阅读说明：本技术 一种钙钛矿/mwt异质结串并联复合电池的制备方法 (Preparation method of perovskite/MWT heterojunction series-parallel composite battery ) 是由 王浩 王伟 吴仕梁 张凤鸣 于 2021-11-01 设计创作，主要内容包括：本发明公开了一种钙钛矿/MWT异质结串并联复合电池的制备方法,涉及太阳能电池生产技术领域。通过引入MWT背接触技术对两个串联电池进行并联来获得更高的光电转换效率。串并联复合电池包括两个钙钛矿/MWT异质结串联电池,所述钙钛矿/MWT异质结串联电池的背面设有背面电极层以及若干正电极点、若干负电极点,所述钙钛矿/MWT异质结串联电池的正面设有正面电极,并且钙钛矿/MWT异质结串联电池中穿设有堵孔电极；若干正电极点与背面电极层相连接,若干负电极点通过堵孔电极与正面电极栅线连接；所述正电极点与正电极点导电引线连接,所述负电极点与负电极点导电引线相连接。该复合电池结构具有更高的叠加效率。(The invention discloses a preparation method of a perovskite/MWT heterojunction series-parallel composite cell, and relates to the technical field of solar cell production. The MWT back contact technology is introduced to connect two series-connected cells in parallel to obtain higher photoelectric conversion efficiency. The series-parallel composite battery comprises two perovskite/MWT heterojunction series batteries, wherein the back surfaces of the perovskite/MWT heterojunction series batteries are provided with a back electrode layer, a plurality of positive electrode points and a plurality of negative electrode points, the front surfaces of the perovskite/MWT heterojunction series batteries are provided with front electrodes, and hole plugging electrodes penetrate through the perovskite/MWT heterojunction series batteries; the positive electrode points are connected with the back electrode layer, and the negative electrode points are connected with the front electrode grid line through the hole plugging electrodes; the positive electrode point is connected with the positive electrode point conductive lead, and the negative electrode point is connected with the negative electrode point conductive lead. The composite battery structure has higher stacking efficiency.)

1. The preparation method of the perovskite/MWT heterojunction series-parallel composite battery is characterized in that the perovskite/MWT heterojunction series-parallel composite battery comprises two perovskite/MWT heterojunction series-connected batteries, the back of each perovskite/MWT heterojunction series-connected battery is provided with a back electrode layer (11), a plurality of positive electrode points (10) and a plurality of negative electrode points (9), the front of each perovskite/MWT heterojunction series-connected battery is provided with a front electrode grid line (12), and a hole plugging electrode penetrates through each perovskite/MWT heterojunction series-connected battery;

the positive electrode points (10) are connected with the back electrode layer (11), and the negative electrode points (9) are connected with the front electrode grid line (12) through the hole plugging electrode;

the back of the perovskite/MWT heterojunction series battery is also provided with a plurality of metal conductive leads (14), and the metal conductive leads (14) are divided into positive electrode point conductive leads and negative electrode point conductive leads; the positive electrode point (10) is connected with a positive electrode point conductive lead, and the negative electrode point (9) is connected with a negative electrode point conductive lead;

two perovskite/MWT heterojunction series batteries are laminated back to back, and conductive leads are laminated together at positive electrode points of the two perovskite/MWT heterojunction series batteries, and conductive leads are laminated together at negative electrodes of the two perovskite/MWT heterojunction series batteries;

the preparation method comprises the following steps:

s1, preparing a perovskite/MWT heterojunction series battery;

s1.1, performing laser drilling on an N-type silicon-based substrate according to a 6 multiplied by 6 array pattern;

s1.2, polishing the double surfaces of the silicon wafer and carrying out thermal oxidation treatment on the back surface to form SiO on the back surface₂A layer;

s1.3, adding a single-sided texturing additive into the texturing groove to perform single-sided texturing treatment on the front side of the silicon wafer;

s1.4, depositing an intrinsic amorphous silicon layer (3) on two sides by using a PECVD (plasma enhanced chemical vapor deposition) technology;

