Solar cell and photovoltaic module

Abstract

The utility model discloses a solar cell and a photovoltaic assembly. The solar cell comprises a silicon substrate layer, a transmission layer, a passivation layer and a grid line layer which are stacked in sequence. The grid line layer comprises a bus grid line and a plurality of current collection grid lines, the bus grid line is connected with the current collection grid lines, the bus grid line extends in the first direction, the current collection grid lines are arranged at intervals in the first direction, and the current collection grid lines extend in the second direction. The passivation layer is provided with a plurality of first holes corresponding to the plurality of collector grid lines, the collector grid lines are electrically connected with the transmission layer through the first holes, the depth difference between any two first holes is delta H, and | delta H | is less than or equal to 200nm. Wherein the thickness direction, the first direction and the second direction are perpendicular to each other. The solar cell provided by the utility model has good stability, and the stability of a photovoltaic module can be improved by carrying the solar cell provided by the invention.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy, in particular to a solar cell and a photovoltaic module. BACKGROUND

[0002] The solar cell uses its semiconductor base layer to receive solar energy and converts the received solar energy into electric energy for users to use. In order to efficiently collect the current generated by the semiconductor base layer after converting solar energy, a large density of grid lines need to be arranged on the surface of the semiconductor base layer. The grid lines usually realize Ohmic contact between the semiconductor base layer through multiple points to collect the current at different positions of the semiconductor base layer.

[0003] However, the grid lines and electrode lines of the solar cell are arranged on the surface of the semiconductor base layer. When the solar cell receives light using the semiconductor base layer and converts solar energy into electric energy, the grid lines and electrode lines will cause shading to the semiconductor base layer, reducing the effective light area of the solar cell, thereby reducing the energy output power of the solar cell. At the same time, the grid lines of the solar cell still have defects, which cause the solar cell to easily appear local overheating and poor product stability and other problems. CONTENT OF THE UTILITY MODEL

[0004] The present application discloses a solar cell and a photovoltaic module, which can improve the stability of the solar cell.

[0005] In a first aspect, the present application discloses a solar cell, comprising:

[0006] a silicon base layer;

[0007] a transport layer, the transport layer is arranged on the silicon base layer along the thickness direction of the silicon base layer, and the transport layer is used for transporting carriers;

[0008] a grid line layer, the grid line layer is arranged on the side of the transport layer away from the silicon base layer along the thickness direction of the silicon base layer, the grid line layer comprises a busbar grid line and a plurality of current collection grid lines, the busbar grid line and the plurality of current collection grid lines are connected, the busbar grid line extends along a first direction, the plurality of current collection grid lines are arranged at intervals along the first direction, and the current collection grid line extends along a second direction;

[0009] a passivation layer, the passivation layer is arranged between the transport layer and the grid line layer, the passivation layer is provided with a plurality of first openings corresponding to the plurality of current collection grid lines, the current collection grid line is electrically connected with the transport layer through the first opening, the depth difference of any two first openings is ΔH, and |ΔH|≤200nm;

[0010] Wherein, the thickness direction, the first direction and the second direction are perpendicular to each other.

[0011] The solar cell of the present application forms a plurality of first openings on the passivation layer corresponding to the positions of the current collecting grid lines, and the depth difference between different first openings is ΔH. By making |ΔH|≤200nm, the depth difference between different first openings is effectively reduced, the ohmic contact between different positions of the current collecting grid lines and the transport layer is ensured to be relatively uniform, the grid line resistance distribution of the solar cell can be made uniform, the local concentration of grid line current can be prevented, and the local overheating of the solar cell can be avoided, so that the thermal runaway of the solar cell can be prevented. At the same time, the consistency of the electrical performance of different positions inside the solar cell can be ensured, and the stability of the power output at the component level can be ensured. In addition, by reducing the depth difference of the first openings at different positions of the passivation layer, the cracks inside the solar cell caused by stress concentration can also be prevented, so that the structural failure of the solar cell under thermal cycling and mechanical load can be avoided.

[0012] In a possible implementation, the passivation layer is provided with a plurality of first openings corresponding to each of the current collecting grid lines, and the plurality of first openings corresponding to at least one of the current collecting grid lines are arranged at intervals in the second direction.

[0013] The passivation layer is provided with a plurality of first openings corresponding to the positions of each current collecting grid line, so that the total contact area between each current collecting grid line and the passivation layer can be increased, and the total contact area is divided into a plurality of small-area contact surfaces, which can maximize the uniformity of the ohmic contact between each position of the grid line and the semiconductor substrate layer, thereby effectively improving the current collection efficiency and performance stability of the current collecting grid line.

[0014] In a possible implementation, the spacing of the plurality of first openings corresponding to at least one of the current collecting grid lines in the second direction first increases in turn and then decreases in turn.

[0015] Alternatively, the spacing of the plurality of first openings corresponding to at least one of the current collecting grid lines in the second direction first decreases in turn and then increases in turn.

[0016] The positions of the first openings are regularly arranged in different ways, which can flexibly design the solar cell according to the actual situation, and can also make the first openings regular, so as to avoid the disorder of the current transmission inside the solar cell.

[0017] In a possible implementation, the plurality of first openings corresponding to at least one of the current collecting grid lines are arranged in a staggered manner in the first direction.

[0018] And / or, the spacing between any two adjacent first openings is d1, the maximum size of the first openings in the second direction is d2, and d1, d2 satisfy the relationship:

[0019] d1≤3d2.

[0020] By properly setting the positions of the different first openings to increase the distance between adjacent first openings, the current of the current collecting grid line is prevented from being too concentrated, thereby preventing the occurrence of current collecting grid line heat concentration.

[0021] In one possible implementation, the inner diameters of at least two of the first openings corresponding to at least one of the current collecting grid lines are different.

[0022] The first openings with different inner diameters are formed at different positions of the passivation layer according to actual needs. For example, the inner diameter of the first opening corresponding to the position of the current collecting grid line away from the bus grid line can be set to be larger, so as to reduce the influence of the long current transmission path, and the inner diameter of the first opening corresponding to the position of the current collecting grid line close to the bus grid line can be appropriately reduced, so that the overall conductive effect of the solar cell is more balanced.

