JP3240825U - thin film solar cell - Google Patents

Abstract

The present invention discloses a thin film solar cell and belongs to the field of solar cell devices. In the thin-film solar cell, the negative electrode layer is provided with a first scribed groove communicating with the glass layer of the conductive glass, the first scribed groove is filled with the absorbing layer, and the upper surface of the first absorbing layer is filled with the absorbing layer. has a second scribed groove communicating with the negative electrode layer, the bottom of the second scribed groove is positioned laterally from the top of the first scribed groove, and the positive electrode layer is provided on the upper surface of the absorbing layer. , a positive electrode layer is filled in the second scribed groove, the positive electrode layer is provided with a third scribed groove communicating with the absorbing layer, and the third scribed groove is on the top side of the second scribed groove; located in the direction of In the present invention, the scribe angle of P2 scribe is selected to achieve direct contact of the electrodes of adjacent sub-cells between P1, P2 and P3, and the positive and negative electrodes of the active layer of the battery dead zone in the typical scribe method. Direct contact can be effectively eliminated, and the problem of short circuit and heat generation in the battery dead zone can be effectively avoided.

Description

The present invention relates to the field of solar cell devices, and in particular to thin film solar cells.

Solar energy is a clean energy that uses sunlight directly.In today's world where fossil energy is depleted and the natural environment continues to deteriorate, countries around the world are placing greater emphasis on the use of solar energy. continue to increase the ratio of Most solar cells, typically produced in thin film format, are fabricated on large-sized conductive glass substrates and separated into interconnected single cells of effective size by a laser scribing process. A typical method of laser scribing is to perform P1, P2, P3 laser scribing with a specific position rule and different depths on the battery substrate to achieve series connection between batteries. In this method, the positive and negative electrodes of the battery dead zone between the P1, P2, and P3 scribes are inevitably in direct contact, causing a short circuit in the battery dead zone to generate heat, which adversely affects the photoelectric conversion efficiency and battery stability of the solar cell. That is, the typical laser scribing process creates a battery dead zone where the positive and negative electrodes of the active layer of the battery in the dead zone are in direct contact, causing the battery in the dead zone to short circuit and generate heat.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thin-film solar cell that overcomes the drawbacks of the prior art that the laser scribing process causes a battery dead zone and the battery in the dead zone is short-circuited to generate heat.

In order to achieve the above object, the present invention is realized by the following technical means.
A thin-film solar cell comprising a conductive glass, an absorption layer provided on the upper surface of the conductive glass, and a positive electrode layer and a negative electrode layer provided on the upper and lower surfaces of the absorption layer, respectively;
The negative electrode layer is provided with a first scribed groove that communicates with the glass layer of the conductive glass, the first scribed groove is filled with an absorbing layer, and the upper surface of the absorbing layer communicates with the negative electrode layer. A second scribed groove is opened, the bottom of the second scribed groove is located laterally to the top of the first scribed groove, a positive electrode layer is provided on the upper surface of the absorbing layer, and is in the second scribed groove Filled with a positive electrode layer, the positive electrode layer is provided with third scribed grooves communicating with the absorbent layer, the third scribed grooves laterally on top of the second scribed grooves.

Preferably, the widths of the first scribed grooves, the second scribed grooves and the third scribed grooves are all 28 to 32 μm.

Preferably, the first scribed groove, the second scribed groove and the third scribed groove are all obtained by laser scribing with a nanosecond laser.

Preferably, said negative electrode layer is a conductive oxide layer or electron transport layer and said positive electrode layer is a conductive oxide layer or hole transport layer.

Preferably, the absorbing layer is a perovskite layer and the conductive glass is ITO glass or FTO glass.

Preferably, the absorption layer has a thickness of 500-700 nm, and the positive electrode layer and the negative electrode layer both have a thickness of 300-700 nm.

Preferably, one end of the bottom of the second scribed groove is connected to one end of the top of the first scribed groove, and one end of the top of the second scribed groove is connected to one end of the bottom of the third scribed groove. be done.

Compared with the prior art, the present invention has the following beneficial effects.

In the present invention, the negative electrode layer has a first scribed groove communicating with the conductive glass, the first scribed groove is filled with an absorbing layer, and the upper surface of the first absorbing layer has a negative electrode A second scribed groove is opened that communicates with the layer, the bottom of the second scribed groove is lateral to the top of the first scribed groove, a positive electrode layer is provided on the top surface of the absorbing layer, and the second A positive electrode layer is filled in the scribed groove of the positive electrode layer, the positive electrode layer is provided with a third scribed groove communicating with the absorbing layer, the third scribed groove is located laterally of the top of the second scribed groove A thin film solar cell is disclosed. By selecting the scribe angle of P2 scribe, the present invention realizes the direct contact of the adjacent sub-cell electrodes between P1, P2, and P3, and the direct contact of the positive and negative electrodes of the active layer of the battery dead zone in the typical scribe method. It can effectively eliminate the contact and effectively avoid the problem of short circuit and heat generation in the dead band of the battery.

