Heterojunction cell and photovoltaic module

Abstract

The utility model relates to a heterojunction cell and a photovoltaic assembly. The heterojunction battery comprises a silicon heterojunction main body, a first transparent conductive layer, a second transparent conductive layer, a first grid line and a second grid line, the first transparent conductive layer and the second transparent conductive layer are arranged on the two sides of the silicon heterojunction main body, and the first grid line and the second grid line are arranged on the sides, away from the silicon heterojunction main body, of the first transparent conductive layer and the second transparent conductive layer respectively; the first transparent conductive layer comprises a first columnar crystal transparent conductive pattern and a first equiaxed crystal transparent conductive pattern which are connected, and the first columnar crystal transparent conductive pattern is in ohmic contact with the first grid line. Transparent conductive patterns with different grain sizes are combined, the conductive advantages of a first equiaxed crystal transparent conductive pattern and a first columnar crystal transparent conductive pattern in different directions are exerted, the resistance loss is reduced, and the first columnar crystal transparent conductive pattern is in ohmic contact with a first grid line, so that the resistance loss is reduced. Therefore, the first grid line is stably attached to the first columnar crystal transparent conductive pattern.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic systems, in particular to a heterojunction battery and a photovoltaic module. Background Art

[0002] With the development of the photovoltaic industry, heterojunction (HJT) solar cells have become a hot topic in the photovoltaic industry. The highest efficiency of HJT has reached 26.81%. Compared with other high-efficiency solar cells, HJT cells require transparent conductive oxide (TCO) films to obtain sufficient carrier transmission. TCO mainly has equiaxed grains with large grain size. Although it has good lateral conductivity and is resistant to moisture and heat, its surface is relatively smooth, which is not conducive to the attachment of the grid line, affecting the stability of the heterojunction cell. Utility Model Content

[0003] Based on this, it is necessary to provide a heterojunction battery to address the technical problem that TCO in the prior art mainly has equiaxed grains with larger grain sizes. Although it has good lateral conductivity and is resistant to moisture and heat, its surface is relatively smooth, which is not conducive to the attachment of the grid line and affects the stability of the heterojunction battery.

[0004] A heterojunction battery comprises a silicon heterojunction body, a first transparent conductive layer, a second transparent conductive layer, a first gate line and a second gate line; the first transparent conductive layer and the second transparent conductive layer are arranged on two opposite sides of the silicon heterojunction body, the first gate line is arranged on a side of the first transparent conductive layer away from the silicon heterojunction body, and the second gate line is arranged on a side of the second transparent conductive layer away from the silicon heterojunction body; the first transparent conductive layer comprises a first columnar crystal transparent conductive pattern and a first equiaxed crystal transparent conductive pattern connected to each other, and the first columnar crystal transparent conductive pattern is in ohmic contact with the first gate line.

[0005] In one embodiment, the first equiaxed crystal transparent conductive pattern is provided with a hollow portion, and the first columnar crystal transparent conductive pattern is at least partially filled in the hollow portion.

[0006] In one embodiment, the first columnar crystal transparent conductive pattern includes a first portion and a second portion connected to each other, the first portion is filled in the hollow portion and is in ohmic contact with the first gate line, and the second portion is arranged on a side of the first equiaxed crystal transparent conductive pattern away from the first gate line.

[0007] In one embodiment, the first columnar crystal transparent conductive pattern is completely filled in the hollow portion.

[0008] In one of the embodiments, in the arrangement direction of the first transparent conductive layer and the second transparent conductive layer, the first equiaxed crystal transparent conductive pattern and the first gate line are staggered.

[0009] In one embodiment, the second transparent conductive layer includes a second columnar crystal transparent conductive pattern and a second equiaxed crystal transparent conductive pattern connected to each other, and the second columnar crystal transparent conductive pattern is in ohmic contact with the second gate line.

[0010] In one embodiment, the thickness of the first transparent conductive layer is 10-200 nm; and / or the thickness of the second transparent conductive layer is 10-200 nm.