s1.5, depositing an N-type doped amorphous silicon layer (4-1) and a P-type doped amorphous silicon layer (4-2) on the front surface and the back surface respectively by using a PECVD (plasma enhanced chemical vapor deposition) technology;

s1.6, depositing TCO layers (5) on two sides by using a PVD (physical vapor deposition) technology;

s1.7, printing annular TCO etching slurry around the round hole on the back of the silicon wafer by using a screen printing technology to realize TCO insulation around a negative electrode point (9), drying at 160 ℃, and then cleaning with purified water, wherein the width of an etching ring is 0.2-0.4 mm;

s1.8, preparing a hole transport layer (6), a perovskite absorption layer, an electron transport layer (7) and a transparent conducting layer (8) on the TCO layer on the front surface of the silicon wafer in sequence;

s1.9, printing a hole plugging electrode, a positive electrode point (10), a back electrode layer and a front electrode grid line in sequence, wherein the hole plugging electrode, the positive electrode point and the front electrode grid line are low-temperature silver paste, and the back electrode layer is conductive tin paste;

s1.10, printing an insulating film on the back electrode layer (11) to expose the positive electrode point and the negative electrode point;

s1.11, respectively printing strip-shaped metal conductive leads on the positive electrode point and the negative electrode point on the back surface, wherein the metal conductive leads are low-temperature silver paste or conductive tin paste;

s2, stacking: taking two prepared perovskite/MWT heterojunction series batteries, stacking the two batteries up and down, and enabling the upper and lower layers of perovskite/MWT heterojunction tandem batteries to be laminated back to back, wherein metal conductive leads in the two perovskite/MWT heterojunction series batteries are vertically aligned, overlapped and stacked together;

s3, curing: the metal conducting leads and the insulating glue of the upper layer and the lower layer are respectively solidified and welded together, so that the battery forms a parallel whole.

2. The method for preparing the perovskite/MWT heterojunction series-parallel composite battery according to claim 1, wherein a plurality of positive electrode points (10) on the back surface of the perovskite/MWT heterojunction series-connection battery are uniformly distributed in a plurality of rows, each row is provided with a plurality of positive electrode points (10), and the positive electrode points (10) in the same row are connected with a positive electrode point conductive lead;

the negative electrode points (9) on the back of the perovskite/MWT heterojunction series battery are also uniformly distributed in a plurality of rows, each row is provided with a plurality of negative electrode points (9), and the negative electrode points (9) in the same row are connected with a negative electrode point conducting lead.

3. The method for preparing a perovskite/MWT heterojunction series-parallel composite battery as claimed in claim 2, wherein the positive electrode point conductive lead and the negative electrode point conductive lead are arranged at intervals.

4. A method of manufacturing a perovskite/MWT heterojunction series-parallel composite cell according to claim 1, wherein the areas of the two perovskite/MWT heterojunction series cells are unequal such that the metal conducting lead (14) on the back side of one of the perovskite/MWT heterojunction series cells can be exposed beyond the back side of the other perovskite/MWT heterojunction series cell.

5. The preparation method of the perovskite/MWT heterojunction series-parallel composite battery as claimed in any one of claims 1 to 4, wherein the perovskite/MWT heterojunction series battery comprises a front electrode grid line (12), a transparent conducting layer (8), an electron transport layer (7), a perovskite absorption layer, a hole transport layer (6), a TCO layer (5), an N-type doped amorphous silicon layer (4-1), an intrinsic amorphous silicon layer (3), an N-type silicon-based substrate, an intrinsic amorphous silicon layer (3), a P-type doped amorphous silicon layer (4-2), a TCO layer (5), a back electrode layer (11) and an insulating layer (13) in sequence from the front to the back;

the negative electrode points (9) positioned on the back of the perovskite/MWT heterojunction series battery are insulated from the back electrode layer (11), and the positive electrode points (10) are connected with the back electrode layer (11); the negative electrode points (9) and the positive electrode points (10) penetrate through the insulating layer (13).

