substrate is a translucent substrate, it is considered that the electrode portion of the amorphous silicon solar cell is not exposed and the appearance is not deteriorated unlike a glass substrate, so that the ceramic substrate is formed on the ceramic substrate. The protective layer formed on the amorphous silicon solar cell element need not include a pigment or the like in the epoxy resin.

In the case where an amorphous silicon solar cell is formed on a polymer organic film such as an epoxy resin and an inorganic film, the same material may be used for the protective layer even if there is a difference in mixing a pigment or the like. It is possible.

(Embodiment 2) As shown in FIG.
An electrode group consisting of an Al metal electrode 4 and a transparent conductive film (ITO film) 2 and an amorphous silicon power generation layer 3 were formed on a SUS substrate 6 in the same manner as in Example 1 to form an amorphous silicon solar cell element structure. Thereafter, a protective layer 7 having a smooth surface was formed by screen printing or the like, and an amorphous silicon solar cell using the protective layer 7 as a dial was produced.

In this embodiment, the SUS substrate 6 is used as a substrate for forming the amorphous solar cell element structure. However, physical and chemical properties such as impact resistance, heat resistance, durability and weather resistance of glass or ceramics are used. Any material may be used as long as it is excellent in terms of electrical properties, has good adhesion to the amorphous silicon film and the metal electrode 4, and has an electrically low-resistance contact.

Although the amorphous silicon power generation layer is a laminated film of a hydrogenated amorphous silicon film, it can be formed by using a fluorinated amorphous silicon film as in the first embodiment.

The protective layer 7 is made of an epoxy resin or the like, has a smooth surface, is excellent in appearance without entrapment of bubbles of the epoxy resin itself, and has excellent light transmission, corrosion resistance, weather resistance, insulation, and shock resistance. A dial with a protective layer 7 having characteristics such as properties and stability both physically and chemically was produced.

FIG. 2B shows the amorphous silicon solar cell of the present embodiment viewed from the light receiving surface, in which a clock character 8 is formed on a clock dial 9 by a protective layer 7.

The clock face 8 is the same as the clock face board 9 except that a pigment is added to the same epoxy resin material. Therefore, after the clock face board 9 is formed by screen printing or the like, temporary hardening or full hardening is performed by heating or the like. Thereafter, the clock character 8 is formed on the clock dial 9 by screen printing or the like.

When connecting the respective amorphous silicon solar cell elements in series, the timepiece dial 9 naturally exposes the gap between the amorphous silicon solar cell elements, that is, the electrode portion of the amorphous silicon solar cell. In addition, since uneven brightness can be eliminated, an amorphous silicon solar cell having excellent appearance can be manufactured.

Further, since there is no need to cover the electrode portion due to the improvement of the dial and the like and special specifications, the manufacturing process of the amorphous solar cell can be simplified, and the electrode between the amorphous silicon solar cell elements can be covered. Since it is possible to prevent the light receiving surface from being narrowed due to external factors such as the above, it is possible to expect an improvement in the characteristics of the amorphous solar cell and to produce an amorphous silicon solar cell having excellent appearance.

In the present invention, since the amorphous silicon solar cell element structure can be formed directly on the timepiece dial, it is possible to prevent light loss due to the reflection of the light receiving surface and to improve the characteristics of the amorphous silicon solar cell. Can be expected.

In addition, since the amorphous silicon solar cell element structure is formed on the dial, the timepiece can be reduced in weight and thickness.

[0035]

According to the present invention, it is possible to provide an amorphous silicon solar cell which is excellent in appearance and reliability, and whose manufacturing process is simple, lightweight and thin.

[Brief description of the drawings]

FIG. 1 is a schematic view of an amorphous silicon solar cell according to the present invention.

FIG. 2 (a) is a schematic view of an amorphous silicon solar cell according to the present invention. (B) A plan view of the electrode portion and the timepiece dial when viewed from the light receiving surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Transparent conductive film (ITO) 3 Amorphous silicon power generation layer 4 Al electrode 5 Protective layer of epoxy resin containing black pigment 6 SUS substrate 7 Protective layer 8 Clock character 9 Clock dial 10 Clock mechanism frame

Claims (2)

[Claims] An amorphous silicon power generation layer on a substrate,
An amorphous silicon solar cell having a configuration including an electrode portion composed of a transparent conductive film and a metal electrode, the amorphous silicon power generation layer, and a protective layer for protecting the electrode portion, wherein the substrate also serves as a timepiece dial. Amorphous silicon solar cells. 2. An amorphous silicon power generation layer on a substrate,
An amorphous silicon solar cell element including a transparent conductive film and an electrode part composed of a metal electrode, the amorphous silicon power generation layer, and a protective layer for protecting the electrode part, wherein the protective layer also serves as a timepiece dial. Amorphous silicon solar cell.