Passivated contact solar cell and photovoltaic module

Abstract

The invention provides a passivation contact solar cell and a photovoltaic module, the passivation contact solar cell comprises a silicon substrate, the backlight surface of the silicon substrate comprises a first region and a second region which are arranged at an interval, the first region comprises a first sub-region and a second sub-region, and the first sub-region and the backlight surface of the silicon substrate are provided with dielectric layers. Island-shaped bulge structures are distributed on the surface of the dielectric layer, and the plurality of island-shaped bulge structures are distributed in the first region in an array form; in the second sub-region, the backlight surface of the silicon substrate is provided with a first passivation layer. According to the invention, the photoelectric conversion efficiency of the passivation contact solar cell can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of solar cells, in particular to a passivated contact solar cell and a photovoltaic module. BACKGROUND

[0002] The passivated contact solar cell is a kind of solar cell based on selective carrier transport, which has wide application prospects.

[0003] The passivated contact structure of the current passivated contact solar cell mainly consists of a dielectric layer and a doped layer. Due to the existence of infrared parasitic absorption of the doped layer, the optical loss is increased, and the related technology adopts laser to partially remove it to reduce the optical loss. However, in this process, the laser is easy to cause damage to the silicon substrate, affecting the photoelectric conversion efficiency of the passivated contact solar cell. SUMMARY

[0004] In order to solve the above technical problems, the present application discloses a passivated contact solar cell and a photovoltaic module to reduce the damage to the silicon substrate caused by the laser in the process of removing part of the doped layer, and improve the photoelectric conversion efficiency of the passivated contact solar cell.

[0005] In a first aspect, the present application provides a passivated contact solar cell, comprising:

[0006] A silicon substrate, the back surface of the silicon substrate comprises a first region and a second region arranged at intervals, the first region comprises a first sub-region and a second sub-region, wherein:

[0007] In the first sub-region, the back surface of the silicon substrate is provided with a dielectric layer, the surface of the dielectric layer is distributed with island-shaped protruding structures, and a plurality of island-shaped protruding structures are distributed in the first region in the form of an array;

[0008] In the second sub-region, the back surface of the silicon substrate is provided with a first passivation layer, and the second sub-region is a region in the first region except the first sub-region.

[0009] In some embodiments of the present application, the lateral dimension of the island-shaped protruding structure is d1, and 1 μm≤d1≤50 μm.

[0010] In some embodiments of the present application, the height difference between the island-shaped protruding structure and the first passivation layer in the second sub-region is ΔH1, and 0.5 μm≤ΔH1≤6 μm.

[0011] In some embodiments of the present application, the height difference between the silicon substrate of the first sub-region and the silicon substrate of the second sub-region is ΔH2, and 0.5 μm≤ΔH2≤5 μm.

[0012] In some embodiments of the present application, the island-shaped protruding structure has a height H1, and 100nm≤H1≤200nm.

[0013] In some embodiments of the present application, along the first direction, the average interval of the island-shaped protruding structure is The size of the first region is W1, and the size of the second region is W2, satisfying: and n is an integer greater than 1.

[0014] In some embodiments of the present application, in the second region, the back surface of the silicon substrate is sequentially provided with the dielectric layer, the first doped layer and the first passivation layer.

[0015] In some embodiments of the present application, the back surface of the passivated contact solar cell further comprises a first anti-reflection layer, wherein:

[0016] In the first sub-region, the first anti-reflection layer is located on the back surface of the island-shaped protruding structure;

[0017] In the second sub-region and the second region, the first anti-reflection layer is located on the back surface of the first passivation layer.

[0018] In some embodiments of the present application, the thickness of the first anti-reflection layer is 60nm-150nm.

[0019] In some embodiments of the present application, the thickness of the dielectric layer is 1nm-10nm.

[0020] In some embodiments of the present application, the island-shaped protruding structure comprises a doped polysilicon layer and an aluminum oxide layer.

[0021] In a second aspect, the present application provides a photovoltaic module, comprising the solar cell according to the first aspect.