Technical Field

The invention relates to the technical field of solar cell production, in particular to a preparation method of a perovskite and MWT heterojunction series-parallel composite cell.

Background

With the proposition of the targets of 'carbon peak reaching' and 'carbon neutralization' in China, the photovoltaic industry is confronted with new opportunities for development, and the development of the photovoltaic industry is strongly promoted by pursuing high efficiency all the time, which is one of the most effective modes for realizing great cost reduction at present. Although the photoelectric conversion efficiency of PERC, TOPCon, HJT and IBC high efficiency crystalline silicon cells is continuously recorded, it is difficult for all monocrystalline silicon cell technologies to break the theoretical efficiency limit (about 29%) regardless of the structure design. Therefore, perovskite/silicon based stacked structure systems are one of the main research directions to obtain higher efficiency of solar cells. In recent years, perovskite/silicon tandem cells have also gained increasing attention due to their extremely high photoelectric conversion efficiency (> 30%), with efficiency advantages not comparable to individual cells.

Therefore, how to further improve the photoelectric conversion efficiency on the basis of the above problem becomes a technical problem to be solved by those skilled in the art.

Disclosure of Invention

Aiming at the problems, the invention provides a preparation method of a perovskite/MWT heterojunction series-parallel composite battery, and the MWT back contact technology is introduced to connect two perovskite/MWT heterojunction series-connected batteries in parallel to obtain higher photoelectric conversion efficiency.

The technical scheme of the invention is as follows: the perovskite/MWT heterojunction series-parallel composite battery comprises two perovskite/MWT heterojunction series-connected batteries, wherein the back of each perovskite/MWT heterojunction series-connected battery is provided with a back electrode layer 11, a plurality of positive electrode points 10 and a plurality of negative electrode points 9, the front of each perovskite/MWT heterojunction series-connected battery is provided with a front electrode grid line 12, and a hole plugging electrode penetrates through each perovskite/MWT heterojunction series-connected battery;

a plurality of positive electrode points 10 are connected with a back electrode layer 11, and a plurality of negative electrode points 9 are connected with a front electrode grid line 12 through a hole plugging electrode;

the back of the perovskite/MWT heterojunction series battery is also provided with a plurality of metal conducting leads 14, and the metal conducting leads 14 are divided into positive electrode point conducting leads 15 and negative electrode point conducting leads 16; the positive electrode point 10 is connected with a positive electrode point conductive lead, and the negative electrode point 9 is connected with a negative electrode point conductive lead.

Two perovskite/MWT heterojunction tandem cells are stacked back-to-back and stacked together at their positive electrode points with their negative electrode conductive leads.

A plurality of positive electrode points 10 on the back of the perovskite/MWT heterojunction series battery are uniformly distributed in a plurality of rows, each row is provided with a plurality of positive electrode points 10, and the positive electrode points 10 in the same row are connected with a positive electrode point conductive lead;

the negative electrode points 9 on the back of the perovskite/MWT heterojunction series battery are also uniformly distributed in a plurality of rows, each row is provided with a plurality of negative electrode points 9, and the negative electrode points 9 in the same row are connected with a negative electrode point conductive lead.

The positive electrode point conductive leads and the negative electrode point conductive leads are arranged at intervals.

The areas of the two perovskite/MWT heterojunction series cells are unequal such that the metallic conductive lead 14 of the back side of one of the perovskite/MWT heterojunction series cells may be exposed beyond the back side of the other perovskite/MWT heterojunction series cell.

The perovskite/MWT heterojunction series battery sequentially comprises a front electrode grid line 12, a transparent conducting layer 8, an electron transmission layer 7, a perovskite absorption layer, a hole transmission layer 6, a TCO layer 5, an N-type doped amorphous silicon layer 4-1, an intrinsic amorphous silicon layer 3, an N-type silicon-based substrate, an intrinsic amorphous silicon layer 3, a P-type doped amorphous silicon layer 4-2, a TCO layer 5, a back electrode layer 11 and an insulating layer 13 from the front to the back;

the negative electrode points 9 on the back of the perovskite/MWT heterojunction series battery are insulated from the back electrode layer 11, and the positive electrode points 10 are connected with the back electrode layer 11; the negative electrode points 9 and the positive electrode points 10 penetrate through the insulating layer 13.