[0011] In one embodiment, the silicon heterojunction body includes a substrate, a first intrinsic layer and a first doped layer sequentially stacked on a first surface of the substrate, and a second intrinsic layer and a second doped layer sequentially stacked on a second surface of the substrate;

[0012] The first transparent conductive layer is disposed on a surface of the first doped layer away from the substrate; the second transparent conductive layer is disposed on a surface of the second doped layer away from the substrate;

[0013] The doping type of the first doping layer is opposite to the doping type of the second doping layer.

[0014] In one embodiment, the thickness of the first intrinsic layer and the second intrinsic layer is 3-30 nm; and / or the thickness of the first doped layer and the second doped layer is 5-50 nm.

[0015] The utility model also provides a photovoltaic component, which can solve at least one of the above technical problems.

[0016] A photovoltaic module comprises the above-mentioned heterojunction battery.

[0017] Beneficial effects:

[0018] The heterojunction battery provided by the embodiment of the utility model includes a silicon heterojunction body, a first transparent conductive layer, a second transparent conductive layer, a first gate line and a second gate line; the first transparent conductive layer and the second transparent conductive layer are arranged on two opposite sides of the silicon heterojunction body, the first gate line is arranged on the side of the first transparent conductive layer away from the silicon heterojunction body, and the second gate line is arranged on the side of the second transparent conductive layer away from the silicon heterojunction body; the first transparent conductive layer includes a first columnar crystal transparent conductive pattern and a first equiaxed crystal transparent conductive pattern connected to each other, and the first columnar crystal transparent conductive pattern is in ohmic contact with the first gate line. The first equiaxed crystal transparent conductive pattern has a larger grain size and has better lateral conductivity, the first columnar crystal transparent conductive pattern has a smaller grain size and has better vertical conductivity, and the surface of the first columnar crystal transparent conductive pattern is rougher. In the present application, by combining transparent conductive patterns with different grain sizes, the conductive advantages of the first equiaxed crystal transparent conductive pattern and the first columnar crystal transparent conductive pattern in different directions are fully utilized to reduce the resistance loss of the battery, and the first columnar crystal transparent conductive pattern is in ohmic contact with the first grid line, so that the first grid line can be stably attached to the first columnar crystal transparent conductive pattern, thereby improving the stability of the heterojunction battery.

[0019] The utility model also provides a photovoltaic component, including the above-mentioned heterojunction battery, and the heterojunction battery can achieve at least one of the above-mentioned technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a cross-sectional view of a heterojunction battery provided in accordance with an embodiment of the present invention.

[0021] FIG2 is a cross-sectional view of a heterojunction battery provided by another embodiment of the present invention.

[0022] FIG3 is a cross-sectional view of a heterojunction battery provided in yet another embodiment of the present invention.

[0023] Figure Number:

[0024] 100-silicon heterojunction body; 110-substrate; 120-first intrinsic layer; 130-first doped layer; 140-second intrinsic layer; 150-second doped layer; 200-first transparent conductive layer; 210-first columnar crystal transparent conductive pattern; 211-first part; 212-second part; 220-first equiaxed crystal transparent conductive pattern; 230-hollow part; 300-second transparent conductive layer; 310-second columnar crystal transparent conductive pattern; 320-second equiaxed crystal transparent conductive pattern; 400-first gate line; 500-second gate line. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0028] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0030] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0031] Referring to FIG. 1 , FIG. 1 shows a cross-sectional view of a heterojunction battery in an embodiment of the present invention. The heterojunction battery provided in an embodiment of the present invention includes a silicon heterojunction body 100, a first transparent conductive layer 200, a second transparent conductive layer 300, a first gate line 400 and a second gate line 500; the first transparent conductive layer 200 and the second transparent conductive layer 300 are arranged on opposite sides of the silicon heterojunction body 100, the first gate line 400 is arranged on a side of the first transparent conductive layer 200 away from the silicon heterojunction body 100, and the second gate line 500 is arranged on a side of the second transparent conductive layer 300 away from the silicon heterojunction body 100; the first transparent conductive layer 200 includes a first columnar crystal transparent conductive pattern 210 and a first equiaxed crystal transparent conductive pattern 220 connected to each other, and the first columnar crystal transparent conductive pattern 210 is in ohmic contact with the first gate line 400.