[0022] Compared with the prior art, the present application has at least the following beneficial effects:

[0023] The application provides a passivated contact solar cell and a photovoltaic module, wherein the passivated contact solar cell comprises a silicon substrate, and a back light surface of the silicon substrate comprises first regions and second regions arranged at intervals; the first regions comprise first sub-regions and second sub-regions; in the first sub-regions, the back light surface of the silicon substrate is provided with a dielectric layer, and the surface of the dielectric layer is distributed with island-shaped protruding structures; and the island-shaped protruding structures are distributed in the first regions in an array form; in the second sub-regions, the back light surface of the silicon substrate is provided with a first passivation layer; the island-shaped protruding structures distributed in the array form can effectively remove the first doped layer in the first regions while indicating that the damage caused by laser to the silicon substrate is small, so that the photoelectric conversion efficiency of the passivated contact solar cell is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0025] Figure 1 The structure schematic diagram of the first regions and the second regions in one embodiment of the application is shown in the figure.

[0026] Figure 2 The structure schematic diagram of the solar cell in one embodiment of the application is shown in the figure.

[0027] Figure 3 The structure schematic diagram of the solar cell in another embodiment of the application is shown in the figure. Figure 2 The local enlarged schematic diagram of the dotted box region in the figure is shown in the figure.

[0028] Figure 4 The structure schematic diagram of the solar cell in another embodiment of the application is shown in the figure.

[0029] Figure 5 The schematic diagram of the laser spot in one embodiment of the application is shown in the figure.

[0030] Figure 6 The schematic diagram of the laser spot in another embodiment of the application is shown in the figure.

[0031] Figure 7 The electron microscope (SEM) diagram of the back light surface of the silicon substrate in Example 1 of the application is shown in the figure.

[0032] Figure 8 The SEM diagram of the back light surface of the silicon substrate in Comparative Example 1 is shown in the figure.

[0033] Explanation of reference signs:

[0034] 1-silicon substrate, 2-medium layer, 3-island-shaped protruding structure, 4-first passivation layer, 5-first doped layer, 6-first anti-reflection layer, 7-second doped layer, 8-second passivation layer, 9-second anti-reflection layer, 10-laser spot, 11-first region, 12-second region, 31-doped polysilicon layer, 32-aluminum oxide layer, 111-first sub-region, 112-second sub-region, 121-first electrode, 122-second electrode. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0036] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0037] In addition, in addition to being used to indicate the orientation or positional relationship, the above-mentioned part of the terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain dependent relationship or connection relationship in some cases. Those of ordinary skill in the art can understand the specific meaning of these terms in the present application according to the specific situation.

[0038] In addition, the terms "mount", "set", "set with", "connect", "connect" should be broadly understood. For example, it can be fixedly connected, detachably connected, or integrally constructed; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or internal communication between two devices, elements or components. Those of ordinary skill in the art can understand the specific meaning of the above terms in the present application according to the specific situation.

[0039] In addition, the terms "first", "second" and the like are mainly used to distinguish different devices, elements or components (the specific types and structures can be the same or different), and are not intended to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise stated, the meaning of "multiple" is two or more.

[0040] The technical solution of this application will be further described below with reference to the embodiments and accompanying drawings.

[0041] Firstly, this application provides a passivated contact solar cell, such as... Figure 1 As shown, the passivated contact solar cell includes a silicon substrate 1. The back surface of the silicon substrate 1 includes a first region 11 and a second region 12 arranged at intervals. A first electrode 121 is disposed in the second region 12. (Reference) Figure 2 The first region 11 includes a first sub-region 111 and a second sub-region 112. In the first sub-region 111, a dielectric layer 2 is disposed on the back surface of the silicon substrate 1, and island-shaped protrusion structures 3 are distributed on the surface of the dielectric layer 2. Multiple island-shaped protrusion structures 3 are distributed in an array in the first region 11. Figure 2 (The island-shaped protrusion structure 3 in the diagram is for illustrative purposes only); in the second sub-region 112, a first passivation layer 4 is disposed on the back surface of the silicon substrate 1, and the second sub-region 112 is the region in the first region 11 excluding the first sub-region 111. This array-distributed island-shaped protrusion structure indicates that the laser causes minimal damage to the silicon substrate while effectively removing the first doped layer in the first region, thereby improving the photoelectric conversion efficiency of the passivated contact solar cell.

[0042] The lateral dimension of the island-shaped protrusion structure in this application refers to the maximum dimension of the line connecting any two points on the plane where the bottom of the island-shaped protrusion structure is located.

