Solar cell, preparation method thereof and solar cell pack

Abstract

The invention relates to a solar cell, a preparation method thereof and a solar cell pack comprising the solar cell. The solar cell provided by the invention comprises a transparent electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer and a counter electrode which are stacked in sequence, one side, opposite to the electron transport layer, of the transparent electrode is provided with a photoactive area and a non-photoactive area, and the non-photoactive area is internally provided with a long afterglow material layer. According to the invention, the long-afterglow material is arranged in the inactive area of the cell and is not doped into the cell, so that day-and-night continuous power generation of the solar cell is realized on the premise of avoiding influence on normal work of the cell.

Description

Technical Field

[0001] The present application belongs to the field of batteries, and specifically relates to a solar cell and a preparation method thereof, and a solar cell group including the solar cell. Background Art

[0002] Solar cells can convert inexhaustible solar energy into electrical energy for people to use, and have the potential to improve my country's energy structure as a new type of green renewable energy.

[0003] However, there is a problem with solar power generation that affects its convenience: it cannot generate electricity at night. Solar cells rely on sunlight for energy conversion. After sunset, there is no sunlight at night, and the power supply will be lost. However, even after sunset, there is still a huge demand for electricity in cities, and there is also a demand for electricity for lighting, heating, communications, etc. in rural streets. Existing energy storage technologies that rely on water storage or chemical battery storage have certain defects.

[0004] Long afterglow materials are materials that can emit light for a long time in the dark after being exposed to light. They are widely used in signboards, road signs, luminous toys, etc. At present, there are many high-performance long afterglow materials that can keep emitting light for up to 10 hours in the dark after being exposed to sunlight for more than ten minutes. Using this type of high-brightness long afterglow material, light energy can be accumulated during the day when there is sunlight, and light can be emitted at night after sunset to continue to maintain the power generation of solar cells. Combined with the current cheap and efficient perovskite solar cells, their higher photoelectric conversion efficiency in weak light can better utilize the afterglow at night to generate electricity, thereby achieving uninterrupted power supply day and night. It is a design solution with excellent application prospects for solar cell power supply at night.

[0005] The existing technology modifies the electrode with a long afterglow material to absorb and store the remaining light after the battery generates electricity. It is only applicable to a few light-transmitting cells with poor light absorption capacity, such as dye-sensitized solar cells. The preparation process is cumbersome and costly, and it will also have a certain impact on the semiconductor materials inside the battery. Summary of the invention

[0006] In order to solve the above problems existing in the prior art, the present application proposes a solar cell and a method for preparing the same, as well as a solar cell group including the solar cell. The present application places the long afterglow material in the inactive area of ​​the cell and does not incorporate it into the cell, thereby achieving continuous power generation of the solar cell day and night without affecting the normal operation of the cell.

[0007] In a first aspect, the present application provides a solar cell, comprising a transparent electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer and a counter electrode stacked in sequence, wherein a first photoactive region and a second non-photoactive region are provided on the side of the transparent electrode opposite to the electron transport layer, and a first long afterglow material layer is provided in the first non-photoactive region.

[0008] In some embodiments, the first long afterglow material layer includes a long afterglow material, wherein the average particle size of the long afterglow material is 10 μm-200 μm, for example, 20 μm, 30 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm or any value therebetween. In some embodiments, the average particle size of the long afterglow material is 50 μm-100 μm.

[0009] In some embodiments, the thickness of the first long afterglow material layer is 0.5 mm-2.5 mm, for example, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm or any value therebetween. In some embodiments, the thickness of the first long afterglow material layer is 1 mm-2 mm.

[0010] In some embodiments, the long afterglow material is selected from one or more of a yellow-green long afterglow material, a red long afterglow material, an orange long afterglow material, a blue-green long afterglow material, and a sky blue long afterglow material.

[0011] In some embodiments, the solar cell is selected from a perovskite solar cell.

[0012] In some embodiments, the transparent electrode is selected from one or more of indium tin oxide conductive glass, fluorine-doped tin dioxide conductive glass, and polyethylene terephthalate flexible substrate.

[0013] In some embodiments, the electron transport layer is selected from lead sulfate, lead titanate, PbTi3O7, Pb9TiO 11 、Pb5Ti5O 14 、Pb8Ti8O 23 , lead acetate, lead oxide, lead hydroxide, lead carbonate, lead nitrate, lead phosphate, lead chloride, lead iodide and lead bromide.

