WO2023020515A1 - Heterojunction solar cell and manufacturing method therefor and heterojunction photovoltaic module - Google Patents

Abstract

Disclosed are a heterojunction solar cell and a manufacturing method therefor and a heterojunction photovoltaic module. The manufacturing method comprises: obtaining a silicon wafer having amorphous silicon film layers deposited on the front and back sides; depositing a TCO film layer on the surface of the amorphous silicon film layer on the front side; flipping the silicon wafer by 180 degrees, and covering the edge of the surface of the amorphous silicon film layer on the back side with a mask, wherein the width of the mask ranges from 0.05 mm to 0.5 mm, comprising endpoint values; depositing a TCO film layer on the surface of the amorphous silicon film layer covered with the mask; and manufacturing electrodes on the surfaces of the TCO film layers on the front and back sides to obtain the heterojunction solar cell. According to the present application, the TCO film layer is deposited on the surface of the amorphous silicon film layer on the front side, then the silicon wafer is flipped, the surface of the amorphous silicon film layer on the back side is covered with the mask, the width of the mask ranges from 0.05 mm to 0.5 mm, the shielding width of the mask is narrowed, the area of the TCO film layer on the back side is increased, and the efficiency of the cell is improved.

Description

Heterojunction solar cell and manufacturing method thereof, heterojunction photovoltaic module

This application claims the priority of the Chinese patent application with application number CN202110943834.6 filed on August 17, 2021, the entire contents of which are incorporated into this application by reference.

technical field

The present application relates to the field of photovoltaic technology, in particular to a heterojunction solar cell, a manufacturing method thereof, and a heterojunction photovoltaic module.

Background technique

Heterojunction solar cells have a double-sided symmetric structure and excellent passivation effect endowed by the amorphous silicon layer. At the same time, they have the characteristics of high conversion efficiency and high double-sided ratio, and have become a hot spot in industry research.

There are TCO (transparent conductive oxide, transparent conductive oxide) film layers on the front and back of heterojunction solar cells. At present, physical vapor deposition (Physical Vapor Deposition, PVD) is used to deposit the TCO film layer, and the silicon wafer Put it in the pit of the hollow carrier board, and the hollow carrier board is placed in the PVD equipment, and the PVD equipment performs TCO coating on the front and back at one time. Since the silicon wafer is placed in the pit of the carrier board, the four edges of the back of the silicon wafer are covered by about 0.6mm and there is no TCO film layer. According to calculations, about 1.4% of the amorphous silicon film layer is not covered by the TCO film layer, resulting in The photogenerated carriers generated here cannot be effectively exported, and the theoretically calculated efficiency loss is about 0.34%.

Contents of the invention

The purpose of the present application is to provide a heterojunction solar cell, a manufacturing method thereof, and a heterojunction photovoltaic module, so as to improve the efficiency of the heterojunction solar cell.

The present application provides a method for manufacturing a heterojunction solar cell, including:

Obtain a silicon wafer with an amorphous silicon film layer deposited on the front and back;

Depositing a TCO film layer on the surface of the amorphous silicon film layer located on the front side;

Turning the silicon wafer over 180 degrees, and covering the edge of the surface of the amorphous silicon film layer on the back side with a mask; wherein, the width of the mask is between 0.05 mm and 0.5 mm, including the endpoints value;

Depositing a TCO film layer on the surface of the amorphous silicon film layer covered with the mask;

Electrodes are respectively made on the surfaces of the TCO film layers located on the front side and the back side to obtain a heterojunction solar cell.

In some embodiments, before obtaining the silicon wafer with the amorphous silicon film layer deposited on the front and the back, it also includes:

obtaining the wafer;

Depositing an intrinsic amorphous silicon film layer on the front side and the back side of the silicon wafer, respectively;

Depositing a p-type amorphous silicon film layer on the surface of the amorphous silicon film layer located on the front side;

An n-type amorphous silicon film layer is deposited on the surface of the amorphous silicon film layer located on the back side.

In some embodiments, after said obtaining said silicon wafer, it also includes:

The silicon wafer is subjected to double-sided texturing treatment.

In some embodiments, after the electrodes are fabricated on the surfaces of the TCO film layers located on the front side and the back side respectively, it also includes:

Perform EL test and IV curve test to screen out unqualified heterojunction solar cells.

