Back contact solar cell and photovoltaic module

Abstract

The application of the invention is a divisional application of 202410242801.2. The invention discloses a back contact solar cell and a photovoltaic module, and belongs to the technical field of solar cells. The battery comprises a substrate, conductive layers and an electrode structure, the adjacent conductive layers are opposite in conductive polarity and are arranged in an electric insulation mode, the electrode structure comprises a grid electrode and a grid line which intersects with the grid electrode and is electrically connected with the grid electrode, the grid electrode and the grid line which are opposite in conductive polarity have an intersection, and the grid line at the intersection is disconnected to be spaced from the grid electrode in the second direction. The disconnected grid lines are electrically connected through conductive layers with the same conductive polarity, an insulating layer is arranged between the grid electrode and the conductive layer at the intersection, a connecting layer close to the conductive layer is further arranged at the intersection, the disconnected grid lines form a conductive channel through the connecting layer, the connecting layer and the grid electrode are separated by the insulating layer, and the disconnected grid lines further form a conductive channel through the conductive layer. The battery can avoid contact short circuit of electrodes with different polarities.

Description

[0001] Citation of Related Applications

[0002] This application is a divisional application of the Chinese application with the Chinese application date of March 4, 2024, application number "202410242801.2", and name "Back Contact Solar Cells and Photovoltaic Modules". Technical Field

[0003] The present application belongs to the technical field of solar cells, and in particular to a back-contact solar cell and a photovoltaic module. Background Art

[0004] Solar cells convert light energy into electricity. As a sustainable, clean energy source, they hold tremendous promise. Unlike traditional solar cells with double-sided electrodes, back-contact cells place the metal electrodes on the backside of the cell. This leaves the light-receiving side unobstructed, resulting in high light utilization, higher short-circuit current, and higher conversion efficiency.

[0005] However, the positive and negative electrodes of the back-contact battery are both located on the back, and the electrode structures of the two polarities are staggered, which easily leads to short circuits between the positive and negative electrodes, causing the battery to fail. Summary of the Invention

[0006] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a back-contact solar cell and photovoltaic module that can avoid short circuits caused by electrodes of different polarities, thereby preventing battery failure.

[0007] In a first aspect, the present application provides a back-contact solar cell, comprising:

[0008] substrate;

[0009] A conductive layer, the conductive layer being disposed on one side of the substrate, wherein a plurality of the conductive layers are arranged along a first direction, and adjacent conductive layers have opposite conductive polarities and are electrically insulated;

[0010] an electrode structure, the electrode structure being disposed on a surface of the conductive layer away from the substrate, the electrode structure comprising a gate and a gate line intersecting and electrically connected to the gate, the gates having opposite conductive polarities being arranged at intervals along a second direction intersecting the first direction, the gate lines having opposite conductive polarities being arranged at intervals along the first direction, and the gate lines being located on the conductive layer having the same conductive polarity;

[0011] wherein the gate and the gate line having opposite conductive polarities have an intersection, the gate line at the intersection is disconnected to be spaced apart from the gate in the second direction, the disconnected gate line is electrically connected via the conductive layer having the same conductive polarity, and an insulating layer is provided between the gate and the conductive layer at the intersection;

[0012] A connection layer close to the conductive layer is further provided at the intersection, and the disconnected gate lines form a conductive channel through the connection layer. The insulating layer separates the connection layer and the gate, and the disconnected gate lines also form a conductive channel through the conductive layer.

[0013] According to the back-contact solar cell of the present application, the grid lines are disconnected and an insulating layer is provided at the intersection of the gate and grid lines of opposite conductive polarities, so that the grid lines are separated from the gate. The disconnected grid lines are electrically connected through the conductive layer and the connecting layer, which can avoid the occurrence of short circuits caused by contact between electrodes of different polarities and prevent battery failure. At the same time, the consumption of raw materials for electrode preparation can be reduced, thereby reducing the cost of battery manufacturing.

[0014] According to one embodiment of the present application, at the intersection, the width of the insulating layer in the second direction is greater than or equal to the width of the gate in the second direction.

[0015] According to an embodiment of the present application, at the intersection, the distance at which the gate line is disconnected is greater than the width of the gate in the second direction.

[0016] According to an embodiment of the present application, at the intersection, the width of the insulating layer in the second direction is greater than or equal to the distance at which the gate line is disconnected.

[0017] According to one embodiment of the present application, when the width of the insulating layer in the second direction is equal to the distance at which the gate line is disconnected, the two ends of the insulating layer are in contact with the two ends at which the gate line is disconnected, and the insulating layer is filled between the two ends at which the gate line is disconnected, separating the gate above the insulating layer and the conductive layer below.

[0018] According to one embodiment of the present application, when the width of the insulating layer in the second direction is greater than the distance at which the gate line is disconnected, the insulating layer covers both ends of the disconnected gate line, and the two ends of the disconnected gate line are wrapped in the insulating layer, separating the gate above the insulating layer and the conductive layer below.

[0019] According to one embodiment of the present application, the sheet resistance of the conductive layer is 20 ohm / sq-1000 ohm / sq.

[0020] According to one embodiment of the present application, the sheet resistance of the connection layer is 0.001 ohm / sq-10 ohm / sq.

[0021] According to one embodiment of the present application, a projection area of ​​the insulating layer on the substrate is greater than or equal to a projection area of ​​the connecting layer on the substrate.

[0022] According to one embodiment of the present application, the projection area of ​​the connecting layer is located within the projection area of ​​the insulating layer.

[0023] According to one embodiment of the present application, the width of the insulating layer along the first direction is greater than or equal to the width of the connecting layer along the first direction, and the width of the insulating layer along the second direction is greater than or equal to the width of the connecting layer along the second direction.

[0024] According to an embodiment of the present application, at the intersection, the width of the connection layer in the second direction is greater than or equal to the distance at which the gate line is disconnected.

[0025] According to an embodiment of the present application, when the width of the connection layer in the second direction is equal to the distance at which the gate line is disconnected, both ends of the connection layer are in contact with both ends of the disconnected gate line.

[0026] According to an embodiment of the present application, when the width of the connection layer in the second direction is greater than the distance at which the gate line is disconnected, two ends of the connection layer cover two ends of the disconnected gate line.

