JPS62173767A - Solar battery module - Google Patents

Abstract

PURPOSE:To improve the module efficiency of a solar battery module by so disposing that opposed ends of adjacent solar battery cells are contacted through an insulating member made of a plastic member. CONSTITUTION:In a solar module, a plurality of solar battery cells 1a, 1b... are planely disposed in a package 10 in which a photodetecting surface 11 is formed of a transparent glass plate, and a back surface 12 is formed of a resin film. The cells 1a, 1b... are produced by forming an amorphous Si film 3 having photoelectric conversion characteristic by plasma discharge on a conductive substrate 2, and a transparent conductive film 4 is formed by depositing thereon. A negative electrode 5 is formed on the film 4, and a positive electrode 6 is formed. The cells 1a, 1b... are so disposed that the adjacent solar battery cells are contacted at the ends through the insulating member 7 of the transparent plastic film. Thus, the cells are disposed densely at an interval of the thickness of the film 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a solar cell module configured by housing a plurality of solar cells in a puff cage.

(Prior Art) A solar cell module is constructed by arranging a plurality of solar cells in a package in a planar manner.

FIGS. 4(a) and 4(b) show an example of the structure of a conventional solar cell module.

In the figure, the solar cell module is packaged in a package C whose light-receiving surface a is made of a transparent glass plate and whose back surface is made of a resin film.
Inside, a plurality of solar cells d.

d... are arranged at regular intervals on a plane. In this solar cell d, an amorphous Si film J having photoelectric conversion properties is formed on a four-electrode substrate i such as stainless steel or aluminum (A/R).
A transparent conductive film k is formed on an i film j. A negative electrode e that collects electromotive force is formed on this transparent conductive film,
A positive electrode f is formed on the transparent conductive film by etching or the like and in a portion where the amorphous Si film j is removed,
One positive electrode f and the other negative electrode e of adjacent solar cells d, d are connected by a wiring member g. Note that the solar cells d, d, . . . are embedded and fixed in the package C using a sealing resin such as Si resin or EVA resin, and absorb shocks from the outside.

In the above configuration, adjacent solar cells d.

d is arranged to have an interval of about 0.5 to 511 for electrical insulation.

(Problems to be Solved by the Invention) In the conventional structure described above, it is necessary to arrange each solar cell d, d, etc. at the above-mentioned interval for electrical insulation. There is a lot of wasted area within the package C that does not contribute to power generation, and from the viewpoint of miniaturization, the module efficiency decreases. ■Solar cell d, d
The wiring material g connecting between the two becomes longer and the potential drop increases. (2) As a result, the external extraction efficiency of photoelectric conversion decreases.

There were many problems such as.

(Means for Solving the Problems) The solar cell module of the present invention has a plurality of solar cells arranged in a pan cage in a flat manner, and in this state the solar cells are resin-sealed. In a battery module, opposing end surfaces of adjacent solar cells are arranged so as to be in contact with each other through an insulating member made of, for example, a plastic film, and this insulating member is multilayered with two or more types of resin members with different melting points. In addition, it is formed of a material whose refractive index is the same as or close to the refractive index of the sealing resin.

(Function) Since adjacent solar cells are reliably insulated by the insulating member, the space between each solar cell can be minimized and the wasted area in the pan cage can be reduced. Moreover, this insulating member prevents movement of the solar cell and prevents electrical short circuit. Furthermore, when the insulating member is multilayered with two or more types of resin materials with different melting points, the low melting point material is melted by heat treatment during module creation and fused to the ends of the solar cells, so that no gaps are created. Furthermore, if the refractive index of the insulating material is set to be the same as or close to the refractive index of the sealing resin, there will be almost no surface reflection at the interface between the sealing resin and the insulating material, and the insulating member will hardly be visible from the outside of the module. .

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) show the solar cell module of the present invention.

The solar cell module has a plurality of solar cells 1a, 1b, . . . arranged in a plane in a puff cage 10 in which a light-receiving surface 11 is made of a transparent glass plate and a back surface 12 is made of a resin film.

In solar cells la, lb..., an amorphous Si film 3 having photoelectric conversion properties is formed on a conductive substrate 2 made of stainless steel, aluminum (AN), etc. by plasma discharge, etc. A transparent conductive film 4 is formed by vapor deposition or the like. A negative electrode 5 for output output is formed on the transparent conductive film 4 by screen printing or the like, and a positive electrode 6 is formed on the portion where the transparent conductive film 4 and the amorphous Si film 3 are removed by etching or the like.
is formed. And the adjacent solar cell la
, lb, the positive electrode 6 and the negative electrode 5 are electrically connected by a wiring 8. Note that the positive and negative electrodes of the positive electrode 6 and the negative electrode 5 may be reversed depending on the method of forming the amorphous Si film 3.

The solar cells la, lb, . . . having such a structure are arranged such that adjacent solar cells la, lb are in contact with each other with their end faces interposed through a transparent plastic film (insulating member) 7. That is, each solar cell l
a, lb, . . . are arranged closely with an interval equal to the thickness of the transparent plastic film 7. Even if they are arranged densely in this way, each solar cell la, lb, . . . is reliably insulated by the transparent plastic film 7.