[0023] In one possible implementation, the inner diameters of the first openings corresponding to at least one of the current collecting grid lines first increase in sequence and then decrease in sequence in the second direction.

[0024] Alternatively, the inner diameters of the first openings corresponding to at least one of the current collecting grid lines first decrease in sequence and then increase in sequence in the second direction.

[0025] Since the inner diameters of the first openings can be adjusted according to actual needs, the inner diameters of the first openings in different regions can be adapted to the internal structure of the solar cell, which is beneficial to flexibly setting and matching the internal structure of the solar cell.

[0026] In one possible implementation, the first openings corresponding to the current collecting grid line are a plurality of first openings, and the plurality of first openings are arranged in an array on the passivation layer.

[0027] And / or, the part corresponding to the connection of the bus grid line and the current collecting grid line is a crossing part, the passivation layer has an opening film area corresponding to the crossing part, the opening film area is used to set the second opening, the size of the bus grid line in the second direction is D1, the size of the current collecting grid line in the first direction is D2, and the area of the opening film area is S, S, D1 and D2 satisfy the relationship:

[0028] S≤D1*D2.

[0029] By arranging the first openings in an array, the points of ohmic contact between the current collecting grid lines and the transmission layer are increased, which can improve the current collecting efficiency and performance stability of the current collecting grid lines, and can also improve the uniformity of the ohmic contact between the grid lines and the semiconductor substrate layer, thereby improving the consistency of the electrical parameters at different positions inside the solar cell. In addition, by limiting the size of the opening film area, the opening area of the passivation layer can be reduced, i.e., the damage to the passivation layer is reduced, and the protection of the passivation layer to the internal structure of the solar cell is ensured.

[0030] In a possible implementation, the grid line layer includes a first polarity grid line layer and a second polarity grid line layer, the first polarity grid line layer and the second polarity grid line layer are arranged alternately and insulated from each other along the second direction;

[0031] The first polarity grid line layer includes a first polarity bus grid line and a plurality of first polarity current collecting grid lines, the first polarity bus grid line and the plurality of first polarity current collecting grid lines are connected, the first polarity bus grid line extends along the first direction, and the plurality of first polarity current collecting grid lines extend along the second direction and are arranged at intervals along the first direction;

[0032] The second polarity grid line layer includes a second polarity bus grid line and a plurality of second polarity current collecting grid lines, the second polarity bus grid line and the plurality of second polarity current collecting grid lines are connected, the second polarity bus grid line extends along the first direction, and the plurality of second polarity current collecting grid lines extend along the second direction and are arranged at intervals along the first direction.

[0033] Since a plurality of first openings are arranged corresponding to the current collecting grid lines, the current collecting and conducting effect of the current collecting grid lines is improved, so that the grid lines of different polarities of the solar cell can be integrated into one side of the solar cell, and the other side of the solar cell can not be provided with grid lines, thereby reducing the shading of the light exposure area by the structure of the solar cell itself, increasing the light exposure area of the solar cell, and increasing the energy output efficiency of the solar cell.

[0034] In a possible implementation, the distance between any two adjacent current collecting grid lines corresponding to the first polarity grid line layer is D3, the distance between any two adjacent first openings on the first polarity current collecting grid lines corresponding to the two adjacent first polarity grid line layers is D4, and D3 and D4 satisfy the following relationship:

[0035] (D3+10) μm≤D4≤(D3+200) μm;

[0036] And / or, the distance between any two adjacent second polarity current collecting grid lines corresponding to the second polarity grid line layer is D5, the distance between any two adjacent first openings on the current collecting grid lines corresponding to the two adjacent second polarity grid line layers is D6, and D5 and D6 satisfy the following relationship:

[0037] (D5+10)pm≤D6≤(D5+200)pm.

[0038] When (D3+10)pm≤D4≤(D3+200)pm, it can be ensured that the collector grid lines of the first polarity grid line layer can completely cover the first openings, avoiding that the first openings expose the internal structure of the solar cell due to the grid lines not completely covering the first openings, and ensuring the effective protection of the passivation layer on the internal structure of the solar cell. Similarly, when (D5+10)pm≤D6≤(D5+200)pm, it can be ensured that the collector grid lines of the second polarity grid line layer can completely cover the first openings, avoiding that the first openings expose the internal structure of the solar cell due to the grid lines not completely covering the first openings, and ensuring the effective protection of the passivation layer on the internal structure of the solar cell.

[0039] In a second aspect, the present application discloses a photovoltaic module, comprising the solar cell according to any one of the above.

[0040] Compared with the prior art, the present application has at least the following beneficial effects:

[0041] The solar cell disclosed in the present application forms a plurality of first openings on the passivation layer corresponding to the positions of the collector grid lines, and the depth difference between different first openings is ΔH. By making |ΔH|≤200nm, the depth difference between different first openings is effectively reduced, the ohmic contact between different positions of the collector grid lines and the transport layer is ensured to be relatively balanced, the grid line resistance distribution of the solar cell can be balanced, local concentration of grid line current can be prevented, and local overheating of the solar cell can be avoided, so that thermal runaway of the solar cell can be prevented. At the same time, the consistency of the electrical performance of different positions in the solar cell can be ensured, and the stability of the power output at the module level can be ensured. In addition, by reducing the depth difference of the first openings of the passivation layer at different positions, cracks caused by stress concentration in the solar cell can also be prevented, so that structural failure of the solar cell under thermal cycling and mechanical load can be avoided. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the present application, the drawings required to be used in the application will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0043] Figure 1 is a structural schematic diagram of a solar cell in the embodiments of the present application;

[0044] Figure 2 is Figure 1A partial cross-sectional view of the solar cell along the A-A' direction is shown.

