Perovskite solar cell and preparation method thereof

Abstract

This application discloses a perovskite solar cell and its fabrication method, comprising a transparent electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode stacked together. The transparent electrode has a patterned structure on the side near the electron transport layer. The transparent electrode side is the light-incident side, and the patterned structure includes multiple repeating units. The size of the repeating unit or the gap between adjacent repeating units is an integer multiple of the cell parameters of the perovskite material in the perovskite layer. This application increases the light-capturing area, optimizes the light transmission path, enables the utilization of large-angle light, and reduces light reflection loss. By defining the parameters of the patterned structure to regulate the crystal growth order, it improves the crystal quality of the perovskite film, reduces grain boundaries, and reduces carrier recombination losses caused by defects, thereby increasing carrier lifetime and reducing carrier binding losses, thus improving the photoelectric conversion efficiency of the perovskite solar cell.

Description

Technical Field

[0001] This application relates to the photovoltaic field, specifically to a perovskite solar cell and its fabrication method. Background Technology

[0002] Perovskite solar cells are a new type of solar cell. The basic structure of a perovskite solar cell includes a transparent electrode, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and a metal electrode.

[0003] Perovskite solar cells have become a research hotspot in the field of solar energy due to their advantages such as high efficiency, low cost and ease of fabrication.

[0004] Light passes through the transparent electrode and irradiates the perovskite light-absorbing layer, directly converting light energy into electrical energy through the photoelectric effect or photochemical reaction. In order to maximize the conversion efficiency of perovskite solar cells, it is necessary to develop the materials and crystal quality of perovskite, and also to improve the transmittance of light through each functional film layer or reduce the light loss during the light path propagation process, so as to improve the photoelectric conversion efficiency. Summary of the Invention

[0005] This application provides a perovskite solar cell and its fabrication method. By adjusting the surface structure of the transparent electrode near the electron transport layer, the utilization rate of the perovskite solar cell for light at different angles is improved. The patterned surface makes the annealed perovskite crystal have fewer crystal interfaces, improving the crystal quality of the perovskite and enhancing the carrier transport capability.

[0006] This application provides a perovskite solar cell, comprising:

[0007] A transparent electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode are stacked in sequence.

[0008] The transparent electrode has a patterned structure on the side near the electron transport layer; the transparent electrode side is the light incident side, and the patterned structure includes multiple repeating units;

[0009] The size of the repeating unit is an integer multiple of the cell parameter of the perovskite material in the perovskite layer; or

[0010] The gap between two adjacent repeating units is an integer multiple of the cell parameter of the perovskite material in the perovskite layer.

[0011] Preferably, the patterned structure includes protrusions and / or grooves, the protrusions and grooves having light-refracting or reflecting surfaces, and the refractive index of the transparent electrode is less than the refractive index of the electron transport layer.

[0012] Preferably, the patterned structure includes repeating units surrounded by protrusions, and the repeating units include regular polygons.

[0013] Preferably, the protrusions of the patterned structure include a dam-like structure with an inclined surface, the inclined surface having an acute angle α with the horizontal plane of the transparent electrode, and 30° < α < 70°.

[0014] Preferably, the size of the repeating unit, or the gap between two adjacent repeating units, is in the range of 10nm-200nm.

[0015] Preferably, the electron transport layer is made of an electron transport sublayer and a seed layer, wherein the seed layer is made of CsPbI3 or RbPbI3.

[0016] Preferably, the electron transport material includes tin dioxide (SnO2), titanium dioxide (TiO2), zinc oxide (ZnO), and [6,6]-phenyl C. 61 Isomethyl butyrate (PC) 61 BM) and fullerene (C 60 Any one of them.

[0017] Preferably, the material of the transparent electrode includes one of indium zinc oxide (IZO), indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped tin oxide (AZO), indium tungsten oxide (IWO), and cesium indium oxide (ICO).

[0018] Preferably, the perovskite layer comprises a perovskite material, wherein the perovskite material comprises ABX3, wherein A comprises CH3NH3. + CH(NH2) 2+ CH(NH2)2 + Cs + 、Rb + At least one of them, B includes Pb 2+ Sn 2+ 、Ge 2+ X includes at least one of Cl, Br, and I.

[0019] A method for fabricating a perovskite solar cell, comprising:

[0020] Provides a transparent electrode comprising a transparent insulating layer and a transparent conductive layer;

[0021] Provides a transparent electrode comprising a transparent insulating layer and a transparent conductive layer;

[0022] A patterned structure is formed on the transparent conductive layer, the patterned structure comprising a plurality of repeating units;

[0023] An electron transport layer is formed on the transparent electrode, and the material of the electron transport layer covers the surface of the transparent electrode.

[0024] A perovskite layer, a hole transport layer, and a metal electrode are sequentially formed on the electron transport layer.