[0014] In some embodiments, the photoelectric conversion layer is selected from perovskite thin films.

[0015] In some embodiments, the hole transport layer is selected from one or more of 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], nickel oxide, and a mixture of poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate).

[0016] In some embodiments, the counter electrode is selected from a silver electrode and / or a gold electrode.

[0017] In a second aspect, the present application provides a method for preparing the solar cell according to the first aspect, comprising:

[0018] S1: sequentially preparing an electron transport layer, a photoelectric conversion layer, a hole transport layer and a counter electrode on a transparent electrode;

[0019] S2: preparing a first long afterglow material layer on a first non-photoactive region on a side of the transparent electrode opposite to the electron transport layer.

[0020] In some embodiments, preparing the first long afterglow material layer includes coating a slurry containing a long afterglow material on the first non-photoactive region.

[0021] In some embodiments, the coating is selected from printing coating, such as screen printing coating.

[0022] In some embodiments, the slurry further includes a curable resin and a dispersant.

[0023] In some embodiments, the curable resin is selected from one or more of PMMA resin (polyacrylic resin), PET resin (polyterephthalate resin) and EA resin (epoxy acrylate resin).

[0024] In some embodiments, the dispersant is selected from one or more of ethyl acetate, chloroform and isopropanol.

[0025] In some embodiments, based on the mass of the slurry, the mass content of the long afterglow material is 40%-85%, for example, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80% or any value therebetween. In some embodiments, the mass content of the long afterglow material is 55%-75%.

[0026] In a third aspect, the present application provides a solar cell group, which includes a housing and the solar cell described in the first aspect or the solar cell prepared by the preparation method described in the second aspect.

[0027] In some embodiments, the housing has a second photoactive region and a second non-photoactive region on a side opposite to the transparent electrode, light can irradiate the transparent electrode through the first photoactive region, and a second long afterglow material layer is disposed on the second non-photoactive region.

[0028] In some embodiments, the second photoactive region is a light-transmitting hole opened on the housing. In some embodiments, the light-transmitting hole is directly opposite to the transparent electrode.

[0029] In some embodiments, the second long afterglow material layer includes a long afterglow material, wherein the average particle size of the long afterglow material is 10 μm-200 μm, for example, 20 μm, 30 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm or any value therebetween. In some embodiments, the average particle size of the long afterglow material is 50 μm-100 μm.

[0030] In some embodiments, the thickness of the second long afterglow material layer is 0.5 mm-2.5 mm, for example, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm or any value therebetween. In some embodiments, the thickness of the second long afterglow material layer is 1 mm-2 mm.

[0031] In some embodiments, the long afterglow material is selected from one or more of a yellow-green long afterglow material, a red long afterglow material, an orange long afterglow material, a blue-green long afterglow material, and a sky blue long afterglow material.

[0032] In some embodiments, there are multiple solar cells, and the multiple solar cells are connected in series, in parallel, or mixed, and the multiple solar cells share a transparent electrode.

[0033] This application uses high-brightness long-afterglow materials to construct light-absorbing and energy-storing sites on the outside of the battery. The preparation is simple and does not damage the structure and stability of the battery itself. In the process of long-afterglow materials absorbing and emitting light, the sunlight that is not used by the battery during the day is stored and released at night, so that the power generation time of the solar cell is extended to the night, the power generation of the solar cell is increased, and the solar cell can also provide power output on nights without sunlight, thereby increasing the production and efficiency of solar cell power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of a solar cell provided for some embodiments of the present application.

[0035] Figure 2 A schematic cross-sectional view of a solar cell provided in some embodiments of the present application.

[0036] In the figure: 1. transparent electrode; 2. electron transport layer; 3. photoelectric conversion layer; 4. hole transport layer; 5. counter electrode; 6. photoactive region; 7. non-photoactive region; 8. long afterglow material layer.

[0037] Figure 3 The JV curves of the perovskite solar cell prepared in Example 1 of the present application under 1 standard simulated sunlight and under dark light of a long afterglow material are shown.

