CN213519988U - Heterojunction solar cell string - Google Patents
Heterojunction solar cell string Download PDFInfo
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- CN213519988U CN213519988U CN202022498312.3U CN202022498312U CN213519988U CN 213519988 U CN213519988 U CN 213519988U CN 202022498312 U CN202022498312 U CN 202022498312U CN 213519988 U CN213519988 U CN 213519988U
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Abstract
The utility model provides a heterojunction solar cell string, wherein the heterojunction solar cell that relates includes the cell piece body, set up in the first transparent conductive film layer of cell piece body sensitive surface one side, and set up in the second transparent conductive film layer of cell piece body backlight surface one side, heterojunction solar cell still including set up in first transparent conductive film layer and/or second transparent conductive film layer surface and extending direction and the perpendicular compound auxiliary grid of first direction, compound auxiliary grid includes first grid line layer and sets up in the second grid line layer of first grid line layer deviating from cell piece body side surface, second grid line layer is different with first grid line layer material and covers the relative both sides surface of first grid line layer in the width direction; the utility model relates to an among the heterojunction solar cell, provide one kind and be different from the compound vice bars of traditional low temperature thick liquids printing vice bars structure, provide more choices for heterojunction solar cell's collecting electrode preparation.
Description
Technical Field
The utility model relates to a photovoltaic field of making especially relates to a heterojunction solar cell string.
Background
The heterojunction solar cell is a relatively high-efficiency crystalline silicon solar cell at present, combines the characteristics of a crystalline silicon cell and a silicon-based thin film cell, and has the advantages of short manufacturing process, low process temperature, high conversion efficiency, more generated energy and the like. The heterojunction solar cell has a small temperature degradation coefficient and double-sided power generation, so that the annual power generation amount can be 15-30% higher than that of a common polycrystalline silicon cell under the condition of the same area, and therefore the heterojunction solar cell has great market potential.
Fig. 1 is a schematic structural diagram of a heterojunction solar cell according to the prior art, which sequentially includes a first collector electrode 51 ', a first transparent conductive film 41 ', a first doped amorphous layer 31 ', a first intrinsic amorphous layer 21 ', a silicon substrate 10 ', a second intrinsic amorphous layer 22 ', a second doped amorphous layer 32 ', a second transparent conductive film 42 ', and a second collector electrode 52 ' from a light-receiving surface side to a backlight surface side. The first and second collector electrodes 51 ', 52' referred to therein each typically comprise a primary and a secondary grid connected to each other.
In the prior art, the method is limited by a low-temperature process, only low-temperature slurry can be adopted when the screen plate is adopted to print the first collector 51 'and the second collector 52', the manufacturing cost of the low-temperature slurry is high, the conductivity of the conductive slurry with higher conductivity is poor, the contact resistivity is high, and the filling factor FF of the heterojunction solar cell is not improved favorably.
In view of the above, there is a need to provide an improved solution to the above problems.
SUMMERY OF THE UTILITY MODEL
The utility model discloses aim at solving one of the technical problem that prior art exists at least, for realizing the utility model purpose of the aforesaid, the utility model provides a heterojunction solar cell cluster, its concrete design as follows.
A heterojunction solar cell string comprises a plurality of heterojunction solar cells which are serially connected along a first direction, wherein each heterojunction solar cell comprises a cell body, a first transparent conductive film layer arranged on one side of an illuminated surface of the cell body, and a second transparent conductive film layer arranged on one side of a backlight surface of the cell body, the heterojunction solar cell further comprises a composite auxiliary grid which is arranged on the surface of the first transparent conductive film layer and/or the second transparent conductive film layer and has an extending direction perpendicular to the first direction, the composite auxiliary grid comprises a first grid line layer and a second grid line layer which is arranged on the surface of the first grid line layer and deviates from one side surface of the cell body, and the second grid line layer covers the two opposite side surfaces of the first grid line layer in the width direction.
Further, the first grid line layer is one of a nickel metal layer, a copper metal layer and an aluminum metal layer, and the second grid line layer is a silver metal layer; or, the first grid line layer is a conductive carbon layer, and the second grid line layer is a nickel metal layer.
Furthermore, the composite auxiliary grid also comprises a third grid line layer which is arranged on the surface of one side of the first grid line layer facing the battery piece body and is connected with the second grid line layer.
Further, the first grid line layer is one of a nickel metal layer, a copper metal layer and an aluminum metal layer, and the third grid line layer is a silver metal layer; or, the first grid line layer is a conductive carbon layer, and the third grid line layer is a nickel metal layer.
Furthermore, the width of the composite auxiliary grid is 40-65 μm, and the thickness of the composite auxiliary grid is 12-21 μm.
Furthermore, the heterojunction solar cell further comprises a composite main grid which is arranged on the surface of the first transparent conductive film layer and/or the second transparent conductive film layer, the extending direction of the composite main grid is consistent with the first direction, the composite main grid comprises a fourth grid line layer and a fifth grid line layer which is arranged on the surface of one side, deviating from the cell body, of the fourth grid line layer, and the fifth grid line layer covers the surfaces of two opposite sides of the fourth grid line layer in the width direction.
Further, the fourth gate line layer is one of a nickel metal layer, a copper metal layer, an aluminum metal layer and a glass powder layer, and the fifth gate line layer is a silver metal layer; or, the fourth grid line layer is a conductive carbon layer, and the fifth grid line layer is a nickel metal layer.
Furthermore, the composite main grid also comprises a sixth grid line layer which is arranged on the surface of one side of the fourth grid line layer facing the battery piece body and is connected with the fifth grid line layer.
