CN217507346U - Photovoltaic cell slotting structure and photovoltaic cell piece - Google Patents

Abstract

The utility model relates to a photovoltaic technology field, concretely relates to photovoltaic cell fluting structure, photovoltaic cell fluting structure includes the same fluting unit of a plurality of, every the fluting unit includes two at least fluting line segments that are parallel to each other, and every fluting line segment is including the notched real section that sets up around in turn and the virtual section of non-fluting, and the length of each real section is the same and the length of each virtual section is the same in every fluting line segment, and the proportion of virtual section and real section is virtual-real than, and the virtual-real ratio of each fluting line segment is all inequality in every fluting unit. The utility model provides a pair of photovoltaic cell fluting structure can obtain the promotion of specific efficiency, has both guaranteed open circuit voltage and short-circuit current, has prevented the loss of fill factor again to reduce the whole damage because of laser brings, promoted the whole mechanical properties of battery piece, can deal with the problem that the trade descends because of the more and more thin three-point bending resistance who forms of silicon chip material thickness.

Description

Photovoltaic cell slotting structure and photovoltaic cell piece

Technical Field

The utility model relates to a photovoltaic technology field, concretely relates to photovoltaic cell fluting structure and photovoltaic cell piece.

Background

The photovoltaic cell, also called solar cell, is used to convert solar energy directly into electric energy, and the silicon solar cells used in ground photovoltaic systems are divided into monocrystalline silicon, polycrystalline silicon and amorphous silicon solar cells.

In order to reduce the cost, the thickness of the solar cell is continuously reduced, and with the reduction of the thickness of a silicon wafer, the diffusion length of minority carriers in the conventional crystalline silicon solar cell is possibly greater than the thickness of the silicon wafer, a part of the minority carriers are diffused to the back of the cell for recombination, so that the recombination rate is high, and the cell efficiency is reduced; in addition, as the thickness of the silicon wafer is reduced, the light absorption of long wavelength is reduced, the utilization rate is low, the conversion efficiency is further restricted, and the development trend of reducing cost and improving efficiency is not met.

At present, a PREC cell with high conversion efficiency is generally adopted, a passivation layer is added on the back of a silicon wafer to perform the passivation effect on the silicon wafer, the back recombination is extremely low, and the long-wave response is improved due to the increase of the back reflection. Because the passivation layer on the back of the silicon wafer is aluminum oxide or silicon oxide, which belongs to an insulating layer, the passivation layer on the back of the silicon wafer needs to be punched out by adopting a laser grooving technology to expose the silicon substrate, so that the passivation layer can be in electrical contact with the back electrode.

The laser grooving structures in the prior art are of three types, as shown in fig. 1-3, namely a linear type, a point type and a line section type, wherein the linear type is adopted, so that the contact area between a silicon substrate and a back electrode is large, the contact resistance is small, but a back passivation layer is removed more, so that the open-circuit voltage and the short-circuit current are low; although dot mode is adopted, the back passivation layer is removed less, and higher open-circuit voltage and short-circuit current can be obtained, but because the contact area of the silicon substrate and the back electrode is small, the contact resistance is large, and a cavity is easy to form; the performance of the battery plate adopting the line-segment type slotted structure is between that of a straight line type and that of a point type, so that the battery plate is used more frequently. However, no matter which slotting structure is adopted, the improvement of specific efficiency cannot be obtained, for example, for a straight line type, the efficiency is fixed, and the improvement efficiency cannot be changed; for the point mode, the distance between the holes can be changed only, and the adjusting range is small; for the line segment type, the virtual-to-real ratio of each upper and lower line is the same, and the adjustment range is limited, so that the improvement of specific efficiency cannot be obtained.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a solve among the prior art photovoltaic cell back laser fluting structure and have the technical problem that can't obtain specific efficiency and promote, provided a photovoltaic cell back fluting structure, can obtain the promotion of specific efficiency.

The technical scheme of the utility model:

the utility model provides a photovoltaic cell fluting structure, includes the same fluting unit of a plurality of, every the fluting unit includes at least two fluting line segments that are parallel to each other, and every fluting line segment is including the grooved real section and the not grooved virtual section that set up around the turn, and the length of each real section is the same and the length of each virtual section is the same in every fluting line segment, and the proportion of virtual section and real section is virtual-real ratio, and the virtual-real ratio of each fluting line segment is all inequality in every fluting unit.

Furthermore, the real section and the virtual section of two adjacent slotting line sections in each slotting unit are staggered up and down.

