JPH06252429A - Solar cell element, and solar cell and manufacture thereof - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] To provide a low-cost solar cell element, cell, and manufacturing method thereof. [Construction] In the solar cell element 12, the entire surface or a part of the surface of a p- or n-type silicon semiconductor 8 coated around the conductive thin wire 7 is an n- or p-type silicon semiconductor 9, respectively, A pn junction surface 10 is formed on the
Alternatively, a metal electrode 11 connected to the p-type silicon semiconductor 9
With. In the solar cell 16, the n-type or p-type silicon semiconductor 9 of the solar cell element 12 contacts the conductive substrate 13 and is arranged in parallel. The solar cell 16 is manufactured by a method in which a conductive thin wire 7 is coated with a p- or n-type silicon semiconductor 8 in parallel, and a plurality of these are coated in parallel with a conductive material containing a group V or group III impurity. It is arranged on the flexible substrate 13 and heat-treated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a silicon semiconductor pn.
The present invention relates to a solar cell element having a junction, a solar cell, and an improvement in the manufacturing method.

[0002]

2. Description of the Related Art With the background of environmental problems such as depletion of petroleum resources and global warming, photovoltaic power generation, that is, power generation by solar cells has attracted attention as one of power generation means by solar energy, and in particular semiconductor materials are used As an effective means, solar cells have been vigorously developed in various countries in terms of materials, configurations, and manufacturing methods.However, compared with the current price of commercial power, the power generated by the solar cell power generation system High price is the biggest barrier to practical use, and development of low-cost solar cell elements and cells is indispensable for solving this.

In a conventional solar cell element, for example, as shown in FIG. 3, n-type impurities are diffused in a p-type silicon semiconductor plate 1 to form an n-type silicon semiconductor layer 3 with a pn junction surface 2 sandwiched therebetween. When the solar light 4 is irradiated, an electromotive force is generated from the electrode 5 provided on the p-type silicon semiconductor plate 1 toward the electrode 6 provided on the n-type silicon semiconductor layer 3, and the solar energy is directly converted into electrical energy. Can be converted to.

[0004]

However, although the silicon semiconductor plate 1 is obtained by slicing a silicon rod, the silicon single crystal rod has a high manufacturing cost, and the polycrystalline rod has a low manufacturing cost, but both are sliced and polished. As a result, the cost of the silicon semiconductor plate is increased due to the large loss. When amorphous silicon is used, the material cost is low because it is a thin film, but the equipment cost is high and the durability is also problematic.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a new solar cell element and cell which have higher energy conversion efficiency than conventional ones and can be significantly reduced in cost. A silicon semiconductor is coated around the thin wire,
A solar cell element, characterized in that the thin wire is used as one electrode, and another electrode is brought into contact with the pn junction or a Schottky type energy barrier interposed therebetween, the second invention is
The solar cell according to the first invention is characterized in that the n-type or p-type silicon semiconductors are arranged in parallel in contact with a conductive substrate, and the third invention is a conductive thin wire. A solar cell characterized by coating a p- or n-type silicon semiconductor around a substrate, arranging the silicon semiconductor in parallel on a substrate coated with an alloy containing a group V or group III impurity, and heat-treating the substrate. The method is the gist.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1 (a), a CV is formed around the conductive thin wire 7.
After coating the n-type silicon semiconductor 8 with D, from the surface
If the group III impurities are diffused to make the entire surface of the n-type silicon semiconductor 8 a p-type silicon semiconductor 9 to a certain depth before reaching the conductive thin line 7, a pn junction surface 10 is formed between the semiconductors 8 and 9. To be done. The solar cell element 12 is obtained by connecting the metal electrode 11 to the p-type silicon semiconductor 9. When the element 12 is irradiated with the solar rays 4, an electromotive force is generated from the metal electrode 11 toward the conductive thin wire 7, and the solar energy can be directly converted into electric energy. The silicon semiconductor may be either crystalline or amorphous. A suitable thickness of the semiconductor silicon to be coated is 0.1 to 1000 μm.

Next, as shown in FIGS. 1 (b) and 1 (c),
A plurality of the solar cell elements 12 are arranged in parallel on the conductive substrate 13 in ohmic contact, and the conductive thin wires 7 of each solar cell element 12 are collectively connected to the output terminal 14 and connected to the conductive substrate 13. When the output terminal 15 is provided as a result, the solar battery cell 16 is obtained. When this is irradiated with the sunlight 4, an electromotive force is generated from the output terminal 15 toward the output terminal 14.

As another embodiment of the method for manufacturing a solar battery cell, as shown in FIG. 1D, an n-type silicon semiconductor 8 is coated around the conductive thin wire 7, and this is coated with aluminum 21. When a plurality of glass substrates 13 are arranged in parallel on each other and heat-treated in a furnace, the aluminum on the substrate 13 diffuses into the n-type silicon semiconductor 8 to form a p-type silicon semiconductor 17, and the p-type silicon semiconductor 17 is formed at the boundary between the two semiconductors. pn junction surface 10
Is formed, and a solar battery cell 18 in which a part of the surface of the n-type silicon semiconductor 8 is used as the p-type silicon semiconductor 17 is manufactured.
However, at this time, the p-type silicon semiconductor 17 is the conductive thin wire 7
The depth is not reached.

The conductive thin wire may have a diameter of 5 to 500 μm and may be a metal that does not cause any trouble during the coating and heat treatment of the silicon semiconductor, such as Cu, Al, Ag, Ti, W,
Any of Mo, Ta, etc., or alloys containing one or more of these are suitable.

