JPS5854684A - Solar energy converter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a large-scale photoelectric conversion device and a method for manufacturing the same, which are manufactured at low temperatures and are thus inexpensive and can tolerate some circuit errors.

As we increasingly realize that our remaining biofuel resources are finite, and as the need to develop renewable and effective energy resources increases, a significant amount of research is being directed toward the development of solar energy. It is being said.

What are the important issues regarding the development of photoelectric conversion devices?

The problem was the cost of materials for semiconductor conversion devices.

This semiconductor material, usually silicon, uses a PM junction to create a potential when exposed to light. However, for accurate operation, typical systems require large amounts of semiconductor material to cover a relatively small area. A further problem encountered was that the thickness of the semiconductor material must be able to withstand the tension caused by bending.

It is necessary that the cell be a small unit, constructed to have the minimum degree of flexibility necessary for normal operation or use. The third problem is tolerance to defects in large area cell arrays. That is, when only one short circuit occurs, the generated electricity may escape through the shorted cell, thereby affecting all units.

One of the solutions to these problems is the 14th issue of 1960.
M and B published on page 26 of the Annual Power Source Society of Japan.

This is suggested in a paper titled "Large-scale silicon solar cells" by Primis. He suggests using semiconductor spheres in a plastic matrix. However, problems arose with making electrical connections.

For examples, see section G, chapter 9, page 209 of the text "Semiconductors and Metalloids" by Harold Hoyle.

Therefore, it is an object of the present invention to
An object of the present invention is to provide a large-area photoelectric conversion element array.

A second object of the present invention is to provide a flexible array of photoelectric transducers that can be bent and deformed without damage even when manufactured in thin film form.

A third object of the present invention is to provide a large area optoelectronic device with tolerance to malfunctions due to short circuits, which can handle several shorted cells without seriously degrading the electrical performance. is to develop an array.

A fourth object of the present invention is also to provide a low cost manufacturing process for making large area optoelectronic device arrays in which the maximum temperature required is less than 400°C.

Another object of the invention is to provide a continuous interconnection system that is coplanar with the array and is connected during the manufacturing process of the array at very little additional cost to complete one assembly. It is to be.

According to the present invention, a radiant energy conversion system can be provided that includes a matrix support member having a metal foil. The metal foil has first and second layers of polymeric material disposed on opposite sides thereof and has a hole extending at least through the foil spaced from each other in the support member. A substantially spherical semiconductor cell is formed in each hole, and each cell has PR1! It has an N-type region and an N-type region.

The N-type region contacts the metal foil in each hole.

Seven conductive means are formed on the support member and connect the P chain regions of each cell. Each connection to the P chain region consists of an electrode with a predetermined resistance. Further, the plurality of matrix-supported sphere assemblies described above are serially and internally connected, and the successive internal connections are coplanar with the assembly and substantially less than the thickness of the assembly. It is provided so that it has a thickness that is not too large.

A method for making a radiant energy conversion element includes doping the surface of a plurality of semiconductor spheres of P-type material with an N-type dopant, providing a metal foil between two layers of polymeric material, and making holes in the foil. The process of placing these spheres in order to make a
making electrical connection with the 'fj1 surface area; enclosing and sealing around the sphere; and removing the first side of the sphere's foil to expose the P chain area on the second surface. and a step of making an Ausec contact to each P-made chain clay with a predetermined resistance.

The method described above may also include the step of adding another layer of plastic material to the spherical foil assembly to increase the thickness of the matrix-supporting layer to approximately the average diameter of the spherical spheres.

Each step in the above method is performed at a temperature of 400'O or less.

Additionally, the spherical foil assembly is electrically interconnected in series such that the thickness of each successive interconnect is no greater than the average diameter of the sphere.

The present invention will be described in detail below with reference to the figures.

Referring first to FIG. 1, a perspective view of a portion of the completed transducer array is shown, with several silicon spheres 110 mounted on top of the completed assembly. A metal foil 103 forms an electrical connection to the sphere on the N-type surface area indicated at 104. metal foil 105
is electrically connected to the chain region made of P shown at 109. Sphere 1
The top part of 06 is buried within the matrix assembly, leaving a small portion of the top of the sphere exposed to the air.

The plastic layer 102 is made of polyester material,
It is transparent to incident light and allows it to pass through. The plastic layer 101 is also made of an ester material, and the metal foil 105 and metal foil 103, which serve as both a matrix support and an electrical insulator, are cut.
07. This makes the fully conductive sphere 1
The provision of 11 provides coplanar electrical interconnections between the assembled portions of the matrix, thus allowing series interconnections.