Further, the fourth gate line layer is one of a nickel metal layer, a copper metal layer, an aluminum metal layer and a glass powder layer, and the sixth gate line layer is a silver metal layer; or, the fourth grid line layer is a conductive carbon layer, and the sixth grid line layer is a nickel metal layer.
Furthermore, the width of the composite main grid is 0.1-0.2mm, and the thickness is 17-33 μm.
Further, the cell body comprises a silicon substrate, a first intrinsic amorphous layer and a first doped amorphous layer which are sequentially arranged on one side of a light receiving surface of the silicon substrate, a second intrinsic amorphous layer and a second doped amorphous layer which are sequentially arranged on one side of a backlight surface of the silicon substrate and have opposite doping types to the first doped amorphous layer, and the first transparent conductive film and the second transparent conductive film are respectively arranged on the surfaces of one sides, far away from the silicon substrate, of the first doped amorphous layer and the second doped amorphous layer.
The utility model has the advantages that: the utility model relates to a heterojunction solar cell, which provides a composite auxiliary grid different from the auxiliary grid structure printed by the traditional low-temperature slurry, and provides more choices for manufacturing the collector of the heterojunction solar cell; through rational configuration the utility model discloses the material on first grid line layer and second grid line layer in the compound vice bars of heterojunction solar cell can effectively reduce heterojunction solar cell's cost of manufacture, and can improve the high problem of low temperature thick liquids contact resistivity among the prior art, has reduced the loss of fill factor FF.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts. The front and back sides referred to herein are only defined with respect to the positional relationship in the drawings of the embodiments, that is, the front side corresponds to the upper surface of the drawings, and the back side corresponds to the lower surface of the drawings.
FIG. 1 is a schematic diagram of a prior art heterojunction solar cell;
fig. 2 is a schematic diagram of a first embodiment of a heterojunction solar cell according to the present invention;
fig. 3 is a schematic diagram of a second embodiment of a heterojunction solar cell according to the present invention;
fig. 4 is a schematic diagram of a third embodiment of a heterojunction solar cell according to the present invention;
fig. 5 is a schematic diagram illustrating a fourth embodiment of a heterojunction solar cell according to the present invention;
in the figure, 10 is a silicon substrate, 21 is a first intrinsic amorphous layer, 31 is a first doped amorphous layer, 41 is a first transparent conductive film layer, 51 is a front composite sub-gate, 511 is a front first gate line layer, 512 is a front second gate line layer, 513 is a front third gate line layer, 22 is a second intrinsic amorphous layer, 32 is a second doped amorphous layer, 42 is a second transparent conductive film layer, 52 is a back composite sub-gate, 521 is a back first gate line layer, 522 is a back second gate line layer, and 523 is a back third gate line layer.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying 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. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
The utility model provides a heterojunction solar cell cluster, including a plurality of heterojunction solar cells that set up along the first direction series connection, it is shown with reference to fig. 2-5, heterojunction solar cell includes the battery piece body, sets up in the first transparent electrically conductive rete 41 of battery piece body sensitive surface one side and sets up in the transparent electrically conductive rete 42 of second of battery piece body backlight surface one side.
In this embodiment, the cell body includes a silicon substrate 10, a first intrinsic amorphous layer 21 and a first doped amorphous layer 31 sequentially disposed on a light receiving surface side of the silicon substrate 10, and a second intrinsic amorphous layer 22 and a second doped amorphous layer 32 sequentially disposed on a backlight surface side of the silicon substrate 10. Accordingly, in this embodiment, the first transparent conductive film 41 and the second transparent conductive film 42 are respectively disposed on the surfaces of the first doped amorphous layer 31 and the second doped amorphous layer 32 away from the silicon substrate 10.
The utility model provides a method for forming battery piece body, it includes: providing a silicon substrate 10; forming a first intrinsic amorphous layer 21 and a second intrinsic amorphous layer 22 on a light receiving surface and a backlight surface of the silicon substrate 10 by a PECVD process; a first doped amorphous layer 31 and a second doped amorphous layer 32 are formed on the surfaces of the first and second intrinsic amorphous layers 21 and 22, respectively, by a PECVD process.
In addition, the first transparent conductive film layer 41 and the second transparent conductive film layer 42 according to the present invention can be formed on the surface of the first doped amorphous layer 31 and the surface of the second doped amorphous layer 32 by PVD processes, respectively. The first transparent conductive film layer 41 and the second transparent conductive film layer 42 may be ITO, IWO, ITO, or the like.
Preferably, the silicon substrate 10 according to the present invention is a single crystal silicon substrate.
In a specific implementation process, the light receiving surface of the silicon substrate 10 according to this embodiment is a surface of the heterojunction solar cell directly receiving sunlight, and the back surface is a surface of the heterojunction solar cell not directly receiving sunlight, that is, a surface opposite to the light receiving surface. The first and second intrinsic amorphous layers 21 and 22 are intrinsic amorphous silicon. The doping types of the first doped amorphous layer 31 and the second doped amorphous layer 32 are opposite, wherein one of the first doped amorphous layer and the second doped amorphous layer is doped with N type, namely phosphorus is adopted for doping; the other is P-type doping, namely boron doping is adopted.
In the present invention, although the silicon substrate 10 may be a P-type silicon substrate, an N-type single crystal substrate silicon may be selected; however, in a preferred embodiment of the present invention, the silicon substrate 10 is an N-type silicon substrate. Typically, the silicon substrate 10 is 90-16um thick with sides 156-210 mm. Further preferably, the first doped amorphous layer 31 is an N-type doped amorphous layer, and the second doped amorphous layer 32 is a P-type doped amorphous layer.
