Perovskite / crystalline silicon laminated solar cell and preparation method thereof

Abstract

The invention discloses a perovskite / crystalline silicon laminated solar cell and a preparation method thereof. The perovskite / crystalline silicon laminated solar cell comprises a crystalline silicon bottom cell, a transparent conductive oxide thin film and a perovskite top cell, the transparent conductive oxide thin film is arranged between the crystalline silicon bottom cell and the perovskite top cell, and a plurality of blocking grooves are distributed in the main surface, facing the perovskite top cell, of the transparent conductive oxide thin film. The transparent conductive oxide film is used for blocking transverse migration of carriers on the transparent conductive oxide film. According to the perovskite / crystalline silicon laminated solar cell, the risks of electric leakage, short circuit and failure of the perovskite solar cell can be effectively reduced, and the voltage loss of the perovskite / crystalline silicon laminated solar cell is reduced.

Description

Technical Field

[0001] The present invention relates to a perovskite / silicon heterojunction solar cell and a preparation method thereof. Background Art

[0002] For a two-terminal perovskite / silicon heterojunction solar cell, a transparent conductive oxide film with high conductivity and high light transmittance is often selected as the intermediate tandem layer between the perovskite solar cell and the silicon solar cell.

[0003] Due to the excellent lateral conductivity of the transparent conductive oxide film, on the one hand, the carriers transported by the carrier transport layer of the perovskite solar cell move laterally in the transparent conductive oxide film and recombine with the defects of the transparent conductive oxide film, resulting in short circuit and leakage of the perovskite solar cell, and there is a relatively high risk of failure; on the other hand, when the carrier transport layer in the perovskite solar cell is uneven, the carriers transported by the carrier transport layer move laterally in the transparent conductive oxide film and recombine with the perovskite solar cell, which will also easily cause short circuit and failure of the perovskite solar cell, resulting in voltage loss of the perovskite / silicon heterojunction solar cell. Summary of the Invention

[0004] In view of this, the present invention provides a perovskite / silicon heterojunction solar cell and a preparation method thereof. By reducing the lateral conductivity of the transparent conductive oxide film used to connect the perovskite solar cell and the silicon-based solar cell, the lateral transport of carriers in the transparent conductive oxide film is blocked, and the recombination probability of carriers with the transparent conductive oxide film and the recombination of carriers with the functional layer of the perovskite solar cell are reduced, thereby effectively reducing the risks of leakage, short circuit and failure of the perovskite solar cell and reducing the voltage loss of the perovskite / silicon heterojunction solar cell.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a perovskite / silicon heterojunction solar cell, comprising: a silicon bottom cell, a transparent conductive oxide film, and a perovskite top cell, wherein the transparent conductive oxide film is disposed between the silicon bottom cell and the perovskite top cell;

[0007] A plurality of blocking grooves are distributed on the main surface of the transparent conductive oxide film facing the perovskite top cell, for blocking the lateral migration of carriers in the transparent conductive oxide film.

[0008] In a second aspect, an embodiment of the present invention provides a preparation method of a perovskite / silicon heterojunction solar cell, comprising:

[0009] Step 1: Prepare a transparent conductive oxide film on the crystalline silicon bottom cell;

[0010] Step 2: Open a plurality of distributed blocking grooves on the main surface of the transparent conductive oxide film away from the crystalline silicon bottom cell;

[0011] Step 3: Prepare a perovskite top cell on the main surface of the transparent conductive oxide film provided with the blocking grooves.

[0012] The technical solution of the first aspect of the above invention has the following advantages or beneficial effects:

[0013] In the structure of the perovskite / crystalline silicon tandem solar cell provided by the embodiment of the present invention, since a plurality of distributed blocking grooves are provided on the main surface of the transparent conductive oxide film between the crystalline silicon bottom cell and the perovskite top cell facing the perovskite top cell, the existence of the blocking grooves can reduce the lateral conductivity of the transparent conductive oxide film, thereby blocking the lateral transport of carriers in the transparent conductive oxide film, reducing the probability of carrier recombination with the transparent conductive oxide film, and being able to reduce the recombination of carriers with the functional layer of the perovskite solar cell, thereby effectively reducing the risk of leakage, short circuit and failure of the perovskite solar cell and reducing the voltage loss of the perovskite / crystalline silicon tandem solar cell. Description of the Drawings

[0014] Figure 1 is a schematic cross-sectional structure diagram of a perovskite / crystalline silicon tandem solar cell according to an embodiment of the present invention;