This transparent plastic film 7 is bent into a substantially Z shape, and its upper piece 7a is brought into contact with the transparent conductive film 4 of one of the adjacent solar cells 1a, and its lower piece 7b is brought into contact with the transparent conductive film 4 of the other solar cell 1b. The vertical piece 7C is in contact with the end faces of both solar cells la and lb and is held from both sides.

A plurality of solar cells arranged in sequence in this way
a, lb, . . . are embedded and fixed in the package 1O with a sealing resin 9 such as Si resin or EVA resin.

FIG. 2 shows an enlarged sectional view of the transparent plastic film 7. In addition, in the figure, the negative electrode 5, the positive electrode 6, and the wiring 8 are omitted to simplify the drawing.

The transparent plastic film 7 has a two-layer structure consisting of a low melting point layer 7e and a high melting point layer 7f, and the low melting point layer 7e is melted by the heat treatment temperature during module creation, and heat is applied to the edge of the solar cell 1a without any gaps. fused. Note that the high melting point layer 7f has a melting point higher than the heat treatment temperature of the module,
This prevents adjacent solar cells 1b from short-circuiting during heat treatment.

Next, regarding light reflection around the connections of solar cells,
This will be explained with reference to FIGS. 3(al) and (b).

First, in FIG. 3 (al), the light reflection R+ at the interface between the sealing resin 9 and the transparent plastic film 7 is R+=
((n+ nz)/(n+ +nz)) 2
・Represented by "m". In formula 411, nl is the refractive index of the sealing resin 9, and n2 is the refractive index of the transparent plastic film 7.
is the refractive index of

In this example, since the refractive index n2 of the transparent plastic film 7 is set to be the same as or close to the refractive index n of the sealing resin 9, (from equation 11, R, = O, and light reflection at the interface is In addition, since the transparent plastic film 7 is fused to the solar cell la by low melting point Ji7e, there is no air layer between the transparent plastic film 7 and the solar cell 1a.
There is no difference in light reflection on the surface of the solar cell 1a depending on the location, and the transparent plastic film 7 is almost invisible in appearance.

Further, FIG. 3 (bl) shows how light is reflected when the transparent plastic film 7 is not fused to the solar cell 1a and an air layer (or vacuum layer) 15 is present.

In the figure, a transparent plastic film 7 and an air layer 1 are shown.
The light reflection R2 at the interface with 5 is Rz= ((nz-ni)/(nz+n*))"
...It is expressed as (2). In equation (2), n2 is the refractive index of the transparent plastic film 7, and n is the refractive index of the air layer 15.

Light reflection R3 at the interface between the air layer 15 and the solar cell 1a
is R3= ((n+-rz)/(rz+n4)) 2
−(31) In formula (3), n4 is the refractive index of the solar cell la.

In addition, light reflection R4 at the interface between the sealing resin 9 and the solar cell la is Ra-((rz n4)/(n++n4)) 2
”・(Represented by 41.(3), (By formula 41,
R:l≠R4, and the light reflection on the surface of the solar cell 1a differs depending on the location.

Therefore, since the light reflection at the transparent plastic film 7 is different from that at other parts, in this case, the transparent plastic film 7 is visible from the outside of the module.

(Effects of the Invention) As explained above, according to the present invention, the arrangement interval of the solar cells can be reduced to a minute interval equal to the thickness of the insulating member. It can be made smaller than a battery module, and the module efficiency can be dramatically improved. Additionally, when the insulating material is multi-layered using two or more resin materials with different melting points, the layer with the lower melting point is thermally fused to the edge of the solar cell, and no gap is created between the solar cell and the insulating member. So,
Light reflection on the surface of the solar cell is made uniform, and the insulating material is not visible from the outside. Therefore, the appearance can be improved.

[Brief explanation of drawings]

Figures 1(a) and (bl are partially enlarged plan views and vertical cross-sectional views of the solar cell module of the present invention, and Figure 2 is an insulating member and its surrounding structure with the positive electrode, negative electrode, wiring, etc. omitted). 3(a) and 3(b) are schematic diagrams illustrating the state of light reflection around the connection portion of the solar cell;
Figures (al, (bl) are partially enlarged plan views and vertical cross-sectional views of conventional solar cell modules. la, lb...Solar cell self...Transparent plastic film (insulating member) 9...
・Sealing resin 10...Pan cage Fig. 7 θ H570θ 5 θ /'J/ Ill ,・ ,
1 ,・1 11Figure 2
,, / ・ 11
i 1 72 234 7c 77e 7b 432 Elementary 3
Diagram (a) 7 birds and insects 3 layers (b)

Claims (1)

[Claims] 1) In a solar cell module in which a plurality of solar cells are housed and arranged in a planar manner within a package, and in this state the solar cells are resin-sealed within the package, A solar cell module characterized in that battery cells are arranged so that opposing end surfaces are in contact with each other with an insulating member interposed therebetween. 2) The solar cell module according to claim 1, wherein the insulating member is a plastic film. 3) The solar cell module according to claims 1 and 2, wherein the insulating member is multilayered with two or more types of resin materials having different melting points. 4) The solar cell module according to claims 1, 2, and 3, wherein the insulating member has a refractive index that is the same as or close to the refractive index of the sealing resin.