阅读说明：本技术 一种双面发电异质结太阳能电池的制备方法及其叠瓦模组 (Preparation method of double-sided power generation heterojunction solar cell and tile-stacked module thereof ) 是由 林朝晖 王树林 杨与胜 温跃忠 张超华 于 2018-07-16 设计创作，主要内容包括：本发明公开了一种双面发电异质结太阳能电池的制备方法及其叠瓦模组,所述方法包括如下步骤：提供制绒清洗后的N型单晶硅片；在硅片背面依次沉积第一本征非晶硅薄膜层、第一掺杂非晶硅薄膜层；在硅片正面依次沉积第二本征非晶硅薄膜层、第二掺杂非晶硅薄膜层；在硅片正、背面分别沉积透明导电薄膜层；在硅片背面透明导电薄膜层上沉积金属叠层；在硅片正面透明导电薄膜层形成银浆电极栅线。本发明通过在硅片背面透明导电薄膜层上沉积电阻率低、成本低的金属叠层替代银浆印刷,大幅降低了电池成本,太阳能电池正背面通过导电胶相互重叠在一起实现串联,显著降低了传导电流,从而大幅降低功率损耗,提高吸光面积,进而提高了模组转换效率。(The invention discloses a preparation method of a double-sided power generation heterojunction solar cell and a tile-stacked module thereof, wherein the method comprises the following steps: providing an N-type monocrystalline silicon wafer after texturing and cleaning; depositing a first intrinsic amorphous silicon thin film layer and a first doped amorphous silicon thin film layer on the back of the silicon wafer in sequence; depositing a second intrinsic amorphous silicon thin film layer and a second doped amorphous silicon thin film layer on the front surface of the silicon wafer in sequence; depositing transparent conductive thin film layers on the front and back surfaces of the silicon wafer respectively; depositing a metal lamination on the transparent conductive film layer on the back surface of the silicon wafer; and forming a silver paste electrode grid line on the transparent conductive film layer on the front surface of the silicon wafer. According to the invention, silver paste printing is replaced by depositing the metal lamination with low resistivity and low cost on the transparent conductive film layer on the back surface of the silicon wafer, so that the cost of the solar cell is greatly reduced, and the front surface and the back surface of the solar cell are mutually overlapped through the conductive adhesive to realize series connection, so that the conduction current is obviously reduced, the power loss is greatly reduced, the light absorption area is increased, and the conversion efficiency of the module is further improved.)

1. A preparation method of a double-sided power generation heterojunction solar cell is characterized by comprising the following steps: the method comprises the following steps:

providing an N-type monocrystalline silicon wafer after texturing and cleaning;

depositing a first intrinsic amorphous silicon thin film layer and a first doped amorphous silicon thin film layer on the back of the silicon wafer in sequence;

depositing a second intrinsic amorphous silicon thin film layer and a second doped amorphous silicon thin film layer on the front surface of the silicon wafer in sequence;

depositing transparent conductive thin film layers on the front and back surfaces of the silicon wafer respectively;

depositing a metal lamination on the transparent conductive film layer on the back surface of the silicon wafer;

and forming a silver paste electrode grid line on the transparent conductive film layer on the front surface of the silicon wafer.

2. The method for manufacturing a double-sided power generation heterojunction solar cell according to claim 1, wherein: the first intrinsic amorphous silicon thin film layer, the first doped amorphous silicon thin film layer, the second intrinsic amorphous silicon thin film layer and the second doped amorphous silicon thin film layer are subjected to plasma enhanced chemical vapor deposition, the thickness of the first intrinsic amorphous silicon thin film layer is 3-10 nm, and the thickness of the first doped amorphous silicon thin film layer is 3-10 nm; the thickness of the second intrinsic amorphous silicon thin film layer is 3-10 nm, and the thickness of the second doped amorphous silicon thin film layer is 3-10 nm.

3. The method for manufacturing a double-sided power generation heterojunction solar cell according to claim 1, wherein: when the first doped amorphous silicon thin film layer is an n-type amorphous silicon thin film layer, the second doped amorphous silicon thin film layer is a p-type amorphous silicon thin film layer; and when the first doped amorphous silicon thin film layer is a p-type amorphous silicon thin film layer, the second doped amorphous silicon thin film layer is an n-type amorphous silicon thin film layer.

4. The method for manufacturing a double-sided power generation heterojunction solar cell according to claim 1, wherein: the transparent conductive thin film layer is an ITO layer or an indium oxide layer doped with other elements, and the thickness of the transparent conductive thin film layer is 30-200 nm.

5. The method for manufacturing a double-sided power generation heterojunction solar cell according to claim 1, wherein: the metal lamination layer is 100-1000 nm in thickness and has a sheet resistance smaller than 0.1 omega/□, the metal lamination layer comprises a metal conducting layer and a metal protection layer, wherein the metal conducting layer is at least one of Cu, Al, Ag and Ni, and the metal protection layer is an oxidation-resistant metal material or a metal conducting oxide material.