[0038] Figure 4 This is a physical picture of a perovskite solar cell prepared according to some embodiments of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in conjunction with the embodiments and drawings. The specific embodiments described herein are only used to explain the present application and are not intended to constitute any limitation to the present application. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present disclosure. Such structures and technologies are also described in many publications.

[0040] Figure 1A schematic diagram of a perovskite solar cell according to some embodiments of the present application is shown, which includes a transparent electrode 1, an electron transport layer 2, a photoelectric conversion layer 3 (perovskite layer), a hole transport layer 4 and a counter electrode 5 which are stacked in sequence. The transparent electrode 1 can be FTO glass, ITO glass, etc. The transparent electrode 1 has good light transmittance, so that sunlight can penetrate the transparent electrode 1 and irradiate the inside of the perovskite solar cell. The electron transport layer 2 is usually a titanium dioxide film, the material of the hole transport layer 4 is PEDOT-PSS, and the counter electrode 5 is usually a metal electrode (opaque). A long afterglow material layer 8 is arranged on the outside of the transparent electrode 1. The long afterglow material layer 8 is located on the outside of the solar cell and does not need to be arranged inside the solar cell.

[0041] Specifically, after the sunlight passes through the transparent electrode 1 and the electron transport layer 2 successively, it irradiates the perovskite layer 3, so that the photons are absorbed by the perovskite layer 3 to generate excitons, and the excitons are separated in the perovskite layer 3 into holes and electrons. The holes move toward the hole transport layer 4 and gather on the counter electrode 5, and the electrons move toward the electron transport layer 2 and gather on the transparent electrode 1.

[0042] Thus, the transparent electrode 1 serves as the positive electrode of the perovskite battery, and the counter electrode 5 serves as the negative electrode of the perovskite battery. When the load is connected to the positive and negative electrodes through a wire, the current forms a loop.

[0043] The long afterglow material layer 8 itself is not light-transmissive, so the area on the transparent electrode 1 covered by the long afterglow material layer 8 will not allow sunlight to irradiate the perovskite layer 3. This area is called the non-photoactive area 7, which means an area that receives light irradiation but does not generate photocurrent.

[0044] However, it should be noted that the long afterglow material layer 8 cannot completely cover the transparent electrode 1, because this will prevent all sunlight from irradiating the perovskite layer 3. That is, a portion of the outer side of the transparent electrode 1 that is not covered by the long afterglow material layer 8 needs to be left, and this portion of the area is called the photoactive area 6, which means the area that can generate photocurrent when receiving light.

[0045] That is, the photoactive region 6 and the non-photoactive region 7 are arranged on the outer surface of the transparent electrode 1, and the long afterglow material layer 8 is arranged in the non-photoactive region 7. In addition, the photoactive region 6 and the non-photoactive region 7 are arranged adjacent to each other. For example, the non-photoactive region 7 extends around the edge of the transparent electrode 1 to form a ring, and the photoactive region 6 is located inside the ring.

[0046] It should be noted that the long afterglow material layer 8 can be formed by coating the long afterglow material on the outer surface of the transparent electrode 1 .

[0047] Thus, at night, the light emitted by the long afterglow material layer 8 can partially illuminate the photoactive region 6, and then these lights can pass through the transparent electrode 1 and illuminate the perovskite layer, so that the solar cell can also generate electricity at night. In addition, since the long afterglow material layer 8 is arranged on the outside of the solar cell, the long afterglow material layer 8 is easy to prepare, for example, it can be arranged on the outside of the transparent electrode 1 by coating. In addition, the long afterglow material layer 8 arranged on the outside of the solar cell will not affect the internal structure of the solar cell.

[0048] In the prior art, a plurality of solar cells are usually assembled together to form a solar cell module. Specifically, the solar cell module includes a shell and a plurality of solar cells arranged in the shell. These solar cells are connected in series, in parallel, or mixed with each other. The plurality of solar cells can be in the shape of narrow strips, so that the solar cell module has a larger surface area. In addition, these solar cells can share a transparent electrode 1 to reduce the resistance of the transparent electrode 1.

[0049] Specifically, a photoactive region 6 and a non-photoactive region 7 are provided on the side of the housing opposite to the transparent electrode 1, and the photoactive region 6 is directly opposite to the transparent electrode 1 in the solar cell, and external light can irradiate the transparent electrode 1 from the photoactive region 6. A long afterglow material layer 8 is provided on the non-photoactive region 7.