In another embodiment, instead of one sphere 111, metal wires are placed in the positions of these spheres, and the upper foil 103
and the foil 105 below.

Referring now to FIG. 2, FIG.
2 layers of polyester sheet 2 with a thickness of 127 mm
02 and 201 as a thin film.
, 127 mm) thick aluminum foil. Figure 2b shows the thin film after the hole punching process;
Figure C shows the thin film after placing the semiconductor sphere 204 in the hole. Prior to insertion, one sphere 204 consists essentially of a KP-type region and has a region of N'fli doso material diffused over the surface 205. An electrical connection is formed between the mold surface area 205 and the aluminum foil 203 by insertion into the hole. The sphere can be centered using a pressure process in which pressure is applied between two relatively soft surfaces of the foil plastic assembly of the sphere to center the sphere within a hole made in the membrane.

Referring now to FIG. 3, FIG. 3a shows the result of a second pressurization step to create a seal in which the layer of plastic material surrounds the sphere 301. This is done by applying approximately 0.1 pounds of pressure to each sphere at a temperature of approximately 250°C. Therefore, the /lysester material forms a seal at position 301 and adheres firmly to one bulb.

Figure 3b is a cross-sectional view of the sphere after an etch step in which an N-type selective etch is performed on one side of the matrix of firmly anchored spheres. This removes surface material from the sphere.

An N-type surface material 302 remains that connects with the metal foil, and a P-type region 303 is subjected to the next processing step.

Referring to FIG. 4, the assembly shown in FIG. 4a is upside down, and a connection foil 407 on the back side is formed in the P chain area exposed on the surface. Additional polyester material 405
is formed to provide electrical isolation to the X-shaped surface region 406. An electrical connection to P-type region 401 is formed at location 408 by applying pressure across the matrix. An additional polyester sheet is formed over the cell 411 and the sheet 410 is pressed against a surface such as stainless steel foil with a Teflon coating 409.
is provided to maintain symmetry during one compression process. Teflon coating 409.

It is provided to avoid bonding to the N-type surface area of the sphere and is provided to facilitate removal after the final compression bonding step.

In Figure 4b, an electrical connection is formed between the P chain region and the foil by applying approximately 5 bonds of pressure on each sphere at a temperature of approximately 260°C, so that layer 413 is essentially continuous. M) I
The sheets of polyester are bonded together in such a way that they form a J-X support material. When a 14 mil (0.3556 mm) diameter ball is bonded to a 0.5 inch (0.127 mm) aluminum foil, in this embodiment a pressure of from 0.5 mm to 10 lb. is applied to each sphere. Although effective in use, sufficient pressure is required to create a repeatable connection as it significantly deforms the metal. Silicon spheres can also crack if excessive pressure is applied.

Light impinging on the surface reaches junction 414 and creates an electrical potential between foils 412 and 407, and the sheet of lyester 413 is essentially transparent to light;
Additionally, the N-type region is isolated from the PM connection region. Furthermore, the top foil 412 acts as an optical reflector that causes diffuse reflection, making it easier for the bulb 414 to receive light.

This is possible by turning the dull side of the foil towards the light abyss.

By exposing the entire upper hemisphere of the semiconductor cell and placing the spheres in close proximity, the effective P-N junction area exposed to light is larger than the planar surface area of the array.

It is easily formed using a generally conductive sphere 111, which is a generally N-diffused cell that acts as a short circuit between the wire and the connecting foil.

Furthermore, shorting balls, such as aluminum or nickel galleys, or lengths of wire with a diameter approximately the same as the diameter of the balls can be used to form the shorting connection between the foils.

Referring to FIG. 5, it is shown how adjacent assemblies are interconnected to form a series electrical connection. Foil 51 is shown connected to the N-type region of sphere 53 and connected to the P-chain region of one sphere 54.

A series connection is shown at 52. A layer of pre-ester insulating and support material 55 surrounds the continuous interconnect in a substantially continuous manner.

The foil used in the examples in this specification was 6 mil (0.15
It is intended to be a metal sheet having a thickness of 24 mm (IJ) or less and having special punchable properties. The foil used in this example is a commonly available roll that is typically used for cooking or wrapping things and has a thickness of 0.5 to 2ξ mil (0.0127 to 0.127 mm). A variety of common 3 mil foils. Aluminum alloys are also effective.

By manufacturing using the method described above, it is possible to manufacture a large-area solar energy conversion element that converts incident energy into electrical potential.

The process of the present invention has the great advantage of being able to produce large area arrays at relatively low temperatures, resulting in low cost and being highly tolerant to short circuits. Therefore, we are confident that we have been able to provide a more economical energy conversion device.