The utility model discloses in, heterojunction solar cell is still including setting up in first transparent conductive film layer 41 and/or the transparent conductive film layer 42 surface of second and extending direction and the compound vice bars of first direction vertically, and compound vice bars include first grid line layer and set up in the second grid line layer that first grid line layer deviates from battery piece body side surface, and the first grid line layer of second grid line layer cover is on the relative both sides surface of width direction.
Referring to fig. 2, in this embodiment, the surfaces of the first transparent conductive film layer 41 and the second transparent conductive film layer 42 are both provided with composite sub-grids. Specifically, the composite sub-grid includes a front composite sub-grid 51 disposed on the surface of the first transparent conductive film layer 41 and a back composite sub-grid 52 disposed on the surface of the second transparent conductive film layer 42.
As shown in the figure, the front composite auxiliary grid 51 includes a front first grid line layer 511 and a front second grid line layer 512 disposed on a surface of the front first grid line layer 511 facing away from the cell body, and the front second grid line layer 512 covers two opposite side surfaces of the front first grid line layer 511 in the width direction. In this embodiment, the front second gate line layer 512 completely covers two opposite side surfaces of the front first gate line layer 511 in the width direction, so as to form a direct connection with the first transparent conductive film layer 41; in this embodiment, the material of the front second gate line layer 512 is different from that of the front first gate line layer 511.
Accordingly, in the embodiment shown in fig. 2, the back composite sub-grid 52 includes a back first grid line layer 521 and a back second grid line layer 522 disposed on a surface of the back first grid line layer 521 facing away from the cell body, and the back second grid line layer 522 covers two opposite side surfaces of the back first grid line layer 521 in the width direction. In this embodiment, the back second gate line layer 522 completely covers two opposite side surfaces of the back first gate line layer 521 in the width direction, so as to form a direct connection with the second transparent conductive film layer 42; in this embodiment, the material of the front second gate line layer 512 is different from that of the front first gate line layer 511.
It is understood that in other embodiments of the present invention, only one of the first transparent conductive film layer 41 and the second transparent conductive film layer 42 may be provided with a composite sub-grid having the above-mentioned structure on the surface, and the other is provided with a sub-grid structure, such as a silver sub-grid, which is the same as the conventional one.
The utility model relates to a heterojunction solar cell, which provides a composite auxiliary grid different from the auxiliary grid structure printed by the traditional low-temperature slurry, and provides more choices for manufacturing the collector of the heterojunction solar cell; through rational configuration the utility model discloses the material on first grid line layer and second grid line layer in the compound vice bars of heterojunction solar cell can effectively reduce heterojunction solar cell's cost of manufacture, and can improve the high problem of low temperature thick liquids contact resistivity among the prior art, has reduced the loss of fill factor FF.
In still other embodiments of the present invention, the composite sub-grid may further include a third grid line layer disposed on a side surface of the first grid line layer facing the cell body and connected to the second grid line layer.
In an embodiment of the present invention, referring to fig. 3, the structure of the back composite subgrid 52 is the same as the structure of the back composite subgrid 52 in the embodiment shown in fig. 2. The difference is that in the embodiment shown in fig. 3, the front composite auxiliary grid 51 further includes a front third grid line layer 513 disposed on a surface of the front first grid line layer 511 facing the cell body and connected to the front second grid line layer 512. Preferably, the material of the front third gate line layer 513 is the same as that of the front second gate line layer 512.
In another embodiment of the present invention, referring to fig. 4, the structure of the front composite auxiliary grid 51 is the same as the structure of the front composite auxiliary grid 51 in the embodiment shown in fig. 2. The difference is that in the embodiment shown in fig. 4, the back composite auxiliary grid 52 includes a back third grid line layer 523 disposed on a surface of the back first grid line layer 521 facing the cell body and connected to the back second grid line layer 522. Preferably, the back third gate line layer 523 and the back second gate line layer 522 are made of the same material.
Further, referring to fig. 5, in this embodiment, the front composite sub-grid 51 includes a front third grid line layer 513 disposed on a surface of the front first grid line layer 511 facing the cell body and connected to the front second grid line layer 512; the back composite auxiliary grid 52 comprises a back third grid line layer 523 which is arranged on the surface of the back first grid line layer 521 facing the cell body and connected with the back second grid line layer 522.
In the utility model, the first grid line layer is one of a nickel metal layer, a copper metal layer and an aluminum metal layer, and the second grid line layer is a silver metal layer; or the first grid line layer is a conductive carbon layer, and the second grid line layer is a nickel metal layer. The utility model discloses in the first grid line layer that relates including positive first grid line layer 511 and the first grid line layer 521 in the back, the utility model discloses in the second grid line layer that relates including positive second grid line layer 512 and back second grid line layer 522.
It is to be understood that when the front composite sub-gate 51 and the back composite sub-gate 52 further have a front third gate line layer 513 and a back third gate line layer 523 respectively, it is preferable that the front third gate line layer 513 is made of the same material as the corresponding front second gate line layer 512, and the back third gate line layer 523 is made of the same material as the corresponding back second gate line layer 522.
Based on the above design mode, the utility model discloses guaranteeing that compound vice bars has under the prerequisite of lower resistance relatively, can effectively reduce the cost of manufacture of compound vice bars.