Furthermore, a conductive glass such as ITO glass or FTO glass is selected, and a transparent conductive oxide is deposited on these glasses, so that the conductivity of the fabricated battery can be improved.

FIG. 3 is a schematic view of the cell cross-sectional structure after depositing a negative electrode layer on the conductive glass of the thin film solar cell according to the present invention; 1 is a schematic view of a cell cross-sectional structure after laser P1 scribing of a thin film solar cell according to the present invention; FIG. 1 is a schematic view of a cell cross-sectional structure after an absorption layer is deposited in a thin film solar cell according to the present invention; FIG. FIG. 2 is a schematic view of the cell cross-sectional structure after laser P2 scribing of the thin-film solar cell according to the present invention; FIG. 2 is a schematic view of the cell cross-sectional structure after depositing the positive electrode layer of the thin-film solar cell according to the present invention; 1 is a schematic view of a cell cross-sectional structure after laser P3 scribing of a thin film solar cell according to the present invention; FIG. It is a figure which shows the relative position of a intense light lens and a battery in a scribing process.

In order to allow those skilled in the art to better understand the method of the present invention, the technical solutions in the embodiments of the present invention will be hereinafter clearly and completely described in conjunction with the drawings in the embodiments of the present invention. The embodiments are only some embodiments of the present invention, but not all embodiments. Any embodiment obtained by a person skilled in the art without creative efforts based on the embodiments in the present invention shall fall within the protection scope of the present invention.

It should be noted that terms such as "first" and "second" in the specification, claims, and drawings of the present invention are used to distinguish similar objects, and are not necessarily in a specific order or priority. is not intended to explain It should be understood that the data used in this manner are interchangeable where appropriate, such that the embodiments of the invention described herein may be implemented in an order other than that illustrated or described herein. Also, the terms "comprising" and "comprising" and any variations thereof are intended to cover non-exclusive inclusion, such as a series of steps or units of processes, methods, systems, products or devices but are not limited to explicitly listed steps or units and may include those not explicitly listed or other steps or units inherent in these processes, methods, products or devices.

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

(Example 1)
The thin-film solar cell includes a conductive glass 102, an absorption layer 301 is provided on the upper surface of the conductive glass 102, a positive electrode layer 501 and a negative electrode layer 101 are provided on the upper and lower surfaces of the absorption layer 301, respectively, and a negative electrode layer 301 is provided. A first scribed groove 201 communicating with the conductive glass 102 is formed in the electrode layer 101, an absorption layer 301 is filled in the first scribed groove 201, and a negative electrode layer 301 is formed on the upper surface of the first absorption layer 301. A second scribed groove 401 is formed to communicate with the electrode layer 101 , the bottom of the second scribed groove 401 is lateral to the top of the first scribed groove 201 , and the positive electrode layer 501 is formed on the upper surface of the absorption layer 301 . is provided, the positive electrode layer 501 is filled in the second scribed groove 401, the positive electrode layer 501 is provided with a third scribed groove 601 communicating with the absorption layer 301, and the third scribed groove 601 is It is positioned laterally of the top of the second scribed groove 401 . One end of the bottom of the second scribed groove 401 is connected to one end of the top of the first scribed groove 201 , and one end of the top of the second scribed groove 401 is connected to one end of the bottom of the third scribed groove 601 . be done.

(Example 2)
All remaining contents are the same as Example 1, except for the following contents.
The widths of the first scribed grooves 201, the second scribed grooves 401 and the third scribed grooves 601 are all 28 to 32 μm. The first scribed groove 201, the second scribed groove 401 and the third scribed groove 601 are all obtained by laser scribing with a nanosecond laser. Both the first scribed groove 201 and the third scribed groove 601 have a cuboid structure, the second scribed groove 401 has a parallelepiped structure, and the second scribed groove 401 rotates clockwise or counterclockwise from the vertical direction. It is tilted 30 to 75 degrees around.

(Example 3)
All remaining contents are the same as Example 1, except for the following contents.
The negative electrode layer 101 is a conductive oxide layer or electron transport layer, and the positive electrode layer 501 is a conductive oxide layer or hole transport layer. The absorber layer 301 consists of copper indium gallium selenium, perovskite and cadmium telluride. The conductive glass 102 is ITO glass or FTO glass. The absorption layer 301 is a perovskite layer, the thickness of the absorption layer 301 is 500 nm, and the thickness of the positive electrode layer 501 and the negative electrode layer 101 are both 300 nm.