[0027] According to an embodiment of the present application, the distance at which the gate lines are disconnected is the distance between the two ends of the gate lines at the intersection.

[0028] According to one embodiment of the present application, the connection layer and the conductive layer are provided at the intersection of two opposite sides of the back-contact solar cell along the second direction.

[0029] According to one embodiment of the present application, the conductive layer is provided at the intersection of the middle portion of the back-contact solar cell along the second direction, or the connecting layer and the conductive layer are provided.

[0030] According to one embodiment of the present application, the connection layer includes a conductive metal.

[0031] According to one embodiment of the present application, the conductive metal is silver and / or copper.

[0032] According to one embodiment of the present application, the size of the conductive metal is at least one of nanometer scale, submicron scale and micron scale.

[0033] According to one embodiment of the present application, the insulating layer is made of insulating glue or insulating ink.

[0034] According to one embodiment of the present application, the conductive layer is made of transparent conductive oxide.

[0035] According to one embodiment of the present application, a cross-sectional area of ​​the gate line is smaller than a cross-sectional area of ​​the gate.

[0036] According to one embodiment of the present application, an isolated opening is provided between the first conductive layer and the second conductive layer having opposite conductive polarities.

[0037] According to one embodiment of the present application, the gate lines are made of low-temperature silver paste.

[0038] According to one embodiment of the present application, the insulating layer is disposed between the connecting layer and the gate.

[0039] According to one embodiment of the present application, the projection shape of the connection layer on the substrate is rectangular, circular, elliptical or irregular.

[0040] According to one embodiment of the present application, the substrate includes a doped semiconductor layer, a passivation layer, and a semiconductor substrate sequentially arranged in a direction away from the conductive layer.

[0041] In a second aspect, the present application provides a photovoltaic module, comprising:

[0042] A back-contact solar cell as described in the first aspect above.

[0043] According to the photovoltaic module of the present application, the back-contact solar cell of the photovoltaic module disconnects the grid line and sets an insulating layer at the intersection of the grid and grid line with opposite conductive polarities, so that the grid line is separated from the grid. The disconnected grid line is electrically connected through the conductive layer and the connecting layer, which can avoid the occurrence of short circuits caused by contact between electrodes of different polarities and prevent battery failure. At the same time, it can also reduce the consumption of raw materials for electrode preparation and reduce the cost of battery manufacturing.

[0044] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0046] Figure 1 This is one of the top views of the back-contact solar cell provided in an embodiment of the present application;

[0047] Figure 2 This is the second top view of the back-contact solar cell provided in an embodiment of the present application;

[0048] Figure 3 This is one of the cross-sectional schematic diagrams of the intersection of the back contact solar cell provided in the embodiment of the present application;

[0049] Figure 4 This is the second cross-sectional schematic diagram of the intersection of the back contact solar cell provided in an embodiment of the present application;

[0050] Figure 5 This is the third cross-sectional schematic diagram of the intersection of the back contact solar cell provided in the embodiment of the present application;

[0051] Figure 6 This is the fourth cross-sectional schematic diagram of the intersection of the back contact solar cell provided in the embodiment of the present application;

[0052] Figure 7 is a schematic cross-sectional view of a back-contact solar cell provided by an embodiment of the present application along the second direction;

[0053] Figure 8 is a cross-sectional schematic diagram of a solar cell in the related art;

[0054] Figure 9 It is a schematic cross-sectional view of a back-contact solar cell provided in an embodiment of the present application along a first direction.

[0055] Reference numerals:

[0056] Substrate 100, semiconductor substrate 101, first polarity region 102, second polarity region 103, first passivation layer 111, first doped semiconductor layer 112, second passivation layer 121, second doped semiconductor layer 122, third passivation layer 130, anti-reflection layer 140, insulating dielectric layer 150,

[0057] The first conductive layer 210, the second conductive layer 220,

[0058] The first gate 310, the first gate line 311, the second gate 320, the second gate line 321,

[0059] A first insulating layer 410 , a second insulating layer 420 , a first connecting layer 510 , and a second connecting layer 520 . DETAILED DESCRIPTION

[0060] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0061] The back-contact solar cell and photovoltaic module provided in the embodiments of the present application are described below through specific embodiments and their application scenarios in conjunction with the accompanying drawings.

[0062] like Figure 1 As shown, the back-contact solar cell includes a substrate 100 , a conductive layer, and an electrode structure.

[0063] The substrate 100 has a side facing the sunlight and a side facing away from the sunlight.

[0064] In this embodiment, the conductive layer is disposed on one side of the substrate 100, ie, the side facing away from sunlight, and the electrode structure is disposed on the side of the conductive layer away from the substrate 100, ie, the conductive layer is located between the substrate 100 and the electrode structure.

[0065] The electrode structure includes a gate and a gate line that intersects and is electrically connected to the gate, wherein the cross-sectional area of ​​the gate line can be smaller than the cross-sectional area of ​​the gate, that is, the gate line is thinner than the gate. The gate line that intersects and is electrically connected to the gate transfers the collected carriers to the gate, which is then output by the gate.

[0066] In actual implementation, the electrode structure can be made of conductive metals such as silver and / or copper.

[0067] It can be understood that the back-contact solar cell includes two types of electrode structures with different conductive polarities, which are used to transmit different carriers respectively.

[0068] For example, Figure 1 As shown, the back-contact solar cell includes a first electrode structure and a second electrode structure with opposite conductive polarities. The first electrode structure includes a first grid electrode 310 and a first grid line 311 , and the second electrode structure includes a second grid electrode 320 and a second grid line 321 .

[0069] The first gate line 311 intersects and is electrically connected to the first gate electrode 310 , and transmits the collected carriers to the first gate electrode 310 . The second gate line 321 intersects and is electrically connected to the second gate electrode 320 , and transmits the collected carriers to the second gate electrode 320 .

[0070] In this embodiment, the back-contact solar cell may include two types of conductive layers with opposite conductive polarities. The multiple conductive layers are arranged along a first direction, and adjacent conductive layers have opposite conductive polarities and are electrically insulated.

[0071] The first direction is a direction on the plane where the substrate 100 is located.

