KR20130068666A - Solar cell - Google Patents

Abstract

PURPOSE: A solar cell is provided to affect the whole P-type semiconductor with a magnetic field and to prevent an electron from disappearing by recombination. CONSTITUTION: A P-type semiconductor(102) is formed on the lower end of an N-type semiconductor(100). A metal electrode layer(104) is formed on the lower end of the P-type semiconductor. An N pole magnetic thin film(108) and an S pole magnetic thin film(110) are formed on the lower end of the metal electrode layer. The number of N pole magnetic thin films is equal to the number of S pole magnetic thin films. A ribbon wire(106) is formed on the lower end of the metal electrode layer.

Description

Solar cell {Solar cell}

The present invention relates to a method of preventing electrons generated in a P-type semiconductor inside a solar cell from being diffused to the P-type semiconductor electrode and recombined and extinguished.

In general, a solar cell is a device for converting solar energy into electrical energy, and has a junction form of a p-type semiconductor and an n-type semiconductor, and the basic structure is the same as a diode.

The operation principle of the solar cell will be described as follows.

Most of the solar cells consist of large-area pn junction diodes. The basic requirement for the photovoltaic energy conversion of the solar cell is that the p-type semiconductor region has a small electron density and a large hole density hole density, and the n-type semiconductor region has a large electron density and a small hole density, electrons must exist asymmetrically within the semiconductor structure. Therefore, in the thermal parallel state, a diode composed of a junction of a p-type semiconductor and an n-type semiconductor has an imbalance of charge due to diffusion due to a concentration gradient of a carrier, which causes an electric field to be formed. Carrier diffusion does not occur. When such a diode is applied with light above the band gap energy, which is the energy difference between the conduction band and the valence band of the material, the electrons subjected to light energy are excited by the conduction band in the valence band. (excite) At this time, the electrons excited by the conduction band can move freely, and holes are generated in the valence band where electrons escape. This is called an excess carrier, and the excess carrier diffuses due to the difference in concentration in the conduction band or the valence band. At this time, electrons excited in the p-type semiconductor and holes made in the n-type semiconductor are called minority carriers, respectively, and carriers in the p-type semiconductor or the n-type semiconductor before bonding (that is, holes of the p-type semiconductor and n The electrons of the type semiconductors are called majority carriers separately from minority carriers.

The majority carriers are interrupted by flow due to an energy barrier created by an electric field, but electrons, which are minority carriers of the p-type semiconductor, may move toward the n-type semiconductor, respectively. The diffusion of the minority carriers causes a potential drop inside the pn junction diode, and when the electromotive force generated at the anode terminal of the pn junction diode is connected to an external circuit, it acts as a solar cell.

Such solar cells may be largely classified into silicon based compounds, compound based organic materials, and the like based on materials used therein.

In addition, silicon-based solar cells are classified into single crystalline silicon, polycrystalline silicon, and amorphous silicon solar cells according to the phase of a semiconductor.

In addition, the solar cell is classified into a bulk solar cell and a thin film solar cell according to the thickness of the semiconductor. The thin film solar cell is a solar cell having a thickness of a semiconductor layer of several tens to several micrometers or less.

As such, bulk silicon solar cells having high energy conversion efficiency and relatively low manufacturing cost are widely used for ground power.

In solar cells, electric current flows by sending electrons generated by light energy from a P-type semiconductor to an N-type semiconductor. At this time, the P-type semiconductor electrons should move to the N-type semiconductor without any loss. However, electrons generated in the P-type semiconductor far from the electric field of the P-type semiconductor and the N-type semiconductor junction have a high probability of being diffused into the P-type semiconductor electrode and recombined to disappear.

Currently, P-type semiconductors are doped with N-type semiconductors toward the electrodes to prevent electron diffusion and recombination, but they are not prevented over the entire surface of the P-type semiconductor electrodes.

The problem to be solved by the present invention is to propose a method for reducing the probability that the electrons generated in the P-type semiconductor far from the electric field of the P-type semiconductor and the N-type semiconductor junction is dissipated by the recombination to the P-type semiconductor electrode.

