Solar cell, photovoltaic module, power generation device and power utilization device

Abstract

The utility model discloses a solar cell, a photovoltaic module, a power generation device and a power utilization device. The solar cell includes a first sub-cell, a second sub-cell, and a substrate. The substrate is provided with two opposite surfaces in the thickness direction of the substrate, the first sub-battery and the second sub-battery are located on the two surfaces of the substrate respectively, and the first sub-battery and the second sub-battery are electrically connected with each other to form a sub-battery pack. Wherein each of the first sub-cell and the second sub-cell comprises a layer structure arranged on the substrate, each layer structure comprises a light absorption layer, a first electrode layer and a second electrode layer which are stacked, the light absorption layer is located on the light incident side, and the first electrode layer and the second electrode layer are located on the backlight side of the light absorption layer and are insulated from each other. The two-end structure of the solar cell is stable in performance, the optical loss of incident light can be reduced, and the light utilization rate can be improved, so that the theoretical efficiency of the solar cell can be improved, and the actual output current and the photoelectric conversion efficiency of the solar cell are higher.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a solar cell, a photovoltaic module, a power generation device, and an electricity-consuming device. Background Art

[0002] In recent years, global energy shortages and environmental pollution have become increasingly prominent, and solar cells, as an ideal renewable energy source, have garnered increasing attention. Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric or photochemical effects. Due to their cost advantages, solar cells hold great promise for industrialization.

[0003] With the continuous development of battery technology, how to improve the light utilization rate and photoelectric conversion efficiency of solar cells is one of the research topics in the industry. Utility Model Content

[0004] In order to solve the above technical problems, the present application provides a solar cell, a photovoltaic module, a power generation device and an electricity-consuming device with stable performance, high light utilization rate and high photoelectric conversion efficiency.

[0005] This application is implemented through the following technical solutions.

[0006] In a first aspect, an embodiment of the present application provides a solar cell, comprising: a first sub-cell; a second sub-cell; and a substrate having two opposite surfaces along its own thickness direction, wherein the first sub-cell and the second sub-cell are respectively located on the two surfaces of the substrate, and the first sub-cell and the second sub-cell are electrically connected to each other to form a sub-cell group; wherein the first sub-cell and the second sub-cell both include a layer structure provided on the substrate, the layer structure including a stacked light absorption layer, a first electrode layer and a second electrode layer, the light absorption layer is located on the light incident side, and the first electrode layer and the second electrode layer are both located on the backlight side of the light absorption layer and are insulated from each other.

[0007] Since the first sub-cell and the second sub-cell are provided on both sides of the substrate along its own thickness direction, the solar cell can absorb light energy from both the front and back sides simultaneously. In addition to incident light, it can also make full use of reflected light and diffusely reflected light, thereby improving light utilization and reducing reflection loss, thereby converting light energy into electrical energy more efficiently and improving power generation efficiency.

[0008] In addition, since the light-absorbing layers of the first sub-cell and the second sub-cell are both located on the light-incident side, and the first electrode layer and the second electrode layer are both located on the backlight side of the light-absorbing layer, no matter which side of the solar cell the light is incident on, it will not pass through the electrode layer, but can be directly absorbed by the light-absorbing layer, thereby effectively reducing optical parasitic losses and improving the efficiency limit of the solar cell, thereby improving the output current and photoelectric conversion efficiency of the solar cell, making the performance of the solar cell better.

[0009] In some embodiments, the first electrode layer of the first sub-cell is electrically connected to the second electrode layer of the second sub-cell, or the second electrode layer of the first sub-cell is electrically connected to the first electrode layer of the second sub-cell.

[0010] This allows the first and second subcells of the solar cell to be connected in series, forming a well-designed two-terminal structure. This two-terminal solar cell is relatively simple to manufacture, offers improved reliability, reduces production costs, and is more suitable for large-scale mass production.

[0011] In some embodiments, the band gap of the light absorbing layer of the first sub-cell is different from the band gap of the light absorbing layer of the second sub-cell.

[0012] Thus, by adjusting the band gaps of the light absorbing layer of the first subcell and the light absorbing layer of the second subcell, the first subcell and the second subcell connected in series can form current matching, which is beneficial to improving the stability and reliability of the solar cell.

[0013] In some embodiments, the first sub-cell faces the bright light side, and the second sub-cell faces the dim light side; the band gap of the light absorption layer of the first sub-cell is greater than the band gap of the light absorption layer of the second sub-cell.

[0014] Because the smaller the band gap of the light-absorbing layer, the larger the light absorption range, and the larger the band gap, the smaller the light absorption range, the band gap of the light-absorbing layer of the first sub-cell facing the strong light side is larger than the band gap of the light-absorbing layer of the second sub-cell facing the weak light side. This allows the first sub-cell to absorb only a portion of the wavelength range of light, while the second sub-cell can absorb at least the wavelength range that cannot be absorbed by the first sub-cell. This reduces the possibility of the second sub-cell failing to absorb light and thus failing to generate current, maintains the current balance of the two-terminal solar cell, and makes the solar cell more stable and reliable. It also improves the solar cell's absorption and utilization of the light spectrum, further improving the efficiency of the solar cell.

[0015] In some embodiments, the band gap of the light absorbing layer of the first sub-cell is between 1.7 eV and 1.8 eV; the band gap of the light absorbing layer of the second sub-cell is between 1.2 eV and 1.3 eV.

[0016] This provides a reasonable bandgap selection range for the first and second subcells, allowing the bandgap of the light-absorbing layer to be selected based on the wavelength range of the actual incident light. This allows the first and second subcells, facing the strong and weak light sides, to achieve current matching. Furthermore, this improves the absorption and utilization of the spectrum, further increasing the efficiency of the solar cell.

[0017] In some embodiments, the layer structure further includes an insulating layer, which is located between the first electrode layer and the second electrode layer; in a projection plane perpendicular to the stacking direction of the layer structure, the projection area of ​​the first electrode layer is smaller than the projection area of ​​the second electrode layer, or the projection area of ​​the second electrode layer is smaller than the projection area of ​​the first electrode layer.

[0018] As a result, the insulating layer can insulate the first and second electrode layers from each other, reducing the possibility of short circuits. Furthermore, the position and shape of the first and second electrode layers can be flexibly changed according to actual conditions, thereby further facilitating the electrical connection between the first and second sub-cells and better achieving the two-terminal output structure of the solar cell.

[0019] In some embodiments, the layer structure further includes a first carrier transport layer and a second carrier transport layer, the first carrier transport layer is located between the light absorbing layer and the first electrode layer, and the second carrier transport layer is located between the light absorbing layer and the second electrode layer; the first carrier transport layer is a hole transport layer, and the second carrier transport layer is an electron transport layer; or the first carrier transport layer is an electron transport layer, and the second carrier transport layer is a hole transport layer.

[0020] Thus, by providing the first carrier transport layer and the second carrier transport layer, the dissociation effect of electrons and holes can be enhanced, and the recombination of electrons and holes can be reduced, thereby improving the photoelectric conversion efficiency of the solar cell.

