JPH0322574A - Solar cell - Google Patents

Abstract

PURPOSE:To mutually connect cells together easily and securely by a method wherein a conductive board is provided with side faces whose opposite long sides are bent against the surface of the board, an upper electrode, a photovoltaic layer, and a lower electrode are formed on the board, and an electrical and mechanical means which connects a cell with another cell is provided to the side face of the board. CONSTITUTION:A U-shaped metal board 1 is composed of a board surface 2 and board side faces 3a and 3b. The side faces 3a and 3b are formed in such a structure that their opposite long sides are bent against the board surface 2. A photovoltaic layer 4 of amorphous Si, polycrystalline Si, or the like are formed on the board 1 excluding at least a part of the side faces 3a and 3b, and a transparent electrode film 5 is formed on the photovoltaic layer 4. A metal ribbon or a metal wire 7 is extended over the transparent conductive film 5 and an insulating material 6 and bonded to them with such as Ag paste 8. Holes 9 and 10 are provided to both the board side faces 3a and 3b distant from each other by a prescribed space as penetrating through them, and the surface of the hole 9 is covered with insulating material 6, whereby a solar cell is prevented from being electrically shortcircuited to a screw when the screw is driven into the hole concerned.

Description

[Detailed Description of the Invention] [Industrial Application Field] The invention of B relates to a solar cell, and particularly to a solar cell suitable for modularization.

[Conventional technology]

FIG. 5(a) is a perspective view showing an example of a solar battery cell according to the prior art (see Japanese Utility Model Application No. 194355/1983). In this figure, 31 is made of polycrystalline silicon (Si), for example.
It is a solar cell consisting of.

This solar cell 31 has a pn junction formed in p-type polycrystalline Ueno by a known method such as a diffusion method, an epitaxial/L growth method, and a 2-ion implantation method.

32 is a lattice electrode provided on the n-type surface of this polycrystalline wafer. It is usually formed by screen printing a silver base 1 and firing it at high temperature.

Back side contacts 1 and 33 are formed on almost the entire surface of the back side of B by printing and firing, for example, Ag base l.

This sun! In the cell, the grid electrode 32 is used as one electrode (upper electrode), and the back contact 33 is used as the other electrode (lower electrode). When constructing a module by connecting multiple solar cells in series, with conventional technology,
For example, arrange them as shown in Figure 5(b), and
A tab electrode 34 consisting of a lip is welded to the grid electrode 32 by soldering or the like, and the tab electrode 34 is sequentially connected to the back contacts 1 and 33 of adjacent corresponding battery cells, and a metal ribbon 35 is used to connect each row of solar cells. A serial interconnection of cells was performed between the two connected cells. Furthermore, as shown in FIG. 5(C), these interconnected solar cells (1) and (2) are bonded to the surface protective glass 37 and the back sheet 1/material 38 via the sealing resin 36. After enclosing with
By filling the end face with, for example, a butyl-based sealing material 39 and fixing the periphery with a frame material 40, a solar cell module having moisture resistance and mechanical strength is obtained.

[Problem to be solved by the invention]

In this manner, in order to obtain a predetermined output, in a conventional solar cell module, one side of the tab electrode 34, which is made of a metal strip soldered to the surface electrode of a plurality of arrayed solar cells, is placed adjacent to the surface electrode. Back contact 1 of solar cell
・In addition to 33, since it is necessary to connect the cells by soldering, etc., not only is it necessary to use an arrangement jig to accurately position the cells, but also it is necessary to invert multiple cells at the same time when soldering. There were many problems when the assembly process was complicated. In addition, simply sealing with the surface protection glass 37, the sealing resin 36, the back sheet 1 and the material 38, etc. will easily bend the frame material 40, which has been shaped with At' etc. in order to provide mechanical strength. Must be fixed. Furthermore, the position of each solar cell is determined by the pressure applied when sealing the arrayed and interconnected solar cell cells with the sealing tree Illi 3 6 , the surface protection glass 37 and the back surfaces No. 1 and No. 38. There was also a reliability problem in that misalignment was likely to occur and excessive scratches were applied to the soldered portions of the tab electrodes 34 connecting each solar cell. B's invention was made to eliminate the above-mentioned problems, and it not only makes it possible to easily interconnect multiple solar cells, but also makes it possible to use a strong frame material. The objective is to obtain a solar cell with high mechanical strength.

[Means to solve the problem]

In the solar cell according to the present invention, an upper electrode, a photovoltaic layer, and a lower electrode are formed on a conductive substrate having a substrate side surface with at least opposing long sides bent with respect to the substrate surface. At the same time, electrical connection means and mechanical connection means for connection with other solar cells are provided on the side surface of the substrate (3) (4).

[Effect]

The solar cells of the present invention have mechanical strength against bending, and can be interconnected on the sides of the solar cells, and can be mechanically firmly fixed.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a solar cell according to the present invention, and FIG. a) is the first
2(b) is an enlarged cross-sectional view of the solar cell shown in the figure taken at the position of the metal ribbon, and FIG. 2(b) is an enlarged cross-sectional view taken at the position of the through hole.