[0015] Figure 2 is a first schematic structural diagram of a transparent conductive oxide film according to an embodiment of the present invention;

[0016] Figure 3 is a second schematic structural diagram of a transparent conductive oxide film according to an embodiment of the present invention;

[0017] Figure 4 is a third schematic structural diagram of a transparent conductive oxide film according to an embodiment of the present invention;

[0018] Figure 5 is a fourth schematic structural diagram of a transparent conductive oxide film according to an embodiment of the present invention;

[0019] Figure 6 is a fifth schematic structural diagram of a transparent conductive oxide film according to an embodiment of the present invention;

[0020] Figure 7 is a main process schematic diagram of a preparation method of a single crystal silicon rod according to an embodiment of the present invention.

[0021] Reference Signs:

[0022] 10 - crystalline silicon bottom cell; 20 - transparent conductive oxide thin film; 21 - blocking groove; 211 - first blocking groove; 212 - second blocking groove; 30 - perovskite top cell; 31 - first carrier transport layer; 32 - perovskite absorption layer; 33 - second carrier transport layer; 34 - transparent conductive layer; 41 - bottom electrode; 42 - top electrode. Specific embodiments

[0023] For a perovskite / silicon tandem solar cell (referred to as a tandem cell) with a two-terminal structure, generally the top cell is a perovskite solar cell, the bottom cell is a silicon solar cell, and a transparent conductive oxide thin film is provided between the perovskite solar cell and the silicon solar cell. This transparent conductive oxide thin film serves as an interconnect layer to connect the perovskite solar cell and the silicon solar cell. This perovskite / silicon tandem solar cell can broaden the spectral response of the cell, make the most of the incident light, and improve the efficiency of the tandem cell. Since the transparent conductive oxide thin film has relatively good conductivity, a high electrical conductivity, and light transmittance, the transparent conductive oxide thin film is often selected as the interconnect layer between the top cell and the bottom cell in the two-terminal structure perovskite / silicon tandem solar cell. In addition to being able to transport carriers from the bottom cell to the top cell and from the top cell to the bottom cell, the excellent electrical conductivity of this transparent conductive oxide thin film gives it a relatively high lateral electrical conductivity. This relatively high lateral electrical conductivity of the transparent conductive oxide thin film makes it easy for carriers to undergo lateral transport in the transparent conductive oxide thin film. The laterally transported carriers are prone to getting trapped in the structural defects existing in the transparent conductive oxide thin film, increasing the recombination loss of carriers. Additionally, due to the possible existence of leakage points in the prepared transparent conductive oxide thin film, the laterally transported carriers are very likely to pass through the leakage points, resulting in short-circuit and failure of the top cell, which is not conducive to the large-scale industrial production of perovskite / silicon tandem solar cells.

[0024] To solve the above problems existing in the prior art and the existing structure of perovskite / silicon tandem solar cells, an embodiment of the present invention provides a novel perovskite / silicon tandem solar cell and a preparation method for this novel perovskite / silicon tandem solar cell.

[0025] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described by referring to the drawings below are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0026] It should be noted that the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0027] Among them, Figure 1 FIG. shows a schematic cross-sectional structure diagram of a perovskite / silicon heterojunction solar cell provided by an embodiment of the present invention; Figures 2 to 6 FIG. exemplarily shows a schematic structural diagram of transparent conductive oxide films of various structures; Figure 7 FIG. shows a schematic main process diagram of a method for manufacturing a perovskite / silicon heterojunction solar cell provided by an embodiment of the present invention.

[0028] A perovskite / silicon heterojunction solar cell provided by an embodiment of the present invention. As Figure 1 shown, the perovskite / silicon heterojunction solar cell may include: a silicon bottom cell 10, a transparent conductive oxide film 20, and a perovskite top cell 30. The transparent conductive oxide film 20 is disposed between the silicon bottom cell 10 and the perovskite top cell 30.

[0029] Among them, the silicon bottom cell 10 may be one of a PERC (Passivated Emitter Rear Cell) cell, a TOPCon (Tunnel Oxide Passivated Contact) cell, an HJT (Heterojunction with Intrinsic Thin-film) cell, or a back contact cell.

[0030] Regarding the perovskite top cell 30, as Figure 1 shown, the perovskite top cell 30 may include: a first carrier transport layer 31, a perovskite absorption layer 32, a second carrier transport layer 33, and a transparent conductive layer 34.