The present application also provides a heterojunction solar cell, which is manufactured by using any one of the heterojunction solar cell manufacturing methods described above.

The present application also provides a heterojunction photovoltaic module, including a first substrate, a first adhesive film layer, a battery layer, a second adhesive film layer, and a second substrate sequentially stacked from bottom to top, wherein the battery layer includes multiple sheet of the heterojunction solar cell described above.

In some embodiments, both the first adhesive film layer and the second adhesive film layer are EVA adhesive film layers.

In some embodiments, the first adhesive film layer is an anti-crack adhesive film layer.

In some embodiments, the first substrate is a glass substrate.

In some embodiments, the side surface of the second substrate is a slope inclined toward the battery layer.

A method for manufacturing a heterojunction solar cell provided by the present application includes: obtaining a silicon wafer with an amorphous silicon film layer deposited on the front and back; depositing TCO on the surface of the amorphous silicon film layer located on the front film layer; turn the silicon wafer 180 degrees, and cover the surface of the amorphous silicon film layer on the back side with a mask along the edge; wherein, the width of the mask is between 0.05 mm and 0.5 mm , including endpoint values; deposit a TCO film layer on the surface of the amorphous silicon film layer covered with the mask; make electrodes on the surface of the TCO film layer located at the front side and the back side respectively to obtain a heterojunction Solar battery.

It can be seen that in the heterojunction solar cell manufacturing method in this application, after obtaining the silicon wafer with the amorphous silicon film layer deposited on the front and back, first deposit the TCO film layer on the surface of the amorphous silicon film layer on the front side, and then turn it over The silicon wafer makes the back of the silicon wafer face up, covering the surface of the amorphous silicon film layer on the back with a mask along the edge, and depositing a TCO film layer on the surface of the amorphous silicon film layer on the back, and finally preparing the electrode, the shielding of the mask Realize the electrical isolation of the front and back TCO film layers, and at the same time make the symmetry and appearance of the heterojunction solar cells better, and the width of the mask is between 0.05mm and 0.5mm, and the shielding of the back amorphous silicon film layer The width is narrowed, and the area of the TCO film layer on the back is increased, thereby improving the efficiency of the heterojunction solar cell.

In addition, the present application also provides a method for manufacturing a heterojunction solar cell and a heterojunction photovoltaic module having the above-mentioned advantages.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the accompanying drawings that need to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are only For some embodiments of the present application, those of ordinary skill in the art can also obtain other drawings based on these drawings without creative effort.

FIG. 1 is a flow chart of a method for manufacturing a heterojunction solar cell provided in an embodiment of the present application;

FIG. 2 is a top view after covering the mask in the embodiment of the present application;

Fig. 3 is a flow chart of another method for manufacturing a heterojunction solar cell provided by the embodiment of the present application;

FIG. 4 is a schematic structural view of a heterojunction solar cell provided by the present application;

Fig. 5 is a schematic structural diagram of a heterojunction photovoltaic module provided by the present application.

Detailed ways

In order to enable those skilled in the art to better understand the solution of the present application, the present application will be further described in detail below in conjunction with the drawings and specific implementation methods. Apparently, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

In the following description, a lot of specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described here, and those skilled in the art can do it without departing from the meaning of the present invention. By analogy, the present invention is therefore not limited to the specific examples disclosed below.

As mentioned in the background technology section, physical vapor deposition is currently used to deposit the TCO film layer. The silicon wafer is placed in the pit of the hollow carrier, and the hollow carrier is placed in the PVD equipment. and TCO coating on the back. Since the silicon wafer is placed in the pit of the carrier board, the four edges of the back of the silicon wafer are covered by about 0.6mm and there is no TCO film layer. According to calculations, about 1.4% of the amorphous silicon film layer is not covered by the TCO film layer, resulting in The photogenerated carriers generated here cannot be effectively exported, and the theoretically calculated efficiency loss is about 0.34%.

The TCO film layer mainly includes oxides of In, Sb, Zn and Cd and their composite multi-element oxide film materials.

In view of this, the present application provides a method for manufacturing a heterojunction solar cell, please refer to FIG. 1 , which is a flow chart of a method for manufacturing a heterojunction solar cell provided in an embodiment of the present application. The method includes:

Step S101: Obtain a silicon wafer with amorphous silicon film layers deposited on both the front and back sides.