[0032] Specifically, the first equiaxed crystal transparent conductive pattern 220 has a larger grain size and has better lateral conductivity, the first columnar crystal transparent conductive pattern 210 has a smaller grain size and has better vertical conductivity, and the surface of the first columnar crystal transparent conductive pattern 210 is rougher. In the present application, by combining transparent conductive patterns with different grain sizes, the conductive advantages of the first equiaxed crystal transparent conductive pattern 220 and the first columnar crystal transparent conductive pattern 210 in different directions are fully utilized to reduce the resistance loss of the battery, and the first columnar crystal transparent conductive pattern 210 is in ohmic contact with the first grid line 400, so that the first grid line 400 can be stably attached to the first columnar crystal transparent conductive pattern 210, thereby improving the stability of the heterojunction battery.

[0033] In this embodiment, the conductive dominant direction of the first equiaxed crystal transparent conductive pattern 220 is perpendicular to the conductive dominant direction of the first columnar crystal transparent conductive pattern 210. Preferably, the conductive dominant direction of the first equiaxed crystal transparent conductive pattern 220 is perpendicular to the arrangement direction of the first transparent conductive layer 200 and the second transparent conductive layer 300. The conductive dominant direction of the first columnar crystal transparent conductive pattern 210 is parallel to the arrangement direction of the first transparent conductive layer 200 and the second transparent conductive layer 300.

[0034] It should be noted that the first transparent conductive layer 200 in the present embodiment is a transparent conductive oxide (TCO). Considering the crystal structure of TCO, the current TCO mainly has equiaxed grains with larger grain size, which have better lateral conductivity and are resistant to moisture and heat, but the surface is relatively smooth, which is not conducive to the attachment of the gate line. The second is columnar grains with smaller grain size. Due to the small grain size and more grain boundaries, the lateral conductivity is poor and not resistant to moisture and heat, but it has excellent vertical conductivity, and the columnar crystal is characterized by a rough surface, which can increase the adhesion of the gate line. That is, the material of the first equiaxed crystal transparent conductive pattern 220 in the present application is equiaxed crystal TCO, and the material of the first columnar crystal transparent conductive pattern 210 is the first columnar crystal transparent conductive pattern 210. In the present application, by combining different grain TCOs, the conductivity advantages of columnar crystal TCO and equiaxed crystal TCO in different directions and the adhesion advantages with the gate line are fully utilized, the resistance loss of the battery is reduced, and the performance of the heterojunction battery is improved.

[0035] Referring to Figures 1 and 2, Figure 2 is a cross-sectional view of a heterojunction battery provided by another embodiment of the present invention. In one embodiment, the first equiaxed crystal transparent conductive pattern 220 has a hollow portion 230, and the first columnar crystal transparent conductive pattern 210 is at least partially filled in the hollow portion 230.

[0036] Specifically, the hollow portion 230 is arranged in the area corresponding to the first grid line 400, and the first columnar crystal transparent conductive pattern 210 is at least partially filled in the hollow portion 230, so that the first grid line 400 is stably attached to the first columnar crystal transparent conductive pattern 210, thereby improving the reliability of the heterojunction battery. Among them, the part outside the hollow area is provided with the first equiaxed crystal transparent conductive pattern 220, and the first equiaxed crystal transparent conductive pattern 220 has good lateral conductivity and waterproofness, so that the heterojunction battery has excellent lateral conductivity and longitudinal conductivity, and can also give play to the waterproof performance of the first equiaxed crystal transparent conductive pattern 220, thereby improving the service life of the heterojunction battery.