[0031] Understandably, the above-mentioned perovskite / silicon heterojunction solar cell may further include a bottom electrode 41 disposed at the bottom of the silicon bottom cell 10 and electrically connected to the silicon bottom cell 10, and a top electrode 42 disposed on the transparent conductive layer 34. It should be noted that the conductive types of the first carrier transport layer 31 and the second carrier transport layer 33 in the perovskite top cell 30 are opposite. That is, the first carrier transport layer 31 is an electron transport layer, and correspondingly, the second carrier transport layer 33 is a hole transport layer. In addition, the first carrier transport layer 31 may also be a hole transport layer, and correspondingly, the second carrier transport layer 33 is an electron transport layer. Which conductive type is selected for the first carrier transport layer 31 and the second carrier transport layer 33 is related to the doping type of the silicon bottom cell 10. The conductive types of the first carrier transport layer 31 and the second carrier transport layer 33 and the doping type of the silicon bottom cell 10 are conventional settings for the two-terminal perovskite / silicon heterojunction solar cell, which will not be elaborated here.

[0032] Furthermore, for the perovskite / silicon heterojunction solar cell provided in the embodiment of the present invention, as Figures 2 to 6 shown, a plurality of blocking grooves 21 are distributed on the main surface of the transparent conductive oxide film 20 facing the perovskite top cell 30, and the blocking grooves 21 are used to block the lateral migration of carriers in the transparent conductive oxide film 20.

[0033] Through the design of the blocking grooves 21, the lateral conductivity of the transparent conductive oxide film is reduced, and the lateral transport of carriers in the transparent conductive oxide film 20 is blocked, thereby reducing the probability of carrier recombination with the transparent conductive oxide film 20 and the functional layers of the perovskite solar cell, effectively reducing the risks of leakage, short circuit and failure of the perovskite solar cell, and reducing the voltage loss of the perovskite / silicon heterojunction solar cell.

[0034] Among them, the thickness of the transparent conductive oxide film 20 can be 5 nm to 150 nm. For example, the thickness of the transparent conductive oxide film 20 can be 5 nm, 10 nm, 15 nm, 20 nm, 30 nm, 50 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm or 150 nm, etc. Through the design of the thickness of the transparent conductive oxide film 20, the potential energy barrier in the vertical direction of the transparent conductive oxide film 20 can enable most carriers to pass through the transparent conductive oxide film 20. In addition, the design of the thickness of the transparent conductive oxide film 20 can also meet the design requirements of the blocking groove 21, so that the setting of the blocking groove 21 has a relatively high operable process window, facilitating the realization of the industrialization and mass production of the blocking groove 21. Moreover, through the cooperation of the design of the thickness of the transparent conductive oxide film 20 and the blocking groove 21, the lateral conductivity of the transparent conductive oxide film 20 can be effectively reduced without affecting the longitudinal conductivity of the transparent conductive oxide film 20.

[0035] Specifically, the transparent conductive oxide film 20 can be a single-layer film or a laminated film formed by any one or more of indium tin oxide (ITO), indium oxide doped with zinc (IZO), indium oxide doped with tungsten (IWO), zinc oxide doped with aluminum (AZO), tin oxide doped with fluorine (FTO), and zinc oxide doped with boron.

[0036] Regarding the structure of the blocking groove 21, the depth of the blocking groove 21 is generally less than or equal to the thickness of the transparent conductive oxide film 20. That is, the blocking groove 21 can penetrate the transparent conductive oxide film 20. Preferably, the depth of the blocking groove 21 is less than the thickness of the transparent conductive oxide film 20. More preferably, the depth of the blocking groove 21 is generally not less than one-third of the thickness of the transparent conductive oxide film 20.

[0037] More specifically, the multiple blocking grooves 21 can have various structures. Such as Figures 2 to 6 shown, generally, the various structures include: multiple rows of first blocking grooves 211 parallel to each other and multiple columns of second blocking grooves 212 parallel to each other. The multiple rows of first blocking grooves 211 and the multiple columns of second blocking grooves 212 are arranged in an interleaved manner; the first blocking grooves 211 extend along a first direction; the second blocking grooves 212 extend along a second direction, wherein the first direction is perpendicular to the second direction. Specifically, the "row" and "column" involved in the embodiments of the present invention are relative concepts, and generally, the "row" is perpendicular to the "column". Figures 2 to 6 The "row" in Figures 2 to 6 can also be used as a "column", and correspondingly, Figure 2The shown multi - rows are A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11 and A12. Correspondingly, the multi - columns are B1, B2, B3, B4, B5, B6, B7, B8, B9, B10, B11, B12, B13, B14, B15 and B16. For another example, Figure 5 The shown multi - rows are A1', A2', A3', A4', A5', A6', A7', A8', A9' and A10'. Correspondingly, the multi - columns are B1', B2', B3', B4', B5', B6', B7', B8', B9' and B10'. Still for another example, Figure 6 One row in the multi - rows given exemplarily is A13. Correspondingly, one column in the multi - columns is B17.