6. The method for manufacturing a double-sided power generation heterojunction solar cell according to claim 1, wherein: the transparent conductive film layer and the metal lamination layer are deposited in a magnetron sputtering or evaporation mode.

7. The method for manufacturing a double-sided power generation heterojunction solar cell according to claim 1, wherein: the pattern of the metal lamination is composed of 3-5 groups of fine grids, each group of fine grids is composed of 30-300 fine grids, one end of each group of fine grids can be provided with or without a main grid, the width of each fine grid is 0.5-5 mm, the distance between the fine grids is 0.5-5 mm, the width of each main grid is 1-5 mm, the metal lamination pattern is formed through a MASK MASK during deposition or through a printing protection layer wet etching mode, and the metal lamination occupies no more than 50% of the area of the battery.

8. The method for manufacturing a double-sided power generation heterojunction solar cell according to claim 1, wherein: the pattern of the silver paste electrode grid line is composed of 3-5 groups of fine grids, the width of each fine grid is 0.03-0.1 mm, the distance between the fine grids is 1-3 mm, and the silver paste electrode grid line is formed in a screen printing mode.

9. A tiled module employing the double-sided power generating heterojunction solar cell of claim 1, wherein: the solar cell comprises a back plate body, first packaging adhesive arranged on the back plate body, at least one solar cell which is formed by cutting the silicon wafer in an equal division manner according to claim 1 and arranged on the first packaging adhesive, wherein the equal division cutting manner is consistent with the grouping quantity of fine grids with electrode grid line patterns, the front surface and the back surface of the solar cell are overlapped together through conductive adhesive to realize series connection, second packaging adhesive is arranged on the solar cell, the first packaging adhesive and the second packaging adhesive are coated on the periphery of the solar cell, and a front plate body arranged on the second packaging adhesive is arranged.

10. The tiled module of bifacial power generating heterojunction solar cells of claim 9, wherein: the overlapping width of the mutually overlapped solar cells is 0.5-3 mm.

Technical Field

The invention relates to the technical field of solar cells, in particular to a preparation method of a double-sided power generation heterojunction solar cell and a tile-stacked module thereof.

Background

The solar cell is a semiconductor device which can convert solar energy into electric energy, and photo-generated current is generated in the solar cell under the illumination condition, and the electric energy is output through an electrode. In recent years, solar cell production technology is continuously improved, production cost is continuously reduced, conversion efficiency is continuously improved, and solar cell power generation is increasingly widely applied and becomes an important energy source for power supply.

The heterojunction solar cell is a novel efficient cell technology, integrates the advantages of the monocrystalline silicon solar cell and the amorphous silicon solar cell, and has the characteristics of low preparation process temperature, higher conversion efficiency, good high-temperature characteristic and the like, so that the heterojunction solar cell has great market potential.

The basic structure of the existing heterojunction solar cell is as follows: depositing an intrinsic amorphous silicon layer on the front and back surfaces of the N-type monocrystalline silicon wafer; depositing a p-type amorphous silicon layer and an n-type amorphous silicon layer on the surfaces of the intrinsic amorphous silicon layers on the front surface and the back surface respectively; depositing a conductive film on the front surface and the back surface of the battery; and manufacturing silver gate electrodes on the front and back surfaces of the battery. The corresponding heterojunction solar cell module is connected in series by adopting a solder strip, and then is laminated with the packaging adhesive and the front back plate body to form the module.

However, the silver paste printed on the back of the heterojunction solar cell is very large in amount and extremely high in cost, and the resistance of the welding strip introduced by the module formed by welding in series can cause great power loss, so that the production cost of the cell is remarkably increased, and the efficiency of the module is reduced.

Disclosure of Invention

Aiming at the problems, the invention provides a preparation method of a double-sided power generation monocrystalline silicon heterojunction solar cell and a tiling module thereof, aiming at reducing the use amount of silver paste in the existing heterojunction solar cell and reducing the power loss after the module is manufactured, finally realizing the reduction of the production cost and improving the conversion efficiency of the module.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a preparation method of a double-sided power generation heterojunction solar cell comprises the following steps:

providing an N-type monocrystalline silicon wafer after texturing and cleaning;

depositing a first intrinsic amorphous silicon thin film layer and a first doped amorphous silicon thin film layer on the back of the silicon wafer in sequence;

turning over the silicon wafer, and depositing a second intrinsic amorphous silicon thin film layer and a second doped amorphous silicon thin film layer on the front surface of the silicon wafer in sequence;

depositing transparent conductive thin film layers on the front and back surfaces of the silicon wafer respectively;

depositing a metal lamination on the transparent conductive film layer on the back surface of the silicon wafer;

and forming a silver paste electrode grid line on the transparent conductive film layer on the front surface of the silicon wafer.