[0045] Figure 3 is a schematic diagram of the first opening being arranged at equal intervals in the embodiment of the present application;

[0046] Figure 4 is a schematic diagram of the first opening having an increasing interval first and then decreasing in the embodiment of the present application;

[0047] Figure 5 is a schematic diagram of the first opening having a decreasing interval first and then increasing in the embodiment of the present application;

[0048] Figure 6 is a schematic diagram of the first opening having a decreasing interval in the direction away from the busbar in the embodiment of the present application;

[0049] Figure 7 is a schematic diagram of the first opening having an increasing interval in the direction away from the busbar in the embodiment of the present application;

[0050] Figure 8 is a schematic diagram of the first opening being arranged in a staggered manner in the first direction in the embodiment of the present application;

[0051] Figure 9 is Figure 3 is an enlarged schematic diagram of the A area in the embodiment of the present application;

[0052] Figure 10 is a schematic diagram of the first opening being arranged in an array manner in the embodiment of the present application;

[0053] Figure 11 is a schematic diagram of the first opening being communicated with each other in the embodiment of the present application;

[0054] Figure 12 is another schematic diagram of the first opening being communicated with each other in the embodiment of the present application;

[0055] Figure 13 is still another schematic diagram of the first opening being communicated with each other in the embodiment of the present application;

[0056] Figure 14 is a schematic diagram of the first opening being arranged in an array manner and communicated with each other in the embodiment of the present application;

[0057] Figure 15 is a schematic diagram of the inner diameter of the first opening increasing in the direction away from the busbar in the embodiment of the present application;

[0058] Figure 16 is a schematic diagram of the inner diameter of the first opening decreasing in the direction away from the busbar in the embodiment of the present application;

[0059] Figure 17is a schematic diagram of the first opening in the embodiment of the present application, in which the inner diameter of the first opening increases first and then decreases in the direction away from the busbar grid line;

[0060] Figure 18 is a schematic diagram of the first opening in the embodiment of the present application, in which the inner diameter of the first opening decreases first and then increases in the direction away from the busbar grid line;

[0061] Figure 19 is a schematic diagram of the first opening in the embodiment of the present application, in which the inner diameters of a plurality of first openings with different sizes are arranged alternately in the direction away from the busbar grid line;

[0062] Figure 20 is a schematic diagram of the structure of the solar cell with the second opening in the embodiment of the present application;

[0063] Figure 21 is a schematic diagram of the structure of the solar cell with the second opening in the embodiment of the present application; Figure 20 is an enlarged schematic diagram of the B region in

[0064] Figure 22 is a schematic diagram of the solar cell with the first polarity grid line layer and the second polarity grid line layer in the embodiment of the present application;

[0065] Figure 23 is a schematic diagram of the solar cell with the first polarity grid line layer and the second polarity grid line layer in the embodiment of the present application; Figure 22 is an enlarged schematic diagram of the C region in

[0066] Figure 24 is an enlarged schematic diagram of the D region in Figure 22

[0067] is a schematic diagram of the structure of a photovoltaic module in the embodiment of the present application. Figure 25 Legend of Reference Signs

[0068] Solar cell 1;

[0069] Silicon substrate layer 11;

[0070] Transport layer 12;

[0071] Grid line layer 13, busbar grid line 131, collector grid line 132, first polarity grid line layer 133, first polarity busbar grid line 133a, first polarity collector grid line 133b, second polarity grid line layer 134, second polarity busbar grid line 134a, second polarity collector grid line 134b;

[0072] Passivation layer 14, first opening 141, second opening 142;

[0073] Crossing portion A1, film opening region A2;

[0074] Photovoltaic module 2;

[0075] Inverter 21;

[0076] Inverter 21;

[0077] Thickness direction P1, first direction P2, second direction P3. Detailed Implementation

[0078] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0079] In this application, the terms "upper," "inner," "outer," "middle," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0080] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0081] Furthermore, the terms "provided with" and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0082] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0083] Solar cells receive solar energy and convert it into electrical energy for users to use, saving on electricity costs. Users can also store the converted energy for emergency use during power outages. In a solar cell, a semiconductor substrate (usually silicon) is typically used to receive solar energy and convert it into electrical energy (current). Grid lines are placed on the semiconductor substrate to collect the converted current, which is then output through electrodes.

[0084] At present, the solar cell still has the problems of low current collection efficiency, local heat concentration of the solar cell, uneven overall efficiency and large power loss. Moreover, the passivation layer and the grid line of the solar cell have low durability and are prone to cracking and damage during use, resulting in failure of the battery structure. These problems either affect the component-level output of the solar cell or affect the service life of the solar cell, and solving the related technical problems is very important for improving the overall performance of the solar cell.

[0085] In related designs, the above defects are generally improved by increasing the cross-sectional area of the grid line and / or increasing the via area of the passivation layer to increase the contact area between the grid line and the semiconductor base layer. For example, by increasing the cross-sectional area of the grid line (thickening), the current flow area can be increased, the current flow efficiency can be improved, and because the grid line is thickened, the mechanical strength of the grid line is improved and is not prone to damage. Increasing the contact area between the grid line and the semiconductor base layer can also increase the current flow efficiency between the grid line and the semiconductor base layer. However, thickening the grid line will directly result in an increase in the weight of the solar cell and an increase in the use of grid line materials, which is not conducive to cost control. Moreover, the area of the solar cell is fixed, and thickening the grid line directly affects the number of grid lines that can be arranged on the surface of the solar cell, which also affects the current collection effect. Increasing the via of the passivation layer will directly reduce the protection of the internal structure of the solar cell by the passivation layer, thereby reducing the stability of the solar cell.

[0086] It can be seen that the related technical means for solving the above technical problems still have obvious defects, and there is an urgent need in the art for a technical solution that can effectively solve the above technical problems.