[0072] For example, a back-contact solar cell may include a first conductive layer 210 and a second conductive layer 220 with opposite conductive polarities. The first conductive layer 210 and the second conductive layer 220 are arranged at intervals along a first direction from top to bottom on the substrate 100. The electrical insulation between the conductive layers with opposite conductive polarities can prevent recombination of different carriers.

[0073] In actual implementation, the conductive layers with opposite conductive polarities can be physically separated, for example, by providing an isolated opening between the first conductive layer 210 and the second conductive layer 220 to achieve electrical insulation between the conductive layers with opposite conductive polarities.

[0074] In this embodiment, gate electrodes with opposite conductive polarities are arranged at intervals along a second direction intersecting the first direction, and gate lines with opposite conductive polarities are arranged at intervals along the first direction. The gate lines are located on a conductive layer with the same conductive polarity.

[0075] The second direction is a direction on the plane where the substrate 100 is located, and the second direction intersects with the first direction.

[0076] In actual implementation, the second direction and the first direction may be perpendicular to each other.

[0077] like Figure 1 As shown, the back-contact solar cell may include a first grid 310 and a second grid 320 with opposite conductive polarities, the first grid 310 and the second grid 320 are arranged at intervals along a second direction from left to right on the substrate 100, and a first grid line 311 and a second grid line 321 with opposite conductive polarities are arranged at intervals along a first direction from top to bottom on the substrate 100.

[0078] The gate line is located on a conductive layer with the same conductive polarity. The conductive layer can collect carriers generated by the substrate 100 and transmit them to the gate line, and then the gate line transmits the collected carriers to the gate.

[0079] It should be noted that the gates and gate lines of the electrode structure are arranged along the intersecting first and second directions respectively, the gates and gate lines with the same conductive polarity are intersected and connected, and the gates and gate lines with opposite conductive polarities are insulated to prevent battery short circuit.

[0080] In this embodiment, the gate and gate line with opposite conductive polarities have an intersection, the gate line at the intersection is disconnected to be spaced apart from the gate in the second direction, the disconnected gate line is electrically connected through a conductive layer with the same conductive polarity, and an insulating layer is provided between the gate and the conductive layer at the intersection.

[0081] For example, Figure 2 As shown, the second gate line 320 and the first gate line 311 have an intersection, at which the first gate line 311 is disconnected, and the first gate line 311 is spaced apart from the second gate line 320 along the second direction.

[0082] The first gate 310 and the second gate line 321 have an intersection, at which the second gate line 321 is disconnected. The second gate line 321 is spaced apart from the first gate 310 along the second direction to prevent gate lines and gates with opposite conductive polarities from contacting each other.

[0083] The insulating layer of the back contact solar cell may include a first insulating layer 410 and a second insulating layer 420 , which are respectively disposed at different intersections.

[0084] For example, Figure 3As shown, the first gate line 311 is disconnected at the intersection with the second gate 320, and the disconnected first gate line 311 is electrically connected through the first conductive layer 210 with the same conductive polarity. A second insulating layer 420 is provided between the second gate 320 and the first conductive layer 210 to prevent the second gate 320 from contacting the first conductive layer 210.

[0085] like Figure 5 As shown, the second gate line 321 is disconnected at the intersection with the first gate 310, and the disconnected second gate line 321 is electrically connected through the second conductive layer 220 with the same conductive polarity. A first insulating layer 410 is provided between the first gate 310 and the second conductive layer 220 to prevent the first gate 310 from contacting the second conductive layer 220.

[0086] In actual implementation, the insulating layer provided between the conductive layer and the gate can be made of materials such as insulating glue and insulating ink.

[0087] In the related art, low-temperature silver paste is printed by screen printing and sintered at a temperature of about 200°C to form the electrode of the back-contact battery. The silver powder used in the low-temperature silver paste is mostly a mixture of flake and spherical silver powder. The size span of the silver powder is large, resulting in the final formed secondary grid having a rough morphology, large height fluctuations, and many protrusions. It is easy to pierce the insulating layer provided between the main grid and the secondary grid with opposite conductive polarities, so that the main grid and the secondary grid with opposite conductive polarities contact and form an electrical connection, resulting in a short circuit and causing the battery to fail.

[0088] And, as Figure 8 As shown, in the related art, when the main grid S10 intersects with the auxiliary grid S21 with opposite conductive polarity and the auxiliary grid S11 with the same conductive polarity, an insulating layer J1 exists between the main grid S10 and the auxiliary grid S21 with opposite conductive polarity, resulting in a higher height of the main grid S10. When the main grid S10 contacts the auxiliary grid S11 with the same conductive polarity, the height of the main grid S10 is lower. There is a height difference H2 between the two locations of the main grid S10, which is about tens of microns. This height difference not only affects the testing and string welding of the battery, but also increases the consumption of silver paste and increases the cost of battery manufacturing.

[0089] In an embodiment of the present application, in a back-contact solar cell, the gate and gate line with opposite conductive polarities have an intersection. The gate line is disconnected at the intersection and is spaced apart from the gate in a second direction. This physically avoids contact between possible spikes on the gate line and the gate, solves the short circuit problem caused by spikes in low-temperature silver paste, and prevents battery failure. The disconnected gate lines are electrically connected through a conductive layer with the same conductive polarity, and the conductive layer realizes the transmission of carriers between the two disconnected gate lines. An insulating layer is arranged between the gate and the conductive layer at the intersection to prevent the gate with opposite conductive polarities from contacting the conductive layer and causing a short circuit.

[0090] And, as Figure 7As shown, in the embodiment of the present application, the first gate 310 is in contact with the first gate line 311 of the same conductive polarity, the first gate line 311 is below the first gate 310, and at the intersection of the first gate 310 and the second gate line 321 of the opposite conductive polarity, the second gate line 321 is disconnected, and the first gate 310 is below the first insulating layer 410. The height of the first gate 310 here is relatively low, which can effectively reduce the height difference H1 between the two places of the first gate 310. H1 is less than H2, which can reduce the consumption of silver paste in battery preparation and reduce the battery manufacturing cost.

