Solar cell and preparation method thereof, and laminated solar cell and preparation method thereof

Abstract

The invention discloses a solar cell, a preparation method of the solar cell, a laminated solar cell and a preparation method of the laminated solar cell. The solar cell comprises a substrate, a bottom electrode layer, a functional layer and a top electrode layer, the bottom electrode layer is provided with a first scribing groove, the first scribing groove divides the bottom electrode layer into more than two first conductive blocks which are not connected with each other, and a bottom wire connected with the corresponding first conductive block and an insulating layer covering the bottom wire are arranged in the first scribing groove; the top electrode layer is provided with a third scribed line groove at a position corresponding to the bottom wire. The top electrode layer is provided with a top electrode layer connecting end at a position corresponding to the first scribed line groove. According to the solar cell, only two scribed line grooves are formed in the solar cell, the positions of the two scribed line grooves are overlapped in the longitudinal direction, meanwhile, the functional layer corresponding to the ineffective area is reserved, and therefore the stability, efficiency and yield of the solar cell can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a solar cell and a method for preparing the same, and a stacked solar cell and a method for preparing the same. Background Art

[0002] Photovoltaic power generation is one of the energy sources that is expected to replace fuel. In the development of solar cells, the cost of materials and processing is as important as the conversion efficiency. This means that for technology research and development and industrial industrialization applications, the discovery of novel, low-cost optoelectronic materials is very important. At present, in the photovoltaic industry. With the continuous advancement of thin film technology, the development trend of thin film solar cells is gradually moving towards the design of gradient energy gaps. By absorbing the corresponding wavelengths of sunlight with different energy gaps, the absorbed sunlight is generated as much as possible. Photocurrent to improve the efficiency of the component. Nowadays, different solar cells are stacked, so that the band gaps of different solar cells are used to absorb sunlight of different wavelengths, thereby improving the conversion efficiency of the overall solar cell. However, the compatibility characteristics and light receiving capabilities of different solar cells are different. For example, some solar cells are incompatible with each other, or some solar cells can only receive light on one side, which limits the development of stacked solar cells.

[0003] In the production of photovoltaic modules, how to increase the effective light-emitting area, improve process continuity, and reduce the pollution of the P2 segment to the effective light-emitting area to improve the efficiency and yield of the modules is a very important research direction.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a solar cell and a method for preparing the same, a stacked solar cell and a method for preparing the same, which are beneficial to reducing the area of ​​the ineffective area in the solar cell and improving the stability of the operation of the solar cell.

[0006] The present invention is achieved in that:

[0007] In a first aspect, the present invention provides a solar cell, comprising a substrate and a bottom electrode layer, a functional layer and a top electrode layer sequentially stacked on the substrate;

[0008] The bottom electrode layer is provided with a first scribed groove, the first scribed groove divides the bottom electrode layer into two or more first conductive blocks which are not connected to each other, and the first scribed groove is provided with a bottom conductive wire connected to the corresponding first conductive block and an insulating layer covering the bottom conductive wire;

[0009] A third groove is provided at a position corresponding to the top electrode layer and the bottom conductive line, and the third groove separates the top electrode layer into two or more second conductive blocks which are not connected to each other. A top electrode layer connection terminal is provided at a position corresponding to the second conductive block and the first groove.

[0010] In an optional embodiment, the solar cell includes at least one of a perovskite cell, a cadmium telluride thin film cell, a CIGS thin film cell, an OPV thin film cell, and a PVK thin film cell.

[0011] In an optional embodiment, the functional layer includes a hole transport layer, a perovskite layer, a passivation layer and an electron transport layer;

[0012] Alternatively, the functional layer includes a cadmium telluride window layer and a cadmium telluride absorption layer.

[0013] In an optional embodiment, the perovskite cell satisfies at least one of the following features af:

[0014] a. The width of the first groove is 30um to 120um;

[0015] b. The substrate is polyester (PET), polyimide (PI), polyetheretherketone (PEEK), transparent conductive polyester, polyacrylate, fluorinated polymer, polycarbonate (PC), polyester film (BOPET), ultra-thin flexible glass (UTG), metal foil, polyetherimide, polyimide, ITO glass or FTO glass;

[0016] c. The material of the electron transport layer is fullerene C60;

[0017] d. The top electrode layer structure is at least one of metal oxide + metal, metal oxide + metal + metal oxide, metal oxide + metal composite structure, metal oxide + metal composite structure + metal oxide;

[0018] e. The material of the bottom conductor is at least one of graphite, carbon nanotubes, metal nanoparticles, and metal nanowires;

[0019] f. The bottom conductive line is prepared by one of stamping, screen printing, evaporation, ALD, CVD, sputtering, spraying or printing.

[0020] In a second aspect, the present invention provides a method for preparing a solar cell according to any one of the aforementioned embodiments, comprising:

[0021] Forming a bottom electrode layer on a substrate, and etching a first scribed groove on the bottom electrode layer to divide the bottom electrode layer into first conductive blocks that are not connected to each other;

[0022] forming a metal conductive layer in the first groove, then etching away one side of the metal conductive layer to obtain the bottom conductive line, and then forming an insulating layer on the bottom conductive line to obtain a substrate;

[0023] forming a functional layer and a top electrode layer on the substrate in sequence;

[0024] A third groove is formed by etching on the top electrode layer in a region corresponding to the bottom conductive line to obtain the solar cell.