[0021] In some embodiments, the first subcell includes a plurality of first unit subcells connected in series; and / or the second subcell includes a plurality of second unit subcells connected in series.

[0022] In this way, the arrangement flexibility of the first sub-cell and the second sub-cell can be improved, and the multiple first unit sub-cells of the first sub-cell and the multiple second unit sub-cells of the second sub-cell can be arranged into different forms according to different application scenarios of the solar cell, thereby changing the overall form of the solar cell, so that the solar cell is basically not restricted by the installation scenario.

[0023] In some embodiments, there are multiple sub-battery groups, and the multiple sub-battery groups are electrically connected to each other.

[0024] The plurality of sub-cell groups can improve the light absorption capability of the solar cell, thereby improving the photoelectric conversion efficiency of the solar cell, and further increasing the total output power of the solar cell.

[0025] In some embodiments, the first sub-cell and the second sub-cell share a common substrate.

[0026] This can reduce the number of parts and components and lower production costs.

[0027] In some embodiments, the light absorbing layer is a perovskite light absorbing layer.

[0028] Perovskite light-absorbing layers have a higher absorbance and can absorb a wider spectrum of light under the same lighting conditions. Furthermore, perovskite has a long carrier diffusion length and low exciton binding energy, making it easier for perovskite to dissociate into free carriers, thereby increasing the photoelectric conversion efficiency of solar cells using perovskite as a light-absorbing layer.

[0029] In a second aspect, an embodiment of the present application further provides a photovoltaic assembly, which includes the solar cell as described in the first aspect above.

[0030] Since photovoltaic modules include solar cells with stable performance, high light utilization rate, and high photoelectric conversion efficiency, photovoltaic modules can generate more current and have greater output power.

[0031] In a third aspect, an embodiment of the present application further provides a power generation device, which includes the solar cell as described in the first aspect above.

[0032] As a result, a power generation device equipped with solar cells with high light utilization rate and high photoelectric conversion efficiency can be provided, which increases the power generation of the power generation device, enables the power generation device to meet relatively sufficient electrical energy, and improves the reliability of the power generation device.

[0033] In a fourth aspect, an embodiment of the present application further provides an electrical device, which includes the solar cell as described in the first aspect above.

[0034] Thus, an electric device equipped with a solar cell having high light utilization rate and high photoelectric conversion efficiency can be provided, and the electric device can obtain sufficient current to operate, thereby improving the reliability of the electric device.

[0035] The solar cells, photovoltaic modules, power generation devices, and power-consuming devices of the embodiments of the present application have stable performance and high photoelectric conversion efficiency.

[0036] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to denote the same components. In the drawings:

[0038] Figure 1 A schematic structural diagram of a solar cell provided in some embodiments of the present application;

[0039] Figure 2 for Figure 1 A schematic structural diagram of a solar cell provided from another perspective;

[0040] Figure 3 for Figure 1 A schematic structural diagram of a solar cell is provided from another perspective.

[0041] Description of Reference Numerals

[0042] 1. First subcell; 11. First unit subcell; 2. Second subcell; 21. Second unit subcell; 3. Substrate; 4. Layer structure; 40. Light-absorbing layer; 401. Thin layer portion; 402. Thick layer portion; 41. First electrode layer; 42. Second electrode layer; 43. Insulating layer; 44. First carrier transport layer; 45. Second carrier transport layer; 5. Bus bar; 10. Subcell group; 100. Solar cell. DETAILED DESCRIPTION

[0043] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions.

[0045] In the description of the embodiments of this application, the technical terms "first," "second," "third," etc. are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise specifically defined.

[0046] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0048] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0049] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0050] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and can be direct contact, contact through an intermediate medium layer, contact with essentially no interaction force between the two contacting parties, or contact with interaction force between the two contacting parties.

[0051] Below, this application is described in detail.

[0052] Currently, new energy batteries are increasingly being used in everyday life and industry. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in a variety of fields such as aerospace. As the application of power batteries continues to expand, market demand is also growing.

[0053] In recent years, global energy shortages and environmental pollution have become increasingly prominent, and solar cells, as an ideal renewable energy source, have garnered increasing attention. Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric or photochemical effects. Due to their cost advantages, solar cells hold great promise for industrialization.

[0054] Optical losses in solar cells mainly include reflection loss and parasitic absorption. When incident light hits the surface of a solar cell, some of the light is reflected and diffusely reflected, preventing it from entering the cell. This causes some optical losses and affects the efficiency of the solar cell.

[0055] In addition, in related technologies, solar cells usually adopt a "sandwich" structure of two layers of electrode layer and light-absorbing layer. This means that no matter which direction the incident light comes from, it will at least pass through the electrode layer before reaching the light-absorbing layer, causing inevitable optical parasitic absorption, affecting the utilization rate of light by solar cells, and thus reducing the photoelectric conversion efficiency of solar cells.

[0056] In response to the problems existing in the above-mentioned related technologies, the present application proposes a solar cell, which includes a first sub-cell, a second sub-cell and a substrate. The substrate has two opposite surfaces along its own thickness direction, and the first sub-cell and the second sub-cell are respectively located on the two surfaces of the substrate, and the first sub-cell and the second sub-cell are electrically connected to each other to form a sub-cell group. The first sub-cell and the second sub-cell each include a layer structure provided on the substrate, and the layer structure includes a stacked light-absorbing layer, a first electrode layer and a second electrode layer. The light-absorbing layer is located on the light-entering side, and the first electrode layer and the second electrode layer are both located on the backlight side of the light-absorbing layer and are insulated from each other.

[0057] Since the first sub-cell and the second sub-cell are provided on both sides of the substrate along its own thickness direction, the solar cell can absorb light energy from both the front and back sides simultaneously. In addition to incident light, it can also make full use of reflected light and diffusely reflected light, improve light utilization, reduce reflection loss, and thus convert light energy into electrical energy more efficiently, thereby improving power generation efficiency.

[0058] In addition, since the light-absorbing layers of the first sub-cell and the second sub-cell are both located on the light-incident side, and the first electrode layer and the second electrode layer are both located on the backlight side of the light-absorbing layer, no matter which side of the solar cell the light is incident on, it will not pass through the electrode layer, but can be directly absorbed by the light-absorbing layer, thereby effectively reducing optical parasitic losses and improving the efficiency limit of the solar cell, thereby improving the output current and photoelectric conversion efficiency of the solar cell, making the performance of the solar cell better.

[0059] Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric or photochemical effect. Examples of solar cells include, but are not limited to, perovskite solar cells, cadmium zinc telluride solar cells, copper indium gallium selenide solar cells, copper indium selenide photovoltaic solar cells, and copper indium gallium sulfur solar cells.

[0060] Solar cells can be used in, but are not limited to, energy storage power supply systems, electrical devices such as vehicles, ships or aircraft, as well as energy storage devices such as energy storage containers and energy storage cabinets.