[0091] According to the back-contact solar cell provided in the embodiment of the present application, the grid lines are disconnected and an insulating layer is provided at the intersection of the gate and grid lines of opposite conductive polarities, so that the grid lines are separated from the gate. The disconnected grid lines are electrically connected through the conductive layer, which can avoid the occurrence of short circuits caused by contact between electrodes of different polarities, prevent battery failure, and at the same time reduce the consumption of raw materials for electrode preparation and reduce battery manufacturing costs.

[0092] In some embodiments, at the intersection, a width of the insulating layer in the second direction is greater than or equal to a width of the gate in the second direction.

[0093] In this embodiment, an insulating layer is provided between the gate and the conductive layer of opposite conductive polarity at the intersection. The width of the insulating layer in the second direction is greater than or equal to the width of the gate in the second direction. The insulating layer can effectively prevent the gate from contacting the conductive layer of opposite conductive polarity below, thereby improving the insulating effect of the insulating layer.

[0094] For example, Figure 5 As shown, at the intersection, the width of the first gate 310 in the second direction is D1, and the width of the first insulating layer 410 below the first gate 310 in the second direction is D3, D3 can be greater than or equal to D1, and the first gate 310 and the second conductive layer 220 are isolated by the first insulating layer 410 to prevent the first gate 310 from contacting the second conductive layer 220 below and causing a short circuit problem.

[0095] In some embodiments, at the intersection, a distance by which the gate line is disconnected is greater than a width of the gate in the second direction.

[0096] In this embodiment, the distance at which the gate line is disconnected is the distance between the two ends of the gate line at the intersection, that is, the width of the gate line disconnected along the second direction. The distance at which the gate line is disconnected is greater than the width of the gate in the second direction, which can improve the spacing effect between the gate and the gate line with opposite conductive polarities, avoid possible contact between the gate and the gate line, and at the same time, the disconnected gate line can also reduce the amount of silver paste used in the electrode structure and reduce the battery manufacturing cost.

[0097] For example, Figure 5As shown, at the intersection, the width of the first gate 310 in the second direction is D1, and the distance along the second direction where the second gate line 321 is disconnected is D2, D2 is greater than D1, and the first gate 310 and the second gate line 321 are physically separated to avoid contact between gates and gate lines with opposite conductive polarities.

[0098] In actual implementation, the distance at which the gate line is disconnected can be adjusted according to the conductive properties of the underlying conductive layer, the position of the gate line, etc.

[0099] For example, for a conductive layer with higher conductivity, the distance between the gate lines may be larger, and for a conductive layer with lower conductivity, the distance between the gate lines may be smaller.

[0100] In some embodiments, at the intersection, a width of the insulating layer in the second direction is greater than or equal to a distance at which the gate line is disconnected.

[0101] In this embodiment, when the width of the insulating layer in the second direction is equal to the distance of the gate line disconnection, the two ends of the insulating layer are in contact with the two ends of the gate line disconnection, and the insulating layer is filled between the two ends of the gate line disconnection, separating the gate above the insulating layer and the conductive layer below, thereby achieving an insulation effect.

[0102] When the width of the insulating layer in the second direction is greater than the distance of the disconnected gate line, the insulating layer covers both ends of the disconnected gate line, that is, the two ends of the disconnected gate line are wrapped in the insulating layer, separating the gate above the insulating layer and the conductive layer below. At the same time, covering the disconnected end of the gate line can also prevent the protrusions that may be formed by the gate line from contacting the gate, and can avoid the disconnected end of the gate line from contacting the welding strip when the components are serially soldered, causing a short circuit.

[0103] For example, Figure 5 As shown, at the intersection, the width of the first insulating layer 410 under the first gate 310 in the second direction is D3, and the distance at which the second gate line 321 is disconnected is D2. D3 is greater than or equal to D2, effectively preventing the gate from contacting the gate line and the conductive layer, thereby avoiding the occurrence of a short circuit.

[0104] In some embodiments, at the intersection, the width of the insulating layer in the second direction is greater than the distance of the disconnected gate line, and the distance of the disconnected gate line is greater than the width of the gate in the second direction.

[0105] For example, Figure 5 As shown, at the intersection, the width of the first insulating layer 410 under the first gate 310 in the second direction is D3, the distance at which the second gate line 321 is disconnected is D2, and the width of the first gate 310 in the second direction is D1, D3 is greater than D2, and D2 is greater than D1.

[0106] In this embodiment, the insulating layer covers both ends of the disconnected gate line, the distance of the disconnected gate line is greater than the width of the gate electrode, and the gate line and the gate electrode are physically separated. The insulating layer can also effectively prevent the protrusions that may be formed on the gate line from contacting the gate electrode, and can avoid the disconnected ends of the gate line from contacting the welding strip when the components are serially soldered, causing a short circuit.

[0107] In some embodiments, the sheet resistance of the conductive layer is 20 ohm / sq-1000 ohm / sq.

[0108] Among them, square resistance, also known as sheet resistance, refers to the resistance between square conductive materials, and its unit is ohm per square meter (ohm / sq). The larger the square resistance, the lower the conductive performance of the conductive material.

[0109] In this embodiment, the sheet resistance of the conductive layer is 20 ohm / sq-1000 ohm / sq. The conductive layer within this sheet resistance range can achieve electrical connection between disconnected gate lines.

[0110] In some embodiments, the sheet resistance of the conductive layer is 100 ohm / sq-500 ohm / sq.

[0111] In this embodiment, the conductive layer with a square resistance within the range of 100 ohm / sq-500 ohm / sq can achieve stable electrical connection between disconnected gate lines.

[0112] In actual implementation, the conductive layer can be prepared using materials such as transparent conductive oxide.

[0113] In some embodiments, a connection layer close to the conductive layer is further provided at the intersection, the square resistance of the connection layer is smaller than that of the conductive layer, the disconnected gate lines form a conductive channel through the connection layer, and the insulating layer separates the connection layer and the gate.

[0114] It should be noted that the square resistance of the connecting layer is smaller than that of the conductive layer, and the conductive performance of the connecting layer is better than that of the conductive layer. The connecting layer is set at the intersection to provide a conductive channel formed by the connecting layer and the conductive layer for the disconnected gate line.