[0043] The lateral dimension of the island-shaped protrusion structure 3 is d1, where 1 μm ≤ d1 ≤ 50 μm. For example, d1 can be 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, or 50 μm. The inventors have found that when the lateral dimension of the island-shaped protrusion structure is too small (e.g., less than 1 μm), the laser etching effect on the first doped layer is relatively strong; conversely, when the lateral dimension of the island-shaped protrusion structure is too large (e.g., greater than 50 μm), the laser etching effect on the first doped layer is relatively weak. The island-shaped protrusion structure of this application has dimensions within the aforementioned range, which helps to further reduce laser damage to the silicon substrate while also enabling the removal of the first doped layer in the first region as much as possible.

[0044] In one alternative implementation, refer to Figure 3, the height difference between the island-shaped protruding structure 3 and the first passivation layer 4 in the second sub-region 112 is ΔH1, 0.5 μm≤ΔH1≤6 μm. For example, ΔH1 is 0.5 μm, 1 μm, 2 μm, 3 μm, 5 μm or 6 μm. When ΔH1 is too small (for example, less than 0.5 μm), it indicates that the etching depth of the silicon substrate is not enough, which makes it difficult to clean the denatured substances caused by laser damage by etching and cleaning, and thus increases the recombination and reduces the photoelectric conversion efficiency of the solar cell; when ΔH1 is too large (for example, greater than 6 μm), it indicates that the etching and thinning of the silicon substrate is serious, which reduces the mechanical strength of the solar cell and easily causes the risk of cracking.

[0045] In the present application, ΔH1 refers to the distance between the top of the island-shaped protruding structure 3 and the back surface of the first passivation layer 4. ΔH1 can be regulated by regulating the etching depth of the silicon substrate and / or the height of the island-shaped protruding structure.

[0046] In an optional embodiment, referring to Figure 3 , the height difference between the silicon substrate 1 of the first sub-region 111 and the silicon substrate 1 of the second sub-region 112 is ΔH2, 0.5 μm≤ΔH2≤5 μm. For example, ΔH2 is 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm or 5 μm. By regulating ΔH2 within the above range, the silicon substrate has a suitable etching depth, so that the solar cell has high photoelectric conversion efficiency and mechanical strength.

[0047] In the present application, ΔH2 refers to the distance between the top of the silicon substrate 1 in the first sub-region 111 and the top of the silicon substrate 1 in the second sub-region 112. ΔH2 can be regulated by regulating the etching depth of the silicon substrate.

[0048] In an optional embodiment, referring to Figure 3 , the height of the island-shaped protruding structure 3 is H1, 100 nm≤H1≤200 nm. For example, H1 is 100 nm, 120 nm, 150 nm, 180 nm or 200 nm. By regulating H1 within the above range, it can avoid that the doped polysilicon layer in the island-shaped protruding structure is burned through during the sintering of the grid line, and also reduce the contact resistance, which is conducive to the improvement of the photoelectric conversion efficiency of the solar cell.

[0049] In an optional embodiment, referring to Figure 1 , along the first direction, the average interval of the island-shaped protruding structures is The size of the first region is W1, and the size of the second region is W2, which satisfies and wherein n is an integer greater than 1, for example, n is 2, 3, 4, 5, etc. By regulating W1 and W2 satisfy the above relationship, which is conducive to retaining the first doped layer of a proper thickness in the second region and reducing the risk of damage to the silicon substrate caused by the electrode grid lines falling onto the first region during printing.

[0050] In the present application, the pitch of the island-shaped protruding structures refers to the distance between the geometric centers of adjacent island-shaped protruding structures in the first direction; the average pitch of the island-shaped protruding structures refers to the average value of the pitch of the island-shaped protruding structures in the first direction in the first region. The first direction refers to a direction perpendicular to the extension direction of the first electrode 121 and parallel to the plane in which the silicon substrate 1 is located.

[0051] In an optional embodiment, referring to Figure 2 In the second region 12, the back surface of the silicon substrate 1 is sequentially provided with the dielectric layer 2, the first doped layer 5 and the first passivation layer 4, and the first electrode 121 is in contact with the first doped layer 5 to form an ohmic contact.