[0025] In a third aspect, the present invention provides a stacked solar cell, comprising a solar cell unit, wherein the solar cell unit comprises a first solar cell unit and a second solar cell unit, wherein the first solar cell unit and the second solar cell unit are independently selected from the solar cells described in any one of the preceding embodiments, and the top electrode layers of the first solar cell unit and the second solar cell unit are separated by a light-transmitting insulating layer.

[0026] In an optional embodiment, the effective area in the first solar cell unit includes a light leakage area and two or more compartment areas isolated by the light leakage area, the top electrode layers corresponding to the two or more compartment areas are connected in parallel via the top electrode layer connection end extending to the invalid area, and the bottom electrode layers corresponding to the two or more compartment areas are connected in parallel via the bottom wire.

[0027] In an optional embodiment, the solar cell includes more than two sub-cells, each of the sub-cells is correspondingly provided with an effective area and an invalid area, the area corresponding to the first score line groove is the invalid area, and the area between adjacent first score line grooves is the effective area, and the sub-cells in the solar cell unit are connected in series in sequence through the connection between the bottom wire and the top electrode layer connection end.

[0028] In an optional embodiment, in the first solar cell unit, only the bottom wire corresponding to one sub-cell is connected to the top electrode layer connection terminal in the second solar cell unit;

[0029] Alternatively, in the first solar cell unit, the bottom wire corresponding to each sub-cell is connected to the top electrode layer connection end in the second solar cell unit; in the second solar cell unit, the bottom wire corresponding to each sub-cell is connected to the top electrode layer connection end in the first solar cell unit.

[0030] In a fourth aspect, the present invention provides a method for preparing a stacked solar cell according to any one of the aforementioned embodiments, comprising:

[0031] Etching to form a light leakage area in the effective area of ​​the solar cell unit to obtain the first solar cell unit;

[0032] Take the second solar cell unit and the first solar cell unit, form a light-transmitting insulating layer between the second solar cell unit and the first solar cell unit, and perform lamination packaging;

[0033] The second solar cell unit and the sub-cells in the first solar cell unit are connected in series using a conductive wire to obtain the stacked solar cell.

[0034] The present invention has the following beneficial effects:

[0035] In the present application, there are only two scoring grooves in the solar cell. Compared with the traditional three-time laser scribing, the requirement for film uniformity during P2 scoring is eliminated and the problem of dust scattering in the effective area and prolonging the exposure time of the battery to the air caused by P2 scoring is avoided; at the same time, the area of ​​the invalid area can be effectively reduced, which is beneficial to the improvement of the efficiency of the solar cell; at the same time, the third scoring groove in the present application is correspondingly arranged in the top electrode layer corresponding to the bottom wire, and the positions of the two overlap in the vertical direction, which is beneficial to further reduce the area of ​​the invalid area.

[0036] In the present application, the functional layer corresponding to the invalid area is retained. On the one hand, this part of the functional layer has an ion barrier effect, which can prevent the migration of ions from each layer from the invalid area, thereby helping to improve the stability of the solar cell; on the other hand, it can play a buffering role, reducing or even avoiding the defects of melting, edge bursting, device structure damage, etc. at the edges of the effective areas on both sides of the groove, thereby helping to improve the efficiency and yield of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 It is a schematic diagram of the structure of the solar cell in this application;

[0039] Figure 2 It is a schematic structural diagram of the substrate and the first conductive block in this application;

[0040] Figure 3 It is a schematic diagram of the structure of the metal conductive layer, the substrate and the first conductive block in this application;

[0041] Figure 4 It is a schematic structural diagram of the substrate, the first conductive block, the bottom wire and the insulating layer in the present application;

[0042] Figure 5 This is a schematic diagram of the structure of the perovskite battery in this application;

[0043] Figure 6 A schematic diagram of the structure of a stacked solar cell after lamination and packaging in this application;

[0044] Figure 7 A cross-sectional view of a structure of a first solar cell unit;

[0045] Figure 8 A top view of a structure of a first solar cell unit;

[0046] Fig. 9 A cross-sectional view of a series connection of stacked solar cells;

[0047] Fig.10 A top view of a series connection of stacked solar cells;

[0048] Fig.11 A cross-sectional view of another series connection method for stacked solar cells;

[0049] Fig.12 A top view of another series connection method for stacked solar cells;

[0050] Fig.13 It is a schematic diagram of the structure of the laminated package of stacked solar cells;

[0051] Fig.14 Schematic diagram of the layer structure of the second solar cell unit in Example 2.