[0038] Among them, there can be various structures for the interleaved arrangement of the first blocking grooves 211 in the multi - rows and the second blocking grooves 212 in the multi - columns.

[0039] Specifically, the first structure of the interleaved arrangement of the first blocking grooves 211 in the multi - rows and the second blocking grooves 212 in the multi - columns is as Figure 2 shown. The first blocking grooves 211 set in each row are of an intermittent structure; the intermittent positions of the first blocking grooves 211 in every two adjacent rows are staggered; the second blocking grooves 212 in each column pass through the intermittent positions of the first blocking grooves 211; the second blocking grooves 212 set in each column are of an intermittent structure; the intermittent positions of the second blocking grooves 212 in every two adjacent columns are staggered; the first blocking grooves 211 in each row pass through the intermittent positions of the second blocking grooves 212.

[0040] The second structure of the interleaved arrangement of the first blocking grooves 211 in the multi - rows and the second blocking grooves 212 in the multi - columns is as Figure 3 shown. The first blocking grooves 211 set in each row are of an intermittent structure; the intermittent positions of the first blocking grooves 211 in every two adjacent rows are staggered; the second blocking grooves 212 in each column pass through the intermittent positions of the first blocking grooves 211 and the second blocking grooves 212 set in each column are of a through - hole structure.

[0041] The third structure of the interleaved arrangement of the first blocking grooves 211 in the multi - rows and the second blocking grooves 212 in the multi - columns is as Figure 4 shown. The first blocking grooves 211 set in each row are of a through - hole structure, and the second blocking grooves 212 set in each column are of an intermittent structure; the intermittent positions of the second blocking grooves 212 in every two adjacent columns are staggered; the first blocking grooves 211 in each row pass through the intermittent positions of the second blocking grooves 212.

[0042] The fourth structure of the interleaved arrangement of the first blocking grooves 211 in the multi - rows and the second blocking grooves 212 in the multi - columns is as Figure 5 shown. The first blocking grooves 211 set in each row are of a through - hole structure, and the second blocking grooves 212 set in each column are also of a through - hole structure.

[0043] The fifth structure with multiple rows of first blocking grooves 211 and multiple columns of second blocking grooves 212 arranged in an interleaved manner is as follows Figure 6 shown. The first blocking grooves 211 arranged in each row are of an intermittent structure; the intermittent positions of the first blocking grooves 211 in every two adjacent rows correspond to each other; the second blocking grooves 212 arranged in each column are of an intermittent structure; the intermittent positions of the second blocking grooves 212 in every two adjacent columns correspond to each other; the intermittent positions of the second blocking grooves 212 arranged in multiple columns coincide with the intermittent positions of the first blocking grooves 211 in each row.

[0044] The blocking grooves 21 of the above-mentioned multiple structures can be formed by covering the transparent conductive oxide film 20 with a mask having a set pattern, and the set pattern matches Figures 2 to 6 the shape or structure of any one of the blocking grooves 21 shown by a through groove, and the laser passes through the through groove and acts on the transparent conductive oxide film 20 to form the blocking grooves 21.

[0045] Preferably, the first structure mentioned above is adopted for the multiple structures with multiple rows of first blocking grooves 211 and multiple columns of second blocking grooves 212 arranged in an interleaved manner, so as to better reduce the lateral conductivity of the transparent conductive oxide film 20.