Further preferably, in the implementation process of the present invention, when the front first grid line layer 511 and the back first grid line layer 521 are one of a nickel metal layer, a copper metal layer and an aluminum metal layer, the mass ratio of silver in the corresponding front composite auxiliary grid 51 and the back composite auxiliary grid 52 is 15% to 25%. When the front-side first gate line layer 511 and the back-side first gate line layer 521 are conductive carbon layers, the mass ratio of nickel in the corresponding front-side composite auxiliary gate 51 and back-side composite auxiliary gate 52 is 60% -75%.
The width of the composite auxiliary grid in the utility model is 40-65 μm, and the thickness is 12-21 μm.
Preferably, the width and thickness of the front composite auxiliary grid 51 according to the present invention are smaller than the width and thickness of the back composite auxiliary grid 52, respectively. In the specific implementation process, the width of the front composite auxiliary grid 51 related in the utility model is 40-60 μm, and the thickness is 12-18 μm; the width of the back composite auxiliary grid 52 is 50-65 μm, and the thickness is 14-21 um.
Based on the above arrangement, the shielding effect of each front composite auxiliary grid 51 on solar illumination is smaller than that of each back composite auxiliary grid 52, so that the light receiving intensity of the front surface of the heterojunction solar cell can be effectively improved, and the photo-generated current can be improved.
It can be understood that the auxiliary grid related in the utility model can be a composite auxiliary grid, and can also be an auxiliary grid in a traditional form, such as a silver auxiliary grid. As preferably, the utility model discloses the interval of the adjacent two vice bars in well battery piece body sensitive surface one side is greater than the interval of the adjacent two vice bars in battery piece body backlight surface one side, and the vice bars quantity of sensitive surface is less than the vice bars quantity of backlight surface promptly, and the vice bars of sensitive surface shelters from the area and is less than the vice bars of backlight surface and shelters from the area. Therefore, in a specific application scene, the effective illumination area of the light receiving surface can be increased due to the large distance between the two adjacent sub-grids of the light receiving surface, the series resistance of the heterojunction solar cell can be reduced due to the small distance between the two adjacent sub-grids of the backlight surface, and the photoelectric conversion efficiency of the heterojunction solar cell can be effectively optimized due to the combination of the two.
In the specific implementation, the distance between two adjacent auxiliary grids on one side of the light receiving surface of the cell body is 1.5-2.0 mm; the distance between two adjacent auxiliary grids on one side of the backlight surface of the cell body is 1.0-1.9 mm.
It is understood that in some embodiments of the present invention, the widths of the sub-grids of the light receiving surface and the sub-grids of the backlight surface are the same, and only the difference exists in the sub-grid spacing, and particularly, no further development is made here.
For better understanding the utility model discloses the project organization of well compound vice bars, the utility model discloses still provide its concrete forming method. For the front-side composite auxiliary gate 51, when it only includes the front-side first gate line layer 511 and the front-side second gate line layer 512, the manufacturing method includes printing the first paste and the second paste on the surface of the first transparent conductive film 41 in sequence, and then curing to make the first paste and the second paste form the front-side first gate line layer 511 and the front-side second gate line layer 512, respectively.
It is easy to understand that when the front first gate line layer 511 is a nickel metal layer, a copper metal layer, an aluminum metal layer or a conductive carbon layer, the related first paste is correspondingly conductive nickel paste, conductive copper paste, conductive aluminum paste and conductive carbon paste, respectively; when the second gate line layer 512 on the front surface is a silver metal layer or a nickel metal layer, the related second paste is a conductive silver paste and a conductive nickel paste, respectively.
Further, when the front-side composite sub-grid 51 further includes the front-side third grid line layer 513, in the manufacturing process of the front-side composite sub-grid 51, before printing the first paste, the third paste is printed on the surface of the first transparent conductive film 41, and the related components of the third paste are consistent with those of the second paste.
The utility model discloses the compound vice bars 52 mode of making in back that relates can refer to the compound vice bars 51 mode of making in front, specifically does not do here and describe repeatedly.
The utility model discloses in, heterojunction solar cell is still including setting up in the compound main grid (not show in the picture) that first transparent conductive film layer 41 and/or the transparent conductive film layer 42 surface of second and extending direction are unanimous with the first direction, and compound main grid includes the fourth grid line layer and sets up in the fifth grid line layer that the fourth grid line layer deviates from battery piece body side surface, and fifth grid line layer covers the relative both sides surface of fourth grid line layer on width direction.
In some embodiments of the present invention, the surfaces of the first transparent conductive film layer 41 and the second transparent conductive film layer 42 are both provided with a composite main grid. Specifically, the composite main grid includes a front composite main grid disposed on the surface of the first transparent conductive film layer 41 and a back composite main grid disposed on the surface of the second transparent conductive film layer 42.
In other embodiments of the present invention, only one of the first transparent conductive film layer 41 and the second transparent conductive film layer 42 may be provided with a composite main grid having the above structure on the surface, and the other is provided with a main grid structure, such as a silver main grid, similar to the conventional technology.
The utility model relates to a heterojunction solar cell, which provides a composite main grid different from a main grid structure printed by traditional low-temperature conductive silver paste, and provides more choices for manufacturing a collector of the heterojunction solar cell; through rational configuration the utility model discloses the material on fourth grid line layer and fifth grid line layer in the compound main grid of heterojunction solar cell also can effectively reduce heterojunction solar cell's cost of manufacture, and can improve the high problem of low temperature thick liquids contact resistivity among the prior art, has reduced the loss of fill factor FF.
In still other embodiments of the present invention, the composite main grid may further include a sixth grid line layer disposed on a side surface of the fourth grid line layer facing the cell body and connected to the fifth grid line layer.