Further, the distance between any two adjacent slot segments is equal.

Further, the width of the grooved line segment is 40-50 micrometers.

Further, each slotting unit comprises two slotting line segments which are respectively a first slotting line segment and a second slotting line segment, the first slotting line segment comprises a first real segment and a first virtual segment, the ratio of the first virtual segment to the first real segment is a first virtual-real ratio, the second slotting line segment comprises a second real segment and a second virtual segment, the ratio of the second virtual segment to the second real segment is a second virtual-real ratio, and the first virtual-real ratio is greater than the second virtual-real ratio.

Further, each slotting unit comprises three slotting line segments which are respectively a first slotting line segment, a second slotting line segment and a third slotting line segment, the first slotting line segment comprises a first real segment and a first virtual segment, the ratio of the first virtual segment to the first real segment is a first virtual-real ratio, the second slotting line segment comprises a second real segment and a second virtual segment, the ratio of the second virtual segment to the second real segment is a second virtual-real ratio, the third slotting line segment comprises a third real segment and a third virtual segment, the ratio of the third virtual segment to the third real segment is a third virtual-real ratio, the first virtual-real ratio is greater than the second virtual-real ratio, and the second virtual-real ratio is greater than the third virtual-real ratio.

The utility model discloses an on the other hand provides a photovoltaic cell piece, which comprises a substrate, the substrate includes the PN junction and sets up the passivation layer at the PN junction back, be formed with on the passivation layer as above arbitrary one photovoltaic cell fluting structure.

Furthermore, the back of the photovoltaic cell piece is also provided with a plurality of conductive grids which correspondingly cover the grooved line segments and are electrically connected with the PN junctions in the substrate through the solid segments in the grooved line segments.

After the technical scheme is adopted, compared with the prior art, the utility model, have following beneficial effect: the utility model provides a pair of photovoltaic cell fluting structure replaces among the prior art orthoscopic, point formula or simple segment formula fluting structure through the fluting line section that sets up different virtual-real ratios, can adjust open circuit voltage, short-circuit current and contact resistance, and the adjustment range is big, can obtain the promotion of specific efficiency, has both guaranteed open circuit voltage and short-circuit current, has prevented the loss of fill factor again. And the silicon chip material can keep good mechanical loading capacity under the condition of being thinner and thinner.

Drawings

FIG. 1 is a partial schematic view of a linear slotted structure of the prior art;

FIG. 2 is a partial schematic view of a prior art point-type slot configuration;

FIG. 3 is a partial schematic view of a line-segment type slotting structure in the prior art;

FIG. 4 is a general schematic diagram of a photovoltaic cell slotting structure of the present embodiment;

fig. 5 is a partial schematic view of a photovoltaic cell slotting structure of the present embodiment;

fig. 6 is a partial schematic view of a photovoltaic cell slotting structure in another embodiment of this embodiment.

Wherein the content of the first and second substances,

the slotting unit 1, a first slotting line segment 11, a first real segment 111, a first virtual segment 112, a second slotting line segment 12, a second real segment 121, a second virtual segment 122, a third slotting line segment 13, a third real segment 131 and a third virtual segment 132; a back electrode 2.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms do not have special meanings unless otherwise stated, and therefore, the scope of the present invention should not be construed as being limited.

The utility model aims at providing a photovoltaic cell fluting structure replaces among the prior art orthoscopic, point type or simple segment type fluting structure through the fluting line section that sets up different virtual-real ratios, can adjust open circuit voltage, short-circuit current and contact resistance, and the adjustment range is big, can obtain the promotion of specific efficiency, has both guaranteed open circuit voltage and short-circuit current, has prevented the loss of fill factor again. And the silicon chip material can keep good mechanical loading capacity under the condition of being thinner and thinner. The following is a detailed description of the preferred embodiments.

As shown in fig. 4 to 6, the present embodiment provides a photovoltaic cell slotting structure, where the photovoltaic cell slotting structure includes a plurality of identical slotting units 1, and the slotting units 1 are sequentially arranged up and down. Each slotting unit 1 comprises at least two slotting line segments which are arranged in parallel, each slotting line segment comprises a real slotted segment and an imaginary slotted segment which are alternately arranged front and back, the real segments, the imaginary segments, the real segments and the imaginary segments … … are sequentially arranged, the real segments in each slotting line segment are the same in length, the imaginary segments are the same in length, the proportion of the imaginary segments to the real segments is an imaginary-real ratio, and the imaginary-real ratios of the slotting line segments in each slotting unit 1 are different.