[0087] To solve the above technical problems, the present application discloses a solar cell, which forms a plurality of first openings on the passivation layer corresponding to the positions of the current collecting grid lines, and the depth difference between different first openings is ΔH, by making |ΔH|≤200nm, effectively reducing the depth difference between different first openings, ensuring that different positions of the current collecting grid lines can achieve balanced ohmic contact between the corresponding first openings and the transmission layer, making the grid line resistance distribution of the solar cell balanced, preventing local concentration of grid line current, and avoiding causing local overheating of the solar cell, thereby preventing thermal runaway of the solar cell. At the same time, it can also ensure the consistency of the electrical performance of different positions inside the solar cell, and further ensure the stability of the component-level power output. In addition, by reducing the depth difference of the first openings of the passivation layer at different positions, it can also prevent cracks caused by stress concentration inside the solar cell, thereby avoiding structural failure of the solar cell under thermal cycling and mechanical load.

[0088] It should be noted that the solar cell in the present application can be a back contact cell, a passivation contact cell, etc., and the following will be described by taking a back contact cell as an example, but it does not mean that the related settings are only applicable to this example.

[0089] Please refer to Figure 1 and Figure 2 , Figure 1 is a schematic diagram of a perspective structure of a coil assembly 100 in an embodiment of the present application, Figure 2 is Figure 1 a schematic diagram of a cross section of the coil assembly 100 along the line AA' of

[0090] In a first aspect, an embodiment of the present application provides a solar cell 1, which includes a silicon substrate layer 11, a transport layer 12, a grid line layer 13, and a passivation layer 14. The transport layer 12 is arranged on the silicon substrate layer 11 in a stacking manner along a thickness direction P1 of the silicon substrate layer 11, the passivation layer 14 is arranged on a side of the transport layer 12 away from the silicon substrate layer 11 in a stacking manner along the thickness direction P1 of the silicon substrate layer 11, and the grid line layer 13 is arranged on a side of the passivation layer 14 away from the silicon substrate layer 11 in a stacking manner along the thickness direction P1 of the silicon substrate layer 11.

[0091] The grid line layer 13 includes a busbar grid line 131 and a plurality of current collection grid lines 132. The busbar grid line 131 extends along a first direction P2, the plurality of current collection grid lines 132 are arranged at intervals along the first direction P2, and each of the plurality of current collection grid lines 132 extends along a second direction P3. The busbar grid line 131 and the plurality of current collection grid lines 132 are connected to each other.

[0092] The passivation layer 14 is provided with a plurality of first openings 141 corresponding to the plurality of current collection grid lines 132, and the current collection grid lines 132 are electrically connected to the transport layer 12 through the first openings 141. The depth difference between any two first openings 141 is ΔH, and |ΔH|≤200nm.

[0093] It can be understood that, in the solar cell 1, the silicon substrate layer 11 can be made of N-type silicon or P-type silicon, and is used to receive solar energy and convert the received solar energy into electrical energy. The transport layer 12 can provide an overcurrent channel for the current, and the current collection grid lines 132 can collect the current formed in the silicon substrate layer 11 through the transport layer 12 by being electrically connected (ohmic contact) to the transport layer 12. The busbar grid line 131 can collect the current collected by the plurality of current collection grid lines 132 and output the current to the outside.

[0094] Optionally, the first openings 141 can be realized by laser point touch opening, mechanical punching, chemical etching, wet etching, dry etching, etc., and the present application does not make specific limitation thereto.

[0095] In addition, the grid line layer 13 can directly fill the first openings 141 and be connected to the transport layer 12, or electrodes can be arranged corresponding to the first openings 141, the electrodes are electrically connected to the transport layer 12, and the grid line layer 13 is formed on the electrodes, and the present application does not make specific limitation thereto.

[0096] It should be noted that when the depth difference of the first openings 141 is too large, the current transmission of the current collecting grid lines 132 in some areas will be hindered, resulting in uneven overall resistance distribution of the solar cell 1, thereby reducing the fill factor (FF) and conversion efficiency, which will reduce the current collection efficiency of the solar cell 1. When the depth difference of the first openings 141 is too large, the current may be concentrated in local areas (where the first openings 141 are in good contact), causing local overheating, i.e., hot spot effect, which will accelerate the aging of the solar cell 1 and may cause the solar cell 1 to burn out.

[0097] Further, when the depth difference of the different first openings 141 is too large, it will affect the consistency of the grid line layer 13 at different positions during forming, which may cause poor contact or metal fracture between the grid line layer 13 and the transport layer 12, reducing the long-term reliability of the solar cell 1. In addition, when the depth difference of the different first openings 141 is too large, it will not only affect the grid line layer 13, but also cause stress concentration in some first openings 141, which is prone to cracks when the solar cell 1 is under thermal cycling and / or mechanical load, resulting in structural failure of the solar cell 1.

[0098] In addition, when the depth difference of the first openings 141 in different areas of the same solar cell 1 is too large, the electrical properties of different areas will not match, reducing the uniformity of the overall solar cell 1 efficiency, and further affecting the output power at the component level.

[0099] As can be seen, by making the depth difference |ΔH| between different first openings 141 ≤200nm, the present application ensures that the ohmic contact between different positions of the current collecting grid lines 132 and the transport layer 12 is relatively balanced, which can balance the grid line resistance distribution of the solar cell 1, prevent local concentration of grid line current, and avoid causing local overheating of the solar cell 1, thereby preventing thermal runaway of the solar cell 1, and further ensuring the consistency of the electrical properties of different positions inside the solar cell 1, thereby ensuring the stability of the power output at the component level. In addition, by reducing the depth difference of the first openings 141 at different positions of the passivation layer 14, cracks inside the solar cell 1 caused by stress concentration can also be prevented, thereby avoiding structural failure of the solar cell 1 under thermal cycling and mechanical load.

[0100] In some embodiments, the opening depth of the first openings 141 is greater than the thickness of the passivation layer 14 and less than the sum of the thicknesses of the passivation layer 14 and the transport layer 12. In this way, it can be ensured that the grid line layer 13 can pass through the first openings 141 and form effective ohmic contact with the transport layer 12, while avoiding damage to the silicon substrate layer 11.

[0101] In some embodiments, the first opening 141 has an opening depth of 90-500 nm, for example, 90 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, etc.

[0102] Optionally, the first opening 141 can be a circular, elliptical, square, triangular, polygonal or irregularly shaped opening, and the shapes of different first openings 141 can be the same or different. The present application does not make specific limitations in this regard.