[0061] Photovoltaic modules include welding ribbons that connect multiple solar cells, junction boxes for current transmission, battery packaging components, etc.

[0062] In some embodiments, the photovoltaic module includes tempered glass, with the solar cell positioned between two tempered glass panels. EVA (ethylene-vinyl acetate) can be applied between the tempered glass and the solar cell to secure them relative to each other. Furthermore, silicone can be filled between the sides of the solar cell and the tempered glass to isolate the solar cell and the EVA from the outside air.

[0063] In some embodiments, a photovoltaic module may further include a support frame and a fixing member. The fixing member is disposed around the solar cell to secure the solar cell, and the solar cell is mounted on the support frame via the fixing member. The photovoltaic module may further include a frame, disposed around the solar cell, and the frame may be made of aluminum or an aluminum alloy. The fixing member is connected to the frame, and the solar cell is mounted on the support frame via the fixing member.

[0064] Exemplarily, the power generation device is a solar photovoltaic generator.

[0065] In some embodiments, the electrical device includes, but is not limited to, lighting equipment, energy storage equipment, etc. For example, the electrical device includes a solar water heater, a solar street light, a solar calculator, etc.

[0066] Below, refer to Figures 1 to 3 Some embodiments of the present application are described in detail.

[0067] Figure 1 A schematic structural diagram of a solar cell provided in some embodiments of the present application. Figure 2 for Figure 1 A schematic structural diagram of a solar cell provided from another perspective. Figure 3 for Figure 1 A schematic structural diagram of a solar cell is provided from another perspective.

[0068] In some embodiments of the present application, for ease of description, a first direction, a second direction, and a stacking direction are set, and the first direction, the second direction, and the stacking direction are perpendicular to each other. However, those skilled in the art should understand that the embodiments of the present application are not limited to the case where the three directions are perpendicular to each other. Figures 1 to 3 As shown by the arrows, the direction of arrow X is the first direction, the direction of arrow Y is the second direction, and the direction of arrow Z is the stacking direction.

[0069] like Figure 1 As shown, the first aspect of the present application provides a solar cell 100, which includes a first sub-cell 1, a second sub-cell 2, and a substrate 3. The substrate 3 has two opposing surfaces along its thickness direction. The first sub-cell 1 and the second sub-cell 2 are respectively located on the two surfaces of the substrate 3, and the first sub-cell 1 and the second sub-cell 2 are electrically connected to each other to form a sub-cell group 10. Among them, the first sub-cell 1 and the second sub-cell 2 each include a layer structure 4 provided on the substrate 3, and the layer structure 4 includes a stacked light absorption layer 40, a first electrode layer 41, and a second electrode layer 42. The light absorption layer 40 is located on the light incident side, and the first electrode layer 41 and the second electrode layer 42 are both located on the backlight side of the light absorption layer 40 and are insulated from each other.

[0070] The solar cell 100 is a device that directly converts light energy into electrical energy through the photoelectric effect or the photochemical effect.

[0071] The photoelectric conversion principle of the solar cell 100 is as follows: incident light (for example, sunlight) enters the interior of the device, reaches the light-absorbing layer 40 and is absorbed by it. Under the excitation of the incident light, the light-absorbing layer 40 generates hole-electron pairs. Under the action of the electric field, the holes and electrons are separated, and the electrons are transmitted to one electrode, while the holes are transmitted to the other electrode. Then, a loop is formed through an external circuit, which can be used to drive the load.

[0072] The substrate 3 is a layer of material that serves as the foundation for the solar cell 100 during its manufacturing process, providing support and protection for the other components of the solar cell 100. The substrate 3 of the solar cell 100 can be made of a variety of materials, including but not limited to glass, PCB ceramic, plastic, silicon, silicon oxide, silicon carbide, and the like.

[0073] For example, for crystalline silicon solar cells, the substrate is usually a silicon wafer. This material has good electrical and mechanical properties, can support other components of the solar cell and ensure the overall stability of the cell.

[0074] As another example, for amorphous silicon thin-film solar cells, the substrate is usually a glass plate, which has good transparency and stability.

[0075] As another example, for flexible solar cells, the substrate may be a flexible material such as a stainless steel sheet or a polyester film. These materials enable the solar cell to have characteristics such as foldability and lightness.

[0076] The embodiment of the present application does not impose any specific limitation on the material of the substrate 3 of the solar cell 100 and can be set according to actual conditions and application scenarios.

[0077] In the embodiment of the present application, a first sub-cell 1 and a second sub-cell 2 are formed on both surfaces of the substrate 3 along its thickness direction, and the first sub-cell 1 and the second sub-cell 2 are electrically connected to each other to form a sub-cell group 10 . Figure 2 The dotted-line frame portion schematically illustrates the sub-battery pack 10 of the present application.

[0078] Since the substrate 3 is provided with the first sub-cell 1 and the second sub-cell 2 on both sides along its own thickness direction, the solar cell 100 can absorb light energy from both the front and back sides simultaneously. In addition to incident light, it can also make full use of reflected light and diffusely reflected light, thereby improving light utilization and reducing reflection loss, thereby more efficiently converting light energy into electrical energy and improving power generation efficiency.

[0079] In the embodiment of the present application, the first sub-battery 1 and the second sub-battery 2 of the sub-battery group 10 can be connected in series or in parallel, which can be set according to actual conditions.

[0080] The layer structures 4 of the first sub-cell 1 and the second sub-cell 2 are described in detail below.

[0081] The layer structure 4 refers to any substantially layered structure. Each layer in the layer structure 4 may have a thickness that varies within the range of the layer. Typically, the thickness of a layer is approximately constant. As used herein, the "thickness" of a layer refers to the average thickness of the layer. The thickness of a layer can be measured by conventional methods in the art. The thickness of each layer in the layer structure 4 is not particularly limited herein; thicknesses commonly used in the art may be employed.

[0082] The layer structure 4 of the first sub-cell 1 and the second sub-cell 2 comprises at least a stacked light-absorbing layer 40 , a first electrode layer 41 and a second electrode layer 42 .

[0083] In the embodiment of the present application, the stacking direction of the layer structure 4 is the same as the thickness direction of the substrate 3 .

[0084] The light absorption layer 40 is a key layer structure for the solar cell 100 to convert light energy into electrical energy. The light absorption layer 40 can absorb photons in light and stimulate electrons and holes, thereby generating current.

[0085] In the embodiment of the present application, the solar cell 100 is a perovskite solar cell, that is, the solar cell 100 is a solar cell using a perovskite material as the light absorbing layer 40. Compared with other solar cells, the perovskite solar cell has a high photoelectric conversion efficiency.

[0086] "Perovskite" refers to a material having a three-dimensional crystal structure related to that of CaTiO3, or a material including a layer having a structure related to that of CaTiO3.