[0052] Illustration: 122-substrate; 123-bottom electrode layer; 120-functional layer; 124-hole transport layer; 125-perovskite layer; 126-passivation layer; 127-electron transport layer; 128-top electrode layer; 131-cadmium telluride window layer; 132-cadmium telluride absorption layer; 111-first solar cell unit; 121-second solar cell unit; 130-light-transmitting insulating layer; P1-first groove; P3-third groove; S1-light leakage area; S2-compartment area; S3-bottom wire; S4-insulating layer; S5-connecting line; S6-top electrode layer connecting end; a1-invalid area; b1-effective area. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0054] Solar cells usually use laser engraving to form the first engraved groove P1, the second engraved groove P2 and the third engraved groove P3 to realize the series and parallel connection of the cells; wherein the first engraved groove P1 is used to isolate the connection between adjacent bottom electrodes, the second engraved groove P2 creates a series connection channel between the top electrode and the bottom electrode, and the third engraved groove P3 is used to isolate the connection between the top electrodes of adjacent sub-cells.

[0055] However, the perovskite cell provided by the related technology will produce a large invalid area a1 (ie, inactive area) after the laser scribing process, thereby reducing the effective power generation area of ​​the solar cell and reducing the photoelectric conversion efficiency.

[0056] An embodiment of the present invention provides a solar cell, such as Figure 1 As shown, it includes a substrate 122 and a bottom electrode layer 123, a functional layer 120 and a top electrode layer 128 sequentially stacked on the substrate 122;

[0057] The bottom electrode layer 123 is provided with a first groove P1, the first groove P1 divides the bottom electrode layer 123 into two or more first conductive blocks that are not connected to each other, and the first groove P1 is provided with a bottom wire S3 connected to the corresponding first conductive block and an insulating layer S4 covering the bottom wire S3;

[0058] A third groove P3 is provided at a position corresponding to the top electrode layer 128 and the bottom conductive line S3, and the third groove P3 separates the top electrode layer 128 into two or more second conductive blocks which are not connected to each other. A top electrode layer connection terminal S6 is provided at a position corresponding to the second conductive block and the first groove P1.

[0059] In the present application, there are only two scoring grooves in the solar cell. Compared with the traditional three-time laser scribing, the requirement for film uniformity when forming the second scoring groove P2 is eliminated and the problem of dust scattering in the effective area b1 and prolonging the exposure time of the battery to the air due to the formation of the second scoring groove P2 is avoided; at the same time, the area of ​​the invalid area a1 can be effectively reduced, which is beneficial to the improvement of the efficiency of the solar cell.

[0060] The third scribed groove P3 in the present application is arranged corresponding to the top electrode layer 128 corresponding to the bottom conductive line S3, and the positions of the two overlap in the vertical direction, which is beneficial to further reduce the area of ​​the ineffective area a1.

[0061] In the present application, the functional layer 120 corresponding to the invalid area a1 is retained. On the one hand, this part of the functional layer 120 has an ion barrier effect, which can prevent the migration of ions from each layer from the invalid area a1, thereby helping to improve the stability of the solar cell; on the other hand, it can play a buffering role, reducing or even avoiding defects such as melting, edge bursting, and device structure damage at the edges of the effective area b1 on both sides of the groove, thereby helping to improve the efficiency and yield of the solar cell.

[0062] In an optional embodiment, the solar cell includes at least one of a perovskite cell, a cadmium telluride thin film cell, a CIGS thin film cell, an OPV thin film cell and a PVK thin film cell. By adjusting the structure of the functional layer 120, different thin film cells can be obtained, which has universal applicability.

[0063] In an optional embodiment, the functional layer 120 includes a hole transport layer 124, a perovskite layer 125, a passivation layer 126 and an electron transport layer 127, that is, the solar cell is a perovskite cell, specifically, the perovskite cell structure can be a formal perovskite cell structure or an inverted perovskite cell structure.

[0064] In an optional embodiment, the functional layer 120 includes a cadmium telluride window layer 131 and a cadmium telluride absorption layer 132 .

[0065] In an optional embodiment, the perovskite cell satisfies at least one of the following features af:

[0066] a. The width of the first scribed groove P1 is 30um~120um, specifically can be 30um, 40um, 50um, 60um, 70um, 80um, 90um, 100um, 110um, 120um or any value between 30um and 120um; in the embodiment of the present application, the width of the first scribed groove P1 is similar to the width of the invalid area a1, which can significantly reduce the width and area of ​​the invalid area a1 compared with the prior art.

[0067] b. The material of the substrate 122 is polyester (PET), polyimide (PI), polyetheretherketone (PEEK), transparent conductive polyester, polyacrylate, fluorinated polymer, polycarbonate (PC), polyester film (BOPET), ultra-thin flexible glass (UTG), metal foil, polyetherimide, polyimide, ITO glass or FTO glass;

[0068] c. The material of the electron transport layer 127 is fullerene C60;

[0069] d. The structure of the top electrode layer 128 is at least one of metal oxide + metal, metal oxide + metal + metal oxide, metal oxide + metal composite structure, metal oxide + metal composite structure + metal oxide; wherein the metal oxide includes but is not limited to ITO, FTO, IWO, AZO, IGO and IZO, etc., with a thickness of 12nm to 100nm; the metal includes but is not limited to gold, copper, molybdenum, nickel, silver, aluminum, etc., with a thickness of 7nm to 50nm; the metal composite structure includes but is not limited to molybdenum / copper, molybdenum / copper / molybdenum, molybdenum / silver, molybdenum / silver / molybdenum, nickel / copper, nickel / copper / nickel, etc., with a thickness of 12nm to 50nm;

[0070] e. The material of the bottom wire S3 is at least one of graphite, carbon nanotubes, metal nanoparticles, and metal nanowires;

[0071] f. The bottom conductor S3 is prepared by one of stamping, screen printing, evaporation, ALD, CVD, sputtering, spraying or printing.