The utility model discloses in, the structure that sets up of fourth grid line layer, fifth grid line layer and sixth grid line layer related in the compound main grid can refer to the structure that sets up of first grid line layer, second grid line layer and third grid line layer in the compound vice grid of above-mentioned description respectively, specifically no longer makes the schematic diagram in addition.
In the utility model, the fourth grid line layer is one of a nickel metal layer, a copper metal layer, an aluminum metal layer and a glass powder layer, and the fifth grid line layer is a silver metal layer; or the fourth grid line layer is a conductive carbon layer, and the fifth grid line layer is a nickel metal layer. The utility model discloses in related fourth grid line layer including positive fourth grid line layer and back fourth grid line layer, the utility model discloses in related fifth grid line layer is including positive fifth grid line layer and back fifth grid line layer.
It is understood that when the composite main gate further has a sixth gate line layer, the sixth gate line layer is preferably made of the same material as the corresponding fifth gate line layer.
Based on the above design mode, the utility model discloses guaranteeing that compound owner bars has under the prerequisite of lower resistance relatively, can effectively reduce the cost of manufacture of compound owner bars.
Preferably, in the specific implementation process of the present invention, when the fourth gate line layer is a nickel metal layer, a copper metal layer or an aluminum metal layer, the mass ratio of silver in the corresponding composite main gate is 15% to 25%. When the fourth grid line layer is a glass powder layer, the mass proportion of silver in the corresponding composite main grid is 50-75%. When the positive fourth grid line layer is a conductive carbon layer, the mass proportion of nickel in the corresponding composite main grid is 60-75%.
In the specific implementation process, the width of the composite main grid is 0.1-0.2mm, and the thickness is 17-33 μm.
Wherein, for better understanding the utility model discloses the project organization of well compound owner bars, the utility model discloses still provide its concrete forming method. For the front-side composite main gate, when the front-side composite main gate only includes a front-side fourth gate line layer and a front-side fifth gate line layer, the manufacturing method includes sequentially printing a fourth slurry and a fifth slurry on the surface of the first transparent conductive film 41, and then curing the fourth slurry and the fifth slurry to form the front-side fourth gate line layer and the front-side fifth gate line layer, respectively.
It is easy to understand that when the fourth gate line layer on the front surface is a nickel metal layer, a copper metal layer, an aluminum metal layer, a glass powder layer or a conductive carbon layer, the related fourth paste is correspondingly conductive nickel paste, conductive copper paste, conductive aluminum paste, glass powder paste and conductive carbon paste respectively; when the fifth grid line layer on the front surface is a silver metal layer or a nickel metal layer, the related fifth slurry is correspondingly conductive silver slurry and conductive nickel slurry respectively.
Further, when the front-side composite main grid further includes a front-side sixth grid line layer, in the manufacturing process of the front-side composite main grid, before printing the fourth paste, the sixth paste is printed on the surface of the first transparent conductive film 41, and the related components of the sixth paste are consistent with those of the fifth paste.
The utility model discloses the compound main bars preparation mode in back that relates can refer to positive compound main bars preparation mode, specifically does not do here and gives unnecessary details.
In the more specific implementation process of the present invention, when the composite auxiliary grid and the composite main grid related in the present invention are simultaneously disposed on one side of the battery piece body, in some embodiments, the first grid line layer, the second grid line layer, and the third grid line layer constituting the composite auxiliary grid can be respectively printed and formed simultaneously with the fourth grid line layer, the fifth grid line layer, and the sixth grid line layer constituting the composite main grid; in other embodiments, the composite secondary grid and the composite primary grid can be printed and molded separately.
It can be understood that the main grid related to the present invention can be a composite main grid, and can also be a main grid in a traditional form, such as a silver main grid. The main gate and the sub-gate on the surface of the first transparent conductive film 41 together form a first collector, and the main gate and the sub-gate on the surface of the second transparent conductive film 42 together form a second collector.
Corresponding to the heterojunction solar cell described above, the utility model relates to a heterojunction solar cell manufacturing method includes:
providing a cell body;
depositing a first transparent conductive film layer 41 and a second transparent conductive film layer 42 on the light receiving surface and the backlight surface of the cell body respectively;
and sequentially printing a first slurry and a second slurry on at least one side of the cell body deposited with the first transparent conductive film layer 41 and the second transparent conductive film layer 42 to form a composite auxiliary grid 51 through curing, wherein the second slurry is different from the first slurry in material, and the printed second slurry covers the surfaces of two opposite sides of the first slurry in the width direction of the composite auxiliary grid.
Further, the manufacturing method further comprises the following steps: and before printing the first paste, printing a third paste at the position of printing the first paste, wherein the third paste is the same as the second paste in material, and the printed second paste is connected with the third paste.
Further, the first slurry is one of conductive nickel slurry, conductive copper slurry and conductive aluminum slurry, and the second slurry is conductive nickel slurry; or the first slurry is conductive carbon slurry, and the second slurry is conductive nickel slurry.
In still other embodiments of the present invention, the manufacturing method further includes: and sequentially printing fourth slurry and fifth slurry on at least one side of the cell body deposited with the first transparent conductive film layer 41 and the second transparent conductive film layer 42 to form a composite auxiliary grid with the extending direction perpendicular to the length direction of the composite auxiliary grid through curing, wherein the fifth slurry and the fourth slurry are different in material, and the printed fifth slurry covers the surfaces of two opposite sides of the fourth slurry in the width direction of the composite main grid.
Further, the manufacturing method further comprises the following steps: and printing a sixth paste at the position of printing the fourth paste before printing the fourth paste, wherein the sixth paste is the same as the fifth paste in material, and the printed fifth paste is connected with the sixth paste.