(Example 4)
All remaining contents are the same as Example 1, except for the following contents.
The thickness of the absorption layer 301 is 650 nm, and the thickness of the positive electrode layer 501 and the negative electrode layer 101 are both 500 nm.

(Example 5)
All remaining contents are the same as Example 1, except for the following contents.
The thickness of the absorbing layer 301 is 700 nm, and the thicknesses of the positive electrode layer 501 and the negative electrode layer 101 are both 700 nm.

(Example 6)
All remaining contents are the same as Example 1, except for the following contents.
The thickness of the absorbing layer 301 is 510 nm, and the thicknesses of the positive electrode layer 501 and the negative electrode layer 101 are both 690 nm.

(Example 7)
All remaining contents are the same as Example 1, except for the following contents.
The thickness of the absorption layer 301 is 505 nm, and the thickness of the positive electrode layer 501 and the negative electrode layer 101 are both 310 nm.

(Example 8)
All remaining contents are the same as Example 1, except for the following contents.
The thickness of the absorption layer 301 is 690 nm, and the thickness of the positive electrode layer 501 and the negative electrode layer 101 are both 560 nm.

The thin-film solar cell laser scribing method includes the following steps S1 to S3.
In step S1, as shown in FIG. 1, a negative electrode layer 101 is deposited on a conductive glass 102, and then laser P1 scribing is performed on the negative electrode layer 101 to scribe from the negative electrode layer 101 to the conductive glass 102, As shown in FIG. 2, a plurality of first scribe grooves 201 dividing the negative electrode layer 101 are formed in the negative electrode layer 101, and laser P1 scribing is performed. Mark a Mask point for determining the position of .

In step S2, as shown in FIG. 3, an absorption layer 301 is deposited on the negative electrode layer 101 and the first scribed groove 201, and then, as shown in FIG. A plurality of second scribed grooves 401 are formed in the absorbing layer 301 by scribing from the layer 301 to the negative electrode layer 101 to divide the absorbing layer 301 .

In step S3, as shown in FIG. 5, a positive electrode layer 501 is deposited on the absorbing layer 301 and the second scribed grooves 401, and then laser P3 scribing is performed on the positive electrode layer 501 to form the absorbing layer from the positive electrode layer 501. 31 to form a third scribed groove 601 in the positive electrode layer 501 to divide the positive electrode layer 501, thereby obtaining a thin film solar cell as shown in FIG.

One end of the bottom of the second scribed groove 401 is connected to one end of the top of the first scribed groove 201 , and one end of the top of the second scribed groove 401 is connected to one end of the bottom of the third scribed groove 601 . Connected. The pulse duration during laser scribing is 0.1-100 ns.

From the above, the laser scribing method of the present invention forms a monolithic integrated photovoltaic module by scribing the solar cell structure, separates the solar panel into individual solar cells by scribing, and then uses the scribing method. , forming a plurality of interconnected solar cells. A nanosecond laser, that is, a laser whose pulse frequency is in the nanosecond range, is used to determine the precise position and angle of the laser to achieve precise tilting of the laser P2 scribe.

Note that before the laser P2 scribe, the distance between the first scribed groove 201 and the third scribed groove 601 is estimated to determine the width of the second scribed groove 401, and the thickness of the absorbing layer 301 is Also, it is necessary to determine the inclination angle of the second scribed groove 401 by measuring the distance between the first scribed groove 201 and the third scribed groove 601 . Typically, after P2 scribe, the first scribe groove 201 and the second scribe groove 401 are aligned to ensure that the metal electrode of the positive electrode layer has sufficient deposition space to contact the mating electrode. The scribe spacing should be 30-35 micrometers so that the absorber layer used in this example is a perovskite layer and the thickness of the perovskite layer is in the range of 500-700 nanometers. , the distance between the first scribed groove 201, the second scribed groove 401 and the third scribed groove 601 is 100 nanometers, which requires higher positioning accuracy and stability of the laser.

In FIG. 7, the position of the laser lens 701 during the scribing process operation is shown. With precise positioning of the mask point of the laser and precise control of the tilt angle, the P2 scribe can achieve the scribe effect as shown in FIG. After the P2 scribe is complete, a charge transport electrode layer is fabricated on the cell absorber layer, which generally consists of deposited metal or a combination of charge transport and metal layers. The scribe position of the P3 scribe must be determined based on the predetermined interval between P1 and P3. The P3 scribe width is also on the order of 30 micrometers, which ensures that the metal electrodes are separated by the P3 scribe and reduces the dead area of the cell as much as possible.