Another object of the present invention is to propose a method of reducing the probability that electrons generated in the P-type semiconductor are diffused into the P-type semiconductor electrode and then extinct by being recombined over the entire surface of the P-type semiconductor electrode.

To this end, the solar cell of the present invention includes an N-type semiconductor, a P-type semiconductor formed at the bottom of the N-type semiconductor, a metal electrode layer formed at the bottom of the P-type semiconductor, and an N-pole magnetic thin film formed at the bottom of the metal electrode layer; S-pole magnetic thin film is included.

To this end, the solar cell of the present invention includes an N-type semiconductor, a P-type semiconductor formed at the bottom of the N-type semiconductor, a metal electrode layer formed at the bottom of the P-type semiconductor, and an N-pole magnetic thin film formed at the bottom of the metal electrode layer; S-pole magnetic thin film is formed on the bottom of the metal electrode layer, and includes a ribbon wire for electrical connection with the adjacent solar cell.

The conventional method of doping an N-type semiconductor to the electrode side in the P-type semiconductor is partially applied where the ribbon wire, but the present invention has the effect of preventing electron recombination disappear by affecting the P-type semiconductor as a magnetic field as a whole.

1 illustrates a solar cell according to an embodiment of the present invention.
2 illustrates a solar cell in which a magnetic field is formed according to an embodiment of the present invention.

The foregoing and further aspects of the present invention will become more apparent through the preferred embodiments described with reference to the accompanying drawings. Hereinafter will be described in detail to enable those skilled in the art to easily understand and reproduce through this embodiment of the present invention.

A solar cell is a semiconductor device having a diode junction structure using a photovoltaic effect and a photocurrent effect, in which a semiconductor device such as silicon receives light energy and is converted into electrical energy. In the structure of a silicon solar cell, a p-n junction diode is formed by bonding an n-type semiconductor including a pentavalent element to a tetravalent element on a periodic table and a p-type semiconductor containing a trivalent element.

When the p-n junction is formed, electrons of high concentration are diffused from the n-type semiconductor to the p-type semiconductor due to the difference in concentration of impurities, and at the same time, holes are diffused to the n-type semiconductor in the p-type semiconductor. The electrons diffused into the p-type semiconductor have higher energy in the conduction band than the electrons in the n-type semiconductor, whereas the energy of holes diffused into the n-type semiconductor is higher than that of the p-type semiconductor in the valence band. An internal potential difference is formed. At this time, when a photon having energy of more than the prohibition band is introduced into the solar cell, it is absorbed by the n-type semiconductor, which is a light absorption layer, excites electrons in the valence band, moves to the conduction band, and holes are generated in the valence band. This is called an electron-hole pair, and the electron-hole pair generates a difference in concentration of minority charges inside, and these charges generate photovoltaic force due to the new diffusion force.

At this time, when an external conductor is connected to the p-n junction electrode, electrons flow in the n-type semiconductor and holes flow in the external conductor in the p-type semiconductor. Therefore, the current flow in the solar cell flows from the p-type semiconductor to the n-type semiconductor through the external conductor.

1 illustrates a solar cell according to an embodiment of the present invention. Hereinafter, a solar cell according to an embodiment of the present invention will be described in detail with reference to FIG. 1.

Referring to FIG. 1, the solar cell includes an N-type semiconductor 100, a P-type semiconductor 102, a metal (AL) thin film layer 104, an N-pole magnetic thin film 108, and an S-pole magnetic thin film 110. Of course, in addition to the above-described configuration, other configurations may be included in the solar cell. For example, the solar cell may include a ribbon wire.

In the solar cell module, the solar cells are electrically connected to each other by the ribbon wire 106. The ribbon wire is provided in the form of a solder plated on the ribbon-shaped conductor surface for electrical connection between the solar cells. Usually, the conductor of a solar cell module wire is formed by TPC (tough pitch copper) or OFC (oxygen-free copper), and a solder plating film is formed by solder or SnPb which does not contain Pb. Recently, in order to reduce the manufacturing cost of the solar cell module, there is a trend to thin the silicon wafer for solar cell as much as possible, and accordingly, the thickness of the ribbon wire is also required to be thinned.