Further, the fourth slurry is one of conductive nickel slurry, conductive copper slurry, conductive aluminum slurry and glass powder, and the fifth slurry is conductive nickel slurry; or the fourth slurry is conductive carbon slurry, and the fifth slurry is conductive nickel slurry.
Preferably, the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 according to the present invention each include at least two intrinsic amorphous silicon films stacked on each other, and in the specific implementation process, by controlling the characteristics of each intrinsic amorphous silicon film, the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 having better overall performance can be formed.
Specifically, in the present invention, the hydrogen content of the intrinsic amorphous silicon film near the single crystal silicon substrate 10 in the first intrinsic amorphous layer 21 is higher than the hydrogen content of the intrinsic amorphous silicon film far from the single crystal silicon substrate, and the hydrogen content of the intrinsic amorphous silicon film near the single crystal silicon substrate 10 in the second intrinsic amorphous layer 22 is higher than the hydrogen content of the intrinsic amorphous silicon film far from the single crystal silicon substrate.
It can be easily understood that the intrinsic amorphous silicon films closer to the single crystal silicon substrate 10 of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 have more obvious passivation effect on the single crystal silicon substrate 10, and the intrinsic amorphous silicon films closer to the single crystal silicon substrate 10 have higher hydrogen content, so that the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 have the optimal passivation effect on the single crystal silicon substrate 10.
As a preferred embodiment, when the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 respectively include three intrinsic amorphous silicon films stacked, the hydrogen content of the three intrinsic amorphous silicon films of the first intrinsic amorphous layer 21 and the second intrinsic amorphous layer 22 respectively ranges from 20% to 40%, from 10% to 25%, and from 8% to 20% in this order in a direction away from the single crystal silicon substrate 10.
Preferably, the first doped amorphous layer 31 according to the present invention includes a first doped amorphous silicon film on the surface of the first intrinsic amorphous layer 21 and a doped amorphous silicon oxide film on the surface of the first doped amorphous silicon film.
The doped amorphous silicon oxide has more excellent light transmittance than the doped amorphous silicon. The first doped amorphous layer involved in the prior art is generally a single-layer doped amorphous silicon film structure; in this embodiment, the first doped amorphous layer 31 is designed as a double-layer film, wherein the first doped amorphous silicon film can ensure that the first doped amorphous layer 31 is in good contact with the first intrinsic amorphous layer 21, and the doped amorphous silicon oxide film is equivalent to replace a part of doped amorphous silicon in the prior art with doped amorphous silicon oxide having high light transmittance, so that the overall light transmittance of the first doped amorphous layer 31 can be improved, the loss of sunlight passing through the first intrinsic amorphous layer and the first doped amorphous layer can be reduced, the short-circuit current of the heterojunction solar cell can be further improved, and the optimization of the photoelectric conversion efficiency is facilitated.
Based on the cooperation of first doping amorphous silicon film, doping amorphous silicon oxide film promptly, the utility model provides a heterojunction solar cell has comparatively excellent optics and electrical property.
In a specific implementation process, the thickness of the first doped amorphous silicon film is less than or equal to that of the doped amorphous silicon oxide film; preferably, the thickness of the first doped amorphous silicon film is generally less than the thickness of the doped amorphous silicon oxide film. Thus, while ensuring a good contact between the first doped amorphous layer 31 and the first intrinsic amorphous layer 21, the first doped amorphous layer 31 can have a good transmittance to a great extent.
In other embodiments of the present invention, the first doped amorphous layer 31 further comprises a second doped amorphous silicon film on the surface of the doped amorphous silicon oxide film. The doped amorphous silicon generally has a relatively excellent conductivity, and the second doped amorphous silicon film is disposed to enable the first doped amorphous layer 31 and the first transparent conductive film layer 41 to have a relatively good contact therebetween, so as to further reduce the contact resistance, and enable the cell to have a higher fill factor. In particular, the doping concentration of the second doped amorphous silicon film may be higher than that of the first doped amorphous silicon film.
In this embodiment, the thickness of the second doped amorphous silicon film is less than or equal to the thickness of the doped amorphous silicon oxide film; preferably, the thickness of the second doped amorphous silicon film is also generally smaller than that of the doped amorphous silicon oxide film, thereby allowing the first doped amorphous layer 31 to have a better light transmittance.
Further, in still other embodiments of the present invention, the second doped amorphous layer 32 comprises a third doped amorphous silicon film on the surface of the second intrinsic amorphous layer 22 and a fourth doped amorphous silicon film with a doping concentration higher than that of the third doped amorphous silicon film on the surface of the third doped amorphous silicon film.
Preferably, the carrier concentration of the fourth doped amorphous silicon film is 5E 19-5E 21/cm3. Accordingly, the carrier concentration of the third doped amorphous silicon film is set to 5E 18-5E 19/cm3
In this embodiment, the third doped amorphous silicon film has a relatively low doping concentration, so that the influence on the second intrinsic amorphous layer 22 can be reduced, the lattice distortion of the second intrinsic amorphous layer 22 can be reduced, and the passivation effect of the back surface of the heterojunction solar cell can be effectively ensured; the fourth doped amorphous silicon film has a relatively high doping concentration, so that the contact between the second doped amorphous layer 32 and the second transparent conductive film can be improved, the contact resistance between the second doped amorphous layer and the second transparent conductive film can be reduced, and the cell filling factor can be improved.
In the utility model, the thickness of the third doped amorphous silicon film is less than or equal to that of the fourth doped amorphous silicon film; preferably, the thickness of the third doped amorphous silicon film is generally smaller than that of the fourth doped amorphous silicon film.