It should be noted that the front side of the silicon wafer is the light-facing side, and the back side is the backlight side.

Silicon wafers generally choose N-type silicon wafers. At this time, the amorphous silicon film layer on the front side includes the stacked intrinsic amorphous silicon film layer and the p-type amorphous silicon film layer, and the amorphous silicon film layer on the back includes the stacked intrinsic amorphous silicon film layer. An amorphous silicon film layer and an n-type amorphous silicon film layer.

Step S102: Depositing a TCO film layer on the surface of the amorphous silicon film layer located on the front side.

It should be pointed out that in this step, the TCO film layer is only deposited on the surface of the front amorphous silicon film layer. The TCO film layer on the surface of the amorphous silicon film layer on the front side can be deposited by physical vapor deposition.

Step S103: Flip the silicon wafer by 180 degrees, and cover the edge of the surface of the amorphous silicon film layer on the back with a mask; wherein, the width of the mask is between 0.05 mm and 0.5 mm , including the endpoint value.

As shown in FIG. 2, precise alignment is required when covering the mask. The outer edge of the mask 15 is aligned and coincident with the edge of the amorphous silicon film layer (ie, the n-type amorphous silicon film layer 7). The top view after covering the mask as shown in picture 2.

The mask is used for physical isolation and does not need to be removed. In this application, there is no specific limitation on the material of the mask, as long as it can play a role of isolation, for example, hard materials such as stainless steel can be used.

It should be pointed out that the width of the mask is not specifically limited in this application, and can be set by itself. For example, the width of the mask can be 0.08mm, 0.1mm, 0.15mm, 0.20mm, 0.25mm, 0.28mm, 0.30mm, 0.34mm, 0.37mm, 0.4mm, 0.45mm, 0.48mm, and so on.

For a silicon wafer with a side length of 158.75mm, the width of the mask can be 0.1mm, that is, the distance between the masks of the two opposite sides is 158.55mm; when the side length of the silicon wafer increases, for example, the silicon wafer The side lengths of the mask are 166mm and 210mm, and the width of the mask can be increased accordingly. When the side length of the silicon wafer is 158.75mm and the width of the mask is 0.1mm, the efficiency of the heterojunction solar cell can be increased by about 0.3% compared with the heterojunction solar cell produced by the current related technology.

The silicon wafer is turned over by 180 degrees. In step S102, the front side of the silicon wafer faces upward, and the back side of the silicon wafer faces upward after turning over. To improve efficiency, silicon wafers are flipped using a mechanical transfer device. Of course, manual flipping may also be used, which is not specifically limited in this application.

Step S104: Depositing a TCO film layer on the surface of the amorphous silicon film layer covered with the mask.

In this step, the TCO film layer can be deposited by physical vapor deposition.

Step S105: making electrodes on the surfaces of the TCO film layers located on the front side and the back side respectively to obtain a heterojunction solar cell.

Both the front electrode and the back electrode can use silver electrodes, and the electrodes can be printed by screen printing and cured.

In the manufacturing method of the heterojunction solar cell in this application, after obtaining the silicon wafer with the amorphous silicon film layer deposited on the front and back, first deposit the TCO film layer on the surface of the amorphous silicon film layer located on the front side, and then turn over the silicon wafer Make the back side of the silicon wafer face up, cover the surface of the amorphous silicon film layer on the back side with a mask along the edge, and deposit a TCO film layer on the surface of the amorphous silicon film layer on the back side, and finally prepare electrodes, and the shielding of the mask realizes the front side The electrical isolation from the TCO film layer on the back makes the symmetry and appearance of the heterojunction solar cell better, and the width of the mask is between 0.05mm and 0.5mm, and the shading width of the amorphous silicon film layer on the back becomes smaller. Narrow, increasing the area of the TCO film layer on the back, thereby improving the efficiency of heterojunction solar cells.