[0046] For the multiple structures with multiple rows of first blocking grooves 211 and multiple columns of second blocking grooves 212 arranged in an interleaved manner, the distance between every two adjacent rows of first blocking grooves 211 is 1 to 5 times the perovskite carrier diffusion length; for example, the distance between every two adjacent rows of first blocking grooves 211 is 1 time, 2 times, 3 times, 4 times or 5 times the perovskite carrier diffusion length. Preferably, the distance between every two adjacent rows of first blocking grooves 211 is 2 to 3 times the perovskite carrier diffusion length. For example, the distance between every two adjacent rows of first blocking grooves 211 is 2 times, 2.2 times, 2.5 times, 2.8 times or 3 times the perovskite carrier diffusion length, etc. It should be noted that the distance between every two adjacent rows of first blocking grooves 211 can be the distance between the center lines of two adjacent rows of first blocking grooves 211, or the distance between two adjacent edges of two adjacent rows of first blocking grooves 211 (the two adjacent edges that are close to each other belong to two adjacent rows of first blocking grooves 211).

[0047] In addition, the distance between every two adjacent second blocking grooves 212 is 1 to 5 times the diffusion length of perovskite carriers; preferably, the distance between every two adjacent second blocking grooves 212 is 2 to 3 times the diffusion length of perovskite carriers. For example, the distance between every two adjacent second blocking grooves 212 is 1 time, 2 times, 3 times, 4 times or 5 times the diffusion length of perovskite carriers. Preferably, the distance between every two adjacent second blocking grooves 212 is 2 to 3 times the diffusion length of perovskite carriers. For example, the distance between every two adjacent second blocking grooves 212 is 2 times, 2.2 times, 2.5 times, 2.8 times or 3 times the diffusion length of perovskite carriers, etc. It should be noted that the distance between every two adjacent second blocking grooves 212 can be the distance between the centerlines of every two adjacent second blocking grooves 212, or the distance between two adjacent edges of every two adjacent second blocking grooves 212 (the two adjacent edges that are close to each other belong to every two adjacent second blocking grooves 212).

[0048] By restricting the distance between every two adjacent rows of first blocking grooves 211 and the distance between every two adjacent columns of second blocking grooves 212, and restricting the distance between every two adjacent rows of first blocking grooves 211 and the distance between every two adjacent columns of second blocking grooves 212 according to the diffusion length of perovskite carriers, the design of the first blocking grooves 211 and the second blocking grooves 212 can be made to help improve the lateral conductivity of the transparent conductive oxide film 20, reduce the lateral transport of carriers on the transparent conductive oxide film 20, and thus improve the performance and efficiency of the perovskite / silicon heterojunction solar cell.

[0049] Further, the above-mentioned blocking groove 21 can be formed by laser ablation with a wavelength of 400 nm to 1200 nm and a beam spot size of 1 μm to 20 μm. For example, the laser wavelength used for forming the blocking groove 21 by laser ablation can be 400 nm, 450 nm, 480 nm, 500 nm, 550 nm, 620 nm, 680 nm, 800 nm, 840 nm, 880 nm, 890 nm, 920 nm, 950 nm, 980 nm, 1000 nm, 1080 nm, 1120 nm, 1150 nm, 1180 nm or 1200 nm, etc. The beam spot size can be 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, 5 μm, 5.5 μm, 6 μm, 7 μm, 8 μm, 10 μm, 13 μm, 15 μm, 18 μm or 20 μm, etc. By controlling the wavelength of the laser ablation, the grooving depth of the blocking groove 21 can be ensured, and by controlling the beam spot size, the width of the blocking groove 21 can be better controlled, so that the formation of the blocking groove 21 does not affect the conductivity of the transparent conductive oxide film 20 in the vertical direction (i.e., the direction from the bottom cell to the top cell and the direction from the top cell to the bottom cell), thereby ensuring the vertical conductivity of the transparent conductive oxide film 20, ensuring that carriers are transported between the bottom cell and the top cell through a shorter path in the transparent conductive oxide film 20, and improving the carrier transport ability.

[0050] Further, the above-mentioned perovskite / silicon heterojunction solar cell may further include: a passivation layer (not shown in the figure) disposed in the blocking groove 21. By the cooperation of the passivation layer and the blocking groove 21, the lateral conductivity of the transparent conductive oxide film 20 can be further reduced.