[0072] The insulating layer S4 is made of at least one of photoresist, acrylic resin, epoxy resin, aluminum oxide, silicon oxide, nickel oxide, silicon nitride and inorganic (perhydro) polysilazane.

[0073] In an optional embodiment, the cadmium telluride thin film battery satisfies at least one of the following features AF:

[0074] A. The material of the bottom electrode layer 123 is at least one of In2O3, In2O3:Sn, SnO2:F, ZnO, ZnO:Al, and TiN; the thickness of the bottom electrode layer 123 is 300-500nm;

[0075] B. The cadmium telluride window layer 131 is made of CdSe and has a thickness of 30-200 nm;

[0076] C. A barrier layer is further provided between the bottom electrode layer 123 and the cadmium telluride window layer 131. The material of the barrier layer is at least one of Zn2SnO4, SnO2, and ZnMgO2. The thickness of the barrier layer is 50-100 nm.

[0077] D. The cadmium telluride absorption layer 132 is made of CdTe or CdTeZn, and the thickness of the cadmium telluride absorption layer 132 is 1 μm-6 μm;

[0078] E. The top electrode layer 128 is prepared by magnetron sputtering or solution immersion;

[0079] F. The material of the top electrode layer 128 is at least one of IWO and ITO, and the thickness of the top electrode layer 128 is 30-400 nm.

[0080] An embodiment of the present invention further provides a method for preparing a solar cell according to any one of the above embodiments, comprising:

[0081] A bottom electrode layer 123 is formed on the substrate 122, and a first scribed groove P1 is formed by etching the bottom electrode layer 123 to divide the bottom electrode layer 123 into first conductive blocks that are not connected to each other;

[0082] A metal conductive layer is formed in the first scribed groove P1, and then one side of the metal conductive layer is etched away to obtain the bottom conductive line S3, and then an insulating layer S4 is formed on the bottom conductive line S3 to obtain a substrate;

[0083] Sequentially forming a functional layer 120 and a top electrode layer 128 on the substrate;

[0084] A third scribed groove P3 is formed by etching in a region corresponding to the bottom conductive line S3 on the top electrode layer 128 to obtain the solar cell.

[0085] Taking the preparation of perovskite cells as an example, some embodiments specifically include the following steps:

[0086] Step 1) A first scribe groove P1 is scribed on the substrate 122 using a laser scribe device to divide the bottom electrode layer 123 into first conductive blocks that are not connected to each other. Figure 2 As shown, the width of the first groove P1 is in the range of 30um to 120um, and 60um is preferred;

[0087] Step 2) A metal conductive layer having a greater conductivity than the first conductive block is prepared in the first groove P1 with metal powder as raw material, and a metal conductive layer having a width of 60 μm and a thickness of 150 nm is finally formed after high temperature annealing. Figure 3 As shown. The metal is one or more of iron, copper, aluminum, silver, tin, magnesium, nickel, titanium, vanadium, chromium, manganese, cobalt, nickel, zinc, gallium, germanium, aluminum alloy, copper alloy, stainless steel alloy, and nickel alloy. The morphology of the metal powder is one or more of spherical, needle-shaped, rod-shaped, and flake-shaped; the particle size of the metal powder is 50nm to 300nm. The metal conductive layer is prepared by one or more of screen printing, coating, spraying, photolithography, printing, etc.;

[0088] Step 3) using a laser scribing device to laser etch away the bottom metal conductive layer on one side of the first scribing groove P1 to obtain a bottom wire S3; then, using one or more of the methods of screen printing, coating, spraying, photolithography, printing, evaporation, ALD and sputtering, one or more of the materials with poor insulation or conductivity such as photoresist, polyimide, epoxy resin, acrylic resin, polyparaxylene, silica gel, aluminum oxide, silicon nitride, tantalum nitride, tin oxide, nickel oxide, aluminum fluoride, lithium fluoride, etc., are prepared into the first scribing groove P1 to form an insulating layer S4 that can cover the bottom wire S3 in the first scribing groove P1, such as Figure 4 As shown, the substrate preparation of the perovskite component is completed;

[0089] Step 4) A nickel oxide layer, a perovskite layer 125, a fullerene C60 layer, a tin oxide layer and a top electrode layer 128 are prepared on the surface of the substrate respectively, and the top electrode layer 128 above the bottom wire S3 is cut by a laser scribing device to form a third scribing groove P3, thereby completing the preparation of the perovskite battery. Figure 5 shown.

[0090] Taking the preparation of cadmium telluride thin film batteries as an example, some embodiments specifically include the following steps:

[0091] A bottom electrode layer 123 is formed on a glass substrate 122 by deposition; a cadmium telluride window layer 131 is formed on the bottom electrode layer 123 by evaporation or water bath; a cadmium telluride absorption layer 132 is formed on the cadmium telluride window layer 131 by evaporation deposition; CdCl2 is coated on the cadmium telluride absorption layer 132, and the ambient temperature when coating CdCl2 is controlled to be 200-500°C, specifically, after the cadmium telluride absorption layer 132 is formed, the CdCl2 atmosphere is controlled by spraying, rolling, spin coating, etc., and the temperature is controlled to be 200-500°C during the process; a high-transmittance top electrode layer 128 is formed on the cadmium telluride absorption layer 132 coated with a CdCl2 film by magnetron sputtering or solution immersion, wherein the ambient temperature when the top electrode layer 128 is formed by solution immersion is controlled to be 150-300°C.