[0087] In some embodiments, the perovskite material includes at least one of the compounds shown as [A][B][X]3 and the compounds shown as [A]2[C][D][X]6, wherein A includes at least one inorganic or organic monovalent cation, B includes at least one inorganic divalent cation, C includes at least one inorganic monovalent cation, D includes at least one inorganic trivalent cation, and X includes at least one monovalent anion.

[0088] Exemplary organic monovalent cations include: (NR1R2R3R4) + 、(R1R2N=CR3R4) + 、(R1R2N-C(R5)=NR3R4) + or (R1R2N-C(NR5R6)=NR3R4) + At least one of, wherein R1, R2, R3, R4, R5 and R6 are each independently selected from H, substituted or unsubstituted C1-C20 alkyl or substituted or unsubstituted aryl. For example, the organic monovalent cation includes: ((H2N=CH-NH2) +(abbreviated as FA), CH3NH3 + (abbreviated as MA) at least one.

[0089] Exemplary inorganic monovalent cations include: Li + 、Na + , K + , Rb + 、Cs + 、Cu + 、Ag + 、Au + or Hg + At least one of .

[0090] Exemplary inorganic divalent cations include: Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ 、Cd 2+ 、Cu 2+ 、Mn 2+ 、Pd 2+ 、Yb 2+ or Eu 2+ At least one of .

[0091] Exemplary inorganic trivalent cations include: Bi 3+ 、Sb 3+ Cr 3+ 、Fe 3+ 、Co 3+ 、Ga 3+ 、As 3+ 、Ru 3+ , Rh 3+ 、In 3+ 、Ir 3+ 、Au 3+ or Al 3+ At least one of .

[0092] Exemplary monovalent anions include: F - 、Cl - Br - , I - 、SCN - 、CNO - 、OCN - 、OSCN - SH- OH - 、CN - 、SeCN - At least one of .

[0093] In some embodiments, the perovskite light absorbing layer includes Cs 0.1 MA 0.15 FA 0.75 PbCl 0.15 I 2.85 、MAPbI3、FAPbI3、(FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.83 Br 0.17 )3, at least one of CsPbI3, CsPbI2Br, and CsPbIBr2, wherein FA represents (H2N=CH-NH2) + , MA represents CH3NH3 + Optionally, the perovskite light absorbing layer includes: Cs 0.1 MA 0.15 FA 0.75 PbCl 0.15 I 2.85 The lead-based perovskite materials mentioned above are commonly found in perovskite solar cells, giving the solar cells good reproducibility.

[0094] Of course, those skilled in the art should understand that in some other embodiments, the solar cell 100 may also include a light absorbing layer 40 made of any other suitable material.

[0095] The first electrode layer 41 and the second electrode layer 42 are layers of the solar cell 100 that collect electrons or holes, generating photocurrent and establishing a certain voltage. The electrode layers can conduct this photocurrent so that it can be connected to an external circuit to achieve the collection and use of electrical energy. Of the first electrode layer 41 and the second electrode layer 42, the electrode layer that collects electrons is the negative electrode, and the electrode layer that collects holes is the positive electrode.

[0096] The materials of the first electrode layer 41 and the second electrode layer 42 mainly include transparent conductive materials, metal conductive materials, carbon conductive materials, and organic conductive materials. Among them, transparent conductive materials include but are not limited to tin oxide, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide, antimony-doped tin oxide, indium-doped tungsten oxide (IWO), doped indium hydroxide (IO:H), etc. Metal conductive materials include but are not limited to gold, silver, copper, aluminum, nickel, chromium, bismuth, platinum, magnesium, molybdenum, tungsten, etc. Carbon conductive materials include but are not limited to graphite, graphene, carbon nanotubes, etc. Organic conductive materials include but are not limited to poly (3,4-ethylenedioxythiophene), polythiophene, polyacetylene, etc.

[0097] In the embodiment of the present application, since the light absorbing layers 40 of the first sub-cell 1 and the second sub-cell 2 are both located on the light incident side (the side that first contacts the light), the first electrode layer 41 and the second electrode layer 42 are both located on the backlight side of the light absorbing layer 40 (the side facing away from the light incident side), therefore, no matter which side of the solar cell 100 the light is incident on, it will not pass through the electrode layer first, but can be directly absorbed by the light absorbing layer 40, thereby effectively reducing optical parasitic losses and improving the efficiency limit of the solar cell 100, thereby improving the output current and photoelectric conversion efficiency of the solar cell 100, so that the performance of the solar cell 100 is better.

[0098] Those skilled in the art should understand that the embodiments of the present application do not specifically limit the positions of the first electrode layer 41 and the second electrode layer 42. Along the stacking direction, the first electrode layer 41 can be arranged closer to the substrate 3, or the second electrode layer 42 can be arranged closer to the substrate 3. The positions of the two can be interchanged as long as the first electrode layer 41 and the second electrode layer 42 are both located on the backlight side of the light absorbing layer 40.

[0099] In addition, the positions of the first electrode layer 41 and the second electrode layer 42 of the first sub-cell 1 and the positions of the first electrode layer 41 and the second electrode layer 42 of the second sub-cell 2 may be the same as or different from each other.

[0100] For example, Figure 1 As shown, along the stacking direction, the second electrode layer 42 of the first sub-cell 1 may be arranged closer to the substrate 3 , and the first electrode layer 41 of the second sub-cell 2 may be arranged closer to the substrate 3 .

[0101] As another example, along the stacking direction, the first electrode layer 41 of the first sub-cell 1 may be arranged closer to the substrate 3 , and the second electrode layer 42 of the second sub-cell 2 may be arranged closer to the substrate 3 .

[0102] As another example, along the stacking direction, the first electrode layer 41 of both the first sub-cell 1 and the second sub-cell 2 may be arranged closer to the substrate 3 , or the second electrode layer 42 of both the first sub-cell 1 and the second sub-cell 2 may be arranged closer to the substrate 3 .

[0103] In some embodiments, the first electrode layer 41 of the first sub-cell 1 is electrically connected to the second electrode layer 42 of the second sub-cell 2 , or the second electrode layer 42 of the first sub-cell 1 is electrically connected to the first electrode layer 41 of the second sub-cell 2 .

[0104] Thus, the first sub-cell 1 and the second sub-cell 2 of the solar cell 100 can be connected in series to form a good two-terminal structure.

[0105] The electrode connection method of the two-terminal solar cell 100 is relatively simple, so the preparation process is relatively easy, the reliability is better, it is conducive to reducing production costs, and it is more suitable for large-scale mass production of solar cells 100.