Preferably, in the present invention, the sum of the thicknesses of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 is smaller than the sum of the thicknesses of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32.
For the heterojunction solar cell, the influence of the light absorption effect of the light receiving surface on the photoelectric conversion efficiency of the cell is far larger than the influence of the light absorption effect of the backlight surface on the photoelectric conversion efficiency of the cell, and because the sum of the thicknesses of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 is smaller than the sum of the thicknesses of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32, the loss of sunlight on the light receiving surface when the sunlight passes through the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 can be effectively reduced, the short-circuit current of the heterojunction solar cell can be improved, and the heterojunction solar cell has better photoelectric conversion efficiency.
In some more specific embodiments of the present invention, the sum of the thicknesses of the first intrinsic amorphous layer 21 and the first doped amorphous layer 31 is 6-21nm, and the sum of the thicknesses of the second intrinsic amorphous layer 22 and the second doped amorphous layer 32 is 7-30 nm.
It is further preferable that the thickness of the first intrinsic amorphous layer 21 is less than or equal to the thickness of the second intrinsic amorphous layer 22, and the thickness of the first doped amorphous layer 31 is less than or equal to the thickness of the second doped amorphous layer 32.
In specific implementation, the thickness of the first doped amorphous layer 31 is 3-15nm, and the thickness of the second doped amorphous layer 32 is 3-20 nm. Accordingly, in the embodiment shown in FIG. 1, the first intrinsic amorphous layer 21 has a thickness of 3-6nm and the second intrinsic amorphous layer 22 has a thickness of 4-10 nm.
It is further preferable that the thickness of the first doped amorphous layer 31 is 4 to 5nm and the thickness of the second doped amorphous layer 32 is 4 to 5 nm. Accordingly, in the embodiment shown in FIG. 1, the first intrinsic amorphous layer 21 has a thickness of 4-5nm and the second intrinsic amorphous layer 22 has a thickness of 5-6 nm.
Further, in the present invention, the thickness of the first transparent conductive film layer 41 is less than or equal to the thickness of the second transparent conductive film layer 42. For the heterojunction solar cell, because the thickness of the first transparent conductive film layer 41 is relatively small, the loss of sunlight on the light receiving surface when the sunlight passes through the first transparent conductive film layer 41 can be effectively reduced, and the heterojunction solar cell can have better photoelectric conversion efficiency.
Generally, the thickness of the first transparent conductive film layer 41 and the second transparent conductive film layer 42 is in the range of 65-75 nm.
In the present invention, when the silicon substrate 10 is an N-type silicon substrate, the first doped amorphous layer 31 is an N-type doped amorphous layer, and the second doped amorphous layer 32 is a P-type doped amorphous layer. The first transparent conductive film layer 41 of the present invention includes a first TCO film attached to the surface of the first doped amorphous layer 31 and a second TCO film (not shown in the figure) attached to the surface of the first TCO film, wherein the mass ratio of the doped oxide in the first TCO film 411 is greater than the mass ratio of the doped oxide in the second TCO film 412.
In the heterojunction solar cell structure provided by the utility model, based on the specific design structure, the first TCO film can ensure better contact between the first transparent conductive film layer 41 and the first doped amorphous layer 31 due to high doping, thereby reducing the contact resistance and improving the fill factor of the heterojunction solar cell; the light transmittance of the first transparent conductive film layer 41 can be increased on the whole due to the low doping of the second TCO film, so that the short-circuit current of the heterojunction solar cell can be increased.
Preferably, in the specific implementation process of the present invention, the mass ratio of the doped oxide in the first TCO film is 5% to 20%, and the mass ratio of the doped oxide in the second TCO film is 0.5% to 5%.
Further, the second transparent conductive film layer 42 of the present invention includes a third TCO film attached to the surface of the second doped amorphous layer 32 and a fourth TCO film attached to the surface of the third TCO film, wherein the mass ratio of the doped oxide in the third TCO film is smaller than the mass ratio of the doped oxide in the fourth TCO film.
Since the third TCO film is in direct contact with the second doped amorphous layer 32, when the third TCO film is doped at a lower concentration, the schottky contact barrier between the two is reduced, so that the two can have an optimal contact, and the fill factor of the heterojunction solar cell is improved. In addition, the fourth TCO film has higher doping concentration, so that the fourth TCO film has better conductivity, and is in better electrical contact with the second collector electrode, so that the filling factor of the heterojunction solar cell can be improved. It can be known that, because the second transparent conductive film layer 42 is located the backlight surface of heterojunction solar cell, when specifically applying, shine to the inside sunlight proportion of heterojunction solar cell very low through second transparent conductive film layer 42, its luminousness is little to heterojunction solar cell's wholeness ability influence.
In the specific implementation process, the mass percentage of the doped oxide in the third TCO film is 0.5-5%, and the mass percentage of the doped oxide in the fourth TCO film is 5-20%.
In a more specific embodiment, when the silicon substrate 10 is an N-type silicon substrate, the first doped amorphous layer 31 is an N-type doped amorphous layer, and the second doped amorphous layer 32 is a P-type doped amorphous layer. The first transparent conductive film layer and the second transparent conductive film layer are made of ITO film (SnO)2Doped indium oxide formation).
On the light receiving surface side of the cell body, the first transparent conductive film layer 41 comprises two TCO layers, the first TCO film component is ITO (90:10), the film thickness is 5-10 nm, the second TCO film component is ITO (97:3), and the film thickness is 55-70 nm; on the backlight side of the cell body, the second transparent conductive film layer 42 also comprises two TCO layers, the third TCO film component is ITO (97:3), the film thickness is 5-10 nm, the fourth TCO film component is ITO (90:10), and the film thickness is 55-70 nm.