On the basis of the above-mentioned embodiments, in one embodiment of the present application, before obtaining the silicon wafer with the amorphous silicon film layer deposited on the front and the back, it also includes:

obtaining the wafer;

Depositing an intrinsic amorphous silicon film layer on the front side and the back side of the silicon wafer, respectively;

Depositing a p-type amorphous silicon film layer on the surface of the amorphous silicon film layer located on the front side;

An n-type amorphous silicon film layer is deposited on the surface of the amorphous silicon film layer located on the back side.

In this application, the method of depositing the intrinsic amorphous silicon film layer is not specifically limited, and can be selected by oneself. For example, the intrinsic amorphous silicon film layer can be deposited by physical vapor deposition, or plasma enhanced chemical vapor deposition, and so on.

The p-type amorphous silicon film layer and the n-type amorphous silicon film layer are respectively deposited a layer of intrinsic amorphous silicon film layer, and then respectively doped the intrinsic amorphous silicon film layer to obtain the corresponding p-type amorphous silicon film layer and n-type amorphous silicon film layer. The method of doping is not specifically limited in this application, for example, doping may be performed by diffusion or by ion implantation.

In order to improve the photoelectric conversion efficiency of the heterojunction solar cell, on the basis of the above-mentioned embodiments, in one embodiment of the present application, after the silicon wafer is obtained, it also includes:

The silicon wafer is subjected to double-sided texturing treatment.

It should be pointed out that after the double-sided texturing, the silicon wafer needs to be cleaned to remove the oil and impurities on the surface of the silicon wafer, and then the subsequent process is carried out.

Please refer to FIG. 3 . FIG. 3 is a flow chart of another method for manufacturing a heterojunction solar cell provided in an embodiment of the present application.

Step S201: obtaining the silicon wafer.

Step S202: performing double-sided texturing on the silicon wafer.

Step S203: Depositing an intrinsic amorphous silicon film layer on the front side and the back side of the silicon wafer respectively.

Step S204: depositing a p-type amorphous silicon film layer on the surface of the amorphous silicon film layer located on the front side.

Step S205: Depositing an n-type amorphous silicon film layer on the surface of the amorphous silicon film layer located on the back side.

Step S206: Depositing a TCO film layer on the surface of the amorphous silicon film layer located on the front side.

Step S207: Flip the silicon wafer by 180 degrees, and cover the edge of the surface of the amorphous silicon film layer on the back with a mask; wherein, the width of the mask is between 0.05 mm and 0.5 mm , including the endpoint value.

Step S208: Depositing a TCO film layer on the surface of the amorphous silicon film layer covered with the mask.

Step S209: making electrodes on the surfaces of the TCO film layers located on the front side and the back side respectively to obtain a heterojunction solar cell.

Step S210: Perform EL test and IV (current-voltage) curve test to screen out unqualified heterojunction solar cells.

EL (Electroluminescent, electroluminescent) test can detect abnormal phenomena such as internal defects, hidden cracks, fragments, virtual soldering, and broken gates of heterojunction solar cells. Qualified heterojunction solar cells, improve the quality of heterojunction solar cells, and package qualified heterojunction solar cells.

The present application also provides a heterojunction solar cell, please refer to FIG. 4. FIG. 4 is a schematic structural diagram of a heterojunction solar cell provided in the present application. The heterojunction solar cell manufacturing method described above is prepared, including a back electrode 9, a TCO film layer 8 on the back side, an n-type amorphous silicon film layer 7, an intrinsic amorphous silicon film layer 6 on the back side, a silicon wafer 1, and a front side Intrinsic amorphous silicon film layer 2 , p-type amorphous silicon film layer 3 , front TCO film layer 4 , and front electrode 5 .

The present application also provides a heterojunction photovoltaic module, as shown in FIG. The substrate 14, wherein the cell layer 12 includes a plurality of heterojunction solar cells connected in series and parallel in the above embodiments.

Optionally, as a specific embodiment, both the first adhesive film layer 11 and the second adhesive film layer 13 are EVA (Ethylene Vinyl Acetate Copolymer, ethylene-vinyl acetate copolymer) adhesive film layers. However, this application does not specifically limit it. As another specific implementation manner, the first adhesive film layer 11 and the second adhesive film layer 13 may both be POE adhesive film layers.

In order to improve the performance of the heterojunction photovoltaic module and reduce the probability of cracks in the adhesive film layer, the first adhesive film layer 11 can be an anti-crack adhesive film layer.