[0115] Among them, the setting of the connecting layer can increase the current collection range. The connecting layer has a small square resistance. The disconnected gate line forms a conductive channel through the connecting layer, which can reduce the battery series resistance, improve the carrier transmission efficiency, reduce current loss, and effectively improve the battery photoelectric conversion efficiency.

[0116] In this embodiment, at the intersection of the gate and gate line with opposite conductive polarities, the connecting layer is arranged close to the conductive layer, and the insulating layer is arranged between the connecting layer and the gate. The insulating layer separates the connecting layer and the gate, effectively preventing the connecting layer and the gate from connecting and causing a battery short circuit.

[0117] For example, Figure 4 As shown, a first connection layer 510 is disposed at the intersection of the first gate line 311 and the second gate electrode 320 . The first connection layer 510 is close to the first conductive layer 210 , and the second insulating layer 420 is close to the second gate electrode 320 .

[0118] Among them, the disconnected first gate line 311 forms a conductive channel through the first connecting layer 510, and the disconnected first gate line 311 is also electrically connected through the first conductive layer 210 below the first connecting layer 510. The conductive performance of the first connecting layer 510 is better than that of the first conductive layer 210. The setting of the first connecting layer 510 can improve the stability of the electrical connection between the two ends of the disconnected first gate line 311 and improve the carrier transmission efficiency.

[0119] In this embodiment, the second insulating layer 420 separates the first connection layer 510 and the second gate 320 to prevent the first connection layer 510 and the second gate 320 from contacting each other and causing a short circuit in the battery.

[0120] In some embodiments, the sheet resistance of the connection layer is 0.001 ohm / sq-10 ohm / sq.

[0121] In this embodiment, the square resistance of the connecting layer is 0.001ohm / sq-10ohm / sq. The connecting layer within this square resistance range forms an effective conductive channel between the disconnected gate lines, which can reduce the series resistance, improve the carrier transmission efficiency of the disconnected gate lines, and improve the photoelectric conversion efficiency of the battery.

[0122] In actual implementation, the sheet resistance of the connection layer may be 0.5 ohm / sq-1.5 ohm / sq.

[0123] In some embodiments, the square resistance of the conductive layer is 20ohm / sq-1000ohm / sq, the square resistance of the connecting layer is 0.001ohm / sq-10ohm / sq, the square resistance of the connecting layer is smaller than the square resistance of the conductive layer, a connecting layer is provided at the intersection, and the disconnected gate line has a conductive channel formed by the conductive layer and a conductive channel formed by the connecting layer with better conductive performance, thereby improving the photoelectric conversion efficiency of the back-contact solar cell.

[0124] In some embodiments, the connection layer includes a conductive metal, and the disconnected gate lines are connected together by the conductive metal to form a conductive channel.

[0125] In some embodiments, the conductive metal is silver and / or copper.

[0126] In this embodiment, the electrode structure can be made of metallic silver, and the conductive metal can be silver. The electrical connection of the same metal can effectively reduce the transmission loss at both ends of the disconnected gate and improve the photoelectric conversion efficiency of the battery.

[0127] It should be noted that a connection layer including a conductive metal is provided below the insulating layer, and the size of the conductive metal can be limited so that there are no large protrusions in the formed connection layer and the insulating layer will not be pierced.

[0128] In some embodiments, the conductive metal has a size of at least one of nanometer scale, submicrometer scale, and micrometer scale.

[0129] In this embodiment, nano-scale and / or submicron-scale and / or micron-scale metal particles such as silver can be used to prepare the connection layer to connect the disconnected gate lines together to form a conductive channel, and there are no large protrusions in the connection layer, which will not pierce the insulating layer.

[0130] In actual implementation, the connecting layer can be prepared by inkjet printing of nano-scale and / or submicron-scale silver metal, and the connecting layer can also be prepared by screen printing of nano-scale and / or submicron-scale and / or micron-scale silver metal.

[0131] In some embodiments, the projection area of ​​the insulating layer on the substrate 100 is greater than or equal to the projection area of ​​the connecting layer on the substrate 100 .

[0132] In this embodiment, the projection area of ​​the connecting layer is located within the projection area of ​​the insulating layer, the projection area of ​​the insulating layer is greater than or equal to the projection area of ​​the connecting layer, and the insulating layer can cover the connecting layer, so that the connecting layer forms a conductive channel that disconnects the gate line while improving the effectiveness of the insulation setting of the gate and the connecting layer, thereby avoiding the occurrence of battery short circuit.

[0133] In actual implementation, on the substrate 100, the projected area of ​​the insulating layer is greater than or equal to the projected area of ​​the connecting layer, which can be manifested as the width of the insulating layer along the first direction is greater than or equal to the width of the connecting layer along the first direction, and the width of the insulating layer along the second direction is greater than or equal to the width of the connecting layer along the second direction.

[0134] In some embodiments, the projection shape of the connection layer on the substrate 100 is rectangular, circular, elliptical or irregular.

[0135] In this embodiment, the connecting layer is rectangular, circular, elliptical or irregularly shaped so that the current collection range is wider, and its projection on the substrate 100 is connected to the two ends of the disconnected gate line at both ends along the second direction, so that the connecting layer can form a conductive channel at both ends of the disconnected gate line.

[0136] It should be noted that the projection shape of the insulating layer on the substrate 100 may also be rectangular, circular, elliptical or irregular.

[0137] The rectangular, circular, elliptical or irregularly shaped insulating layer can separate the gate electrode from the underlying connection layer, conductive layer and disconnected gate lines.

[0138] It can be understood that the projected area of ​​the insulating layer on the substrate 100 is greater than or equal to the projected area of ​​the connecting layer on the substrate 100 , and the insulating layer and the connecting layer may be of the same shape or of different shapes.

[0139] In some embodiments, at the intersection, a width of the connection layer in the second direction is greater than or equal to a distance at which the gate lines are disconnected.

[0140] In this embodiment, when the width of the connecting layer in the second direction is equal to the distance of the disconnected gate line, the two ends of the connecting layer contact the two ends of the disconnected gate line, connecting the disconnected gate lines together to form a conductive channel. The amount of conductive metal used to prepare the connecting layer is small, and the battery manufacturing cost is low.