[0050] Specifically, the photoactive region 6 can be a light-transmitting hole opened on the housing, and the transparent electrode 1 is directly opposite to the light-transmitting hole, so that external light can be irradiated from the light-transmitting hole onto the transparent electrode 1. The non-photoactive region 7 surrounds the light-transmitting hole, so that the non-photoactive region 7 is arranged adjacent to the photoactive region 6. When there are multiple solar cells, the photoactive regions 6 and the non-photoactive regions 7 usually appear alternately.

[0051] The photoactive region 6 may also be a transparent region on the housing, for example, a position on the housing directly opposite to the transparent electrode 1 is a transparent material, so that light can pass through the transparent region and shine on the transparent electrode 1. The non-photoactive region 7 is arranged around the transparent region, so that the non-photoactive region 7 is arranged adjacent to the photoactive region 6.

[0052] Since the non-photoactive region 7 and the photoactive region 6 are adjacent to each other, the light emitted by the long afterglow material layer 8 in the non-photoactive region 7 can easily irradiate into the photoactive region 6, thereby enabling the solar cell to operate normally at night.

[0053] It should be noted that the non-photoactive area 7 must exist in the solar cell module, such as the area on the shell not covered by the transparent electrode 1, the dead area formed by laser cutting of the solar cell module, etc.

[0054] It should be noted that the long afterglow material layer 8 can be formed by coating the long afterglow material on the outer surface of the transparent electrode 1 .

[0055] Thus, at night, the light emitted by the long afterglow material layer 8 can partially illuminate the photoactive region 6, and then these lights can pass through the transparent electrode 1 and illuminate the photoelectric conversion layer, so that the solar cell can also generate electricity at night. In addition, since the long afterglow material layer 8 is arranged outside the solar cell, the long afterglow material layer 8 is easy to prepare, for example, it can be arranged on the outer surface of the shell by coating. In addition, the long afterglow material layer 8 arranged on the shell will not affect the internal structure of the solar cell.

[0056] The present application will be further described below through specific embodiments, but the scope of the present application is not limited thereto.

[0057] Experimental instruments and materials

[0058] Laser etching machine: Wuhan Junwei Technology JW-20W-KS;

[0059] Spin coater: Wuhan Junwei Technology JW-A5;

[0060] Solar simulator: Newport;

[0061] Vacuum coating machine: Micro-nano vacuum VZZ-300;

[0062] Rare earth long afterglow powders and the like are commercially available reagents.

[0063] Test Method

[0064] The photoelectric conversion efficiency of the cell was tested under a 1.5AM standard solar simulator. The test was repeated many times, and the data with large deviations from the average value were removed to select the highest efficiency. The long afterglow material was also continuously irradiated under standard simulated sunlight for more than 10 minutes, and then taken to a dark place for afterglow luminescence test.

[0065] Example 1

[0066] Perovskite solar cell preparation:

[0067] The FTO glass was etched using a laser etcher, and ultrasonically washed with acetone, water, and ethanol for 10 minutes in sequence. After being dried using an air compressor, the glass was placed in a muffle furnace for annealing at 500°C for 30 minutes. Then, a 20 mg / mL lead sulfate ethanolamine solution was spin-coated onto the surface of the FTO substrate at 5000 rpm for 25 seconds, followed by annealing at 200°C for 30 minutes. After cooling to room temperature, the perovskite precursor solution was spin-coated in a glove box (800 rpm for 10 seconds, 4000 rpm for 30 seconds), and the anti-solvent chlorobenzene was quickly dropped onto the film surface in the last 3 seconds, followed by annealing at 120°C for 30 minutes to obtain a dense perovskite film. Then, the hole transport material Spiro-OMeTAD was spin-coated onto the surface of the perovskite film at 4000 rpm. Finally, 80 nm of gold was evaporated using a vacuum coating apparatus to obtain the perovskite solar cell.

[0068] Preparation of long afterglow material slurry:

[0069] A yellow-green long afterglow material with an average particle size of 78 μm was mixed with a resin prepolymer (epoxy acrylate (EA) + ethyl acetate), stirred for 5 minutes until the mixture was uniform, and allowed to stand for 30 minutes to eliminate bubbles, to obtain a long afterglow slurry. The mass content of the long afterglow material was 70% based on the mass of the long afterglow slurry.