Thus, in the present embodiment, at least two slot segments are arranged in each slot unit 1, and the virtual-to-real ratios of the slot segments are different, so that the virtual-to-real ratios of the slot segments can be adjusted, thereby not only ensuring the open-circuit voltage and the short-circuit current, but also preventing the loss of the fill factor, and obtaining the improvement of the specific efficiency. Compared with a simple line segment type structure in the prior art, the length of a real segment in each line segment can be changed only singly, the minimum adjustment amount is 1/M when the virtual-real ratio is adjusted on the assumption that a line of light spots is M in total, and a specific overall virtual-real ratio and a specific conversion efficiency cannot be obtained under many conditions; in the embodiment, each slotting unit 1 is provided with a plurality of slotting line segments with different virtual-to-real ratios, assuming that N is equal to or greater than 2, the minimum adjustment amount is 1/(nxm), and thus, the minimum adjustment amount in the embodiment is smaller, so that a specific overall virtual-to-real ratio can be achieved, and thus, a specific conversion efficiency can be obtained.

Preferably, the real section and the virtual section in two adjacent slot line segments in each slot unit are arranged in a vertically staggered manner, that is, the upper side and the lower side of the real section in each slot line segment correspond to the virtual sections in other slot line segments, and the upper side and the lower side of the virtual section in each slot line segment correspond to the real sections in other slot line segments, so that the real sections of each slot are uniformly distributed, the overall damage caused by laser is reduced, the overall mechanical performance of the battery piece can be improved, and the problem of the reduction of three-point bending resistance caused by the thinner and thinner silicon chip material in the industry can be solved. Further, the distance between any two adjacent slotting line segments is equal in the embodiment, so that the slotting is uniformly distributed, and the overall mechanical performance of the battery piece is further improved.

Preferably, the width of each slot segment in this embodiment is 40-50 microns, which results in a significant drop in open circuit voltage if the width of the slot segment is too large, and a small contact resistance and a significant drop in electrical performance if the width of the slot segment is too small. Therefore, the present embodiment sets the width of each slotline segment to be 40-50 microns, which does not affect the improvement of specific conversion efficiency.

As one embodiment of the present invention, as shown in fig. 4-5, each slotting unit 1 includes two slotting segments, which are a first slotting segment 11 and a second slotting segment 12, respectively, the first slotting segment 11 includes a first real segment 111 and a first virtual segment 112, the ratio of the first virtual segment 112 and the first real segment 111 is a first virtual-real ratio, the second slotting segment 12 includes a second real segment 121 and a second virtual segment 122, the ratio of the second virtual segment 122 and the second real segment 121 is a second virtual-real ratio, the first virtual-real ratio is greater than the second virtual-real ratio, as shown in fig. 5, the length of the first real segment 111 in the first slotting segment 11 is shorter than the length of the second real segment 121 in the second slotting segment 12, the length of the first real segment 111 in fig. 5 is 0.12mm, the length of the second real segment is 0.4mm, and the lengths and the virtual ratios of the real segments can be adjusted according to requirements.

As another embodiment of this embodiment, as shown in fig. 6, each slotting unit 1 includes three slotting line segments, which are a first slotting line segment 11, a second slotting line segment 12 and a third slotting line segment 13, the first slotting line segment 11 includes a first real segment 111 and a first virtual segment 112, a ratio of the first virtual segment 112 to the first real segment 111 is a first virtual-real ratio, the second slotting line segment 12 includes a second real segment 121 and a second virtual segment 122, a ratio of the second virtual segment 122 to the second real segment 121 is a second virtual-real ratio, the third slotting line segment 13 includes a third real segment 131 and a third virtual segment 132, a ratio of the third virtual segment 132 to the third real segment 131 is a third virtual-real ratio, the first virtual-real ratio is greater than the second virtual-real ratio, and the second virtual-real ratio is greater than the third virtual-real ratio. As shown in fig. 6, the length of the first real segment 111 in the first slot segment 11 is shorter than the length of the second real segment 121 in the second slot segment 12, the length of the second real segment 121 in the second slot segment 12 is shorter than the length of the third real segment 131 in the third slot segment 13, the length of the first real segment 111 in fig. 6 is 0.12mm, the length of the second real segment 121 is 0.4mm, and the length of the third real segment 131 is 0.5mm, and the length of each real segment and each virtual-real ratio can be adjusted according to the requirement.