[0106] For example, Figure 3 As shown, the first electrode layer 41 of the first sub-cell 1 located on one side of the substrate 3 along its thickness direction extends along the second direction and is bent at the edge of the substrate 3, bent to the other side of the substrate 3 along its thickness direction, and is electrically connected to the second electrode layer 42 of the second sub-cell 2 located on the other side of the substrate 3 along its thickness direction. Bus bars 5 are then provided on the second electrode layer 42 at the other end of the first sub-cell 1 along the second direction and the first electrode layer 41 at the other end of the second sub-cell 2 along the second direction, one of which serves as the positive electrode and the other as the negative electrode, so that the positive and negative electrodes of the solar cell 100 can be led out respectively. Alternatively, the second electrode layer 42 of the first sub-cell 1 located on one side of the substrate 3 along its thickness direction may extend along the second direction and bend at the edge of the substrate 3 to the other side of the substrate 3 along its thickness direction, and be electrically connected to the first electrode layer 41 of the second sub-cell 2 located on the other side of the substrate 3 along its thickness direction, and then bus bars 5 are respectively provided on the first electrode layer 41 at the other end of the first sub-cell 1 along the second direction and the second electrode layer 42 at the other end of the second sub-cell 2 along the second direction, one of which serves as the positive electrode and the other as the negative electrode, so that the positive and negative electrodes of the solar cell 100 can be led out respectively.

[0107] Of course, those skilled in the art should understand that the embodiment of the present application does not specifically limit the arrangement of the first electrode layer 41 and the second electrode layer 42 of the first sub-cell 1 and the second sub-cell 2 .

[0108] In addition, in some other embodiments, the first sub-cell 1 and the second sub-cell 2 may be connected in parallel by changing the connection mode of the electrode layers between the first sub-cell 1 and the second sub-cell 2 .

[0109] In some embodiments, the band gap of the light absorbing layer 40 of the first sub-cell 1 is different from the band gap of the light absorbing layer 40 of the second sub-cell 2 .

[0110] The band gap, also known as the energy gap or forbidden band width, refers to the energy difference between the lowest point of the conduction band and the highest point of the valence band. The band gap of the light absorbing layer 40 can affect the energy range of photons absorbed by the light absorbing layer 40.

[0111] In the embodiment of the present application, since the first sub-cell 1 and the second sub-cell 2 of the solar cell 100 are connected in series, the currents of the two sub-cells will affect each other. If the current of one sub-cell is too large, too small, or even no current is generated, it will affect the output current of the entire solar cell 100. Therefore, the currents of the first sub-cell 1 and the second sub-cell 2 must be matched with each other.

[0112] Therefore, the band gaps of the light absorption layer 40 of the first sub-cell 1 and the light absorption layer 40 of the second sub-cell 2 of the solar cell 100 in the embodiment of the present application are different. Therefore, by adjusting the band gaps of the light absorption layer 40 of the first sub-cell 1 and the light absorption layer 40 of the second sub-cell 2, the first sub-cell 1 and the second sub-cell 2 connected in series can form current matching, which is beneficial to improving the stability and reliability of the solar cell 100.

[0113] Specifically, the first sub-cell 1 faces the bright light side, and the second sub-cell 2 faces the dim light side. The band gap of the light absorption layer 40 of the first sub-cell 1 is greater than the band gap of the light absorption layer of the second sub-cell 2.

[0114] When the band gap of the light absorbing layer 40 is smaller, it means that the light absorbing layer 40 can absorb photons with lower energy. The energy of light is inversely proportional to the wavelength. Therefore, the smaller the band gap of the light absorbing layer 40, the larger the wavelength range of light that the light absorbing layer 40 can absorb.

[0115] On the contrary, when the band gap of the light absorbing layer 40 is larger, it means that the light absorbing layer 40 can only absorb photons with higher energy, that is, it can only absorb light with shorter wavelength. Therefore, the larger the band gap of the light absorbing layer 40, the smaller the wavelength range of light that the light absorbing layer 40 can absorb.

[0116] The bright light side usually refers to the side where light directly hits the object, which is dense and has high intensity. The dim light side refers to the side where light is weaker or indirectly hits the object, which is usually because the light is blocked or reflected, resulting in scattered light and low intensity.

[0117] The first sub-cell 1, located on the bright-light side, receives more photons than the second sub-cell 2, located on the dim-light side. If the first sub-cell 1 absorbs all the photons on the bright-light side, the second sub-cell 2 will only absorb a small number of photons, or may even absorb no photons at all. This will cause the second sub-cell 2 to generate very little current, or even no current at all. Because the first sub-cell 1 and the second sub-cell 2 are connected in series, the low current of the second sub-cell 2 may cause the solar cell 100 to short-circuit, affecting the photoelectric conversion efficiency of the solar cell 100.

[0118] Therefore, in the embodiment of the present application, the optical complementarity principle of the stacked device is utilized to make the band gap of the light-absorbing layer 40 of the first sub-cell 1 facing the strong light side larger than the band gap of the light-absorbing layer 40 of the second sub-cell 2 facing the weak light side. As a result, the first sub-cell 1 absorbs only a portion of light within a smaller wavelength range, while the second sub-cell 2 absorbs light within a larger wavelength range. In this way, the second sub-cell 2 can at least absorb light within the wavelength range that cannot be absorbed by the first sub-cell 1, reducing the possibility of the second sub-cell 2 failing to absorb light and thus failing to generate current. This maintains the current balance of the two-terminal solar cell 100, resulting in better stability and higher reliability of the solar cell 100. It also improves the absorption and utilization of the spectrum by the solar cell 100, further increasing the efficiency of the solar cell 100.

[0119] Of course, those skilled in the art should understand that in some other embodiments, the second sub-cell 2 may face the strong light side and the first sub-cell 1 may face the weak light side, as long as the band gap of the light absorption layer 40 of the sub-cell facing the strong light side is greater than the band gap of the light absorption layer 40 of the sub-cell facing the weak light side.

[0120] In some embodiments, the band gap of the light absorbing layer 40 of the first sub-cell 1 is between 1.7 eV (electron volts) and 1.8 eV, and the band gap of the light absorbing layer 40 of the second sub-cell 2 is between 1.2 eV and 1.3 eV.

[0121] This provides a reasonable bandgap selection range for the first sub-cell 1 and the second sub-cell 2, respectively, so that the bandgap of the light-absorbing layer 40 can be selected according to the wavelength range of the actual incident light, so that the first sub-cell 1 and the second sub-cell 2 facing the strong light side and the weak light side, respectively, can achieve current matching. Moreover, the absorption and utilization of the spectrum are improved, further improving the efficiency of the solar cell 100.

[0122] For example, the band gap of the light absorption layer 40 of the first sub-cell 1 facing the strong light side may be, for example, 1.70 eV, 1.71 eV, 1.72 eV, 1.73 eV, 1.74 eV, 1.75 eV, 1.76 eV, 1.77 eV, 1.78 eV, 1.79 eV, 1.80 eV, etc. The band gap of the light absorption layer 40 of the second sub-cell 2 facing the weak light side may be, for example, 1.20 eV, 1.21 eV, 1.22 eV, 1.23 eV, 1.24 eV, 1.25 eV, 1.26 eV, 1.27 eV, 1.28 eV, 1.29 eV, 1.30 eV, etc.

[0123] As another example, the band gap measurement method may include: first, obtaining an ultraviolet absorption curve through ultraviolet absorption spectrum testing; and then calculating the band gap of the light absorbing layer 40 through the Tauc equation.