[0051] Among them, the passivation layer can be formed by one of the following methods: mask evaporation, atomic layer deposition (ALD), laser-assisted solution spray passivation, and inkjet printing. Specifically, the mask evaporation can be realized by, after forming the blocking groove 21 through a mask with a set pattern, continuously forming a passivation layer on the transparent conductive oxide thin film 20 covered by the mask by evaporation, where the passivation material entering the through groove reaches the blocking groove 21 and forms a passivation layer in the blocking groove 21. Atomic layer deposition also needs to be realized in cooperation with a mask. Laser-assisted solution spray passivation is to impact the blocking groove 21 of the transparent conductive oxide thin film 20 with the material powder particles or solution for passivation at a high speed through preheating and high pressure, and deposit the material powder particles or solution for passivation by plastic deformation in the blocking groove 21 to form the passivation layer. To ensure accuracy, the laser-assisted solution spray passivation can also be combined with a mask. In addition, inkjet printing uses ink containing a passivation material, and by using a fine nozzle, under the action of a strong electric field or by controlling the voltage, the size of the ink droplets is adjusted, and the ink droplets are applied to the blocking groove 21 to form a passivation layer. It should be noted that the inkjet printing can also be combined with a mask to make the formed passivation layer match the blocking groove 21 more accurately and avoid the passivation layer affecting the conductivity of the transparent conductive oxide thin film 20 in the vertical direction.

[0052] Among them, the passivation material for forming the passivation layer can include one or more combinations of the following materials: SiN x , Al 2 O 3 , SiO 2 and SiO x .

[0053] In the structure of the perovskite / crystalline silicon tandem solar cell provided by the above embodiment, since a plurality of blocking grooves are distributed on the main surface of the transparent conductive oxide thin film facing the perovskite top cell between the crystalline silicon bottom cell and the perovskite top cell, the existence of the blocking grooves can reduce the lateral conductivity of the transparent conductive oxide thin film, thereby blocking the lateral transport of carriers in the transparent conductive oxide thin film, reducing the probability of carrier recombination with the transparent conductive oxide thin film, and being able to reduce the recombination of carriers with the functional layers of the perovskite solar cell, thereby effectively reducing the risks of leakage, short circuit and failure of the perovskite solar cell and reducing the voltage loss of the perovskite / crystalline silicon tandem solar cell.

[0054] In addition, the structure of the above perovskite / crystalline silicon tandem solar cell solves the risks of leakage, short circuit and failure of the perovskite solar cell, which is beneficial to the large-scale industrial production of tandem cells.

[0055] Further, an embodiment of the present invention provides a method for manufacturing a perovskite / silicon heterojunction solar cell. As Figure 7 shown, the manufacturing method may include the following steps:

[0056] Step S701: Prepare a transparent conductive oxide film 20 on the silicon bottom cell 10.

[0057] This step can form the transparent conductive oxide film 20 by low-temperature plasma chemical vapor deposition or physical vapor deposition. The raw materials used to form the transparent conductive oxide film 20 may include one or more of the following materials: indium tin oxide (ITO), indium oxide doped with zinc (IZO), indium oxide doped with tungsten (IWO), zinc oxide doped with aluminum (AZO), tin oxide doped with fluorine (FTO), zinc oxide doped with boron, etc.

[0058] Step S702: Open a plurality of distributed barrier grooves 21 on the main surface of the transparent conductive oxide film 20 away from the silicon bottom cell 10.

[0059] This step uses a laser beam with a wavelength of 400 nm to 1200 nm, and the spot size of the laser beam is controlled within the range of 1 μm to 20 μm in wire diameter, acting on the transparent conductive oxide film 20 to form a number of uniformly arranged horizontal and vertical intersecting barrier grooves 21. For example, the laser wavelength used to open the barrier grooves 21 by laser ablation can be 400 nm, 450 nm, 480 nm, 500 nm, 550 nm, 620 nm, 680 nm, 800 nm, 840 nm, 880 nm, 890 nm, 920 nm, 950 nm, 980 nm, 1000 nm, 1080 nm, 1120 nm, 1150 nm, 1180 nm or 1200 nm, etc. The spot size of the beam can be 1 μm, 1.5 μm, 2.5 μm, 3 μm, 4 μm, 5 μm, 5.5 μm, 6 μm, 7 μm, 8 μm, 10 μm, 13 μm, 15 μm, 18 μm or 20 μm, etc. By controlling the wavelength of the laser ablation, the grooving depth of the barrier grooves 21 can be ensured, and by controlling the spot size of the beam, the width of the barrier grooves 21 can be better controlled, so that the opening of the barrier grooves 21 does not affect the conductivity of the transparent conductive oxide film 20 in the vertical direction (i.e., the direction from the bottom cell to the top cell and the direction from the top cell to the bottom cell), thereby ensuring the vertical conductivity of the transparent conductive oxide film 20, ensuring that carriers are transmitted between the bottom cell and the top cell in a shorter path in the transparent conductive oxide film 20, and improving the carrier transmission ability.