[0141] When the width of the connecting layer in the second direction is greater than the distance of the disconnected gate line, the two ends of the connecting layer cover the two ends of the disconnected gate line, and the contact area between the connecting layer and the gate line increases, which can increase the carrier collection range of the connecting layer and improve the photoelectric conversion efficiency of the battery.

[0142] For example, Figure 6 As shown, at the intersection, the width of the second connection layer 520 in the second direction is D4, the distance where the gate line is disconnected is D2, D4 is greater than D2, and the two ends of the second connection layer 520 cover the two ends where the second gate line 321 is disconnected. The contact area between the second connection layer 520 and the second gate line 321 is large, the carrier collection range is wide, and the photoelectric conversion efficiency of the battery is improved.

[0143] In this embodiment, the projected area of ​​the first insulating layer 410 is larger than the projected area of ​​the second connecting layer 520, the width of the first insulating layer 410 along the second direction is D3, and the width of the second connecting layer 520 along the second direction is D4, D3 is larger than D4, and the first insulating layer 410 can cover the second connecting layer 520, thereby improving the effectiveness of the insulation setting of the gate and the connecting layer and avoiding the occurrence of battery short circuit.

[0144] In some embodiments, at the intersection, the width of the connection layer in the second direction is greater than or equal to the distance at which the gate line is disconnected, and the width of the insulation layer in the second direction is greater than or equal to the width of the connection layer in the second direction.

[0145] It is understood that the intersection of the grid line and the grid with opposite conductive polarity in the back contact solar cell can be configured in at least one of the following ways:

[0146] First, an insulating layer is provided between the conductive layer and the gate at the intersection, and the disconnected gate lines are electrically connected through the conductive layer.

[0147] Secondly, an insulating layer and a connecting layer are set between the conductive layer and the gate at the intersection. The insulating layer is close to the gate, and the connecting layer is close to the conductive layer. The square resistance of the connecting layer is smaller than the square resistance of the conductive layer. The disconnected gate line forms a conductive channel through the connecting layer, and the insulating layer separates the connecting layer and the gate.

[0148] In some embodiments, a connection layer and a conductive layer are provided at the intersection of two opposite sides of the back-contact solar cell along the second direction.

[0149] The two sides opposite to each other along the second direction refer to positions of two outermost grid electrodes on the solar cell in contact with the backs along the second direction.

[0150] For example, Figure 1 As shown, the gates of the back-contact solar cell are arranged along a second direction from left to right, and the conductive polarities of adjacent gates are opposite.

[0151] In this embodiment, the two sides opposite to each other along the second direction are the first grid 310 at the leftmost side of the back-contact solar cell and the second grid 320 at the rightmost side of the back-contact solar cell, and a connecting layer and a conductive layer are provided at the corresponding intersections of the outermost first grid 310 and the second grid 320.

[0152] It should be noted that the current collected by the gate lines at the intersection is transmitted to the adjacent gate along the second direction. For the gate line at the position of the outermost gate, its current is transmitted to the adjacent gate on one side. The current loss caused by the transmission of the conductive layer is relatively large, which may cause the battery efficiency to decrease. After setting the connecting layer, the connecting layer with lower square resistance forms a conductive channel between the disconnected gate lines, and its current transmission is equivalent to the situation where the two ends of the gate line are not disconnected, which can make the current loss between the disconnected gate lines smaller or achieve no additional current loss, thereby effectively improving the battery efficiency.

[0153] In some embodiments, a conductive layer is provided at the intersection of the middle portions of the back-contact solar cell along the second direction.

[0154] The middle portion refers to the grid positions except for the two outermost grids distributed along the second direction on the back contact solar cell.

[0155] For example, Figure 1 As shown, the gates of the back-contact solar cell are arranged along a second direction from left to right, and the conductive polarities of adjacent gates are opposite.

[0156] In this embodiment, the middle portion along the second direction is the gate positions except the outermost first gate 310 and the second gate 320 , including the positions of the four middle gates.

[0157] A second insulating layer 420 is provided at the intersection of the second gate 320 and the first gate line 311 in the middle portion. Figure 3As shown, the disconnected first gate line 311 is electrically connected through the first conductive layer 210 .

[0158] A first insulating layer 410 is provided at the intersection of the first gate line 310 and the second gate line 321 in the middle portion. Figure 5 As shown, the disconnected second gate line 321 is electrically connected through the second conductive layer 220 .

[0159] It should be noted that the current collected by the gate lines at the intersection is transmitted to the adjacent gates along the second direction. For the gate lines in the middle part where the gates are located, the current can be transmitted to the adjacent gates on both sides, with less current loss. The disconnection of the gate lines has less impact on the battery efficiency. A connecting layer does not need to be set in the middle part, which effectively reduces the battery manufacturing cost without causing a significant impact on the battery efficiency.

[0160] In some embodiments, a connection layer and a conductive layer are provided at the intersection of the middle portion of the back-contact solar cell along the second direction.

[0161] In this embodiment, a connecting layer is provided at the intersection, and the connecting layer with lower square resistance forms a conductive channel between the disconnected gate lines, and the current transmission thereof is equivalent to the case where both ends of the gate lines are not disconnected. By providing the conductive layer and the connecting layer, the current loss can be effectively reduced and the battery efficiency can be improved.

[0162] In actual implementation, a connection layer may be provided at the intersection corresponding to the two outermost gate positions of the back contact solar cell, and a connection layer may or may not be provided at the middle gate position.

[0163] It can be understood that the electrode structure of the back-contact solar cell is located on the backlight side, and a heterojunction (HJT) structure can be formed in the back-contact solar cell, so that the back-contact solar cell combines the excellent passivation effect and high opening voltage advantage of the heterojunction cell. A passivation contact structure can also be set in the back-contact solar cell, so that the back-contact solar cell combines the carrier selection and passivation contact characteristics of the TOPCon cell to improve the photoelectric conversion efficiency of the cell.

[0164] In some embodiments, the substrate 100 includes a doped semiconductor layer, a passivation layer, and a semiconductor substrate 101 sequentially disposed in a direction away from the conductive layer.

[0165] The doped semiconductor layer includes doped polycrystalline silicon, doped amorphous silicon, doped nanocrystalline silicon or doped microcrystalline silicon; and the passivation layer includes tunneling oxide or intrinsic amorphous silicon.