[0103] Please see Figures 3 to 5 , Figure 3 is a schematic diagram of the first openings being equally spaced in the embodiment of the present application, Figure 4 is a schematic diagram of the first openings having an increasing interval first and then a decreasing interval in the embodiment of the present application, Figure 5 is a schematic diagram of the first openings having a decreasing interval first and then an increasing interval in the embodiment of the present application.

[0104] In some embodiments, the passivation layer 14 is provided with a plurality of first openings 141 corresponding to each collector grid line 132, and the plurality of first openings 141 corresponding to at least one collector grid line 132 are spaced apart along the second direction P3. In this way, the total contact area between each collector grid line 132 and the passivation layer 14 can be increased, and the total contact area is divided into a plurality of small-area contact surfaces, which can maximize the uniformity of the ohmic contact between the grid line layer 13 and the silicon substrate layer 11, thereby effectively improving the current collection efficiency and performance stability of the collector grid line 132.

[0105] Optionally, the plurality of first openings 141 are spaced apart along the second direction P3, wherein the plurality of first openings 141 can be equally spaced apart or non-equally spaced apart. It can be understood that equally spacing the first openings 141 can reduce the difficulty of opening the passivation layer 14, thereby reducing the manufacturing difficulty and cost of the solar cell 1. However, non-equally spacing the first openings 141 can improve the flexibility of opening the passivation layer 14, and the opening positions of the first openings 141 can be appropriately set according to the actual product requirements of the solar cell 1.

[0106] For example, the interval between any two adjacent first openings 141 corresponding to at least one current collecting grid line 132 in the second direction P3 first increases in turn and then decreases in turn. Alternatively, the interval can be set to first decrease in turn and then increase in turn in the second direction P3. Specifically, the above setting mode can be selected according to actual product requirements. It can be understood that the position of the first opening 141 is regularly set in different ways, which can not only flexibly design the solar cell 1 according to the actual situation, but also regularly arrange the first opening 141 to avoid the disorder of current transmission inside the solar cell 1.

[0107] For example, the interval between any two adjacent first openings 141 corresponding to at least one current collecting grid line 132 in the second direction P3 first increases in turn and then decreases in turn. Alternatively, the interval can be set to first decrease in turn and then increase in turn in the second direction P3. Specifically, the above setting mode can be selected according to actual product requirements. It can be understood that the position of the first opening 141 is regularly set in different ways, which can not only flexibly design the solar cell 1 according to the actual situation, but also regularly arrange the first opening 141 to avoid the disorder of current transmission inside the solar cell 1. Figure 6 and Figure 7 , Figure 6 is a schematic view of the first opening interval decreasing in the direction away from the bus grid line in the embodiment of the present application, Figure 7 is a schematic view of the first opening interval increasing in the direction away from the bus grid line in the embodiment of the present application.

[0108] In some embodiments, the interval between any two adjacent first openings 141 corresponding to at least one current collecting grid line 132 in the second direction P3 can decrease in turn in the direction away from the bus grid line 131. It can be understood that the transmission path between the position of the current collecting grid line 132 away from the bus grid line 131 and the bus grid line 131 is longer, and the current loss is larger, so the opening density of the first opening 141 can be increased to increase the current passing efficiency of the current collecting grid line 132 at the corresponding position.

[0109] Of course, in some other embodiments, the interval between any two adjacent first openings 141 corresponding to at least one current collecting grid line 132 in the second direction P3 can increase in turn in the direction away from the bus grid line 131.

[0110] For example, the interval between any two adjacent first openings 141 corresponding to at least one current collecting grid line 132 in the second direction P3 first increases in turn and then decreases in turn. Alternatively, the interval can be set to first decrease in turn and then increase in turn in the second direction P3. Specifically, the above setting mode can be selected according to actual product requirements. It can be understood that the position of the first opening 141 is regularly set in different ways, which can not only flexibly design the solar cell 1 according to the actual situation, but also regularly arrange the first opening 141 to avoid the disorder of current transmission inside the solar cell 1. Figure 8 , Figure 8 is a schematic view of the first opening in the first direction in the embodiment of the present application.

[0111] In some embodiments, the first openings 141 corresponding to at least one current collecting grid line 132 are arranged in the first direction P2. That is, the first openings 141 are arranged in the second direction P3 and can be arranged in the first direction P2, for example, alternately arranged. By arranging the first openings 141 in the first direction P2, the setting density of the first openings 141 can be increased while maintaining the same interval, thereby increasing the contact area between the current collecting grid line 132 and the transmission layer 12 and further optimizing the ohmic contact between the current collecting grid line 132 and the transmission layer 12.

[0112] Referring to Figure 9 , Figure 9 is Figure 3 an enlarged schematic view of the A region in

[0113] In some embodiments, the distance between any two adjacent first openings 141 is defined as d1, and the maximum dimension of the first openings 141 in the second direction P3 is defined as d2, and d1 and d2 satisfy the relationship: d1≤3d2, that is, the distance between any two adjacent first openings 141 is not greater than 3 times the maximum dimension of the first openings 141 in the second direction P3, so that the density of the first openings 141 can be reasonably set, and the situation that the overcurrent efficiency of the grid line layer 13 is reduced due to the small density of the first openings 141 caused by the large distance between the first openings 141 can be avoided.

[0114] It can be understood that when the first openings 141 are circular holes, d2 is the diameter of the first openings 141. When the first openings 141 are square holes, d2 is the long side dimension of the first openings 141. When the first openings 141 are elliptical holes, triangular holes or polygonal holes, d2 is the value at the maximum dimension of the first openings 141 in the second direction P3.

[0115] Referring to Figure 10 , Figure 10 is a schematic view of the first openings arranged in an array in the embodiments of the present application.