Although the invention has been described and illustrated with respect to specific embodiments,
It is believed that variations and modifications may be made without departing from the spirit and spirit of the invention herein.

[Brief explanation of the drawing]

Figure 1 shows a part of the solar energy conversion device,
Figure 2a is a cross-sectional view of the foil-plastic film. Figure 2b is a cross-sectional view of the plastic-foil film after hole b'' has been drilled.
The figure shows the state after the doping has been carried out.
FIG. 2 is a cross-sectional view showing a plastic thin film and a sphere. Figure 3b is a cross-sectional view of the sphere with the foil-plastic film and sealed N-type surface material removed. Figure 4a is a cross-sectional view of the completed assembly before the second metal foil is installed and the final hot press step is performed. Fourth
Figure b is a cross-sectional view of the completed cell connecting the two foils formed in the completed solar energy conversion device. FIG. 5 is a diagram illustrating alternative embodiments of the present invention showing alternative ways of interconnecting adjacent matrix assemblies. Representatives: Asamura and 4 people

Claims (1)

[Claims] (1) a. Doping the surface of a plurality of semiconductor spheres of P-type material with an N-type r-zo material; and b. providing an aluminum foil between the two layers of polymeric material. drilling holes in the foil to place the balls; inserting the balls into the holes so that the aluminum foil creates an electrical connection to the N-type surface area of each ball; forming a ball and foil assembly; d. creating a seal around said ball; selectively removing the first layer of the ball and foil assembly to form a second surface made of P; A method of manufacturing a radiant energy conversion device, comprising: exposing chain regions; f. forming ohmic contact to each said P chain region with a predetermined resistance. (2) the method further comprises adding another layer of plastic material to the ball and foil assembly to form a matrix; (4) the method further comprises forming a series interconnect between a plurality of the ball and foil assemblies; , the maximum thickness of said successive interconnects does not exceed the average diameter of the spheres; The first and second ball and foil assemblies (6
) said series internal connection comprises aluminum foil sheets, each sheet connecting said first ball and foil assembly to an N-type region and said second (7) said method connecting said each said P chain; (8)a of the two layers of polymeric material after making ohmic contact with the first one with a surface layer of a second conductivity type F-zo covering a portion of the surface of each cell; a plurality of substantially spherical semiconductor cells of conductivity type; b. at least one aluminum foil bonding to each said cell in the same conductive region; C0 opposite to the region connecting said aluminum foil; A radiant energy converter system comprising: electrically conductive means for creating an electrical connection to each cell in a region of conductivity type; d. insulating means for electrically isolating said electrically conductive means from said aluminum foil; (9) a. comprising an aluminum foil, at least one layer of polymeric material disposed in association with the aluminum foil, and a plurality of layers spaced within the support member and extending through at least the foil; a matrix support member having holes; b. a substantially spherical semiconductor cell disposed within each hole, each cell having a P-chain region and an N-type region;
A semiconductor cell with an N-type region connected to the aluminum foil in each hole to create a matrix support and sphere assembly; a conductor connected to the conductor, the connection to each P chain region comprising a resistor having a predetermined resistance, the conductor being insulated from the aluminum foil by the layer of polymeric material; Energy converter system. 10. The radiant energy converter system of claim 9, wherein said matrix support member comprises an aluminum foil and first and second layers of polymeric material located opposite the foil. aυ The system further comprises a plurality of said matrix supports and spheres interconnected in series, said successive interconnections creating a coplanar surface, the thickness of which is approximately the thickness of said assembly. The radiant energy converter system of claim 9, which does not exceed the scope of claim 9. (13m) A step of forming both the first convex surface and the second surface, giving one of the surfaces semiconductor properties, and controlling the gap between the first convex surface and the second surface. applying a pressure vessel to a semiconductor material having a predetermined resistance value at a temperature lower than 400°C for a period of time during which the ohmic contact is formed. 13. A method of forming an ohmic contact according to claim 12, comprising the step of maintaining said controlled pressure during a period of reducing the temperature of said second table and said metal foil. A method for forming an electrically conductive ohmic contact according to claim 12.Q9 A method for forming an ohmic contact according to claim 12, wherein the metal foil contains aluminum. (tea, with a semiconductor material; b. A semiconductor device comprising a metal foil connected to the semiconductor material, the metal foil connected to the semiconductor material having a predetermined electrical resistance and the physical bonding characteristics of the foil to the semiconductor material. 17. The semiconductor device of claim 16, wherein the device further has improved physical bonding properties of a foil to the semiconductor material, the polymeric material being located at and around the connection. 17. The semiconductor device of claim 16, wherein the semiconductor material comprises P-type silicon. 17. The semiconductor device of claim 16, wherein the metal foil comprises aluminum.