[0092] In traditional solar cells, the overall current of the series-connected two-terminal stacked battery assembly is limited by the minimum current of its two groups of batteries, the assembly efficiency is not high, and the process requirements are very high, the preparation is complex, and the research and development and production costs are high. Taking the parallel four-terminal perovskite stacked battery assembly as an example, the common process is to prepare the first perovskite layer 125 upward on the same substrate 122, and then cover it with a light-transmitting insulating layer 130, and then prepare the second perovskite layer 125 thereon, and then cover it with glass for packaging. This preparation process is complicated, and there are mutual disturbances in various processes, which will affect the first perovskite layer 125, thereby affecting the efficiency of the overall assembly and increasing the defect rate.

[0093] An embodiment of the present invention also provides a stacked solar cell, including a solar cell unit, wherein the solar cell unit includes a first solar cell unit 111 and a second solar cell unit 121, the first solar cell unit 111 and the second solar cell unit 121 are independently selected from the solar cells described in any one of the aforementioned embodiments, and the top electrode layers 128 of the first solar cell unit 111 and the second solar cell unit 121 are separated by a light-transmitting insulating layer 130.

[0094] The first solar cell unit 111 and the second solar cell unit 121 in the stacked solar cell in the embodiment of the present application are separated by a light-transmitting insulating layer 130, which is conducive to independent manufacturing and processing of the two solar cell units without mutual interference, thereby helping to improve the yield of the stacked solar cell.

[0095] In the embodiment of the present application, the first solar cell unit 111 and the second solar cell unit 121 are used to absorb light of a first wavelength and light of a second wavelength, respectively. The first wavelength and the second wavelength can be the same or different; and the first solar cell unit 111 and the second solar cell unit 121 can be independently selected from narrow bandgap solar cells and wide bandgap solar cells. In some embodiments, the first solar cell unit 111 and the second solar cell unit 121 are both perovskite cells, and the structure of the corresponding stacked solar cell is as follows Figure 6 shown.

[0096] In an optional embodiment, if Figure 7 and Figure 8 As shown, the active area b1 corresponding to the first solar cell unit 111 includes a light leakage area S1 (such as Figure 7 The red dotted line frame position) and two or more compartment areas S2 isolated by the light leakage area S1, the top electrode layers 128 corresponding to the two or more compartment areas S2 are connected in parallel through the top electrode layer connection end S6 extending to the invalid area a1, and the bottom electrode layers 123 corresponding to the two or more compartment areas S2 are connected in parallel through the bottom wire S3.

[0097] In this embodiment, the first solar cell unit 111 and the second solar cell are stacked, and the light not absorbed by the first solar cell unit 111 can be absorbed by the second solar cell, which has a higher conversion rate than the second solar cell alone. At the same time, the first solar cell has lower requirements on the battery, and poor solar cells can be selected, providing a way to utilize poor solar cell units.

[0098] In an optional embodiment, the solar cell includes more than two sub-cells, each of the sub-cells is correspondingly provided with an effective area b1 and an invalid area a1, the area corresponding to the first score groove P1 is the invalid area a1, and the area between adjacent first score grooves P1 is the effective area b1, and the sub-cells in the solar cell unit are connected in series in sequence through the connection between the bottom wire S3 and the top electrode layer connection terminal S6.

[0099] The sub-cells in the solar cell unit are connected in series. Specifically, the sub-cells in the first solar cell unit 111 are connected in series to form a first sub-cell string, the second solar cell unit 121 is connected in series to form a second sub-cell string, and then the first sub-cell string and the second sub-cell string are connected in series. Fig. 9 and Fig.10 As shown, the ends of the bottom wire S3 of a sub-cell in the first solar cell unit 111 are connected to the ends of the top electrode layer connection terminal S6 of the adjacent sub-cell in the first solar cell unit 111, and the ends of the top electrode layer connection terminal S6 of a sub-cell in the second solar cell unit 121 are connected to the ends of the bottom wire S3 of the adjacent sub-cell in the second solar cell unit 121. Finally, as shown in FIG. Fig. 9 As shown in the red dotted box, the ends of the bottom wire S3 of the terminal sub-cell in the first solar cell unit 111 are respectively connected to the ends of the top electrode layer connection terminal S6 of the terminal sub-cell in the second solar cell unit 121 to form a perovskite component structure in which two single-cell perovskite components are connected in series, that is, in the first solar cell unit 111, only the bottom wire S3 corresponding to one sub-cell is connected to the top electrode layer connection terminal S6 in the second solar cell unit 121 to form a stacked solar cell.