[0037] In other embodiments, the first transparent conductive layer 200 may also include a first equiaxed transparent conductive pattern 220 and a first columnar transparent conductive pattern 210 arranged in layers, and the first equiaxed transparent conductive pattern 220 is arranged on a side of the first columnar transparent conductive pattern 210 away from the first gate line 400 .

[0038] Referring to FIG. 1 , in one embodiment, the first columnar crystal transparent conductive pattern 210 is completely filled in the hollow portion 230 .

[0039] Referring to FIG. 1 , in one embodiment, in the arrangement direction of the first transparent conductive layer 200 and the second transparent conductive layer 300, the first equiaxed crystal transparent conductive pattern 220 and the first gate line 400 are staggered, so that the first gate line 400 is completely in ohmic contact with the first columnar crystal transparent conductive pattern 210, thereby improving the stability of the ohmic contact between the first gate line 400 and the first transparent conductive layer 200. Preferably, the size of the hollow portion 230 is adapted to that of the first gate line 400.

[0040] Referring to FIG. 2 , in another embodiment, the first columnar crystal transparent conductive pattern 210 includes a first portion 211 and a second portion 212 connected to each other, the first portion 211 is filled in the hollow portion 230 and is in ohmic contact with the first gate line 400, and the second portion 212 is arranged on the side of the first equiaxed crystal transparent conductive pattern 220 away from the first gate line 400, that is, the first columnar crystal transparent conductive pattern 210 is laid on a plane perpendicular to the arrangement direction of the first transparent conductive layer 200 and the second transparent conductive layer 300, and the first columnar crystal transparent conductive pattern 210 has good vertical conductivity, thereby improving the conductive performance of the first transparent conductive layer 200 in the vertical direction.

[0041] Refer to Figure 3, which is a cross-sectional view of a heterojunction battery provided by another embodiment of the utility model. In one embodiment, the second transparent conductive layer 300 includes a second columnar crystal transparent conductive pattern 310 and a second equiaxed crystal transparent conductive pattern 320 connected to each other, and the second columnar crystal transparent conductive pattern 310 is in ohmic contact with the second grid line 500, so as to give full play to the conductive advantages of the second equiaxed crystal transparent conductive pattern 320 and the second columnar crystal transparent conductive pattern 310 in different directions, reduce the resistance loss of the battery, and through the second columnar crystal transparent conductive pattern 310 and the second grid line 500 ohmic contact, the second grid line 500 can be stably attached to the second columnar crystal transparent conductive pattern 310, thereby improving the stability of the heterojunction battery.

[0042] Furthermore, the second transparent conductive layer 300 has the same structure as the first transparent conductive layer 200 .

[0043] In one embodiment, the thickness of the first transparent conductive layer 200 is 10-200 nm. In one embodiment, the thickness of the second transparent conductive layer 300 is 10-200 nm. Preferably, the first transparent conductive layer 200 and the second transparent conductive layer 300 have the same thickness.

[0044] Referring to FIG. 1 , FIG. 2 and FIG. 3 , in one embodiment, a silicon heterojunction body 100 includes a substrate 110, a first intrinsic layer 120 and a first doped layer 130 stacked sequentially on a first surface of the substrate 110, and a second intrinsic layer 140 and a second doped layer 150 stacked sequentially on a second surface of the substrate 110; a first transparent conductive layer 200 is disposed on a surface of the first doped layer 130 away from the substrate 110; a second transparent conductive layer 300 is disposed on a surface of the second doped layer 150 away from the substrate 110; and the doping type of the first doped layer 130 is opposite to the doping type of the second doped layer 150. The first intrinsic layer 120 and the second intrinsic layer 140 are intrinsic amorphous silicon.

[0045] 1 , 2 and 3 , in one embodiment, the thickness of the first intrinsic layer 120 and the second intrinsic layer 140 is 3-30 nm. In one embodiment, the thickness of the first doping layer 130 and the second doping layer 150 is 5-50 nm.