[0060] Step S703: Prepare a perovskite top cell 30 on the main surface of the transparent conductive oxide film 20 provided with the barrier grooves 21.

[0061] The specific implementation of step S703: A first carrier transport layer 31, a perovskite absorption layer 32, a second carrier transport layer 33, and a transparent conductive layer 34 are sequentially stacked on the main surface of the transparent conductive oxide thin film 20 provided with the blocking groove 21. Among them, the perovskite absorption layer material is of the ABX 3 type, where A can be one or more mixtures of MA (methylamine), FA (formamidine), Cs, Rb, and MDA components, B is one or more mixtures of Pb and Sn elements, and X is one or more mixtures of I, Br, and Cl elements. Among them, the first carrier transport layer 31 can be a hole transport layer or an electron transport layer, and the preparation method can be one of vacuum evaporation, transfer printing, and atomic layer deposition (ALD). Other functional preparation layers such as a passivation layer, a modification layer, and a buffer layer may also be included between the first carrier transport layer and the perovskite absorption layer. Further, the second carrier transport layer and the first carrier transport layer have opposite conduction types, and the preparation method can be one of vacuum evaporation, transfer printing, and atomic layer deposition (ALD). Other functional preparation layers such as a passivation layer, a modification layer, and a buffer layer are included between the second carrier transport layer and the perovskite absorption layer. In addition, the material used to form the transparent conductive layer 34 can include one or more of the following materials: indium tin oxide (ITO), indium oxide doped with zinc (IZO), indium oxide doped with tungsten (IWO), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO), and zinc oxide doped with boron, etc.

[0062] In addition, according to the structure required by the existing perovskite solar cell, other modification layers can be added or the transparent conductive layer 34 can be reduced to the perovskite top cell 30 during the preparation of the perovskite top cell 30.

[0063] Further, after the above step S702, it may further include: forming a passivation layer in the blocking groove 21.

[0064] Among them, the passivation layer can be formed by one of the following methods: mask evaporation, atomic layer deposition (ALD), laser-assisted solution spray passivation, and inkjet printing.

[0065] Among them, the passivation layer can be formed by one of the following methods: mask evaporation coating, atomic layer deposition (ALD), laser-assisted solution spray passivation, and inkjet printing. Specifically, the mask evaporation coating can be specifically realized by, after forming the blocking grooves 21 through a mask with a set pattern, continuously forming a passivation layer on the transparent conductive oxide film 20 covered by the mask by means of evaporation coating. Among them, the passivation material entering the through grooves reaches the blocking grooves 21 and forms a passivation layer in the blocking grooves 21. Atomic layer deposition also needs to be realized in cooperation with a mask. Laser-assisted solution spray passivation is to impact the blocking grooves 21 of the transparent conductive oxide film 20 with the material powder particles or solution for passivation at a high speed through preheating and high pressure, and deposit the material powder particles or solution for passivation by plastic deformation in the blocking grooves 21 to form the passivation layer. In order to ensure accuracy, the laser-assisted solution spray passivation can also be combined with a mask. In addition, inkjet printing uses ink containing a passivation material, and by using a fine nozzle, under the action of a strong electric field or by controlling the voltage, the size of the ink droplets is adjusted, and the ink droplets are applied to the blocking grooves 21 to form a passivation layer. It should be noted that the inkjet printing can also be combined with a mask to make the formed passivation layer match the blocking grooves 21 more accurately and avoid the passivation layer affecting the conductivity of the transparent conductive oxide film 20 in the vertical direction.

[0066] Among them, the passivation material for forming the passivation layer can include one or more combinations of the following materials: SiN x , Al 2 O 3 , SiO 2 and SiO x .

[0067] Furthermore, the preparation method of the above perovskite / crystalline silicon tandem solar cell may further include: preparing a top electrode 42 on the transparent conductive layer 34 of the perovskite top cell 30, and the top electrode 42 can be one or more combinations of gold, silver, aluminum, copper, and platinum.

[0068] The preparation method of the perovskite / crystalline silicon tandem solar cell provided by the above embodiment can reduce the lateral conductivity of the transparent conductive oxide film by preparing a plurality of blocking grooves distributed on the main surface facing the perovskite top cell on the transparent conductive oxide film and forming a passivation layer in the blocking grooves, thereby blocking the lateral transport of carriers in the transparent conductive oxide film, reducing the probability of carrier recombination with the transparent conductive oxide film, and being able to reduce the recombination of carriers with the functional layers of the perovskite solar cell, thereby effectively reducing the risks of leakage, short circuit, and failure of the perovskite solar cell and reducing the voltage loss of the perovskite / crystalline silicon tandem solar cell.