Further, the first intrinsic amorphous silicon thin film layer, the first doped amorphous silicon thin film layer, the second intrinsic amorphous silicon thin film layer and the second doped amorphous silicon thin film layer are subjected to plasma enhanced chemical vapor deposition, the thickness of the first intrinsic amorphous silicon thin film layer is 3-10 nm, and the thickness of the first doped amorphous silicon thin film layer is 3-10 nm; the thickness of the second intrinsic amorphous silicon thin film layer is 3-10 nm, and the thickness of the second doped amorphous silicon thin film layer is 3-10 nm.

Further, when the first doped amorphous silicon thin film layer is an n-type amorphous silicon thin film layer, the second doped amorphous silicon thin film layer is a p-type amorphous silicon thin film layer; and when the first doped amorphous silicon thin film layer is a p-type amorphous silicon thin film layer, the second doped amorphous silicon thin film layer is an n-type amorphous silicon thin film layer.

Further, the transparent conductive thin film layer is an ITO layer or an indium oxide layer doped with other elements, and the thickness of the transparent conductive thin film layer is 30-200 nm.

Further, the thickness of the metal lamination is 100-1000 nm, the sheet resistance is less than 0.1 omega/□, the metal lamination comprises a metal conducting layer and a metal protection layer, wherein the metal conducting layer is at least one of Cu, Al, Ag and Ni, and the metal protection layer is an oxidation-resistant metal material or a metal conducting oxide material.

Further, the transparent conductive film layer and the metal lamination layer are deposited in a magnetron sputtering or evaporation mode.

Furthermore, the pattern of the metal lamination is composed of 3-5 groups of fine grids, each group of fine grids is composed of 30-300 fine grids, one end of each group of fine grids can be provided with or without a main grid, the width of each fine grid is 0.5-5 mm, the distance between the fine grids is 0.5-5 mm, the width of each main grid is 1-5 mm, the metal lamination pattern is formed through a MASK MASK or a printing protection layer wet etching mode during deposition, and the area of the metal lamination does not exceed 50%.

Furthermore, the pattern of the silver paste electrode grid line consists of 3-5 groups of fine grids, the width of each fine grid is 0.03-0.1 mm, the distance between the fine grids is 1-3 mm, and the silver paste electrode grid line is formed in a screen printing mode.

A double-sided power generation heterojunction solar cell's stack tile module, includes the backplate body, establishes the first packaging glue on the backplate body, establishes at least one solar cell after the many divisions of silicon chip as in claim 1 on the first packaging glue, many divisions cutting mode is unanimous with its fine grid grouping quantity of electrode grid line pattern, the positive back of solar cell overlaps mutually through conductive adhesive and together realizes establishing ties, establishes the second packaging glue on solar cell, first, second packaging glue cladding is around this solar cell to and establish the preceding plate body on the second packaging glue.

Further, the overlapping width of the mutually overlapped solar cells is 0.5-3 mm.

From the above description of the structure of the present invention, compared with the prior art, the present invention has the following advantages:

according to the invention, silver paste printing is replaced by depositing the metal lamination with low resistivity and low cost on the transparent conductive thin film layer on the back surface of the silicon wafer, so that the cost of the cell is greatly reduced, meanwhile, the solar cell is cut into a plurality of small cells, and then the front and back surfaces of a plurality of solar cells are mutually overlapped through conductive adhesive to realize series connection, so that the conduction current is obviously reduced, and the gaps among the solar cells are eliminated, so that the power loss is greatly reduced, the light absorption area is improved, and the conversion efficiency of the module is further improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a flow chart of a method of fabricating a double-sided power generation heterojunction solar cell of the present invention;

FIG. 2 is a schematic structural diagram of an amorphous silicon layer deposited by chemical vapor deposition according to the present invention;

FIG. 3 is a schematic structural diagram of the present invention after depositing a transparent conductive film by magnetron sputtering or evaporation;

FIG. 4 is a schematic diagram of a structure of the present invention after depositing a metal stack by using MASK MASK in magnetron sputtering or evaporation;

FIG. 5 is a schematic diagram of a metal layer pattern structure on the back side of a battery according to the present invention;

FIG. 6 is a schematic structural diagram of the front side of the battery of the invention after silver paste grid line electrodes are formed by screen printing;

FIG. 7 is a schematic diagram of a pattern structure of a silver paste grid line on the front side of a battery according to the present invention;

FIG. 8 is a schematic diagram of a cell of the present invention after laser cutting of three equal parts;

FIG. 9 is a schematic side view of a plurality of solar cells stacked together and connected in series by conductive adhesive after laser cutting according to the present invention;

fig. 10 and 11 are schematic plane structures of a plurality of solar cells stacked together and connected in series by conductive adhesive after laser cutting according to the present invention;

FIG. 12 is a schematic diagram of a module structure according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.