[0100] Alternatively, the sub-cells of the first solar cell unit 111 and the sub-cells of the second solar cell unit 121 may be sequentially and alternately connected in series to form a stacked solar cell. Fig.11 and Fig.12 As shown, the bottom conductor S3 of a sub-cell in the second solar cell unit 121 is connected to the top electrode layer connection terminal S6 of a sub-cell in the first solar cell unit 111. At the same time, the top electrode layer connection terminal S6 of the sub-cell in the second solar cell unit 121 is connected to the bottom conductor S3 of another sub-cell in the first solar cell unit 111, and so on, to form a series battery structure, that is: in the first solar cell unit 111, the bottom conductor S3 corresponding to each sub-cell is connected to the top electrode layer connection terminal S6 in the second solar cell unit 121; in the second solar cell unit 121, the bottom conductor S3 corresponding to each sub-cell is connected to the top electrode layer connection terminal S6 in the first solar cell unit 111.

[0101] It should be noted that when it is detected that a certain sub-cell is damaged, has too many defects or the film layer is damaged, which will reduce the light conversion efficiency of the component, the sub-cell can be skipped and connected in series with the next sub-cell.

[0102] An embodiment of the present invention further provides a method for preparing the stacked solar cell according to any one of the aforementioned embodiments, comprising:

[0103] Etching to form a light leakage area S1 in the active area b1 of the solar cell to obtain the first solar cell unit 111;

[0104] Take the second solar cell unit 121 and the first solar cell unit 111, form a light-transmitting insulating layer 130 between the second solar cell unit 121 and the first solar cell unit 111, and perform lamination packaging. Fig.13 As shown;

[0105] The sub-cells in the second solar cell unit 121 and the first solar cell unit 111 are connected in series using conductive wires to obtain the stacked solar cell.

[0106] In an optional embodiment, the active area b1 of the first solar cell unit 111 can be laser etched to completely remove the film layer corresponding to the light leakage area S1, and finally the active area b1 is isolated into a plurality of compartment areas S2 by the light leakage area S1 formed by laser etching, and the plurality of compartment areas S2 are connected in parallel through the ineffective area a1, and finally form the first solar cell unit 111. The light leakage area S1 is arranged in the active area b1, wherein a portion of the top electrode layer 128 extends to the ineffective area a1, and the top electrode layers 128 of the plurality of compartment areas S2 are connected in parallel; and the bottom electrode layers 123 of the plurality of compartment areas S2 are connected in parallel through the bottom wire S3, and finally connected through the connecting wire S5 to form a series sub-cell structure.

[0107] In an optional embodiment, UV-cured epoxy resin glue is coated on the surface of the top electrode layer 128 of the first solar cell unit 111 to form a 20um thick light-transmitting insulating layer 130, and the surface of the top electrode layer 128 of the second solar cell unit 121 is attached to the surface of the adhesive layer and laminated and packaged.

[0108] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0109] Example 1

[0110] This embodiment provides a perovskite tandem solar cell, comprising:

[0111] The first solar cell unit 111, the light-transmitting insulating layer 130 and the second solar cell unit 121 are sequentially stacked along a first direction.

[0112] Conductive wires are printed using a printing device to connect the connecting ends at both ends of the bottom wire S3 in the second solar cell unit 121 to the connecting ends at both ends of the top electrode layer 128 in the first solar cell unit 111, and the connecting ends at both ends of the top electrode layer 128 in the second solar cell unit 121 to the connecting ends at both ends of the bottom wire S3 in the first solar cell unit 111, thereby forming a perovskite component structure in which adjacent sub-cells in two single-cell perovskite components are connected in series.

[0113] The specific preparation method comprises the following steps:

[0114] Step 1) A 400nm bottom electrode layer 123 is provided on the FTO conductive glass. Laser engraving is performed on the bottom electrode layer 123 until the glass substrate 122 is exposed to form a first engraved groove P1, so that a plurality of independent first conductive blocks of the same area are formed on the conductive glass. The width of the first engraved groove P1 is 60um.

[0115] Step 2) Use inkjet printing to print the metal nanoparticle slurry on the bottom of the first groove P1, and anneal it in an annealing furnace at 150°C to finally form a metal nanoparticle slurry with a line width of 60um, a thickness of 200nm and a resistivity of 2×10 -7 The metal lines of Ω / M reconnect the independent first conductive blocks;

[0116] Step 3) The metal line on one side of the bottom of the first scribed groove P1 near the edge of the first conductive block is etched away by a laser scribing process, so that the connected first conductive blocks are separated again to form independent first conductive blocks, and finally a line width of 30 um, a thickness of 200 nm and a resistivity of 2×10 -7 A bottom wire S3 of Ω / M, both ends of the bottom wire S3 are provided with connection ends connected outwards;

[0117] Step 4) Printing a photoresist with a viscosity of 15 cps in the first scribed groove P1 by inkjet printing to fill the first scribed groove P1 completely, thereby obtaining a photoresist insulating layer S4 with a line width of 60 um, a thickness of 350 nm and a resistivity greater than 1 MΩ;

[0118] Step 5) preparing a perovskite layer 125 with a thickness of 450 nm by a slit coating process, and then depositing 20 nm of C60 and 8 nm of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) as a charge transport layer on the perovskite layer 125 by vacuum evaporation or the like, and depositing a 100 nm top electrode layer 128 by vacuum evaporation;

[0119] Step 6) Using a laser to locate through the mask, the top electrode layer 128 is cut on the surface of the top electrode layer 128 by using a laser scribing device to form a third scribing groove P3 with a line width of 40 um and a groove depth of 150 nm;

[0120] Step 7) The copper nanoparticle ink is printed on the top electrode layer 128 on one side of the third groove P3 by using a printing device. The printed line width of the extended connection end is 30um and the thickness is 150nm. The annealing furnace is used to anneal for 5 minutes at 100℃ to complete the sintering, so that the resistivity formed by the top electrode layer 128 and the conductive line is 2.6×10 -8 Ω / M, thus, the preparation of the first solar cell unit 111 and the second solar cell unit 121 is completed.