[0069] The introduction provided in the above steps is only used to help understand the structure, method and core idea of the present invention. For those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A perovskite / crystalline silicon tandem solar cell, comprising: A crystalline silicon bottom cell (10), a transparent conductive oxide film (20) and a perovskite top cell (30), wherein the transparent conductive oxide film (20) is arranged between the crystalline silicon bottom cell (10) and the perovskite top cell (30), characterized in that: A plurality of blocking grooves (21) are distributed on the main surface of the transparent conductive oxide film (20) facing the perovskite top cell (30), for blocking carriers from lateral migration in the transparent conductive oxide film (20).

2. The perovskite / crystalline silicon tandem solar cell according to claim 1, characterized in that: Also includes: A passivation layer is arranged in the blocking groove (21).

3. The perovskite / crystalline silicon tandem solar cell according to claim 1, characterized in that: The plurality of blocking grooves (21) include: a plurality of parallel rows of first blocking grooves (211) and a plurality of parallel columns of second blocking grooves (212), wherein: A plurality of rows of first blocking grooves (211) and a plurality of columns of second blocking grooves (212) are arranged alternately; The first blocking groove (211) extends along a first direction; The second blocking groove (212) extends along a second direction, wherein the first direction is perpendicular to the second direction.

4. The perovskite / crystalline silicon tandem solar cell according to claim 3, characterized in that: The first blocking grooves (211) arranged in each row are of discontinuous structure; The discontinuity positions of the first blocking grooves (211) in every two adjacent rows are staggered; Each row of the second blocking grooves (212) passes through the discontinuous position of the first blocking grooves (211); and / or, The second blocking grooves (212) arranged in each row are of discontinuous structure; The discontinuity positions of the second blocking grooves (212) in every two adjacent rows are staggered; Each row of the first blocking grooves (211) passes through the discontinuous position of the second blocking grooves (212).

5. The perovskite / crystalline silicon tandem solar cell according to claim 3, characterized in that: The spacing between each two adjacent rows of the first blocking grooves (211) is 1 to 5 times the perovskite carrier diffusion length; preferably, the spacing between each two adjacent rows of the first blocking grooves (211) is 2 to 3 times the perovskite carrier diffusion length; and / or, The spacing between each two adjacent columns of the second blocking grooves (212) is 1 to 5 times the perovskite carrier diffusion length; preferably, the spacing between each two adjacent columns of the second blocking grooves (212) is 2 to 3 times the perovskite carrier diffusion length.

6. The perovskite / crystalline silicon tandem solar cell according to any one of claims 1 to 5, characterized in that: The thickness of the transparent conductive oxide film (20) is 5 nm to 150 nm; and / or, The transparent conductive oxide film (20) is a single-layer film or a stacked-layer film formed by any one or more of indium tin oxide (ITO), zinc-doped indium oxide (IZO), tungsten-doped indium oxide (IWO), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO) and boron-doped zinc oxide.

7. The perovskite / crystalline silicon tandem solar cell according to any one of claims 1 to 5, characterized in that: The blocking groove (21) is opened by laser with a wavelength of 400nm to 1200nm and a beam spot size of 1μm to 20μm; and / or, The depth of the blocking groove (21) is less than or equal to the thickness of the transparent conductive oxide film (20).

8. A method for preparing a perovskite / crystalline silicon tandem solar cell, characterized in that: include: Step 1: preparing a transparent conductive oxide film (20) on a crystalline silicon bottom cell (10); Step 2, forming a plurality of distributed blocking grooves (21) on the main surface of the transparent conductive oxide film (20) away from the crystalline silicon bottom cell (10); Step 3: preparing a perovskite top cell (30) on the main surface of the transparent conductive oxide film (20) where the blocking groove (21) is opened.

9. The preparation method according to claim 8, characterized in that: After step 2 and before step 3, the method further includes: Step 2': forming a passivation layer in the blocking groove (21).

10. The preparation method according to claim 9, characterized in that: Step 2' forms the passivation layer by one of the following methods: Mask evaporation, ALD, laser-assisted solution spray passivation, and inkjet printing.

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