阅读说明：本技术 太阳能电池片及光伏组件 (Solar cell and photovoltaic module ) 是由 刘志强 严健 杨均炎 费正洪 于 2018-07-23 设计创作，主要内容包括：本发明提供了一种太阳能电池片,包括至少一条主栅线；若干条副栅线,其沿所述太阳能电池片中心向外依次分布,且在任意三条依次分布的副栅线中,位于中间的副栅线距离其内侧的副栅线的距离小于其距离外侧的副栅线的距离；因此太阳能电池片中心区域的副栅线的分布密度大于边缘区域的副栅线的分布密度,中心区域的外电阻小于边缘区域的外电阻；从而使得中心区域的串联电阻与边缘区域的串联电阻差距较小或无差距的太阳能电池片。(The invention provides a solar cell, which comprises at least one main grid line; the auxiliary grid lines are distributed outwards in sequence along the center of the solar cell piece, and in any three sequentially distributed auxiliary grid lines, the distance from the auxiliary grid line in the middle to the auxiliary grid line on the inner side of the auxiliary grid line is smaller than the distance from the auxiliary grid line on the outer side of the auxiliary grid line; therefore, the distribution density of the secondary grid lines in the central region of the solar cell is greater than that of the secondary grid lines in the edge region, and the external resistance of the central region is less than that of the edge region; therefore, the difference between the series resistance of the central area and the series resistance of the edge area is small or zero.)

1. A solar cell is characterized in that: comprises that

At least one main gate line;

and the auxiliary grid lines are distributed outwards in sequence along the center of the solar cell piece, and in any three sequentially distributed auxiliary grid lines, the distance from the auxiliary grid line positioned in the middle to the auxiliary grid line positioned on the inner side of the auxiliary grid line is smaller than the distance from the auxiliary grid line positioned on the outer side of the auxiliary grid line.

2. The solar cell sheet according to claim 1, wherein: the distance between the middle secondary grid line and the inner secondary grid line is (a + nb) mm, the distance between the middle secondary grid line and the outer secondary grid line is (a + nb + b) mm, and n is an integer greater than or equal to 0.

3. The solar cell sheet according to claim 2, wherein: a is between 1mm and 2 mm.

4. The solar cell sheet according to claim 2, wherein: b is between 1mm and 2 mm.

5. The solar cell sheet according to claim 1, wherein: the plurality of auxiliary grid lines are arc-shaped, the centers of the solar cells are used as arc centers, a space is formed between every two adjacent auxiliary grid lines, and the spaces are gradually increased from inside to outside, so that the distribution density of the auxiliary grid lines on the surfaces of the solar cells is gradually reduced from inside to outside.

6. The solar cell sheet according to claim 5, wherein: several of the pitches increase by the same dimension with each increment.

7. The solar cell sheet according to any one of claims 1 to 6, wherein: the auxiliary grid line is a closed annular grid line and/or a semi-annular grid line.

8. The solar cell sheet according to claim 7, wherein: the solar cell comprises at least one main grid line penetrating through the center of the solar cell.

9. The solar cell sheet according to claim 7, wherein: the solar cell comprises at least two parallel main grid lines, and at least one main grid line penetrates through the center of the solar cell.

10. A photovoltaic module, characterized by: comprising a solar cell sheet according to any of claims 1 to 9.

Technical Field

The invention relates to the field of photovoltaics, in particular to a solar cell and a photovoltaic module, wherein the difference between the series resistance of a central area and the series resistance of an edge area is small or has no difference.

Background

In the existing solar cell, a PN junction is usually formed by diffusion on a silicon wafer, and then a main grid line and a plurality of parallel and equidistant sub-grid lines are screen-printed.

Due to diffusion, after a PN junction is formed, the square resistance in the middle of the silicon wafer is large, the square resistance at the edge is small, and the square resistance can be called as internal resistance; the distances among the existing grid line structures are consistent, and the external resistances are consistent; the sum of the internal resistance and the external resistance forms the series resistance of the battery piece. Therefore, the existing grid line structure has large middle series resistance and small periphery series resistance on the whole silicon chip.