As other embodiments of this embodiment, more slot segments with different virtual-to-real ratios may also be included, which is not described in this embodiment in an expanded manner, and reference may be specifically made to the above embodiments. It should be noted that when the number of the slot segments in each slot unit is odd, since the real segment and the imaginary segment in the two closest slot segments of the two slot units cannot be staggered up and down, the even number of slot segments is preferably used in each slot unit.

The embodiment also provides a photovoltaic cell piece, which comprises a substrate, wherein the substrate comprises a PN junction and a passivation layer from top to bottom, the passivation layer is arranged on the back and comprises an aluminum oxide layer and a silicon nitride layer, the photovoltaic cell slotting structure as described in any one of the above embodiments is formed on the passivation layer, and the PN junction silicon substrate in the substrate can be exposed through laser slotting. Furthermore, a plurality of conductive grids (such as aluminum grid lines, not shown in the figure) are arranged on the back surface of the photovoltaic cell, the conductive grids correspondingly cover the grooved line sections, the conductive grids are electrically connected with the PN junction silicon substrate in the substrate through solid sections in the grooved line sections, and then the conductive grids are electrically connected with the back electrode 2.

From the above, the photovoltaic cell slotting structure provided by the embodiment can improve specific efficiency, not only ensure open-circuit voltage and short-circuit current, but also prevent loss of the filling factor, reduce overall damage caused by laser, improve overall mechanical performance of the cell, and solve the problem of reduction of three-point bending resistance caused by thinner and thinner silicon wafer materials in the industry.

The above, only be the concrete implementation of the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art is in the technical scope of the present invention, according to the technical solution of the present invention and the utility model, the concept of which is equivalent to replace or change, should be covered within the protection scope of the present invention.

Claims (8)

1. The utility model provides a photovoltaic cell fluting structure, its characterized in that includes a plurality of the same fluting unit (1), every fluting unit (1) includes at least two fluting line sections that are parallel to each other and set up, every fluting line section is including the fluting real section and the not fluting imaginary section of alternative setting around, the length of each real section is the same and the length of each imaginary section is the same in every fluting line section, the proportion of imaginary section and real section is the virtual-real ratio, the virtual-real ratio of each fluting line section is all inequality in every fluting unit (1).

2. The photovoltaic cell slotting structure according to claim 1, wherein the real and imaginary sections of two adjacent slotting line sections in each slotting unit (1) are staggered up and down.

3. The photovoltaic cell trenching structure of claim 2, wherein a distance between any two adjacent trenching line segments is equal.

4. The photovoltaic cell trenching structure of claim 3, wherein the width of the trenched line segment is 40-50 microns.

5. The photovoltaic cell notching structure according to claim 1, wherein each of the notching units (1) includes two notching segments, a first notching segment (11) and a second notching segment (12), respectively, the first notching segment (11) including a first real segment (111) and a first imaginary segment (112), a ratio of the first imaginary segment (112) to the first real segment (111) being a first imaginary-to-real ratio, the second notching segment (12) including a second real segment (121) and a second imaginary segment (122), a ratio of the second imaginary segment (122) to the second real segment (121) being a second imaginary-to-real ratio, the first imaginary-to-real ratio being greater than the second imaginary-to-real ratio.

6. The photovoltaic cell notching structure according to claim 1, wherein each of the notching units (1) includes three notching segments, a first notching segment (11), a second notching segment (12), and a third notching segment (13), respectively, the first notching segment (11) including a first real segment (111) and a first imaginary segment (112), a ratio of the first imaginary segment (112) to the first real segment (111) being a first imaginary-real ratio, the second notching segment (12) including a second real segment (121) and a second imaginary segment (122), a ratio of the second imaginary segment (122) to the second real segment (121) being a second imaginary-real ratio, the third notching segment (13) including a third real segment (131) and a third imaginary segment (132), a ratio of the third imaginary segment (132) to the third real segment (131) being a third imaginary-real ratio, the first imaginary ratio being greater than the second imaginary-real ratio, and the second ratio is greater than the third ratio.

7. A photovoltaic cell piece, characterized by comprising a substrate, wherein the substrate comprises a PN junction and a passivation layer arranged on the back of the PN junction, and the passivation layer is provided with the photovoltaic cell slotting structure as defined in any one of claims 1 to 6.

8. The photovoltaic cell slice of claim 7, wherein the back side of the photovoltaic cell slice is further provided with a plurality of conductive grids, the conductive grids correspondingly cover the grooved line segments, and the conductive grids are electrically connected with the PN junction in the substrate through the solid segments in the grooved line segments.

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