In this application, the type of the second substrate 14 is not specifically limited, and can be selected by oneself. For example, the second substrate 14 may be a plexiglass substrate, a tempered glass substrate, an ultra-clear patterned glass substrate or the like.

The type of the first substrate 10 depends on the type of the heterojunction photovoltaic module, for example, when the heterojunction photovoltaic module is a single glass module, the first substrate 10 is the back plate, and when the heterojunction photovoltaic module is a double glass module , the first substrate 10 is a glass substrate.

During transportation, multiple heterojunction photovoltaic modules will be stacked. Since the side of the second substrate is a vertical plane, it is very inconvenient to carry the heterojunction photovoltaic modules one by one. In order to facilitate transportation, the second substrate The side of the board is an inclined slope (inclines gradually approaching the center of the second substrate from top to bottom), and it is very convenient for the carrier to carry it by means of the inclined side.

Unless the context clearly dictates otherwise, the indefinite articles "a", "an" and "an" preceding an element or ingredient herein are intended to state a non-limiting quantity of said element or ingredient. Accordingly, "a", "an" and "an" should be read to include one or at least one, and singular forms of said elements or components also include plural forms.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same or similar parts of each embodiment can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and for the related information, please refer to the description of the method part.

The heterojunction solar cell and its manufacturing method, and the heterojunction photovoltaic module provided in the present application have been introduced in detail above. In this paper, specific examples are used to illustrate the principles and implementation methods of the present application, and the descriptions of the above embodiments are only used to help understand the methods and core ideas of the present application. It should be pointed out that those skilled in the art can make several improvements and modifications to the application without departing from the principle of the application, and these improvements and modifications also fall within the protection scope of the claims of the application.

Claims (11)

1. A method for manufacturing a heterojunction solar cell, comprising:

   Obtain a silicon wafer with an amorphous silicon film layer deposited on the front and back;

   Depositing a TCO film layer on the surface of the amorphous silicon film layer located on the front side;

   Turning the silicon wafer over 180 degrees, and covering the edge of the surface of the amorphous silicon film layer on the back side with a mask; wherein, the width of the mask is between 0.05 mm and 0.5 mm, including the endpoints value;

   Depositing a TCO film layer on the surface of the amorphous silicon film layer covered with the mask;

   Electrodes are respectively made on the surfaces of the TCO film layers located on the front side and the back side to obtain a heterojunction solar cell.
2. The method for manufacturing a heterojunction solar cell according to claim 1, further comprising:

   obtaining the wafer;

   Depositing an intrinsic amorphous silicon film layer on the front side and the back side of the silicon wafer, respectively;

   Depositing a p-type amorphous silicon film layer on the surface of the amorphous silicon film layer located on the front side;

   An n-type amorphous silicon film layer is deposited on the surface of the amorphous silicon film layer located on the back side.
3. The method for manufacturing a heterojunction solar cell according to claim 2, further comprising: after said obtaining said silicon wafer:

   The silicon wafer is subjected to double-sided texturing treatment.
4. The method for manufacturing a heterojunction solar cell according to any one of claims 1 to 3, further comprising:

   Perform EL test and IV curve test to screen out unqualified heterojunction solar cells.
5. A heterojunction solar cell, characterized in that the heterojunction solar cell is manufactured by the method for manufacturing a heterojunction solar cell according to any one of claims 1 to 4.
6. A heterojunction photovoltaic module, characterized in that it includes a first substrate, a first adhesive film layer, a battery layer, a second adhesive film layer, and a second substrate sequentially stacked from bottom to top, wherein the battery layer includes multiple The heterojunction solar cell as claimed in claim 5.
7. The heterojunction photovoltaic module according to claim 6, wherein the first adhesive film layer and the second adhesive film layer are both EVA adhesive film layers.
8. The heterojunction photovoltaic module according to claim 6, wherein the first adhesive film layer is an anti-crack adhesive film layer.
9. The heterojunction photovoltaic module according to claim 6, wherein the first substrate is a glass substrate.
10. The heterojunction photovoltaic module according to any one of claims 6 to 9, characterized in that, the side surface of the second substrate is inclined.
11. The heterojunction photovoltaic module according to claim 10, wherein the side surface of the second substrate gradually approaches the center of the second substrate from top to bottom.

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