[0124] In the embodiment of the present application, the material of the light absorption layer 40 of the first sub-cell 1 includes but is not limited to Pb-Sn mixed perovskite. The material of the light absorption layer 40 of the second sub-cell includes but is not limited to Br wide bandgap perovskite.

[0125] In some embodiments, the layer structure 4 further includes an insulating layer 43, which is located between the first electrode layer 41 and the second electrode layer 42. In a projection plane perpendicular to the stacking direction of the layer structure 4, the projected area of ​​the first electrode layer 41 is smaller than the projected area of ​​the second electrode layer 42, or the projected area of ​​the second electrode layer 42 is smaller than the projected area of ​​the first electrode layer 41.

[0126] Thus, the first electrode layer 41 and the second electrode layer 42 can be insulated from each other by the insulating layer 43 , thereby reducing the possibility of a short circuit.

[0127] Exemplarily, the material of the insulating layer 43 includes but is not limited to aluminum oxide, zirconium oxide, magnesium oxide or ceramic materials.

[0128] like Figure 1 As shown, the light absorbing layer 40 of the first sub-cell 1 and the second sub-cell 2 includes a thin layer portion 401 and a thick layer portion 402 that are interconnected. The thickness of the thin layer portion 401 is less than the thickness of the thick layer portion 402, and along the stacking direction, the thin layer portion 401 is flush with the surface of the thick layer portion 402 on the side away from the substrate 3. Therefore, along the stacking direction, on the side of the light absorbing layer 40 facing the substrate 3, the thickness difference between the thin layer portion 401 and the thick layer portion 402 causes the light absorbing layer 40 to generally form a groove.

[0129] The second electrode layer 42 of the first sub-cell 1 is laminated on the substrate 3 and contacts the partially thick portion 402 of the light absorbing layer 40. The first electrode layer 41 is located within the groove and contacts the inner wall of the groove. The insulating layer 43 is generally located at the groove opening to insulate the first electrode layer 41 from the second electrode layer 42. The first electrode layer 41 of the second sub-cell 2 is laminated on the substrate 3 and contacts the partially thick portion 402 of the light absorbing layer 40. The second electrode layer 42 is located within the groove and contacts the inner wall of the groove. The insulating layer 43 is also generally located at the groove opening to insulate the first electrode layer 41 from the second electrode layer 42.

[0130] In this way, the electrode layers of the first sub-cell 1 and the second sub-cell 2 located within the groove of the light absorbing layer 40 can contact the thin portion 401 and the partially thick portion 402 of the light absorbing layer 40 through the inner wall of the groove, thereby collecting holes or electrons. The electrode layers located outside the groove can contact the partially thick portion 402 of the light absorbing layer 40, thereby collecting holes or electrons. As a result, the first electrode layer 41 and the second electrode layer 42 are both located on the backlight side of the light absorbing layer 40, allowing both the first electrode layer 41 and the second electrode layer 42 to make good contact with the light absorbing layer 40. This reduces optical parasitic absorption while not affecting the first electrode layer 41 and the second electrode layer 42 from collecting electrons or holes generated by the light absorbing layer 40, thereby improving the efficiency of the solar cell 100.

[0131] Those skilled in the art will understand that the embodiments of the present application do not specifically limit the electrode layers of the first sub-cell 1 and the second sub-cell 2 located within or outside the groove. That is, in a projection plane perpendicular to the stacking direction of the layer structure 4, the projected area of ​​the first electrode layer 41 may be smaller than the projected area of ​​the second electrode layer 42, i.e., the first electrode layer 41 is located within the groove; or the projected area of ​​the second electrode layer 42 may be smaller than the projected area of ​​the first electrode layer 41, i.e., the second electrode layer 42 is located within the groove. Furthermore, the electrode layers located within the grooves of the first sub-cell 1 and the second sub-cell 2 may be the same or different.

[0132] Thus, the position and shape of the first electrode layer 41 and the second electrode layer 42 can be flexibly changed according to actual conditions, thereby facilitating electrical connection between the first sub-cell 1 and the second sub-cell 2 and better realizing the two-terminal structure output of the solar cell 100 .

[0133] In some embodiments, the layer structure 4 further includes a first carrier transport layer 44 and a second carrier transport layer 45. The first carrier transport layer 44 is located between the light absorbing layer 40 and the first electrode layer 41, and the second carrier transport layer 45 is located between the light absorbing layer 40 and the second electrode layer 42. The first carrier transport layer 44 is a hole transport layer, and the second carrier transport layer 45 is an electron transport layer, or the first carrier transport layer 44 is an electron transport layer, and the second carrier transport layer 45 is a hole transport layer.

[0134] Thus, by providing the first carrier transport layer 44 and the second carrier transport layer 45, the dissociation effect of electrons and holes can be enhanced, the recombination of electrons and holes can be reduced, and the photoelectric conversion efficiency of the solar cell 100 can be improved. The embodiment of the present application does not specifically limit the types of the first carrier transport layer 44 and the second carrier transport layer 45, as long as the types of the first carrier transport layer 44 and the second carrier transport layer 45 are different.

[0135] Specifically, the electron transport layer has the function of transporting electrons, and is used to transport the electrons generated by the light absorption layer 40 to the adjacent electrode layer, and prevent the transport of holes.

[0136] The material of the electron transport layer may include, for example, at least one of imide compounds, quinone compounds, fullerene and its derivatives, metal oxides, semiconductor material oxides, titanates, fluorides and their derivatives, and doped or passivated materials thereof.

[0137] For example, the imide compound may include at least one of phthalimide, succinimide, N-bromosuccinimide, glutarimide or maleimide. The quinone compound may include at least one of benzoquinone, naphthoquinone, phenanthrenequinone or anthraquinone. For example, fullerene and its derivatives include fullerene C 60 , fullerene C 70 、[6,6]-phenyl C 61 Methyl butyrate (PC 61 BM), [6,6]-phenyl C 71 Methyl butyrate (PC 71 The metal oxide may include one or more of Mg, Cd, Zn, In, Pb, W, Sb, Bi, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, or Cr. Alternatively, the metal oxide may include at least one of tin dioxide (SnO2) and titanium dioxide (TiO2). The semiconductor material oxide may include silicon oxide. Exemplarily, the titanate includes at least one of strontium titanate and calcium titanate. The fluoride may include at least one of lithium fluoride and calcium fluoride.

[0138] The present invention does not impose any particular limitation on the thickness of the electron transport layer, and the thickness of the electron transport layer conventionally used in the art can be adopted. For example, the thickness of the electron transport layer is 15 nm to 30 nm.

[0139] The hole transport layer has the function of extracting and transporting holes, and is used to transport the holes in the light absorbing layer 40 to adjacent electrodes, and prevent the transmission of electrons.