[0070] Slurry coating:

[0071] The prepared long afterglow material slurry is applied to the inactive area of ​​the FTO surface of the perovskite solar cell by screen printing. Specifically, a mask with a specific pattern is covered on the surface of the prepared cell (the mask has holes of corresponding shapes on the inactive area of ​​the cell), and after the mask and the cell are fixed, a layer of slurry is evenly applied on the mask. Remove the mask, and place the printed cell in a ventilated place for 3-7 hours to wait for the slurry to solidify, and a long afterglow material layer with a thickness of 1.8 mm is obtained.

[0072] The perovskite solar cell coated with the long afterglow material layer prepared above was tested for photoelectric conversion efficiency and maximum output power under standard simulated sunlight and maximum output power under dark light under a solar simulator. The results are as follows: Figure 3 The results show that under 1 standard simulated sunlight, the photoelectric conversion efficiency of the battery is 19.03% and the maximum output power is 10.28 milliwatts; under dark light, the maximum output power of the battery is 1.71 milliwatts.

[0073] Example 2

[0074] Preparation of perovskite solar cells: same as in Example 1.

[0075] Preparation of long afterglow material slurry: The only difference is that the average particle size of the long afterglow material is 46μm.

[0076] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 10.17 mW; under dark light, the maximum output power of the cell was 1.37 mW.

[0077] Example 3

[0078] Preparation of perovskite solar cells: same as in Example 1.

[0079] Preparation of long afterglow material slurry: The only difference is that the average particle size of the long afterglow material is 15μm.

[0080] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 9.96 mW; under dark light, the maximum output power of the cell was 0.86 mW.

[0081] Example 4

[0082] Preparation of perovskite solar cells: same as in Example 1.

[0083] Preparation of long afterglow material slurry: The only difference is that the average particle size of the long afterglow material is 147μm.

[0084] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 10.13 mW; under dark light, the maximum output power of the cell was 0.97 mW.

[0085] Example 5

[0086] Preparation of perovskite solar cells: same as in Example 1.

[0087] Preparation of long afterglow material slurry: The only difference is that blue-green long afterglow material is used.

[0088] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 9.93 mW; under dark light, the maximum output power of the cell was 0.89 mW.

[0089] Example 6

[0090] Preparation of perovskite solar cells: same as in Example 1.

[0091] Preparation of long afterglow material slurry: The only difference is that red long afterglow material is used.

[0092] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 10.15 mW; under dark light, the maximum output power of the cell was 0.17 mW.

[0093] Example 7

[0094] Preparation of perovskite solar cells: same as in Example 1.

[0095] Preparation of long afterglow material slurry: The only difference is that sky blue long afterglow material is used.

[0096] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 9.69 mW; under dark light, the maximum output power of the cell was 1.26 mW.

[0097] Example 8

[0098] Preparation of perovskite solar cells: same as in Example 1.

[0099] Preparation of long afterglow material slurry: The only difference is that based on the mass of the long afterglow slurry, the mass content of the long afterglow material is 50%.

[0100] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 10.06 mW; under dark light, the maximum output power of the cell was 1.36 mW.

[0101] Example 9

[0102] Preparation of perovskite solar cells: same as in Example 1.

[0103] Preparation of long afterglow material slurry: The only difference is that based on the mass of the long afterglow slurry, the mass content of the long afterglow material is 60%.

[0104] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 10.11 mW; under dark light, the maximum output power of the cell was 1.41 mW.

[0105] Example 10

[0106] Preparation of perovskite solar cells: same as in Example 1.

[0107] Preparation of long afterglow material slurry: The only difference is that based on the mass of the long afterglow slurry, the mass content of the long afterglow material is 80%.

[0108] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 10.20 mW; under dark light, the maximum output power of the cell was 1.48 mW.

[0109] Embodiment 11

[0110] Preparation of perovskite solar cells: same as in Example 1.

[0111] Preparation of long afterglow material slurry: The only difference is that the long afterglow material is mixed with epoxy acrylate (EA) to obtain the long afterglow slurry.