The thin-film solar cell may be any one of a perovskite solar cell, an amorphous silicon solar cell, a copper indium gallium selenide solar cell, a cadmium telluride solar cell, and the like. An absorption layer is a layer that converts photons in light into electrons. The absorber layer includes copper indium gallium selenium CIGS, perovskite, cadmium telluride, and the like. In the case of perovskite solar cells, the absorber layer is the perovskite layer. In the case of amorphous silicon solar cells, the basic composition of the absorber layer is an amorphous silicon compound, also called a-Si or amorphous silicon. In the case of copper indium gallium selenium solar cells, the absorber layer is a direct bandgap compound semiconductor material composed of metal elements such as copper, indium, and selenium, and CIS and CuGaSe ₂ are mixed in an arbitrary ratio to form CuIn _1-x Ga _x Se. ₂ is formed. For cadmium telluride solar cells, the absorber layer is primarily a combination of p-type CdTe and n-type CdS.

Transparent Conductive Oxide (TCO) is a thin film material with high transmittance and low resistivity in the visible spectral range (380 nm<λ<780 nm). TCO materials are mainly oxides such as CdO, In ₂ O ₃ , SnO ₂ , ZnO and corresponding complex multi-component compound semiconductor materials.

Electron-transporting layers and hole-transporting layers are mainly for perovskite solar cells. Electron-transporting layers are generally materials such as SnO ₂ , FTO, etc., and hole-transporting layers are generally materials such as nickel oxide, spiroOMeTAD°, etc. There is a substance, several tens of nanometers thick.

The thin film solar cell further comprises a negative electrode layer located on one side of the absorber layer and for extracting electrons in the absorber layer, the components of the negative electrode layer being a transparent conductive oxide layer TCO or TCO and an electron transport layer. It may be a combination of The solar cell further comprises a positive electrode layer located on the other side of the absorber layer and for extracting holes in the absorber layer, the components of the positive electrode layer being a transparent conductive oxide layer TCO, a conductive metal layer Or it may be a combination of TCO and a hole transport layer.

The approximate thickness of the positive and negative electrode layers is generally tens of nanometers, and the positive and negative electrode layers are generally composed of metal cells or transparent conductive oxides. Generally, the thickness of conductive glass is mainly 1-3 millimeters, of which the conductive layer is generally several tens of nanometers to more than 200 nanometers.

The above content is only for explaining the technical idea of the present invention, and does not limit the protection scope of the present invention. , are all within the scope of protection of the utility model claims of the present invention.

101 negative electrode layer 102 conductive glass 201 first scribed groove 301 absorption layer 401 second scribed groove 501 positive electrode layer 601 third scribed groove 701 laser lens

Claims (9)

A thin-film solar cell,
comprising a conductive glass (102), an absorption layer (301) is provided on the upper surface of the conductive glass (102), and a positive electrode layer (501) and a negative electrode layer (101) are provided on the upper and lower surfaces of the absorption layer (301), respectively. is provided,
A first scribed groove (201) communicating with a glass layer of conductive glass (102) is opened in the negative electrode layer (101), and an absorption layer (301) is filled in the first scribed groove (201). A second scribed groove (401) communicating with the negative electrode layer (101) is opened on the top surface of the first absorption layer (301), and the bottom of the second scribed groove (401) is the first A positive electrode layer (501) is provided on the upper surface of the absorption layer (301), and the positive electrode layer (501) is provided in the second scribed groove (401). Filled, the positive electrode layer (501) is opened with a third scribed groove (601) communicating with the absorbing layer (301), the third scribed groove (601) is in the second scribed groove (401) located laterally on top of
A thin-film solar cell characterized by: The widths of the first scribed groove (201), the second scribed groove (401) and the third scribed groove (601) are all 28 to 32 μm.
The thin-film solar cell according to claim 1, characterized in that: One end of the bottom of the second scribed groove (401) is connected to one end of the top of the first scribed groove (201), and one end of the top of the second scribed groove (401) is connected to the third scribed groove. connected to one end of the bottom of (601),
The thin-film solar cell according to claim 1, characterized in that: the negative electrode layer (101) is a conductive oxide layer or an electron transport layer,
The thin-film solar cell according to claim 1, characterized in that: the positive electrode layer (501) is a conductive oxide layer or a hole transport layer,
The thin-film solar cell according to claim 1, characterized in that: The conductive glass (102) is ITO glass or FTO glass,
The thin-film solar cell according to claim 1, characterized in that: The absorbing layer (301) is a perovskite layer,
The thin-film solar cell according to claim 1, characterized in that: The absorption layer (301) has a thickness of 500-700 nm, and the positive electrode layer (501) and the negative electrode layer (101) both have a thickness of 300-700 nm.
The thin-film solar cell according to claim 1, characterized in that: The first scribed groove (201), the second scribed groove (401) and the third scribed groove (601) are all obtained by laser scribing with a nanosecond laser,
The thin-film solar cell according to claim 1, characterized in that:

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