It should be understood that reference to ITO (97:3) above refers to indium oxide and SnO in the ITO film2Is 97:3, corresponding to doped oxide (SnO)2) The mass percentage of (A) is 3%; ITO (90:10) refers to indium oxide and SnO in ITO film2In a mass ratio of 90:10, corresponding to doped oxides (SnO)2) The mass ratio of (A) to (B) is 10%. .
In other embodiments of the present invention, the first transparent conductive film layer 41 and the second transparent conductive film layer 42 may also include only one TCO film, and the TCO film may be ITO (97:3) or ITO (90: 10).
The above list of details is only for the practical implementation of the present invention, and they are not intended to limit the scope of the present invention, and all equivalent implementations or modifications that do not depart from the technical spirit of the present invention should be included in the scope of the present invention.
Claims (11)
1. A heterojunction solar cell string comprises a plurality of heterojunction solar cells which are serially connected along a first direction, wherein each heterojunction solar cell comprises a cell body, a first transparent conductive film layer and a second transparent conductive film layer, the first transparent conductive film layer is arranged on one side of an illuminated surface of the cell body, the second transparent conductive film layer is arranged on one side of a backlight surface of the cell body, the composite auxiliary grid is characterized by further comprising a composite auxiliary grid, the composite auxiliary grid is arranged on the surface of the first transparent conductive film layer and/or the surface of the second transparent conductive film layer, the extending direction of the composite auxiliary grid is perpendicular to the first direction, the composite auxiliary grid comprises a first grid line layer and a second grid line layer, the second grid line layer is arranged on the surface of one side, deviating from the cell body, of the first grid line layer, and the second grid line layer covers the surfaces of two opposite sides of the first.
2. The heterojunction solar cell string of claim 1, wherein the first gate line layer is one of a nickel metal layer, a copper metal layer, and an aluminum metal layer, and the second gate line layer is a silver metal layer; or, the first grid line layer is a conductive carbon layer, and the second grid line layer is a nickel metal layer.
3. The heterojunction solar cell string of claim 1 or 2, wherein the composite secondary grid further comprises a third grid line layer disposed on a side surface of the first grid line layer facing the cell body and connected to the second grid line layer.
4. The heterojunction solar cell string of claim 3, wherein the first gate line layer is one of a nickel metal layer, a copper metal layer and an aluminum metal layer, and the third gate line layer is a silver metal layer; or, the first grid line layer is a conductive carbon layer, and the third grid line layer is a nickel metal layer.
5. The heterojunction solar cell string of claim 1 or 2, wherein the width of the composite subgrid is 40-65 μ ι η and the thickness is 12-21 μ ι η.
6. The heterojunction solar cell string of claim 1, further comprising a composite main grid disposed on the surface of the first transparent conductive film layer and/or the second transparent conductive film layer and extending in the same direction as the first direction, wherein the composite main grid comprises a fourth grid line layer and a fifth grid line layer disposed on a side surface of the fourth grid line layer facing away from the cell body, and the fifth grid line layer covers two opposite side surfaces of the fourth grid line layer in the width direction.
7. The heterojunction solar cell string of claim 6, wherein the fourth gate line layer is one of a nickel metal layer, a copper metal layer, an aluminum metal layer and a glass powder layer, and the fifth gate line layer is a silver metal layer; or, the fourth grid line layer is a conductive carbon layer, and the fifth grid line layer is a nickel metal layer.
8. The heterojunction solar cell string of claim 6 or 7, wherein the composite main grid further comprises a sixth grid line layer disposed on a side surface of the fourth grid line layer facing the cell body and connected to the fifth grid line layer.
9. The heterojunction solar cell string of claim 8, wherein the fourth gate line layer is one of a nickel metal layer, a copper metal layer, an aluminum metal layer, and a glass powder layer, and the sixth gate line layer is a silver metal layer; or, the fourth grid line layer is a conductive carbon layer, and the sixth grid line layer is a nickel metal layer.
10. The heterojunction solar cell string of claim 6 or 7, wherein the width of the composite main grid is 0.1-0.2mm and the thickness is 17-33 μm.
11. The heterojunction solar cell string of claim 1, 2, 6 or 7, wherein the cell body comprises a silicon substrate, a first intrinsic amorphous layer and a first doped amorphous layer sequentially disposed on a light receiving surface side of the silicon substrate, a second intrinsic amorphous layer sequentially disposed on a backlight surface side of the silicon substrate, and a second doped amorphous layer with a doping type opposite to that of the first doped amorphous layer, wherein the first transparent conductive film and the second transparent conductive film are respectively disposed on a side surface of the first doped amorphous layer and the second doped amorphous layer away from the silicon substrate.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113594272A (en) * | 2021-07-29 | 2021-11-02 | 安徽华晟新能源科技有限公司 | Heterojunction solar cell and preparation method thereof |
| CN113675302A (en) * | 2021-08-18 | 2021-11-19 | 浙江爱旭太阳能科技有限公司 | HJT battery and processing method thereof |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113594272A (en) * | 2021-07-29 | 2021-11-02 | 安徽华晟新能源科技有限公司 | Heterojunction solar cell and preparation method thereof |
| CN113675302A (en) * | 2021-08-18 | 2021-11-19 | 浙江爱旭太阳能科技有限公司 | HJT battery and processing method thereof |
| CN113675302B (en) * | 2021-08-18 | 2024-04-26 | 浙江爱旭太阳能科技有限公司 | Processing method of HJT battery and HJT battery |
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