Referring to FIG. 1, the solar cell is sequentially stacked with an N-type semiconductor 100, a P-type semiconductor 102, and an AL electrode layer (metal electrode layer) 104 from the top, and an N-pole magnetic thin film 108 at the bottom. The S-pole magnetic thin film 110 is formed. The N-pole magnetic thin film 108 and the S-pole magnetic thin film 110 are sequentially formed one by one. That is, the N-pole magnetic thin film 108 and the S-pole magnetic thin film 110 are sequentially formed one by one. The thickness or number of the N-pole magnetic thin film 108 and the S-pole magnetic thin film 110 may vary depending on the thickness of the N-type semiconductor 100, the P-type semiconductor 102, and the metal electrode layer 104. That is, when the thickness of the N-type semiconductor 100, the P-type semiconductor 102, and the metal electrode layer 104 is thick, the number of the N-pole magnetic thin film 108 or the S-pole magnetic thin film 110 may increase or become thick. Can be.

2 illustrates a solar cell according to an embodiment of the present invention. Hereinafter, a solar cell according to an embodiment of the present invention will be described in detail with reference to FIG. 2.

2 shows an example in which an electric field is formed by the N-pole magnetic thin film 108 and the S-pole magnetic thin film 110. According to FIG. 2, when an electric field is formed by the N-pole magnetic thin film 108 and the S-pole magnetic thin film 110, electrons generated in the P-type semiconductor 104 do not disappear and are stacked by the formed electric field.

In other words, some of the electrons previously generated in the P-type semiconductor 102 disappear within the P-type semiconductor 102 without moving to the N-type semiconductor 102. According to the present invention, when electrons generated in the P-type semiconductor 104 are stacked, the generated electrons are stacked up to the junction of the P-type semiconductor 102 and the N-type semiconductor 100. Therefore, the electrons stacked up to the junction of the P-type semiconductor 102 and the N-type semiconductor 100 may move to the N-type semiconductor 100 more easily than the electrons far from the junction. As described above, the present invention allows the electrons generated in the P-type semiconductor to be laminated to the junction by sequentially stacking the electrons without disappearing.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention .

Claims (7)

N-type semiconductor;
A P-type semiconductor formed at a lower end of the N-type semiconductor;
A metal electrode layer formed under the P-type semiconductor;
A solar cell comprising an N-pole magnetic thin film and an S-pole magnetic thin film formed under the metal electrode layer.
The solar cell of claim 1, wherein the number of the N pole magnetic thin film and the S pole magnetic thin film is the same, and is sequentially formed at the bottom of the metal electrode layer one by one.
The solar cell of claim 2, wherein the number or size of the N-pole magnetic thin film and the S-pole magnetic thin film vary depending on the thickness of the N-type semiconductor, the P-type semiconductor, and the metal electrode layer constituting the solar cell.
The method of claim 3, wherein the metal electrode layer is
Solar cell, characterized in that formed of aluminum (Al).
N-type semiconductor;
A P-type semiconductor formed at a lower end of the N-type semiconductor;
A metal electrode layer formed under the P-type semiconductor;
An N-pole magnetic thin film and an S-pole magnetic thin film formed under the metal electrode layer;
Is formed on the bottom of the metal electrode layer, characterized in that it comprises a ribbon wire for electrical connection with the adjacent solar cell.
The solar cell of claim 5, wherein the number of the N-pole magnetic thin film and the S-pole magnetic thin film is the same, and is sequentially formed at the bottom of the metal electrode layer one by one.
The solar cell of claim 6, wherein the number or size of the N-pole magnetic thin film and the S-pole magnetic thin film vary depending on the thicknesses of the N-type semiconductor, P-type semiconductor, and metal electrode layers constituting the solar cell.

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