[0140] For example, the hole transport material may include nickel oxide (NiO x , 1≤x≤2), vanadium oxide, tungsten oxide, cuprous iodide (CuI), cuprous oxide (Cu2O), cuprous thiocyanate (CuSCN), 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), 2,2',7,7'-tetrakis(di-p-tolylamino)spiro-9,9'-bifluorene (Spiro-TTB), and at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA).

[0141] The present invention does not impose any particular limitation on the thickness of the hole transport layer, and the thickness of the hole transport layer conventionally used in the art may be adopted. For example, the thickness of the hole transport layer is 10 nm to 200 nm.

[0142] In some embodiments, as Figure 2 and Figure 3 As shown, the first sub-cell 1 includes a plurality of first unit sub-cells 11 connected in series, and / or the second sub-cell 2 includes a plurality of second unit sub-cells 21 connected in series.

[0143] For example, the first unit sub-cell 11 and the second unit sub-cell 21 can be formed by separating the first sub-cell 1 and the second sub-cell 2 through a laser scribing process.

[0144] In the embodiment of the present application, each first unit sub-cell 11 and each second unit sub-cell 21 is arranged uniformly and spaced apart along the second direction. In some other embodiments, each first unit sub-cell 11 and each second unit sub-cell 21 may be arranged uniformly and spaced apart along any other direction, such as the first direction, the circumferential direction, or the arc direction. Alternatively, each first unit sub-cell 11 and each second unit sub-cell 21 may be arranged irregularly. The embodiment of the present application does not specifically limit the arrangement of the first unit sub-cell 11 and the second unit sub-cell 21, and may be set according to actual circumstances.

[0145] In this way, the flexibility of the arrangement of the first sub-cell 1 and the second sub-cell 2 can be improved, and the multiple first unit sub-cells 11 of the first sub-cell 1 and the multiple second unit sub-cells 21 of the second sub-cell 2 can be arranged into different forms according to different application scenarios of the solar cell 100, thereby changing the overall form of the solar cell 100, so that the solar cell 100 is basically not restricted by the installation scenario.

[0146] In some embodiments, Figure 2 As shown, there are multiple sub-battery packs 10 , and the multiple sub-battery packs 10 are electrically connected to each other.

[0147] The plurality of sub-cell groups 10 can improve the light absorption capability of the solar cell 100 , thereby improving the photoelectric conversion efficiency of the solar cell 100 , and further improving the total output power of the solar cell 100 .

[0148] For example, the plurality of sub-battery groups 10 may be connected in series, in parallel or in a mixed connection via the positive or negative electrodes led out from the respective bus bars 5 . A mixed connection refers to both a series connection and a parallel connection.

[0149] In the embodiment of the present application, the multiple sub-battery groups 10 are arranged in a first direction at intervals. In some other embodiments, the multiple sub-battery groups 10 can also be arranged in any other direction. The embodiment of the present application does not specifically limit the arrangement of the multiple sub-battery groups 10, and can be set according to actual application and installation scenario.

[0150] In some embodiments, the first sub-cell 1 and the second sub-cell 2 share a substrate 3 .

[0151] This can reduce the number of parts and components and lower production costs.

[0152] In some other embodiments, the first sub-cell 1 and the second sub-cell 2 can also be stacked on different substrates 3 respectively. After the stacking is completed, the substrates 3 stacked with the first sub-cell 1 and the second sub-cell 2 are connected to each other, and the first sub-cell 1 and the second sub-cell 2 are electrically connected to each other, thereby forming a solar cell 100.

[0153] In some embodiments, the light absorbing layer 40 is a perovskite light absorbing layer.

[0154] The perovskite light-absorbing layer has a higher absorbance. Under the same lighting conditions, the perovskite light-absorbing layer can absorb a wider spectrum.

[0155] In addition, the carrier diffusion length of perovskite is long and the exciton binding energy is low, so that the perovskite is more easily dissociated to form free carriers, thereby making the photoelectric conversion efficiency of the solar cell 100 using perovskite as the light absorption layer 40 higher.

[0156] Of course, those skilled in the art should understand that in some other embodiments, the light absorbing layer 40 may also be made of any other suitable material.

[0157] The present embodiment does not specifically limit the preparation method of the layer structure 4 of the solar cell 100, and may include preparation methods commonly used in the art, such as spin coating, spray coating, slit coating, doctor blade coating, chemical bath deposition, electrochemical deposition, chemical vapor deposition, physical epitaxial growth, vacuum thermal evaporation, atomic layer deposition, magnetron sputtering, mechanical pressing, etc.

[0158] The second aspect of the present application further provides a photovoltaic assembly, which includes the solar cell 100 as described in the first aspect above.

[0159] Since the photovoltaic module includes the solar cell 100 with stable performance, high light utilization rate and high photoelectric conversion efficiency, the photovoltaic module can generate more current and have greater output power.

[0160] The third aspect of the present application further provides a power generation device, which includes the solar cell 100 as described in the first aspect above.

[0161] Thus, a power generation device equipped with a solar cell 100 having high light utilization rate and high photoelectric conversion efficiency can be provided, thereby increasing the power generation of the power generation device, enabling the power generation device to meet relatively sufficient electric energy needs, and improving the reliability of the power generation device.

[0162] Exemplarily, the power generation device includes but is not limited to a solar photovoltaic generator.

[0163] The fourth aspect of the present application further provides an electrical device, which includes the solar cell 100 as described in the first aspect above.

[0164] Thus, an electric device equipped with a solar cell 100 having high light utilization efficiency and high photoelectric conversion efficiency can be provided, and the electric device can obtain sufficient current to operate, thereby improving the reliability of the electric device.

[0165] Exemplarily, electrical devices include but are not limited to lighting equipment, energy storage equipment, solar water heaters, etc.

[0166] Below, some specific examples of embodiments of the present application are described with reference to the accompanying drawings.

[0167] The present application designs a perovskite back electrode stack cell structure (solar cell 100), including sub-cells (first sub-cell 1, second sub-cell 2) formed on both sides of a substrate 3. Through optical and electrical design matching, a series-parallel structure of the sub-cells is realized, and photoelectric conversion is achieved with a simpler two-terminal output.

[0168] The electrode layers (first electrode layer 41, second electrode layer 42) and transport layers (first carrier transport layer 44, second carrier transport layer 45) of each sub-cell are all on the backlight side, thereby fundamentally avoiding the parasitic absorption of incident solar light and improving the efficiency limit of the perovskite cell. At the same time, through the principle of optical complementarity of stacked devices, the absorption and utilization of the spectrum are improved, and the device efficiency is further improved. Through the special electrode structure of the back electrode cell, the inter-surface series connection is realized, and the positive and negative poles of the component sub-cell (sub-cell group 10) are connected in parallel to realize a new type of 2T cell.

[0169] In addition, this application takes the second sub-battery 2 as an example to briefly describe several key preparation processes of the second unit sub-battery, wherein the second sub-battery 2 includes a first carrier transport layer 44 and a second carrier transport layer 45 .