[0052] In an optional embodiment, referring to Figure 4 The back surface of the passivated contact solar cell further comprises a first anti-reflection layer 6, wherein:

[0053] In the first sub-region 111, the first anti-reflection layer 6 is located on the back surface of the island-shaped protruding structure 3; in the second sub-region 112, the first anti-reflection layer 6 is located on the back surface of the first passivation layer 4; and in the second region 12, the first anti-reflection layer 6 is located on the back surface of the first passivation layer 4. The first anti-reflection layer can further reduce the reflection of light and improve the utilization rate of light by the passivated contact solar cell, thereby improving the photoelectric conversion efficiency of the passivated contact solar cell.

[0054] In an optional embodiment, the thickness of the first anti-reflection layer is 60-150 nm. By adjusting the thickness of the first anti-reflection layer within the above range, the reflection of light can be reduced, and the problem of light being blocked due to the first anti-reflection layer being too thick can be avoided.

[0055] In an alternative embodiment, the thickness of the dielectric layer is 1 nm to 10 nm. The material of the dielectric layer of the present application can include a variety of dielectric materials, such as at least one of silicon oxide, magnesium fluoride, amorphous silicon, polysilicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide or titanium oxide. Specifically, the dielectric layer can be composed of a silicon oxide layer containing silicon oxide. This is because the silicon oxide layer has excellent passivation performance, can minimize the recombination loss of the semiconductor substrate surface minority carriers, and is a thin film with excellent durability to subsequent high-temperature processes. In order to better provide interface passivation for the substrate, the thickness of the dielectric layer can be 0.1 nm to 5 nm. For example, the thickness of the dielectric layer can be 0.1 nm, 0.5 nm, 1 nm, 1.5 nm, 2 nm, 3 nm, 4 nm, 5 nm, etc., however, the present application is not limited thereto, and the thickness of the dielectric layer can have various values. The dielectric layer, as a potential barrier for electrons and holes, can be combined with the polysilicon layer to prevent the passage of minority carriers. The dielectric layer can also have a pinhole channel effect, allowing the free movement of carriers within the solar cell, and selectively passing majority carriers through the heavily doped polysilicon, which helps to reduce the recombination loss of minority carriers. In addition, the dielectric layer can act as a diffusion barrier to prevent the diffusion of dopants from the doped polysilicon layer into the semiconductor substrate.

[0056] In an alternative embodiment, referring to Figure 2 , the island-shaped protruding structure 3 includes a doped polysilicon layer 31 and an aluminum oxide layer 32, wherein the doped polysilicon layer 31 contains N-type doped polysilicon. The present application can adjust the height of the island-shaped protruding structure by adjusting the thickness of the doped polysilicon layer and / or the aluminum oxide layer in the island-shaped protruding structure.

[0057] In an embodiment, the material of the first passivation layer is selected from aluminum oxide (AlO x , which is beneficial to the full passivation of the interface of the solar cell, thereby improving the performance of the passivated contact solar cell.

[0058] In an embodiment, referring to Figure 4 , the light-receiving surface of the passivated contact solar cell of the present application further sequentially has a second doped layer 7, a second passivation layer 8, a second anti-reflection layer 9 and a second electrode 122, and the light-receiving surface of the silicon substrate 1 has a textured structure. In order to better absorb solar energy, the light-receiving surface of the silicon substrate of the present application has a textured structure, for example, the textured structure can adopt a pyramid-shaped textured structure. Through the textured structure, a higher surface area can be provided for the solar cell while reducing reflection, diffusion, etc. of light. The present application does not have special limitations on the preparation method of the textured structure, as long as the purpose of the present application can be achieved, for example, the existing wet etching process can be used for preparation.

[0059] In a second aspect, the present application provides a photovoltaic module, which comprises the solar cell according to the first aspect.

[0060] The present application also provides a photovoltaic module, which is used for converting received light energy into electric energy and transmitting the electric energy to an external load. The photovoltaic module comprises: at least one cell string, which is connected by a plurality of the above-mentioned solar cells; an encapsulating film, which is used for covering the surface of the cell string; and a cover plate, which is used for covering the surface of the encapsulating film away from the cell string.