In view of the above, there is a need for an improved solar cell and photovoltaic module to solve the above problems.

Disclosure of Invention

The invention aims to provide a solar cell and a photovoltaic module, wherein the difference between the series resistance of a central region and the series resistance of an edge region is small or has no difference.

In order to achieve the above object, the present invention provides a solar cell, including at least one main grid line; and the auxiliary grid lines are distributed outwards in sequence along the center of the solar cell piece, and in any three sequentially distributed auxiliary grid lines, the distance from the auxiliary grid line positioned in the middle to the auxiliary grid line positioned on the inner side of the auxiliary grid line is smaller than the distance from the auxiliary grid line positioned on the outer side of the auxiliary grid line.

As a further improvement of the present invention, the distance between the middle finger and the inner finger is (a + nb) mm, the distance between the middle finger and the outer finger is (a + nb + b) mm, and n is an integer greater than or equal to 0.

As a further improvement of the invention, a is between 1mm and 2 mm.

As a further improvement of the invention, b is between 1mm and 2 mm.

As a further improvement of the invention, the plurality of sub-grid lines are arc-shaped, the centers of the solar cell pieces are used as arc centers, a space is formed between every two adjacent sub-grid lines, and the plurality of spaces gradually increase from inside to outside, so that the distribution density of the sub-grid lines on the surface of the solar cell piece is gradually reduced from inside to outside.

As a further refinement of the invention, several of the pitches are increased by the same dimension at each increment.

As a further improvement of the present invention, the secondary grid lines are closed ring grid lines and/or semi-ring grid lines.

As a further improvement of the present invention, the solar cell sheet includes at least one bus bar passing through the center of the solar cell sheet.

As a further improvement of the invention, the solar cell comprises at least two parallel main grid lines, and at least one main grid line passes through the center of the solar cell.

In order to achieve the above object, the present invention further provides a photovoltaic module, which includes the solar cell sheet as described above.

The invention has the beneficial effects that: according to the solar cell piece, the distance from the secondary grid line positioned in the middle to the secondary grid line positioned at the inner side of any three secondary grid lines is less than that from the secondary grid line positioned at the outer side of the secondary grid line, so that the distribution density of the secondary grid lines in the central area of the solar cell piece is greater than that of the secondary grid lines in the edge area, and the external resistance of the central area is less than that of the edge area; therefore, the difference between the series resistance of the central area and the series resistance of the edge area is small or zero.

Drawings

FIG. 1 is a schematic structural diagram of a solar cell in accordance with a preferred embodiment of the present invention;

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings. These embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present invention.

Referring to fig. 1, a solar cell 100 according to a preferred embodiment of the invention includes at least one main gate line 1 and a plurality of sub-gate lines 2; the plurality of secondary grid lines 2 are distributed outwards in sequence along the center of the solar cell 100, and in any three secondary grid lines 2 distributed in sequence, the distance from the secondary grid line 2 in the middle to the secondary grid line 2 on the inner side is smaller than the distance from the secondary grid line 2 on the outer side.

The solar cell sheet 100 has only one center, and the edge thereof is composed of countless positions; "out of the center of the solar cell sheet 100" means: and the direction extends from the center of the solar cell piece to any point on the edge.

In the solar cell 100, the distance between the sub-grid lines 2 in the central region is smaller than the distance between the sub-grid lines 2 in the edge region, and it can also be understood that the density of the sub-grid lines 2 in the central region is greater than the density of the sub-grid lines 2 in the edge region, so that the resistance of the electric charge in the central region moving to the sub-grid lines 2 is smaller than the resistance of the electric charge in the edge region moving to the sub-grid lines 2, and the external resistance in the central region is smaller than the external resistance in the edge region; so that the series resistance in the middle region differs from the series resistance in the edge region by a small or no amount.