The preparation method comprises the following steps:

s1, preparing a perovskite/MWT heterojunction series battery;

s1.1, performing laser drilling on an N-type silicon-based substrate according to a 6 multiplied by 6 array pattern;

s1.2, polishing the double surfaces of the silicon wafer and carrying out thermal oxidation treatment on the back surface to form SiO on the back surface₂A layer;

s1.3, adding a single-sided texturing additive into the texturing groove to perform single-sided texturing treatment on the front side of the silicon wafer;

s1.4, depositing an intrinsic amorphous silicon layer 3 on two sides by using a PECVD (plasma enhanced chemical vapor deposition) technology;

s1.5, depositing an N-type doped amorphous silicon layer 4-1 and a P-type doped amorphous silicon layer 4-2 on the front surface and the back surface respectively by using a PECVD (plasma enhanced chemical vapor deposition) technology;

s1.6, depositing TCO layers 5 on two sides by using a PVD (physical vapor deposition) technology;

s1.7, printing annular TCO etching slurry around the round hole on the back of the silicon wafer by using a screen printing technology to realize TCO insulation around a negative electrode point 9, drying at 160 ℃, and then cleaning with purified water, wherein the width of an etching ring is 0.2-0.4 mm;

s1.8, preparing a hole transport layer 6, a perovskite absorption layer, an electron transport layer 7 and a transparent conducting layer 8 on the TCO layer on the front surface of the silicon wafer in sequence;

s1.9, printing a hole plugging electrode, a positive electrode point 10, a back electrode layer and a front electrode grid line in sequence, wherein the hole plugging electrode, the positive electrode point and the front electrode grid line are low-temperature silver paste, and the back electrode layer is conductive tin paste;

s1.10, printing an insulating film on the back electrode layer 11 to expose the positive electrode point and the negative electrode point;

s1.11, respectively printing strip-shaped metal conductive leads on the positive electrode point and the negative electrode point on the back surface, wherein the metal conductive leads are low-temperature silver paste or conductive tin paste;

s2, stacking: taking two prepared perovskite/MWT heterojunction series batteries, stacking the two batteries up and down, and enabling the upper and lower layers of perovskite/MWT heterojunction tandem batteries to be laminated back to back, wherein metal conductive leads in the two perovskite/MWT heterojunction series batteries are vertically aligned, overlapped and stacked together;

s3, curing: the metal conducting leads and the insulating glue of the upper layer and the lower layer are respectively solidified and welded together, so that the battery forms a parallel whole.

According to the invention, two perovskite/MWT heterojunction series-connected batteries are connected in parallel back to back and are superposed to form a perovskite/MWT heterojunction series-parallel composite battery structure. The MWT back contact technology is introduced into the structure for laser punching treatment, and currents of the upper and lower light receiving front and back surfaces are led to the back surface (the middle of a battery), so that the light receiving front and back surfaces are not provided with main grids, and metal shading of a light receiving surface can be effectively reduced. In addition, higher stacking efficiency can be obtained by connecting two perovskite/MWT heterojunction series cells in parallel.

Compared with the conventional perovskite-heterojunction laminated cell, the perovskite/MWT heterojunction series connection structure leads the front current to the back surface in a laser drilling mode to reduce shading on the front surface, and then two perovskite/MWT heterojunction series connection cells are connected in parallel to form a composite cell structure, so that the composite cell structure has higher stacking efficiency (the theory can reach more than 50 percent); secondly, the upper and lower layers of laminated series batteries generate power independently, so that the service life of the batteries is prolonged; moreover, the positive electrode point and the negative electrode point of the battery are both designed in the battery, so that the falling risk of the electrode points can be effectively reduced; in addition, compared with the conventional battery, the structural design of the invention does not need to consider the alignment condition of the electrode point at the back of the assembly end and the GPS, can reduce the diameter of the electrode point, reduce the consumption of silver paste and simultaneously avoid the poor assembly caused by the misalignment of the electrode point and the GPS at the conventional assembly end.