The conductive substrate 13 is made of aluminum, copper,
A conductive coating made of a metal that imparts reverse conductivity to the p-type or n-type silicon semiconductor 8 is formed of glass, resin, ceramics, or the like, which is made of iron, gold, silver, or an alloy containing one or more of these. It may be a film formed on the surface of the insulating plate by screen printing, vapor deposition, sputtering, CVD or the like. The metal forming the conductive coating is
It may consist of aluminum, copper, iron, gold or silver or an alloy containing one or more of these.

In order to form a p-type or n-type silicon semiconductor 8 around the conductive thin wire 7, the conductive thin wire 7 is passed through a reaction chamber 19 as shown in FIG. Or forming a layer 8 of n-type silicon semiconductor,
When it exits the reaction chamber 19, it is melted and crystallized by heating with a laser or high frequency, and wound on a drum 20 in a long shape, so that continuous production is possible. Further, the silicon layer can be coated by immersing the conductive thin wire in the p-type or n-type silicon semiconductor melt and pulling it out. If this is cut into a certain length and used, a solar cell can be manufactured with almost no material loss of the silicon semiconductor.

To form a p-type silicon semiconductor-junction surface-n-type silicon semiconductor structure, an impurity imparting reverse conductivity is applied to the p-type or n-type silicon semiconductor formed around the conductive thin wire, or If the reverse conductive layer is formed by vapor phase diffusion, as shown in FIG. 1C, the p, n-type silicon semiconductor and the pn junction surface can be formed concentrically. Further, it is also possible to coat the solar cell with an antireflection material and then coat it with an organic material or cover it with a glass plate.

[0013]

When the solar cell of the present invention is irradiated with sunlight, as shown in FIG. 1 (d), even if a part of the sunlight is reflected from the surface, it is absorbed by the adjacent solar cell element. The conversion efficiency is good, and if the solar cell elements are arranged in the north-south direction so as to coincide with the meridian direction of the sun as much as possible, electric energy can always be efficiently extracted without particularly tracking the sun's rays.

[0014]

EXAMPLE A molybdenum wire having a length of 150 mm and a diameter of 500 μm was dipped in a silicon semiconductor melt and pulled up at a rate of 5 cm / min to form a p-type silicon semiconductor layer having a thickness of 100 μm around a conductive thin wire. Then, an n + layer was formed on the surface of the p-type silicon semiconductor by the vapor phase diffusion method of POCl ₃ , and then cut into 20 mm intervals, and one end was processed to expose the molybdenum wire to 3 mm. Fifteen of these were arranged in parallel on a silver paste printed in a 15 mm square on a glass plate and fired while applying a load to produce a solar battery cell. The converted electric energy was taken out from the output terminal connected to the exposed molybdenum wires all at once and the output terminal connected to the baked silver paste, but the conversion efficiency was 1
It was 0.2%.

[0015]

INDUSTRIAL APPLICABILITY The solar cell element that constitutes the solar cell of the present invention has an extremely high optical collecting performance of solar rays,
Further, if they are arranged in the north-south direction, high collection performance can be obtained, so that the present invention can provide a solar cell having high energy conversion efficiency at a low cost.

[Brief description of drawings]

FIG. 1A is a perspective view of a solar cell element of the present invention,
(B) is a plan view of the solar cell of the present invention, and (c) and (d) are partially enlarged side views of the solar cell obtained by the manufacturing method of the present invention.

FIG. 2 is an explanatory diagram of a method for manufacturing a linear solar cell element used in the solar cell of the present invention.

FIG. 3 is a sectional view for explaining a conventional solar cell element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... P-type silicon semiconductor plate 14, 15 ... Output terminal 2 ... pn junction surface 16 ... Solar cell 3 ... N-type silicon semiconductor layer 17 ... P-type silicon semiconductor 4 ... Solar ray 18 ... Solar cell 5, 6 ... Electrode 19 ... Reaction chamber 7 ... Conductive wire 20 ... Drum 8 ... N-type silicon semiconductor 21 ... Conductive film 9 ... P-type silicon semiconductor 10 ... Pn junction surface 11 ... Metal electrode 12 ... Solar cell element 13 ... Conductivity substrate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruhiko Hirasawa 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Shin-Etsu Chemical Co., Ltd. Corporate Research Center

Claims (11)

[Claims] 1. A silicon is coated around a conductive thin wire,
Using the thin wire as one electrode, sandwiching the pn junction,
A solar cell element having another electrode connected thereto. 2. The solar cell element according to claim 1, wherein the conductive thin wire has a diameter of 5 to 500 μm. 3. The silicon semiconductor is crystalline.
The solar cell element described in 1. 4. The silicon semiconductor is amorphous.
The solar cell element described in 1. 5. The solar cell element according to claim 1, wherein the conductive thin wire is made of any one of copper, aluminum, silver, titanium, tungsten, molybdenum, and thallium, or an alloy containing one or more thereof. 6. A solar battery cell in which the solar battery elements according to claim 1 are arranged in parallel in contact with a conductive substrate. 7. The conductive substrate is aluminum, copper, iron,
The solar cell according to claim 6, which is made of one of gold and silver or an alloy containing one or more of these. 8. The solar cell according to claim 6, wherein the conductive substrate is an insulating plate provided with a conductive coating. 9. The conductive coating is aluminum, copper, iron,
The solar cell according to claim 8, which is made of one of gold and silver or an alloy containing one or more of these. 10. The solar battery cell according to claim 8, wherein the insulating plate is made of resin, glass, or ceramics. 11. A method of coating a p- or n-type silicon semiconductor around a conductive thin wire, arranging the silicon semiconductor in parallel on a substrate coated with an alloy containing a group V or group III impurity, and performing heat treatment. A method of manufacturing a characteristic solar cell.