[0170] A first electrode layer 41 and a first transport layer (first carrier transport layer 44 ) are sequentially formed on the substrate 3 ;

[0171] First electrode-transport layer scribing process: Laser scribing is used to separate the first electrode layer 41 and the first transport layer (first carrier transport layer 44) along their thickness to form a first groove, thereby separating the first carrier transport layer 44 and the first electrode layer 41 of the adjacent second unit cell. Optionally, the first groove can also be formed using a mask.

[0172] Insulating layer-second electrode front process: an insulating layer (insulating layer 43) is formed on the side of the first carrier transport layer 44 away from the first electrode layer 41, and the insulating layer 43 partially covers the first carrier transport layer 44 (that is, it is set to the opening where the light absorption layer 40 is roughly formed with a groove), and a second groove is prepared in the area where the first carrier transport layer 44 is exposed from the insulating layer 43. The second groove passes through the first carrier transport layer 44, exposing the first electrode layer 41 below, so as to prepare the first electrodes and the second electrodes between adjacent second unit sub-batteries to be connected end to end, thereby completing the series connection of components on the circuit.

[0173] Second Electrode-Transport Layer Process: The second electrode (second electrode layer 42) for each sub-battery connected in series and the second transport layer (second carrier transport layer 45) covering the second electrode need to be sequentially deposited on the central insulating layer. The second electrode layer 42 fills the second groove and is electrically connected to the first electrode layer 41, thereby connecting the first electrode layer 41 and the second electrode layer 42 between adjacent second-unit sub-batteries end to end, completing the series connection of components in the circuit. Furthermore, the conductive material filled in the second groove can also be different from the material of the second electrode layer 42, as long as it can achieve electrical connection between the first electrode layer 41 and the second electrode layer 42 between the second-unit sub-batteries. This is not a limitation here.

[0174] Perovskite deposition and sub-cell segmentation process: deposit a perovskite light-absorbing layer (light-absorbing layer 40) so that the light-absorbing layer 40 covers the second carrier transport layer 45, the second electrode layer 42 exposed from the second carrier transport layer 45, and the surface of the first carrier transport layer 44, and use a laser scribing method to prepare a third groove and a fourth groove. The third groove passes through the second carrier transport layer 45 and the second electrode layer 42, and the fourth groove passes through the light-absorbing layer 40. A plurality of adjacent second unit sub-cells connected in series can be formed through the third groove and the fourth groove.

[0175] Furthermore, the first sub-cell 1 may also be formed into a plurality of first unit sub-cells connected in series in a similar manner.

[0176] The first electrode layer 41 of the first unit subcell at the end of the first subcell 1 along the second direction is extended along the second direction, and is bent at the edge of the substrate 3 to the other side of the substrate 3 along its thickness direction, and is electrically connected to the second electrode layer 42 of the second unit subcell at the end of the second subcell 2 along the second direction on the other side of the substrate 3 along its thickness direction, thereby realizing the series connection of the first subcell 1 and the second subcell 2. Bus bars 5 are then provided on the second electrode layer 42 of the first unit subcell at the other end of the first subcell along the second direction and the first electrode layer 41 of the second unit subcell at the other end of the second subcell along the second direction, respectively, with one serving as the positive electrode and the other as the negative electrode, so that the positive and negative electrodes of the solar cell can be led out respectively.

[0177] The above embodiments are intended only to illustrate the technical solutions of the present application, and are not intended to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they may modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. Such modifications or replacements do not deviate from the essence of the corresponding technical solutions and are intended to be included in the scope of the present application. In particular, as long as there is no structural conflict, the various technical features described in the various embodiments may be combined in any manner.

Claims

1. A solar cell, characterized in that: The solar cell comprises: first sub-battery; a second sub-battery; and a substrate having two opposite surfaces along a thickness direction thereof, wherein the first sub-cell and the second sub-cell are respectively located on the two surfaces of the substrate, and the first sub-cell and the second sub-cell are electrically connected to each other to form a sub-cell group; Among them, the first sub-cell and the second sub-cell both include a layer structure arranged on the substrate, and the layer structure includes a stacked light-absorbing layer, a first electrode layer and a second electrode layer. The light-absorbing layer is located on the light-incident side, and the first electrode layer and the second electrode layer are both located on the backlight side of the light-absorbing layer and are insulated from each other.

2. The solar cell according to claim 1, wherein The first electrode layer of the first sub-cell is electrically connected to the second electrode layer of the second sub-cell; or The second electrode layer of the first sub-cell is electrically connected to the first electrode layer of the second sub-cell.

3. The solar cell according to claim 2, wherein The band gap of the light absorbing layer of the first sub-cell is different from the band gap of the light absorbing layer of the second sub-cell.

4. The solar cell according to claim 3, characterized in that The first sub-cell faces the strong light side, and the second sub-cell faces the weak light side; The band gap of the light absorbing layer of the first sub-cell is greater than the band gap of the light absorbing layer of the second sub-cell.

5. The solar cell according to claim 4, wherein The band gap of the light absorbing layer of the first sub-cell is between 1.7 eV and 1.8 eV; The band gap of the light absorbing layer of the second sub-cell is between 1.2 eV and 1.3 eV.

6. The solar cell according to any one of claims 1 to 5, characterized in that The layer structure further comprises an insulating layer, the insulating layer being located between the first electrode layer and the second electrode layer; In a projection plane perpendicular to the stacking direction of the layer structure, the projection area of ​​the first electrode layer is smaller than the projection area of ​​the second electrode layer, or the projection area of ​​the second electrode layer is smaller than the projection area of ​​the first electrode layer.

7. The solar cell according to any one of claims 1 to 5, characterized in that The layer structure further comprises a first carrier transport layer and a second carrier transport layer, the first carrier transport layer being located between the light absorbing layer and the first electrode layer, and the second carrier transport layer being located between the light absorbing layer and the second electrode layer; The first carrier transport layer is a hole transport layer, and the second carrier transport layer is an electron transport layer; or The first carrier transport layer is an electron transport layer, and the second carrier transport layer is a hole transport layer.

8. The solar cell according to any one of claims 1 to 5, characterized in that The first sub-cell includes a plurality of first unit sub-cells, and the plurality of first unit sub-cells are connected in series with each other; and / or The second sub-cell includes a plurality of second unit sub-cells, and the plurality of second unit sub-cells are connected to each other in series.

9. The solar cell according to any one of claims 1 to 5, characterized in that There are multiple sub-battery groups, and the multiple sub-battery groups are electrically connected to each other.

10. The solar cell according to any one of claims 1 to 5, characterized in that The first sub-cell and the second sub-cell share the same substrate.

11. The solar cell according to any one of claims 1 to 5, characterized in that The light absorbing layer is a perovskite light absorbing layer.

12. A photovoltaic module, characterized in that: The photovoltaic module comprises: The solar cell according to any one of claims 1 to 11.

13. A power generation device, characterized in that: The power generation device comprises: The solar cell according to any one of claims 1 to 11.

14. An electrical device, characterized in that: The electrical device comprises: The solar cell according to any one of claims 1 to 11.

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