Preferably, along the extending direction of the sub-grid lines 2, the distance between each sub-grid line 2 and the adjacent sub-grid line 2 is not changed; the series resistance uniformity of the respective regions is higher.

Specifically, the distance from the middle finger 2 to the inner finger 2 is (a + nb) mm, the distance from the middle finger 2 to the outer finger 2 is (a + nb + b) mm, and n is an integer greater than or equal to 0. From the center outwards, every two adjacent auxiliary grid lines 2 are provided with intervals, the intervals between the plurality of auxiliary grid lines 2 are gradually increased in an equal difference mode, the intervals are opposite to the change of internal resistance formed in diffusion, and the consistency of series resistance can be guaranteed to a greater extent.

The distance between adjacent secondary grid lines 2 is not particularly limited, and in this embodiment, a is 1mm to 2 mm; b is between 1mm and 2 mm; the charge can be well collected, and the consistency of the series resistors can be ensured.

The plurality of sub-grid lines 2 are arc-shaped, the center of the solar cell piece 100 is used as an arc center, a space is formed between every two adjacent sub-grid lines 2, and the plurality of spaces gradually increase from inside to outside, so that the distribution density of the sub-grid lines 2 on the surface of the solar cell piece 100 is gradually reduced from inside to outside. The arc-shaped auxiliary grid lines 2 are sequentially arranged and matched with the variation trend of the square resistance formed in the diffusion process, so that the difference between the series resistance of the middle area and the series resistance of the edge area is small or zero.

Preferably, a number of said spacings, increasing from the center outwards by the same dimension at each increment; i.e. the difference between any two adjacent said spacings is the same. The consistency of the series resistance can be ensured to a greater extent, contrary to the variation of the internal resistance formed during diffusion.

In any of the solar cell pieces 100 described above, the secondary grid lines 2 are closed ring-shaped grid lines 21; or the secondary grid line 2 can also be a semi-ring grid line, and the semi-ring grid line 22 herein refers to a segment of grid line that cannot form a complete ring, and is not particularly referred to as a semicircular grid line; alternatively, the solar cell piece 100 is generally square or rectangular, the center of the secondary grid line 2 is a closed ring grid line 21, and the edge of the secondary grid line 2 is set as a semi-ring grid line 22 due to the shape limitation of the solar cell piece 100. The closed ring-shaped grid line 21 may be a circular ring-shaped grid line shown in fig. 1, a polygonal ring-shaped grid line, or a ring-shaped grid line of any other shape.

In the solar cell sheet 100 with the annular grid lines 21 and/or the semi-annular grid lines 22, all the secondary grid lines 2 are roughly in a radial shape diffused from the center to the edge; the distance between two adjacent annular grid lines 21 is kept constant along the extending direction of the annular grid lines 21; from the center to the outside, the distance between two adjacent ring grid lines 21 is gradually increased, and the series resistance on the whole solar cell 100 is relatively uniform.

Accordingly, the solar cell sheet 100 includes at least one bus bar 1 passing through the center of the solar cell sheet 100; or the solar cell comprises at least two parallel main grid lines 1, and at least one main grid line 1 penetrates through the center of the solar cell 100; to ensure that all the secondary grid lines 2 intersect the main grid line 1.

The photovoltaic module of the present invention includes any of the solar cells 100 having a small or no difference between the series resistance of the central region and the series resistance of the edge region, and other structures and connection methods thereof are consistent with those of the photovoltaic module in the prior art, and are not described herein again.

In summary, in the solar cell 100 of the present invention, outward from the center of the solar cell 100, in any three sub-grid lines 2, the distance from the middle sub-grid line 2 to the sub-grid line 2 inside the middle sub-grid line is less than the distance from the middle sub-grid line 2 to the outer sub-grid line 2, so that the difference between the series resistance in the central region and the series resistance in the edge region is small or zero.

It should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can also be combined appropriately to form other embodiments understood by those skilled in the art.

The above-listed detailed description is only a specific description of a possible embodiment of the present invention, and they are not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the scope of the present invention.