[0121] Step 8) Print conductive wires using a printing device to connect the bottom wire S3 of a sub-cell in the second solar cell unit 121 in step 7 to the top electrode layer connection terminal S6 of a sub-cell in the first solar cell unit 111. At the same time, the top electrode layer connection terminal S6 of the sub-cell in the second solar cell unit 121 is connected to the bottom wire S3 of another sub-cell in the first solar cell unit 111, and so on, to form a structure as shown in FIG. Fig.12 The perovskite module structure shown is a series connection of adjacent sub-cells in two single-cell perovskite modules.

[0122] Example 2

[0123] This embodiment provides a perovskite tandem solar cell and a preparation method thereof, which is different from the embodiment 1 in that the second solar cell unit 121 is a cadmium telluride module, and the structure is as follows: Fig.14 As shown:

[0124] The band gap of the perovskite absorption layer of the first solar cell unit 111 is 1.1-1.4 eV, and the band gap of the cadmium telluride absorption layer 132 of the second solar cell unit 121 is 1.4-1.6 eV. The preparation method of the cadmium telluride module of the second solar cell unit 121 includes:

[0125] Step 1) forming an In2O3 bottom electrode layer 123 with a thickness of 400 nm on a glass substrate 122 by deposition;

[0126] Step 2) forming a Zn2SnO4 barrier layer with a thickness of 80 nm on the bottom electrode layer 123, the barrier layer plays an insulating isolation role; forming a CdSe cadmium telluride window layer 131 with a thickness of 100 nm on the barrier layer by evaporation.

[0127] Step 3) forming a CdTe cadmium telluride absorption layer 132 with a thickness of 4 μm on the cadmium telluride window layer 131 by evaporation deposition;

[0128] Step 4) coating CdCl2 on the cadmium telluride absorption layer 132 to modify and passivate the surface of the cadmium telluride film layer, and controlling the ambient temperature during coating of CdCl2 to be 350° C.;

[0129] Step 5) A high-transmittance back electrode layer with a thickness of 400 nm (50 nm IWO film layer superimposed with 350 nm ITO) is formed by solution immersion on the cadmium telluride absorption layer 132 coated with the CdCl2 film, wherein the thickness of the back electrode layer is 300 nm, and the ambient temperature when the back electrode layer is formed by solution immersion is controlled at 200°C.

[0130] Example 3

[0131] This embodiment provides a perovskite tandem solar cell and a preparation method, which is different from Embodiment 1 only in that the following is included between Step 7 and Step 8:

[0132] Laser etching is performed on the active area b1 of the first solar cell unit 111, such as Figure 8 As shown, a part of the perovskite film layer is removed to form a light leakage area S1, and finally the effective area b1 is isolated into a plurality of compartment areas S2 by the light leakage area S1 formed by laser etching, and the plurality of compartment areas S2 are connected in parallel through the ineffective area a1, and finally form a first solar cell unit 111. The light leakage area S1 is set within the effective area b1, wherein the portion of the top electrode layer 128 extending to the ineffective area a1 connects the top electrode layers 128 of the plurality of compartment areas S2 in parallel, and the bottom electrode layers 123 of the plurality of compartment areas S2 are connected in parallel through the bottom wire S3.

[0133] Example 4

[0134] The present embodiment provides a perovskite stacked solar cell and a preparation method, which differs from the embodiment 1 only in that step 8 comprises: printing a connecting wire S5 by a printing device, connecting the ends of the bottom wire S3 of a sub-cell in the first solar cell unit 111 to the ends of the top electrode layer connection terminal S6 of the adjacent sub-cell in the first solar cell unit 111, and connecting the ends of the top electrode layer connection terminal S6 of a sub-cell in the second solar cell unit 121 to the ends of the bottom wire S3 of the adjacent sub-cell in the second solar cell unit 121, and finally connecting the ends of the bottom wire S3 of the terminal sub-cell in the first solar cell unit 111 to the ends of the top electrode layer connection terminal S6 of the terminal sub-cell in the second solar cell unit 121, to form a solar cell as shown in FIG. Fig.10 The perovskite module structure shown is two single-section perovskite modules connected in series.