[0116] In some embodiments, the first openings 141 are arranged in an array, that is, a plurality of first openings 141 can be arranged as a group, and there are a plurality of groups of first openings 141, and the plurality of groups of first openings 141 are arranged at intervals along the first direction P2, and the plurality of first openings 141 in each group of first openings 141 can be arranged at intervals along the second direction P3. That is, the first openings 141 on at least one current collecting grid line 132 can be arrayed openings. In this way, the plurality of arrayed points on the current collecting grid line 132 can achieve ohmic contact with the transmission layer 12, which can improve the current collection efficiency and performance stability of the current collecting grid line 132, and also can improve the consistency of the electrical parameters at different positions inside the solar cell 1, thereby improving the stability of the solar cell 1.

[0117] Optionally, the number of first openings 141 in each group can be equal or unequal. The first openings 141 in different groups can be arranged in correspondence or staggered in the second direction P3. The shapes of the first openings 141 in different groups can be the same or different, and the shapes of the first openings 141 in the same group can be the same or different. The distance between any two adjacent openings in one group of first openings 141 can be the same as or different from the distance between any two adjacent openings in another group of first openings 141, and the distance between different first openings 141 in one group can be the same or different.

[0118] Please see Figures 11 to 14 , Figure 11 is a schematic view of the first openings being in communication with each other in an embodiment of the application, Figure 12 is another schematic view of the first openings being in communication with each other in an embodiment of the application, Figure 13 is still another schematic view of the first openings being in communication with each other in an embodiment of the application, Figure 14 is a schematic view of the arrayed first openings being in communication with each other in an embodiment of the application.

[0119] In some other embodiments, the different first openings 141 can also be connected, that is, at least two adjacent first openings 141 can partially overlap. When the multiple first openings 141 overlap and are in communication with each other, a linear groove extending in the second direction P3 can be formed on the current collecting grid line 132. By making the first openings 141 in communication with each other, the area of the current collecting grid line 132 in ohmic contact with the transmission layer 12 in the first openings 141 can be increased, and the overcurrent efficiency can be improved. At the same time, increasing the opening area of the first openings 141 can also make it easier for the material forming the grid line layer 13 to enter the first openings 141 when the grid line layer 13 is manufactured.

[0120] It can be understood that when the first openings 141 are arrayed, at least some of the first openings 141 can be in communication with each other. That is, in the first direction P2, at least some of the first openings 141 are arranged in an alternating manner of linear grooves and openings. Of course, at least some of the first openings 141 can also be arranged in an alternating manner of linear grooves and openings in the second direction P3.

[0121] When the first openings 141 are connected to form linear grooves, the linear grooves can be linear grooves with regular edges, such as square linear grooves, waist-round linear grooves, wave-shaped linear grooves, etc. Of course, the linear grooves can also be linear grooves with irregular edges.

[0122] Please see Figures 15 to 19 , Figure 15is a schematic diagram of the first opening in the embodiment of the present application, in which the inner diameter of the first opening increases in the direction away from the busbar line, Figure 16 is a schematic diagram of the first opening in the embodiment of the present application, in which the inner diameter of the first opening decreases in the direction away from the busbar line, Figure 17 is a schematic diagram of the first opening in the embodiment of the present application, in which the inner diameter of the first opening increases first and then decreases in the direction away from the busbar line, Figure 18 is a schematic diagram of the first opening in the embodiment of the present application, in which the inner diameter of the first opening decreases first and then increases in the direction away from the busbar line, Figure 19 is a schematic diagram of the first opening in the embodiment of the present application, in which the inner diameters of the plurality of first openings with different sizes are arranged alternately in the direction away from the busbar line.

[0123] In some embodiments, among the plurality of first openings 141 corresponding to at least one current collecting grid line 132, there can be at least two first openings 141 with different sizes, for example, different areas. When the first openings 141 are circular holes, they can also have different inner diameters. According to actual requirements, first openings 141 with different inner diameters can be opened at different positions of the passivation layer 14, for example, the inner diameter of the first opening 141 corresponding to the position of the current collecting grid line 132 away from the busbar line 131 can be set larger to reduce the impact of the longer current transmission path, and the inner diameter of the first opening 141 corresponding to the position of the current collecting grid line 132 close to the busbar line 131 can be appropriately reduced to make the overall conductive effect of the solar cell 1 more balanced.

[0124] Of course, in some other embodiments, the inner diameters of the plurality of first openings 141 corresponding to at least one current collecting grid line 132 can increase first and then decrease in the second direction P3; or, the inner diameters of the plurality of first openings 141 corresponding to at least one current collecting grid line 132 can decrease first and then increase in the second direction P3; or, the plurality of first openings 141 with different sizes corresponding to at least one current collecting grid line 132 can be arranged alternately in the second direction P3. That is, the first openings 141 at different positions of the current collecting grid line 132 can be adjusted according to actual product requirements, so that the internal structure of the solar cell 1 can be flexibly set, and then the first openings 141 can be adaptively set according to the internal structure of the solar cell 1.

[0125] It can be understood that when the first openings 141 are arranged in an array, at least part of the plurality of first openings 141 can be set to different inner diameters / sizes in the above manner.

[0126] Please refer to Figure 20 and Figure 21 , Figure 20 is a schematic diagram of the structure of the solar cell with the second opening in the embodiment of the present application, Figure 21 is Figure 20 an enlarged schematic diagram of the B area in

[0127] The corresponding connection part of the bus grid lines 131 and the collector grid lines 132 is a cross section A1, and the passivation layer 14 is provided with an opening film area A2 corresponding to the cross section A1, wherein the cross section A1 is rectangular. In some embodiments, the size of the bus grid line 131 in the second direction P3 is D1, the size of the collector grid line 132 in the first direction P2 is D2, and the area of the opening film area A2 is S, and S, D1 and D2 satisfy the relationship: S≤D1*D2. That is, the area of the opening film area A2 is smaller than the area of the cross section A1. In this way, by limiting the size of the opening film area A2, the opening area of the passivation layer 14 can be reduced, that is, the damage to the passivation layer 14 is reduced, and the protection of the passivation layer 14 to the internal structure of the solar cell 1 is ensured.