Drawings

FIG. 1 is a schematic structural diagram of the present disclosure;

FIG. 2 is a schematic diagram of the structure of the back side of an upper MWT heterojunction cell in the present case;

in the figure, 1-1 is an upper N-type silicon-based substrate, 1-2 is a lower N-type silicon-based substrate, 2-1 is an upper perovskite absorption layer, and 2-2 is a lower perovskite absorption layer;

3 is an intrinsic amorphous silicon layer, 4-1 is an N-type doped amorphous silicon layer, 4-2 is P-type doped amorphous silicon, 5 is a TCO layer, 6 is a hole transport layer, 7 is an electron transport layer, 8 is a transparent conductive layer;

9 is a negative electrode point, 10 is a positive electrode point, 11 is a back electrode layer, and 12 is a front electrode grid line;

13 is an insulating layer, 14 is a metal conductive lead;

15 is a positive electrode point conductive lead, and 16 is a negative electrode point conductive lead.

Detailed Description

In order to clearly explain the technical features of the present patent, the following detailed description of the present patent is provided in conjunction with the accompanying drawings.

As shown in fig. 1-2, the perovskite/MWT heterojunction series-parallel composite battery comprises two perovskite/MWT heterojunction series-connected batteries, wherein the back surfaces of the perovskite/MWT heterojunction series-connected batteries are provided with a back electrode layer 11, a plurality of positive electrode points 10 and a plurality of negative electrode points 9, the front surfaces of the perovskite/MWT heterojunction series-connected batteries are provided with front electrode grid lines 12, and hole plugging electrodes penetrate through the perovskite/MWT heterojunction series-connected batteries;

a plurality of positive electrode points 10 are connected with a back electrode layer 11, and a plurality of negative electrode points 9 are connected with a front electrode grid line 12 through a hole plugging electrode;

the back of the perovskite/MWT heterojunction series battery is also provided with a plurality of metal conducting leads 14, and the metal conducting leads 14 are divided into positive electrode point conducting leads and negative electrode point conducting leads; the positive electrode point 10 is connected with a positive electrode point conductive lead, and the negative electrode point 9 is connected with a negative electrode point conductive lead.

Two perovskite/MWT heterojunction tandem cells are stacked back-to-back and stacked together at their positive electrode points with their negative electrode conductive leads.

The invention provides a perovskite/MWT heterojunction series-parallel composite battery structure which mainly comprises an upper layer of perovskite/MWT heterojunction series-connected batteries and a lower layer of perovskite/MWT heterojunction series-connected batteries, wherein the area of the upper layer of perovskite/MWT heterojunction series-connected batteries is slightly larger, and the area of the lower layer of perovskite/MWT heterojunction series-connected batteries is slightly smaller. The design is to reserve the position of a metal conducting lead wire for the upper layer battery when two layers of batteries are connected in parallel. The perovskite/MWT heterojunction series battery is formed by superposing perovskite batteries on an MWT heterojunction structure in series, the upper layer (light receiving layer) is a perovskite battery layer, the lower layer is an MWT heterojunction battery layer, and current on the light receiving surface of the perovskite battery layer is led to the back of the MWT heterojunction battery through laser drilling. And then connected with another perovskite/MWT heterojunction series battery in parallel through a metal conductive lead wire to form a composite battery. The metal conducting lead wire is respectively contacted with the positive electrode point and the negative electrode point on the back surface of the perovskite/MWT heterojunction series battery so as to transmit and extract current.