[0166] When the passivation layer is a tunneling oxide and the doped semiconductor layer is doped polysilicon, a TOPCon structure can be formed; when the passivation layer is intrinsic amorphous silicon and the doped semiconductor layer is doped amorphous and / or microcrystalline silicon, a HJT structure can be formed.

[0167] In this embodiment, the electrode structure of the back-contact solar cell is located on the backlight side. By setting a TOPCon structure (such as the first passivation layer 111 is a tunneling oxide, and the first doped semiconductor layer 112 is doped polycrystalline silicon) and a HJT structure (such as the second passivation layer 121 is intrinsic amorphous silicon, and the second doped semiconductor layer 122 is doped amorphous and / or microcrystalline silicon), the cell efficiency is effectively improved and the process complexity is reduced. The back-contact solar cell is a hybrid back-contact cell (Hybrid BC).

[0168] In some embodiments, the electrode structure of the back-contact solar cell is located on the backlight side, and the cell efficiency is effectively improved by setting a heterojunction structure (such as the first passivation layer 111 and the second passivation layer 121 are intrinsic amorphous silicon, and the first doped semiconductor layer 112 and the second doped semiconductor layer 122 are amorphous and / or microcrystalline silicon with opposite doping types). The back-contact solar cell is a heterojunction back-contact cell (HJT-BC).

[0169] In actual implementation, when preparing the electrode structure of the HJT metallization of the back contact solar cell, a low-temperature silver paste can be printed by screen printing and sintered at a temperature of about 200°C.

[0170] Among them, the silver powder used in low-temperature silver paste is mostly a mixture of flake silver powder and spherical silver powder. The size span of the flake silver powder is large, and the large particles in it cause the final grid line to have a rough morphology, large height fluctuations, and many protrusions.

[0171] In this embodiment, at the intersection of the gate and gate line with opposite conductive polarity, the gate line is disconnected and spaced apart from the gate in the second direction. For the gate line formed by low-temperature silver paste, it can effectively prevent possible spikes in the gate line from piercing the insulating layer and contacting the gate with opposite conductive polarity to form an electrical connection, thereby avoiding battery short circuit failure.

[0172] Moreover, disconnecting the gate lines at the intersection can also reduce the height difference at the intersection of the gate and the gate lines of different conductive polarities, which is convenient for battery testing and series welding. The reduced height difference can also reduce the silver paste consumption of the electrode structure and reduce the battery manufacturing cost.

[0173] The backlight surface of the back-contact solar cell forms two types of polarity regions with opposite conductive polarities, corresponding to the two types of electrode structures with opposite conductive polarities. Each polarity region includes a passivation layer, a doped semiconductor layer and a conductive layer. The front of the back-contact solar cell can also be provided with a third passivation layer 130 and an anti-reflection layer 140. The anti-reflection layer 140 is used to improve the absorption rate and conversion rate of sunlight inside the cell.

[0174] For example, Figure 9As shown, the backlight surface forms a first polarity region 102 and a second polarity region 103 arranged at intervals along the second direction, the first polarity region 102 includes a first passivation layer 111, a first doped semiconductor layer 112 and a first conductive layer 210, the first gate line 311 of the first electrode structure is arranged in the first polarity region 102, the second polarity region 103 includes a second passivation layer 121, a second doped semiconductor layer 122 and a second conductive layer 220, and the second gate line 321 of the second electrode structure is arranged in the second polarity region 103.

[0175] Among them, the first passivation layer 111 may include tunneling oxide or intrinsic amorphous silicon, the first doped semiconductor layer 112 may include doped polycrystalline silicon or doped amorphous silicon (amorphous silicon may also be replaced by nanocrystalline silicon or microcrystalline silicon), the second passivation layer 121 includes intrinsic amorphous silicon, and the second doped semiconductor layer 122 includes doped amorphous silicon (amorphous silicon may also be replaced by nanocrystalline silicon or microcrystalline silicon).

[0176] It can be understood that the two types of doped semiconductor layers are located in different polarity regions, the doping type of the first doped semiconductor layer 112 is the same as or opposite to the doping type of the semiconductor substrate 101 , and the doping type of the second doped semiconductor layer 122 is opposite to the doping type of the first doped semiconductor layer 112 .

[0177] like Figure 9 As shown, the first conductive layer 210 and the second conductive layer 220 are electrically insulated from each other. An isolated opening may be provided between the first conductive layer 210 and the second conductive layer 220 to achieve electrical insulation.

[0178] In actual implementation, the passivation layer and the doped semiconductor layer form a hierarchical structure for transmitting carriers. The hierarchical structures for transmitting different carriers may not overlap, or may have partially overlapping regions.

[0179] It can be understood that different polarity regions transmit different carriers, and an insulating dielectric layer 150 can be provided in the overlapping region of the hierarchical structures that transmit different carriers to separate the different hierarchical structures.

[0180] For example, Figure 9 As shown, there is an overlapping area between the first passivation layer 111, the first doped semiconductor layer 112 and the second passivation layer 121, the second doped semiconductor layer 122, and there is an insulating dielectric layer 150 between the first passivation layer 111, the first doped semiconductor layer 112 and the second passivation layer 121, the second doped semiconductor layer 122 in the overlapping area.

[0181] In actual implementation, the insulating dielectric layer 150 may include at least one of phosphosilicate glass, borosilicate glass, silicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide.

[0182] The embodiment of the present application also provides a photovoltaic module.

[0183] The photovoltaic module includes: at least one back-contact solar cell as described above.

[0184] A plurality of back-contact solar cells may be connected in series or in parallel.

[0185] According to the photovoltaic module provided in the embodiment of the present application, the back-contact solar cell of the photovoltaic module disconnects the grid line and sets an insulating layer at the intersection of the grid and grid line with opposite conductive polarities, so that the grid line is separated from the grid. The disconnected grid line is electrically connected through the conductive layer, which can avoid the occurrence of short circuits caused by contact between electrodes of different polarities and prevent battery failure. At the same time, it can also reduce the consumption of raw materials for electrode preparation and reduce the cost of battery manufacturing.

[0186] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0187] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this application.

[0188] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0189] In the description of this application, “plurality” means two or more.