[0061] The present application does not have special restrictions on the preparation method of the passivated contact solar cell, and exemplarily, the passivated contact solar cell can be prepared by the following method:

[0062] Step A, providing a prepared solar cell initial structure, which comprises a silicon substrate, the back surface of the silicon substrate has a dielectric layer and a first doped layer, and the light receiving surface of the silicon substrate has a second doped layer;

[0063] Step B, performing laser etching treatment on the back surface of the silicon substrate by laser, and then performing wet etching treatment, so as to form first regions and second regions arranged at intervals on the back surface of the silicon substrate. Wherein, the dielectric layer surface at some positions in the first regions forms a plurality of island-shaped protruding structure initial bodies, which are residual structures generated when the first doped layer in the first regions is removed under the action of laser etching and wet etching;

[0064] Step C, depositing an aluminum oxide layer on the back surface of the etched silicon substrate, so as to form a first passivation layer, and in the process, an aluminum oxide layer is also deposited on the surface of the island-shaped protruding structure initial body, so as to form an island-shaped protruding structure. The region where the island-shaped protruding structure is located is a first sub-region, and the region in the first region except the first sub-region is a second sub-region;

[0065] Step D, depositing a silicon nitride layer on the back surface of the etched silicon substrate, so as to form a first antireflection layer;

[0066] Step E, forming a second passivation layer on the light receiving surface of the second doped layer, and forming a second antireflection layer on the light receiving surface of the second passivation layer;

[0067] Step F, preparing a first electrode and a second electrode on the back surface and the light receiving surface of the solar cell initial structure, respectively.

[0068] In step A of the present application, the silicon substrate can be of a first conductivity type, and the second doped layer has a second conductivity type. One of the first conductivity type and the second conductivity type is N type and the other is P type. For example, when the first conductivity type is N type, the second conductivity type is P type; when the first conductivity type is P type, the second conductivity type is N type. The silicon substrate can be a texturing silicon substrate, and the thickness of the silicon substrate is 100-200 μm, which can meet the purpose of the present application, and the present application is not limited in this regard.

[0069] In step B of the present application, the laser can be any one of nanosecond, picosecond, femtosecond pulse laser; referring to Figure 5 and Figure 6 , the laser spot 10 can be a circular spot or a chamfered rectangular spot, the size of the laser spot 10 is 100 μm*100 μm-1000 μm*1000 μm, the frequency of the laser is 400 kHz-1000 kHz, the scanning rate of the laser is 0 m / s-80 m / s, and the power of the laser is 60 W-200 W; referring to Figure 5 or Figure 6 , the gap distance of the laser spot 10 is L1, and the size of the single laser spot 10 is L2, which satisfies: 0.1

[0070] In step C of the present application, the first passivation layer can be formed based on a plasma enhanced chemical vapor deposition (PECVD) process.

[0071] In step D of the present application, the first anti-reflective layer can be formed based on a PECVD process.

[0072] In step E of the present application, the second passivation layer can be formed based on an atomic layer deposition (ALD) process, and the second anti-reflective layer can be formed based on a PECVD process. The second passivation layer can be an aluminum oxide layer, which plays a passivation role; and the second anti-reflective layer can be a silicon oxynitride layer, which plays a role of reducing reflection.

[0073] In step F of the present application, the first electrode and the second electrode can be prepared on the back light surface and the light receiving surface of the initial structure of the solar cell by means of screen printing.

[0074] The thickness of each functional layer is not particularly limited in the present application, as long as the object of the present application can be achieved. For example, the thickness of the first passivation layer 4 is 70-120 nm, the thickness of the second passivation layer 8 is 1-5 nm, and the thickness of the second anti-reflective layer 9 is 60-100 nm.

[0075] The present application does not have a particular restriction on the way of regulating the lateral size d1 of the island-shaped protrusion structure, for example, d1 generally increases with the increase of the ratio between the laser spot gap distance and the size of a single laser spot (i.e. L1 / L2) during the laser etching process, and based on this, d1 can be regulated by regulating L1 / L2.

[0076] Embodiment

[0077] The passivated contact solar cell and photovoltaic module of the embodiment of the present application will be further described below in combination with more specific embodiments.

[0078] Embodiment 1

[0079] <Providing a solar cell initial structure>

[0080] A solar cell initial structure with texturing is provided, which includes a silicon substrate, the back surface of the silicon substrate has a dielectric layer and a first doped layer, and the light receiving surface of the silicon substrate has a second doped layer. The silicon substrate is an N-type silicon wafer with a thickness of 125 μm, the doping element of the first doped layer is phosphorus (P) element, and the doping element of the second doped layer is boron (B) element.