[0128] In some embodiments, the passivation layer 14 is provided with at least one second opening 142 corresponding to the opening film area A2, so that the bus grid line 131 can realize ohmic contact with the transport layer 12 through the second opening 142, and the bus grid line 131 directly contacts the transport layer 12, so that the current transmission path is shorter and the current conduction effect is higher.

[0129] It can be understood that when the number of the second openings 142 is multiple, the setting mode of the second openings, such as the spacing, inner diameter and arrangement mode of different second openings 142, can be set according to the setting mode of the first openings 141, which will not be described herein.

[0130] The bus grid line 131 is connected with multiple collector grid lines 132 at the same time, so that one bus grid line 131 has multiple cross sections A1, that is, one bus grid line 131 has multiple opening film areas A2, and at least one of the multiple opening film areas A2 is provided with a second opening 142.

[0131] Similarly, the second opening 142 can be realized by laser point touch opening, mechanical punching, chemical etching, wet etching, dry etching and the like, which will not be limited herein.

[0132] Since the passivation layer 14 is provided with multiple first openings 141 corresponding to each collector grid line 132, the bus and current conduction effect of the collector grid line 132 is improved, so that the grid lines of different polarities of the solar cell 1 can be integrated into the same surface of the solar cell 1, and the other surface of the solar cell 1 can not be provided with grid lines, so as to reduce the shading of the light illumination area by the structure of the solar cell 1 itself, thereby increasing the light illumination area of the solar cell 1, and the energy output efficiency of the solar cell 1 can be increased.

[0133] Please see Figures 22 to 24 , Figure 22 is a schematic diagram of a solar cell with a first polarity grid line layer and a second polarity grid line layer in the embodiments of the present application, Figure 23 is Figure 22An enlarged schematic view of the middle C region, Figure 24 is Figure 22 An enlarged schematic view of the middle D region.

[0134] In some embodiments, the gate line layer 13 includes two different polarity gate line layers, i.e., a first polarity gate line layer 133 and a second polarity gate line layer 134, such as an anode gate line layer and a cathode gate line layer. The first polarity gate line layer 133 and the second polarity gate line layer 134 can be alternately arranged along the second direction P3, and any two adjacent first polarity gate line layers 133 and second polarity gate line layers 134 are insulated from each other. For example, any two adjacent first polarity gate line layers 133 and second polarity gate line layers 134 can be separated by a passivation layer 14 to achieve insulation.

[0135] In some embodiments, any two first polarity gate line layers 133 can be arranged to have the same shape, any two second polarity gate line layers 134 can also be arranged to have the same shape, and any two first polarity gate line layers 133 and second polarity gate line layers 134 in the same row can be arranged to have complementary shapes.

[0136] For example, the first polarity gate line layer 133 includes a first polarity bus gate line 133a and a plurality of first polarity current collecting gate lines 133b connected to each other, the first polarity bus gate line 133a extends along the first direction P2, the plurality of first polarity current collecting gate lines 133b are arranged at intervals along the first direction P2, and the plurality of first polarity current collecting gate lines 133b extend along the second direction P3. The second polarity gate line layer 134 includes a second polarity bus gate line 134a and a plurality of second polarity current collecting gate lines 134b connected to each other, the second polarity bus gate line 134a extends along the first direction P2, the plurality of second polarity current collecting gate lines 134b are arranged at intervals along the first direction P2, and the plurality of second polarity current collecting gate lines 134b extend along the second direction P3. Among them, the space between any two adjacent first polarity current collecting gate lines 133b in one first polarity gate line layer 133 is provided with one second polarity current collecting gate line 134b of the second polarity gate line layer 134 adjacent to the first polarity gate line layer 133, that is, the current collecting gate lines of the adjacent first polarity gate line layer 133 and the second polarity gate line layer 134 are arranged alternately in the first direction P2. In this way, the surface of the solar cell 1 can be maximized, the distribution density of the current collecting gate lines of the gate line layer 13 can be increased, and the bus effect of the gate line layer 13 can be improved.

[0137] The first polarity current collecting gate lines 133b of any two first polarity gate line layers 133 can be arranged one by one in the first direction P2, and the second polarity current collecting gate lines 134b of any two second polarity gate line layers 134 can be arranged one by one in the first direction P2.

[0138] It can be understood that at least one of the first polarity busbar line 133a and the second polarity busbar line 134a can be provided with the second opening 142, or can also not be provided with the second opening 142, and the specific selection can be made according to the actual product needs.

[0139] It should be noted that, in order to avoid the first opening 141 and / or the second opening 142 exposing the transmission layer 12 to the air environment, the grid line layer 13 should completely cover all the first openings 141 and the second openings 142, that is, the opening range of the first opening 141 should not exceed the setting range of the grid line layer 13.

[0140] In some embodiments, the distance between the corresponding first polarity busbar line 133b of any two adjacent first polarity grid line layers 133 in the first direction P2 is D3, and the distance between the two first openings 141 adjacent to the two first polarity busbar lines 133b is D4, and D3, D4 satisfy the relationship: (D3+10) pm≤D4≤(D3+200) pm. That is, the distance between the corresponding two first polarity busbar lines 133b on the adjacent two first polarity grid line layers 133 is less than the distance between the two first openings 141 adjacent to the two first polarity busbar lines 133b. It can be ensured that the first polarity busbar line 133b of the first polarity grid line layer 133 can completely cover the first opening 141, avoid the first opening 141 being exposed due to the grid line not completely covering the first opening 141, and ensure the effective protection of the passivation layer to the internal structure of the solar cell 1. At the same time, it can avoid the first polarity grid line layer 133b exceeding the setting range of the first opening 141 too much and causing space waste.

[0141] Similarly, for the second polarity grid line layer 134, the distance between the corresponding second polarity busbar line 134b of any two adjacent second polarity grid line layers 134 in the first direction P2 is D5, and the distance between the two first openings 141 adjacent to the two second polarity busbar lines 134b is D6, and D5, D6 satisfy the relationship: (D5+10) pm≤D6≤(D5+200) pm.