The MWT back contact technology is introduced into the structure for laser punching treatment, and currents of the upper and lower light receiving front and back surfaces are led to the back surface (the middle of a battery), so that the light receiving front and back surfaces are not provided with main grids, and metal shading of a light receiving surface can be effectively reduced. In addition, higher stacking efficiency can be obtained by connecting two perovskite/MWT heterojunction series cells in parallel.

A plurality of positive electrode points 10 on the back of the perovskite/MWT heterojunction series battery are uniformly distributed in a plurality of rows, each row is provided with a plurality of positive electrode points 10, and the positive electrode points 10 in the same row are connected with a positive electrode point conductive lead;

the negative electrode points 9 on the back of the perovskite/MWT heterojunction series battery are also uniformly distributed in a plurality of rows, each row is provided with a plurality of negative electrode points 9, and the negative electrode points 9 in the same row are connected with a negative electrode point conductive lead.

The positive electrode point conductive leads and the negative electrode point conductive leads are arranged at intervals.

The areas of the two perovskite/MWT heterojunction series cells are unequal such that the metallic conductive lead 14 of the back side of one of the perovskite/MWT heterojunction series cells may be exposed beyond the back side of the other perovskite/MWT heterojunction series cell. That is, the metal conductive lead 14 at the edge of the back side of one of the perovskite/MWT heterojunction series cells does not overlap with the other perovskite/MWT heterojunction series cell, but is exposed to the outside of the perovskite/MWT heterojunction series cell, thereby facilitating subsequent use; in addition, the positive electrode point and the negative electrode point of the battery are both designed in the battery, so that the falling risk of the electrode points can be effectively reduced.

The perovskite/MWT heterojunction series battery sequentially comprises a front electrode grid line 12, a transparent conducting layer 8, an electron transmission layer 7, a perovskite absorption layer, a hole transmission layer 6, a TCO layer 5, an N-type doped amorphous silicon (N-a-Si: H) layer 4-1, an intrinsic amorphous silicon (i-a-Si: H) layer 3, an N-type silicon-based substrate, an intrinsic amorphous silicon (i-a-Si: H) layer 3, a P-type doped amorphous silicon (P-a-Si: H) layer 4-2, a TCO layer 5, a back electrode layer 11 and an insulating layer 13 from the front to the back;

the negative electrode points 9 on the back of the perovskite/MWT heterojunction series battery are insulated from the back electrode layer 11, and the positive electrode points 10 are connected with the back electrode layer 11; the negative electrode points 9 and the positive electrode points 10 penetrate through the insulating layer 13.

The area of an upper layer battery in the two perovskite/MWT heterojunction series batteries is slightly larger, the area of a lower layer battery is slightly smaller, namely the area of an upper layer N-type silicon-based substrate 1-1 is larger than that of a lower layer N-type silicon-based substrate 1-2, an upper layer perovskite absorption layer 2-1 in the upper layer battery can serve as a light receiving front side, and a lower layer perovskite absorption layer 2-2 in the lower layer battery can serve as a light receiving back side.

The first embodiment is as follows:

the invention provides a perovskite/MWT heterojunction series-parallel composite battery structure (figure 1), which is formed by welding and connecting an upper perovskite/MWT heterojunction series battery and a lower perovskite/MWT heterojunction series battery in parallel through a middle metal lead, wherein the area of the upper battery is larger, a larger light receiving area is obtained, and the area of the lower battery is smaller, so that the middle metal conductive lead is exposed.

The perovskite/MWT heterojunction series battery is formed by superposing a perovskite battery on the MWT heterojunction battery, the front current is collected to a back negative electrode point through a hole plugging electrode, the back is covered with a back electrode layer which is in point contact with a positive electrode and is isolated from the negative electrode point, an insulating film is printed on the back electrode layer, only the positive electrode point and the negative electrode point are exposed to be in contact with a metal conductive lead, and the metal conductive lead is exposed at the edge (the width is about 2-3 mm) of the back of the upper-layer battery, as shown in figure 2.