[0081] <Laser etching process and wet etching process>

[0082] A picosecond laser is used to scan the predetermined pattern area (i.e. the first area) designed on the back surface of the solar cell initial structure to remove the first doped layer and the dielectric layer in the first area; then a wet etching process is used to etch the silicon substrate in the first area to form the first area and the second area arranged at intervals on the back surface of the silicon substrate, and a plurality of island-shaped protrusion structure initial bodies are formed on the surface of the dielectric layer at some positions in the first area; wherein the laser spot shape is a chamfered rectangular spot, the gap distance L1 of the laser spot is 25 μm, the size L2 of the laser spot is 100 μm, and therefore the ratio of L1 / L2 is 0.25.

[0083] <Preparation of the first passivation layer>

[0084] An aluminum oxide layer is deposited on the back surface of the etched silicon substrate by PECVD process to form the first passivation layer, so that an aluminum oxide layer is also deposited on the surface of the island-shaped protrusion structure initial body to form the island-shaped protrusion structure.

[0085] <Preparation of the first anti-reflective layer>

[0086] A first anti-reflective layer is formed by depositing a silicon nitride layer on the back surface of the etched silicon substrate by a PECVD process;

[0087] <Preparation of the second passivation layer and the second anti-reflective layer>

[0088] A second passivation layer is formed by depositing an aluminum oxide layer on the light-receiving surface of the second doped layer by an ALD process; and then a second anti-reflective layer is formed by depositing a silicon oxynitride layer on the light-receiving surface of the second passivation layer by a PECVD process;

[0089] <Preparation of the electrodes>

[0090] The first electrode and the second electrode are respectively prepared on the back surface and the light-receiving surface of the initial structure of the solar cell by a screen printing method, to form Figure 4 the solar cell structure as shown in the figure.

[0091] Example 2

[0092] Except that in the <laser etching treatment and wet etching treatment>, the gap distance L1 of the laser spot is adjusted to 15 μm, so that L1 / L2 = 0.15, and the lateral size d1 of the island-shaped protrusion structure is adjusted according to Table 1, the rest is the same as in Example 1.

[0093] Example 3

[0094] Except that in the <laser etching treatment and wet etching treatment>, the gap distance L1 of the laser spot is adjusted to 40 μm, so that L1 / L2 = 0.4, and the lateral size d1 of the island-shaped protrusion structure is adjusted according to Table 1, the rest is the same as in Example 1.

[0095] Comparative Example 1

[0096] Except that in the <laser etching treatment and wet etching treatment>, the gap distance L1 of the laser spot is adjusted to 0 μm, so that the overlapping area between adjacent laser spots increases, resulting in that the first region does not form an island-shaped protrusion structure, the rest is the same as in Example 1.

[0097] Test method:

[0098] Measurement of the lateral size of the island-shaped protrusion structure:

[0099] A 3D measuring instrument is used to measure the length of the longest diagonal of the bottom surface of the island-shaped protrusion structure as the lateral size of the island-shaped protrusion structure.

[0100] Open-circuit voltage, short-circuit current, fill factor, and photoelectric conversion efficiency test:

[0101] The current (I)-voltage (V) of the solar cells of each example and the comparative example was measured using an I-V tester (Model: MX-MPVC-A20, manufacturer: Suzhou Maiwei Technology Co., Ltd.), to obtain the open-circuit voltage (Voc), short-circuit current (Isc), short-circuit current density (Jsc), fill factor (FF) and photoelectric conversion efficiency (Eff) of the solar cells. 200 pieces of the solar cells prepared in each example or the comparative example were tested, and the 200 pieces were divided into 3 groups and tested under the same conditions, and then the average value of the test results of the 3 groups was taken to eliminate accidental errors in the testing process.

[0102] Table 1: Related data of each example and the comparative example

[0103]

[0104] In Table 1, " / " indicates that there is no related preparation parameter.