In FIGS. 1 and 2, reference numeral 1 denotes a U-shaped metal substrate consisting of a substrate surface 2 and substrate side surfaces 3a and 3b on both sides.

The substrate side surfaces 3a and 3b are formed by bending opposing long sides with respect to the substrate surface 2. 4 is a photovoltaic layer made of, for example, amorphous Si, polycrystalline Si, etc., which is formed leaving at least a part of both side surfaces of the metal substrate 1;
5 is a transparent conductive film formed on the photovoltaic layer 4 of the photovoltaic layer 4; 6 is the photovoltaic layer 4 on one substrate side surface, for example, the right substrate side surface 3b;
This is the insulating material that is left behind, such as a face coated on the surface and behind the surface. A metal ribbon (or metal wire) 7 is extended and bonded onto the transparent conductive film 5 and the insulating material 6 by, for example, Ag bases 1 and 8. Note that 7a indicates a metal ribbon adhered to the side surface 3a of the substrate. Further, the other substrate side surface 3b is not coated with any layer, and the metal substrate surface is exposed.

As shown in FIG. 2(b), the board side surfaces 3a and 3b on both sides
Holes 9 and 10 penetrate through the hole 9 at a predetermined interval.
The surface of the solar cell is also covered with an insulating material 6 to prevent an electrical short circuit between the solar cell and the screw when a screw or the like is passed through it.

FIG. 3 is a partially enlarged sectional view showing how two solar cells manufactured in this manner are connected in series. The first solar cell (located on the left and indicated by (5) (6) The side surface 3b of the substrate (shown as a conductive base)
11, and both solar cells are firmly screwed at the positions of holes 9 and 10 with screws 12 and nuts 1 and 13.

These screws 12 and nuts 1 and 13 are insulated from the substrates of both solar cells, and are connected to the metal substrates 1 of both solar cells.
However, there is no chance that this screw will cause a short circuit. By this method, it is possible to easily and firmly connect one upper electrode to the metal substrate 1 of the adjacent solar cell (having opposite polarities).

A structure in which solar cells formed on a plurality of metal substrates 1 are connected in series in this way is shown in FIG. 4(.). On the side surface of the solar cell located at the farthest end, there is a TEPCO bus electrode 14 made of a metal ribbon attached, for example, to a large number of metal ribbons 7 that extend to the side surface and are glued.
is placed, and the terminal of one polarity is taken out from there.

The terminal of the other polarity is similarly taken out from the pass electrode arranged on the opposite substrate side surface 3b.

After connecting a plurality of solar cells, filling with resin 15,
It is sealed with glass 16. Furthermore, in order to prevent moisture from entering from the connection parts of the solar cells on the end face and the back face, by covering those parts with a butyl-based sealant or a suitable coating material 17, as shown in Fig. 4(b). A solar cell module as shown can be obtained.

In the above embodiment, the metal substrate 1 of the U-shaped solar cell has two opposing long side surfaces 3a and 3b.
However, by using a box-shaped metal substrate having four side surfaces, the strength of the module is further improved. Moreover, although the method of connecting adjacent solar cells in the case of connecting the solar cells in series has been shown, it is clear that parallel connection is also possible.

Furthermore, although we have shown the case where glass 16 is used as the surface adhesive for the module of the invention of Party B, it is also possible to use an insulating coat 1 material (such as silica coat 1) that transmits visible light (7) (8). You can also do it.

[Effects of the Invention] As explained above, the present invention provides an upper electrode, a photovoltaic layer, and a conductive substrate having a substrate side surface formed by bending at least the opposing long sides with respect to the substrate surface. In addition to forming the lower electrode, electrical connection means and mechanical connection means for connection with other solar cells are provided on the side surface of the substrate, so interconnection between cells can be easily and reliably performed. In addition, there is an effect that a solar cell module with high mechanical strength and reliability can be obtained without providing a frame around the module.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of a solar cell according to an embodiment of the present invention, FIG. b) is an enlarged sectional view at the position where the through holes are arranged, FIG. 3 is an enlarged sectional view showing the connection state of adjacent solar cells, and FIG. 4(a) is an enlarged sectional view showing the connection state of adjacent solar cells. , FIG. 4(b) is a sectional view of the module, and FIG. 5(b) is a perspective view of the assembled module.
R) is a perspective view of a conventional solar cell, FIG. 5(b) is a plan view of multiple solar cells interconnected, and FIG. 5(e) is a perspective view of a conventional solar cell.
is a cross-sectional view showing the module structure. , In the figure,
1 is a metal substrate, 2 is a substrate surface, 3a, 3b is a substrate side surface,
4 is a photovoltaic layer, 5 is a transparent conductive film, 6 is an insulating material, 7 is a metal ribbon, 8 is an Ag base 1, 9 and 10 are holes, 11 is a conductive base 1, 12 is a screw, 13 is a It's 1. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] An upper electrode,
1. A solar cell comprising a photovoltaic layer and a lower electrode, and further comprising electrical connection means and mechanical connection means for connection to other solar cells on the side surface of the substrate.