[0112] The perovskite solar cell coated with the long afterglow material layer prepared above was tested under a solar simulator. Under 1 standard simulated sunlight, the maximum output power of the cell was 10.21 mW; under dark light, the maximum output power of the cell was 0.02 mW.

[0113] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, the technical solution of the present application can be subjected to a variety of simple modifications, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed in the present application and belong to the protection scope of the present application.

Claims

1. A solar cell comprising a transparent electrode, an electron transport layer, a photoelectric conversion layer, a hole transport layer and a counter electrode stacked in sequence, wherein: A first photoactive region and a first non-photoactive region are disposed on a side of the transparent electrode opposite to the electron transport layer, and a first long afterglow material layer is disposed in the first non-photoactive region.

2. The solar cell according to claim 1, characterized in that The first long afterglow material layer includes a long afterglow material, wherein the average particle size of the long afterglow material is 10 μm-200 μm, preferably 50 μm-100 μm.

3. The solar cell according to claim 1 or 2, characterized in that: The thickness of the first long afterglow material layer is 0.5 mm-2.5 mm, preferably 1 mm-2 mm.

4. The solar cell according to any one of claims 1 to 3, characterized in that: The long afterglow material is selected from one or more of a yellow-green long afterglow material, a red long afterglow material, an orange long afterglow material, a blue-green long afterglow material and a sky blue long afterglow material.

5. The solar cell according to any one of claims 1 to 4, characterized in that: The solar cell is selected from perovskite solar cells, Preferably, the transparent electrode is selected from one or more of indium tin oxide conductive glass, fluorine-doped tin dioxide conductive glass and polyethylene terephthalate flexible substrate; and / or The electron transport layer is selected from lead sulfate, lead titanate, PbTi3O7, Pb9TiO 11 、Pb5Ti5O 14 、Pb8Ti8O 23 , one or more of lead acetate, lead oxide, lead hydroxide, lead carbonate, lead nitrate, lead phosphate, lead chloride, lead iodide and lead bromide; and / or The photoelectric conversion layer is selected from perovskite thin films; and / or The hole transport layer is selected from one or more of 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], nickel oxide and a mixture of poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate); and / or The counter electrode is selected from a silver electrode and / or a gold electrode.

6. A method for preparing a solar cell according to any one of claims 1 to 5, comprising: S1: sequentially preparing an electron transport layer, a photoelectric conversion layer, a hole transport layer and a counter electrode on a transparent electrode; S2: preparing a first long afterglow material layer on a first non-photoactive region on a side of the transparent electrode opposite to the electron transport layer; Preferably, the preparation of the first long afterglow material layer comprises coating a slurry containing the long afterglow material in the first non-photoactive region. More preferably, the coating is selected from printing coating, such as screen printing coating.

7. The preparation method according to claim 6, characterized in that: The slurry further comprises a curable resin and a dispersant, preferably, the curable resin is selected from one or more of PMMA resin, PET resin and EA resin, preferably, the dispersant is selected from one or more of ethyl acetate, chloroform and isopropanol; and / or Based on the mass of the slurry, the mass content of the long afterglow material is 40%-85%, preferably 55%-75%.

8. A solar cell group, comprising a housing and a solar cell according to any one of claims 1 to 5 or a solar cell prepared by the preparation method according to claim 6 or 7, Preferably, the housing has a second photoactive region and a second non-photoactive region on a side opposite to the transparent electrode, light can irradiate the transparent electrode through the first photoactive region, and a second long afterglow material layer is disposed on the second non-photoactive region.

9. The solar cell group according to claim 8, characterized in that: The second photoactive region is a light-transmitting hole opened on the housing, and the light-transmitting hole is directly opposite to the transparent electrode; and / or The second long afterglow material layer comprises a long afterglow material, wherein the average particle size of the long afterglow material is 10 μm-200 μm, preferably 50 μm-100 μm; and / or The thickness of the second long afterglow material layer is 0.5 mm-2.5 mm, preferably 1 mm-2 mm; and / or The long afterglow material is selected from one or more of a yellow-green long afterglow material, a red long afterglow material, an orange long afterglow material, a blue-green long afterglow material and a sky blue long afterglow material.

10. The solar cell group according to claim 8 or 9, characterized in that: The number of the solar cells is multiple, and the multiple solar cells are connected in series, in parallel, or mixed, and the multiple solar cells share a transparent electrode.

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