[0135] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A solar cell, characterized in that: It comprises a substrate (122) and a bottom electrode layer (123), a functional layer (120) and a top electrode layer (128) which are sequentially stacked on the substrate (122); The bottom electrode layer (123) is provided with a first scribed groove (P1), the first scribed groove (P1) divides the bottom electrode layer (123) into two or more first conductive blocks that are not connected to each other, and the first scribed groove (P1) is provided with a bottom conductive wire (S3) connected to the corresponding first conductive block and an insulating layer (S4) covering the bottom conductive wire (S3); A third groove (P3) is provided on the top electrode layer (128) at a position corresponding to the bottom conductive line (S3); the third groove (P3) separates the top electrode layer (128) into two or more second conductive blocks that are not connected to each other; and a top electrode layer connection terminal (S6) is provided at a position corresponding to the second conductive block and the first groove (P1).

2. The solar cell according to claim 1, characterized in that The solar cell includes at least one of a perovskite cell, a cadmium telluride thin film cell, a CIGS thin film cell, an OPV thin film cell and a PVK thin film cell.

3. The solar cell according to claim 1, characterized in that The functional layer (120) includes a hole transport layer (124), a perovskite layer (125), a passivation layer (126) and an electron transport layer (127); Alternatively, the functional layer (120) includes a cadmium telluride window layer (131) and a cadmium telluride absorption layer (132).

4. The solar cell according to claim 2, characterized in that: The perovskite cell satisfies at least one of the following features af: a. The width of the first scored groove (P1) is 30um to 120um; b. The substrate (122) is polyester, polyimide, polyetheretherketone, transparent conductive polyester, polyacrylate, fluorinated polymer, polycarbonate, ultra-thin flexible glass, metal foil, polyetherimide, polyimide, ITO glass or FTO glass; c. The material of the electron transport layer (127) is fullerene C60; d. The structure of the top electrode layer (128) is at least one of metal oxide + metal, metal oxide + metal + metal oxide, metal oxide + metal composite structure, metal oxide + metal composite structure + metal oxide; e. The material of the bottom wire (S3) is at least one of graphite, carbon nanotubes, metal nanoparticles, and metal nanowires; f. The bottom conductive line (S3) is prepared by one of embossing, screen printing, evaporation, ALD, CVD, sputtering, spraying or printing.

5. A method for preparing a solar cell according to any one of claims 1 to 4, characterized in that: include: Forming a bottom electrode layer (123) on a substrate (122), and etching a first scribed groove (P1) on the bottom electrode layer (123) to divide the bottom electrode layer (123) into first conductive blocks that are not connected to each other; Forming a metal conductive layer in the first scribed groove (P1), then etching away one side of the metal conductive layer to obtain the bottom conductive line (S3), and then forming an insulating layer (S4) on the bottom conductive line (S3) to obtain a substrate; Sequentially forming a functional layer (120) and a top electrode layer (128) on the substrate; A third groove (P3) is formed by etching in a region corresponding to the bottom conductive line (S3) on the top electrode layer (128) to obtain the solar cell.

6. A stacked solar cell, characterized in that: The invention comprises a solar cell unit, wherein the solar cell unit comprises a first solar cell unit (111) and a second solar cell unit (121), wherein the first solar cell unit (111) and the second solar cell unit (121) are independently selected from the solar cells according to any one of claims 1 to 4, and the top electrode layers (128) of the first solar cell unit (111) and the second solar cell unit (121) are separated by a light-transmitting insulating layer (130).

7. The tandem solar cell according to claim 6, characterized in that: The solar cell unit comprises more than two sub-cells, each of the sub-cells is correspondingly provided with an effective area (b1) and an ineffective area (a1), the area corresponding to the first scribed groove (P1) is the ineffective area (a1), and the area between adjacent first scribed grooves (P1) is the effective area (b1), and the sub-cells in the solar cell unit are sequentially connected in series through the connection of the bottom wire (S3) and the top electrode layer connection end (S6).

8. The tandem solar cell according to claim 7, characterized in that: The effective area (b1) in the first solar cell unit (111) includes a light leakage area (S1) and two or more compartment areas (S2) isolated by the light leakage area (S1); the top electrode layers (128) corresponding to the two or more compartment areas (S2) are connected in parallel via a top electrode layer connection end (S6) extending to the ineffective area (a1); and the bottom electrode layers (123) corresponding to the two or more compartment areas (S2) are connected in parallel via a bottom wire (S3).

9. The tandem solar cell according to claim 7, characterized in that: In the first solar cell unit (111), only a bottom conductor (S3) corresponding to a subcell is connected to a top electrode layer connection terminal (S6) in the second solar cell unit (121); Alternatively, in the first solar cell unit (111), the bottom conductor (S3) corresponding to each sub-cell is connected to the top electrode layer connection end (S6) in the second solar cell unit (121); in the second solar cell unit (121), the bottom conductor (S3) corresponding to each sub-cell is connected to the top electrode layer connection end (S6) in the first solar cell unit (111).

10. A method for preparing a stacked solar cell according to any one of claims 6 to 9, characterized in that: include: Etching to form a light leakage area (S1) in the effective area (b1) of the solar cell unit to obtain the first solar cell unit (111); Taking the second solar cell unit (121) and the first solar cell unit (111), forming a light-transmitting insulating layer (130) between the second solar cell unit (121) and the first solar cell unit (111), and performing lamination packaging; The sub-cells in the second solar cell unit (121) and the first solar cell unit (111) are connected in series using conductive wires to obtain the stacked solar cell.

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