The preparation method comprises the following steps:

s1, preparing a perovskite/MWT heterojunction series battery;

s1.1, performing laser drilling on an N-type silicon-based substrate according to a 6 x 6 array pattern, wherein the drilling diameter is 150-250 microns;

s1.2, polishing the double surfaces of the silicon wafer and performing thermal oxidation treatment on the back surface to form SiO with the thickness of 2-5 nm on the back surface₂A layer;

s1.3, adding a single-sided texturing additive into the texturing groove to perform single-sided texturing treatment on the front side of the silicon wafer;

s1.4, depositing an intrinsic amorphous silicon (i-a-Si: H) layer 3 with the thickness of 5-10 nm on two sides by using a PECVD (plasma enhanced chemical vapor deposition) technology;

s1.5, depositing an N-type doped amorphous silicon (N-a-Si: H) layer 4-1 and a P-type doped amorphous silicon (P-a-Si: H) layer 4-2 with the thicknesses of 5-10 nm on the front surface and the back surface respectively by using a PECVD technology;

s1.6, depositing TCO layers 5 with the thickness of 50-100 nm on two sides by using a PVD (physical vapor deposition) technology;

s1.7, printing annular TCO etching slurry around the round hole on the back of the silicon wafer by using a screen printing technology to realize TCO insulation around a negative electrode point 9, drying at 160 ℃, and then cleaning with purified water, wherein the width of an etching ring is 0.2-0.4 mm;

s1.8, preparing a hole transport layer 6, a perovskite absorption layer, an electron transport layer 7 and a transparent conducting layer 8 on the TCO layer on the front surface of the silicon wafer in sequence;

wherein the hole transport layer may be NiO_x/MoO_xAny one or a combination of more of/PTAA/Spiro-TBB/Spiro-OMeTAD, the thickness is 10-50 nm, and the preparation method is spin coating or evaporation and the like;

the perovskite absorption layer may be ABX₃(A= CH₃NH₃ ⁺，B= Pb²⁺、Sn²⁺，X=I^-、Cl^-、Br^-) The thickness is 200-1000 nm, and the preparation method comprises spin coating, spray coating, evaporation coating and the like;

the electron transport layer can be LiF/C₆₀/ZnO/SnO_x/TiO_xAny one or a combination of a plurality of the components, the thickness is 10-50 nm, and the preparation method comprises PVD, CVD and the like;

the transparent conducting layer is mainly ITO and the like, the thickness is 20-100nm, and the preparation method comprises PVD, RPD and the like;

s1.9, screen printing, namely printing a hole plugging electrode, a positive electrode point 10, a back electrode layer and a front electrode grid line in sequence, and drying and curing at the temperature of 180-200 ℃, wherein the hole plugging electrode, the positive electrode point and the front electrode grid line are low-temperature silver paste, the diameters of the positive electrode point and the negative electrode point are 1.2-2 mm, the back electrode layer is conductive tin paste, and the thickness is 5-10 microns;

s1.10, screen printing, namely printing an insulating film with the thickness of 5-10 mu m on the back electrode layer 11 to expose a positive electrode point and a negative electrode point;

s1.11, screen printing, namely respectively printing strip-shaped metal conductive leads which can be low-temperature silver paste or conductive tin paste on the positive electrode point and the negative electrode point on the back surface, wherein the width of the metal conductive leads is 1.2-2 mm, and the thickness of the metal conductive leads is 5-10 mu m; forming a positive electrode point conductive lead and a negative electrode point conductive lead;

s2, stacking: taking two prepared perovskite/MWT heterojunction series batteries, stacking the two batteries up and down, and enabling the upper and lower layers of perovskite/MWT heterojunction tandem batteries to be laminated back to back, wherein metal conductive leads in the two perovskite/MWT heterojunction series batteries are vertically aligned, overlapped and stacked together;

s3, curing: the metal conducting leads and the insulating glue of the upper layer and the lower layer are respectively solidified and welded together, so that the battery forms a parallel whole.

While the invention has been described in terms of its preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.