[0105] As can be seen from Examples 1 to 3 and the comparative example 1, the photoelectric conversion efficiency of the solar cell of the comparative example 1 is low, which may be due to the fact that the solar cell of the comparative example 1 does not have an island-shaped protruding structure, indicating that although it can completely remove the first doped layer in the first region, it also causes damage to the silicon substrate at the same time; while the open-circuit voltage, short-circuit current, short-circuit current density and fill factor of the solar cell of the present application are improved, indicating that the damage caused by the laser to the silicon substrate is small at the same time and the first doped layer in the first region is removed as much as possible, thereby improving the photoelectric conversion efficiency.

[0106] Figure 7 The SEM image of the back light surface of the silicon substrate of Example 1 of the present application is shown in Figure 1, from which Figure 7 It can be seen that there are several island-shaped protruding structures arranged in an array on the back light surface of the silicon substrate, and the shape of these island-shaped protruding structures presents an irregular island-like morphology, which can be approximated as a dot under a macroscopic scale.

[0107] Figure 8 The SEM image of the back light surface of the silicon substrate of the comparative example 1 is shown in Figure 2, from which Figure 8 It can be seen that there are burn marks (shown in the black circle area in the figure) on the back light surface of the silicon substrate due to the high overlap of the laser spots, indicating that the back light surface of the silicon substrate is damaged by the laser.

[0108] The above has carried on the detailed introduction to the passivated contact solar cell and photovoltaic module disclosed by the application, the principle and implementation mode of the application are described by applying specific examples in the paper, the above example description is only for helping understanding the technical scheme and core invention points of the embodiments of the application; meanwhile, for the general technical personnel in the art, according to the idea of the application, the specific implementation mode and application range will have changes, and on the basis of the above, the content of the specification should not be understood as the limitation of the application.

Claims

1. A passivated contact solar cell, characterized in that, include: A silicon substrate, wherein the backlight surface of the silicon substrate includes a first region and a second region arranged at intervals, the first region including a first sub-region and a second sub-region, wherein: In the first sub-region, a dielectric layer is disposed on the back surface of the silicon substrate, and island-shaped protrusion structures are distributed on the surface of the dielectric layer, with multiple island-shaped protrusion structures distributed in an array in the first region; In the second sub-region, a first passivation layer is provided on the back surface of the silicon substrate, and the second sub-region is the region in the first region other than the first sub-region.

2. The passivated contact solar cell according to claim 1, characterized in that, The lateral dimension of the island-shaped protrusion structure is d1, where 1μm≤d1≤50μm.

3. The passivated contact solar cell according to claim 1, characterized in that, The height difference between the island-shaped protrusion structure and the first passivation layer in the second sub-region is ΔH1, where 0.5μm≤ΔH1≤6μm.

4. The passivated contact solar cell according to claim 2, characterized in that, The height difference between the silicon substrate in the first sub-region and the silicon substrate in the second sub-region is ΔH2, where 0.5μm≤ΔH2≤5μm.

5. The passivated contact solar cell according to claim 1, characterized in that, The height of the island-shaped protrusion structure is H1, where 100nm ≤ H1 ≤ 200nm.

6. The passivated contact solar cell according to claim 1, characterized in that, Along the first direction, the average spacing of the island-shaped protrusions is The size of the first region is W1, and the size of the second region is W2, satisfying the following conditions: and n is an integer greater than 1.

7. The passivated contact solar cell according to claim 1, characterized in that, In the second region, the back surface of the silicon substrate is sequentially provided with the dielectric layer, the first doped layer, and the first passivation layer.

8. The passivated contact solar cell according to claim 7, characterized in that, The back surface of the passivated contact solar cell also includes a first anti-reflection layer, wherein: In the first sub-region, the first anti-reflection layer is located on the back surface of the island-shaped protrusion structure; In the second sub-region and the second region, the first antireflection layer is located on the back surface of the first passivation layer.

9. The passivated contact solar cell according to claim 8, characterized in that, The thickness of the first antireflective layer is 60nm to 150nm.

10. The passivated contact solar cell according to claim 1, characterized in that, The thickness of the dielectric layer is 1 nm to 10 nm.

11. The passivated contact solar cell according to claim 1, characterized in that, The island-shaped protrusion structure includes a doped polycrystalline silicon layer and an aluminum oxide layer.

12. A photovoltaic module, characterized in that, The photovoltaic module includes the passivated contact solar cell as described in any one of claims 1 to 11.

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