[0142] The solar cell 1 provided by the embodiments of the present application can ensure that the ohmic contact between the different positions of the current collecting grid line 132 and the transport layer 12 is relatively balanced by making the depth difference between different first openings 141 satisfy the condition that |ΔH|≤200nm, so that the grid line resistance distribution of the solar cell 1 can be balanced, the local concentration of the grid line current can be prevented, and the local overheating of the solar cell 1 can be avoided, thereby preventing the thermal runaway of the solar cell 1, and ensuring the consistency of the electrical performance of the solar cell 1 at different positions in the solar cell 1, and further ensuring the stability of the power output at the component level. In addition, by reducing the depth difference of the first openings 141 of the passivation layer 14 at different positions, the cracks caused by stress concentration in the solar cell 1 can also be prevented, so that the structural failure of the solar cell 1 under thermal cycling and mechanical load can be avoided.

[0143] Please refer to Figure 25 , Figure 25 is a structural schematic diagram of a photovoltaic module in the embodiments of the present application.

[0144] In the second aspect, the embodiments of the present application provide a photovoltaic module 2, which comprises the solar cell 1 described in any of the above embodiments.

[0145] In some embodiments, the photovoltaic module 2 further comprises an inverter 21, the inverter 21 being electrically connected to the solar cell 1, and the inverter 21 being capable of receiving the current output by the solar cell 1 and rectifying and regulating the current, so as to output a current meeting the actual use requirements through the inverter 21.

[0146] The above has introduced in detail the solar cell and the photovoltaic module disclosed by the embodiments of the present application, and the principles and implementation manners of the present application have been described by using examples; the above embodiment descriptions are only used to help understand the solar cell and the photovoltaic module of the present application and the core idea thereof; meanwhile, for those skilled in the art, the specific implementation manners and application ranges will be changed according to the idea of the present application, and the above description should not be understood as the limitation of the present application.

Claims

1. A solar cell, characterized in that, The solar cell includes: Silicon substrate; A transport layer is disposed on the silicon substrate along the thickness direction of the silicon substrate, and the transport layer is used to transport charge carriers; A gate line layer is disposed on the side of the transport layer away from the silicon substrate layer along the thickness direction of the silicon substrate layer. The gate line layer includes a bus gate line and a plurality of collector gate lines. The bus gate line and the plurality of collector gate lines are connected. The bus gate line extends along a first direction. The plurality of collector gate lines are spaced apart along the first direction. The collector gate lines extend along a second direction. A passivation layer is disposed between the transmission layer and the gate line layer. The passivation layer has multiple first openings corresponding to multiple collector gate lines. The collector gate lines are electrically connected to the transmission layer through the first openings. The depth difference between any two first openings is ΔH, and |ΔH| ≤ 200nm. The thickness direction, the first direction, and the second direction are all perpendicular to each other.

2. The solar cell according to claim 1, characterized in that, The passivation layer has a plurality of first openings for each of the collector grid lines, and the plurality of first openings corresponding to at least one collector grid line are spaced apart along the second direction.

3. The solar cell according to claim 2, characterized in that, The spacing between the plurality of first openings corresponding to at least one of the collector grid lines in the second direction first increases sequentially, and then decreases sequentially. Alternatively, the spacing between the plurality of first openings corresponding to at least one of the collector grid lines in the second direction first decreases sequentially and then increases sequentially.

4. The solar cell according to claim 2, characterized in that, At least one of the first openings corresponding to the current collector grid line is staggered in the first direction; And / or, the distance between any two adjacent first openings is d1, the maximum dimension of the first opening in the second direction is d2, and d1 and d2 satisfy the following relationship: d1≤3d2.

5. The solar cell according to claim 2, characterized in that, Of the plurality of first openings corresponding to at least one of the collector grid lines, at least two of the first openings have different inner diameters.

6. The solar cell according to claim 5, characterized in that, The inner diameter of at least one of the first openings corresponding to a collector grid line increases sequentially in the second direction and then decreases sequentially. Alternatively, the inner diameter of at least one of the first openings corresponding to a collector grid line decreases sequentially in the second direction and then increases sequentially.

7. The solar cell according to claim 1, characterized in that, The first opening corresponding to the current collector grid line is multiple, and the multiple first openings are arrayed on the passivation layer; And / or, the portions where the busbar and the collector line are connected are intersection portions, the passivation layer has an open film region corresponding to the intersection portion, the open film region is used to set a second opening, the dimension of the busbar in the second direction is D1, the dimension of the collector line in the first direction is D2, the area of ​​the open film region is S, and S, D1, and D2 satisfy the following relationship: S≤D1*D2.

8. The solar cell according to claim 1, characterized in that, The gate line layer includes a first polar gate line layer and a second polar gate line layer, which are alternately arranged along the second direction and are insulated from each other; The first polarity gate layer includes a first polarity bus gate and a plurality of first polarity collector gates. The first polarity bus gate and the plurality of first polarity collector gates are connected. The first polarity bus gate extends along the first direction, and the plurality of first polarity collector gates extend along the second direction and are spaced apart along the first direction. The second polarity gate layer includes a second polarity bus gate and a plurality of second polarity collector gates. The second polarity bus gate and the plurality of second polarity collector gates are connected. The second polarity bus gate extends along the first direction, and the plurality of second polarity collector gates extend along the second direction and are spaced apart along the first direction.

9. The solar cell according to claim 8, characterized in that, The spacing between any two adjacent first polarity gate lines corresponding to the collector gate lines is D3, and the spacing between two adjacent first apertures on the first polarity collector gate lines corresponding to the two adjacent first polarity gate lines is D4. D3 and D4 satisfy the following relationship: (D3+10)μm≤D4≤(D3+200)μm; And / or, the spacing between any two adjacent collector gate lines corresponding to the second polarity gate line layers is D5, and the spacing between two adjacent first apertures on the second polarity collector gate lines corresponding to the two adjacent second polarity gate line layers is D6, where D5 and D6 satisfy the following relationship: (D5+10)μm≤D6≤(D5+200)μm.

10. A photovoltaic module, characterized in that, Including the solar cell as described in any one of claims 1-9.

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