[0190] In the description of the present application, a first feature being “on” or “under” a second feature may include the first and second features being in direct contact with each other, or the first and second features being in contact with each other not directly but via another feature therebetween.

[0191] In the description of this application, a first feature “on”, “above” and “above” a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0192] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0193] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A back contact solar cell, characterized in that: include: substrate; A conductive layer, the conductive layer being disposed on one side of the substrate, wherein a plurality of the conductive layers are arranged along a first direction, and adjacent conductive layers have opposite conductive polarities and are electrically insulated; an electrode structure, the electrode structure being disposed on a surface of the conductive layer away from the substrate, the electrode structure comprising a gate and a gate line intersecting and electrically connected to the gate, the gates having opposite conductive polarities being arranged at intervals along a second direction intersecting the first direction, the gate lines having opposite conductive polarities being arranged at intervals along the first direction, and the gate lines being located on the conductive layer having the same conductive polarity; wherein the gate and the gate line having opposite conductive polarities have an intersection, the gate line at the intersection is disconnected to be spaced apart from the gate in the second direction, the disconnected gate line is electrically connected via the conductive layer having the same conductive polarity, and an insulating layer is provided between the gate and the conductive layer at the intersection; A connection layer close to the conductive layer is further provided at the intersection, and the disconnected gate lines form a conductive channel through the connection layer. The insulating layer separates the connection layer and the gate, and the disconnected gate lines also form a conductive channel through the conductive layer.

2. The back contact solar cell according to claim 1, wherein: At the intersection, a width of the insulating layer in the second direction is greater than or equal to a width of the gate in the second direction.

3. The back contact solar cell according to claim 1, wherein: At the intersection, the distance at which the gate line is disconnected is greater than the width of the gate in the second direction.

4. The back contact solar cell according to claim 1, wherein: At the intersection, the width of the insulating layer in the second direction is greater than or equal to the distance at which the gate line is disconnected.

5. The back contact solar cell according to claim 4, characterized in that When the width of the insulating layer in the second direction is equal to the distance of the disconnected gate line, the two ends of the insulating layer are in contact with the two ends of the disconnected gate line, and the insulating layer is filled between the two ends of the disconnected gate line, separating the gate above the insulating layer and the conductive layer below.

6. The back contact solar cell according to claim 4, characterized in that When the width of the insulating layer in the second direction is greater than the distance of the gate line disconnection, the insulating layer covers the two ends of the gate line disconnection, and the two ends of the gate line disconnection are wrapped in the insulating layer, separating the gate above the insulating layer and the conductive layer below.

7. The back contact solar cell according to claim 1, wherein: The sheet resistance of the conductive layer is 20 ohm / sq-1000 ohm / sq.

8. The back contact solar cell according to claim 1, wherein: The sheet resistance of the connection layer is 0.001 ohm / sq-10 ohm / sq.

9. The back contact solar cell according to claim 1, wherein: A projection area of ​​the insulating layer on the substrate is greater than or equal to a projection area of ​​the connecting layer on the substrate.

10. The back contact solar cell according to claim 9, characterized in that The projection area of ​​the connecting layer is located within the projection area of ​​the insulating layer.

11. The back contact solar cell according to claim 9, characterized in that The width of the insulating layer along the first direction is greater than or equal to the width of the connecting layer along the first direction, and the width of the insulating layer along the second direction is greater than or equal to the width of the connecting layer along the second direction.

12. The back contact solar cell according to claim 1, wherein: At the intersection, the width of the connection layer in the second direction is greater than or equal to the distance at which the gate line is disconnected.

13. The back contact solar cell according to claim 12, characterized in that When the width of the connection layer in the second direction is equal to the distance at which the gate line is disconnected, both ends of the connection layer are in contact with both ends of the disconnected gate line.

14. The back contact solar cell according to claim 12, characterized in that When the width of the connection layer in the second direction is greater than the distance where the gate line is disconnected, both ends of the connection layer cover both ends of the disconnected gate line.

15. The back contact solar cell according to any one of claims 1 to 14, characterized in that: The distance at which the gate lines are disconnected is the distance between the two ends of the gate lines at the intersection.

16. The back contact solar cell according to any one of claims 1 to 14, characterized in that: The connection layer and the conductive layer are provided at the intersection of two opposite sides of the back contact solar cell along the second direction.

17. The back contact solar cell according to any one of claims 1 to 14, characterized in that: The conductive layer is provided at the intersection of the middle portion of the back-contact solar cell along the second direction, or the connecting layer and the conductive layer are provided.

18. The back contact solar cell according to any one of claims 1 to 14, characterized in that: The connection layer includes a conductive metal.

19. The back contact solar cell according to claim 18, characterized in that The conductive metal is silver and / or copper.

20. The back contact solar cell according to claim 18, characterized in that The size of the conductive metal is at least one of nanometer scale, submicron scale and micron scale.

21. The back contact solar cell according to any one of claims 1 to 14, characterized in that: The insulating layer is made of insulating glue or insulating ink.

22. The back contact solar cell according to any one of claims 1 to 14, characterized in that: The conductive layer is made of transparent conductive oxide.

23. The back contact solar cell according to any one of claims 1 to 14, characterized in that: The cross-sectional area of ​​the gate line is smaller than the cross-sectional area of ​​the gate.

24. The back contact solar cell according to any one of claims 1 to 14, characterized in that: An isolated opening is provided between the first conductive layer and the second conductive layer with opposite conductive polarities.

25. The back contact solar cell according to any one of claims 1 to 14, characterized in that The gate lines are prepared by low-temperature silver paste.

26. The back-contact solar cell according to any one of claims 1 to 14, characterized in that: The insulating layer is disposed between the connecting layer and the gate.

27. The back-contact solar cell according to any one of claims 1 to 14, characterized in that: The projection shape of the connection layer on the substrate is rectangular, circular, elliptical or irregular.

28. The back contact solar cell according to any one of claims 1 to 14, characterized in that: The substrate comprises a doped semiconductor layer, a passivation layer and a semiconductor substrate which are sequentially arranged in a direction away from the conductive layer.

29. A photovoltaic module, characterized in that: include: At least one back-contact solar cell according to any one of claims 1 to 28.

Images