[0046] Furthermore, the first doping layer 130 and the second doping layer 150 are stacked layers of one or more of N-type or P-type doped amorphous / nanocrystalline / microcrystalline silicon, amorphous / nanocrystalline / microcrystalline silicon oxide, and amorphous / nanocrystalline / microcrystalline silicon carbide.

[0047] The embodiment of the utility model also provides a photovoltaic module, including the above-mentioned heterojunction battery. In the present application, by combining transparent conductive patterns with different grain sizes, the conductive advantages of the first equiaxed crystal transparent conductive pattern 220 and the first columnar crystal transparent conductive pattern 210 in different directions are fully utilized to reduce the resistance loss of the battery, and the first columnar crystal transparent conductive pattern 210 is in ohmic contact with the first grid line 400, so that the first grid line 400 can be stably attached to the first columnar crystal transparent conductive pattern 210, thereby improving the stability of the photovoltaic module.

[0048] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A heterojunction battery, characterized in that: The heterojunction battery includes a silicon heterojunction body, a first transparent conductive layer, a second transparent conductive layer, a first gate line and a second gate line; the first transparent conductive layer and the second transparent conductive layer are arranged on opposite sides of the silicon heterojunction body, the first gate line is arranged on a side of the first transparent conductive layer away from the silicon heterojunction body, and the second gate line is arranged on a side of the second transparent conductive layer away from the silicon heterojunction body; the first transparent conductive layer includes a first columnar crystal transparent conductive pattern and a first equiaxed crystal transparent conductive pattern connected to each other, and the first columnar crystal transparent conductive pattern is in ohmic contact with the first gate line.

2. The heterojunction battery according to claim 1, characterized in that: The first equiaxed crystal transparent conductive pattern is provided with a hollow portion, and the first columnar crystal transparent conductive pattern is at least partially filled in the hollow portion.

3. The heterojunction battery according to claim 2, characterized in that: The first columnar crystal transparent conductive pattern includes a first portion and a second portion connected to each other, the first portion is filled in the hollow portion and is in ohmic contact with the first gate line, and the second portion is arranged on a side of the first equiaxed crystal transparent conductive pattern away from the first gate line.

4. The heterojunction battery according to claim 2, characterized in that: The first columnar crystal transparent conductive pattern is completely filled in the hollow portion.

5. The heterojunction battery according to claim 2, characterized in that: In the arrangement direction of the first transparent conductive layer and the second transparent conductive layer, the first equiaxed transparent conductive pattern and the first gate line are staggered.

6. The heterojunction battery according to any one of claims 1 to 5, characterized in that: The second transparent conductive layer includes a second columnar crystal transparent conductive pattern and a second equiaxed crystal transparent conductive pattern connected to each other, and the second columnar crystal transparent conductive pattern is in ohmic contact with the second gate line.

7. The heterojunction battery according to any one of claims 1 to 5, characterized in that: The thickness of the first transparent conductive layer is 10-200 nm; and / or the thickness of the second transparent conductive layer is 10-200 nm.

8. The heterojunction battery according to any one of claims 1 to 5, characterized in that: The silicon heterojunction body comprises a substrate, a first intrinsic layer and a first doping layer sequentially stacked on a first surface of the substrate, and a second intrinsic layer and a second doping layer sequentially stacked on a second surface of the substrate; The first transparent conductive layer is disposed on a surface of the first doped layer away from the substrate; The second transparent conductive layer is disposed on a surface of the second doped layer away from the substrate; The doping type of the first doping layer is opposite to the doping type of the second doping layer.

9. The heterojunction battery according to claim 8, characterized in that: The thickness of the first intrinsic layer and the second intrinsic layer is 3-30 nm; and / or the thickness of the first doped layer and the second doped layer is 5-50 nm.

10. A photovoltaic module, characterized in that: A heterojunction battery comprising any one of claims 1 to 9.

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