[0025] Beneficial effects

[0026] This invention provides a perovskite solar cell. By forming a patterned structure on a transparent electrode, the patterned structure matches the cell parameters of the perovskite material in the perovskite layer. On one hand, this provides multiple optical refractive / reflective surfaces, which, combined with the different refractive indices of adjacent film layers, can modulate the light path, increasing the light-capturing area and optimizing the light transmission path. This allows for the utilization of large-angle light and reduces light reflection losses. On the other hand, by limiting the parameters of the patterned structure, the electron transport layer near the perovskite layer has a textured surface structure that conforms to the regularity of crystal growth. This improves the crystallinity quality of the perovskite film, resulting in larger crystal faces and fewer grain boundaries. This reduces carrier recombination losses caused by defects, increases carrier lifetime, reduces carrier binding losses, and ultimately improves the photoelectric conversion efficiency of the perovskite solar cell. Attached Figure Description

[0027] Figure 1 This is a structural diagram of a perovskite solar cell according to an embodiment of this application;

[0028] Figure 2 This is a partial film structure diagram of a perovskite solar cell according to an embodiment of this application;

[0029] Figure 3 This is a partial film structure diagram of a perovskite solar cell according to another embodiment of this application;

[0030] Figure 4 This is a partial film structure diagram of a perovskite solar cell according to another embodiment of this application;

[0031] Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure of A-A'. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] This application provides a perovskite solar cell and a method for fabricating the same. Detailed descriptions are provided below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative and do not impose numerical requirements or establish an order. Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0034] This application provides a perovskite solar cell, such as... Figures 1-3 As shown, it includes:

[0035] A transparent electrode 10, an electron transport layer 20, a perovskite layer 30, a hole transport layer 40, and a metal electrode 50 are stacked sequentially.

[0036] Among them, such as Figure 2 As shown, the transparent electrode 10 has a patterned structure on the side near the electron transport layer 20; the transparent electrode 30 side is the light incident side, and the patterned structure includes multiple repeating units S;

[0037] The size of the repeating unit S is an integer multiple of the cell parameter of the perovskite material in the perovskite layer; or

[0038] The gap between two adjacent repeating units S is an integer multiple of the cell parameters of the perovskite material in the perovskite layer.

[0039] Specifically, the transparent electrode 10 includes a transparent insulating layer 101 and a transparent conductive layer 102. The size of the transparent electrode 10 is not particularly limited and can be adjusted according to actual conditions. Specifically, the thickness of the transparent electrode 10 is 50nm-200nm; preferably 120nm.

[0040] Specifically, the patterned structure is formed on the transparent conductive layer 102 and is located near the electron transport layer 30.

[0041] Specifically, the material of the transparent conductive layer 102 includes one of indium zinc oxide (IZO), indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped tin oxide (AZO), indium tungsten oxide (IWO), and cesium indium oxide (ICO).

[0042] Specifically, the material of the transparent insulating layer 101 includes any one of transparent glass, polyethylene terephthalate (PET) film, and polyethylene naphthalate (PEN) film.

[0043] It should be noted that the space group of perovskite is cubic Pm-3m, and the cell parameter is, for example, a = 3.848 Å.

[0044] That is, the size of the repeating unit S or the gap between two adjacent repeating units S is an integer multiple of the cell parameter of the perovskite material in the perovskite layer, which means that the size or gap of the repeating unit S is an integer multiple of the cubic cell parameter of perovskite 3.848 Å.

[0045] Further, the integer multiple is preferably 10-500 times, more preferably 30-200 times, that is, the size of the repeating unit S or the gap between the repeating units can be any one of 15.37nm, 23.06nm, 26.90nm, 30.74nm, 38.43nm or 76.86nm;

[0046] Specifically, the size of the repeating unit S ranges from 5 to 100 nm, preferably from 10 nm to 80 nm, and further preferably from 15 to 50 nm.

[0047] Specifically, the electron transport layer 20 is formed on the transparent electrode 10, and the electron transport layer 20 has a structure corresponding to the repeating unit S, so that the electron transport layer 20 has the same contour surface as the transparent electrode 10.

[0048] Specifically, the thickness of the electron transport layer 20 is preferably 20-200 nm, and more preferably 100 nm.

[0049] Specifically, the materials of the electron transport layer 20 include tin dioxide (SnO2), titanium dioxide (TiO2), zinc oxide (ZnO), and [6,6]-phenyl C. 61 Isomethyl butyrate (PC) 61 BM) and fullerene (C 60 Any one of them.

[0050] Specifically, the thickness of the perovskite layer 30 is 200 nm to 700 nm;

[0051] Specifically, the perovskite layer 30 comprises a perovskite material, which includes a compound with an ABX3 type structure, wherein A is one or more of formamidinium ion (FA), methylamine ion (MA), and cesium ion (Cs); B is one or more of divalent lead ion (Pb) and divalent tin ion (Sn); and X is a compound containing Cl-, Br-, etc. - I - One or more of the halide ions included.

[0052] Specifically, the thickness of the hole transport layer 40 is 20nm-200nm, preferably 80nm.

[0053] Specifically, the material of the hole transport layer 40 includes one or more of Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene), P3HT (poly(3-hexylthiophene-2,5-diyl)), PEDOT:PSS (polyethylenedioxythiophene-poly(styrene sulfonate)), NiOx (nickel oxide), CuSCN (cuprous thiocyanate), and PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]).

[0054] It should be noted that a short, thick hole transport layer 40 can improve photoelectric conversion efficiency because it reduces the propagation distance of photoelectrons, improves charge separation efficiency, and reduces reflection and resistance losses. However, an excessively thin hole transport layer may lead to poor contact between the anode and the electrolyte, affecting the stability of the battery.

[0055] Specifically, the thickness of the metal electrode 50 is 50-200 nm, preferably 80 nm.

[0056] Specifically, the material of the metal electrode 50 may be a material that matches the work function of the hole transport layer 40, including but not limited to gold, silver, copper, calcium, barium, chromium, etc.

[0057] In this embodiment, a patterned structure is formed on the transparent electrode 10. The patterned structure matches the cell parameters of the perovskite material in the perovskite layer. On the one hand, it can provide multiple optical refractive / reflective surfaces. On the other hand, it can adjust the light path by cooperating with the different refractive indices of adjacent film layers, optimize the light transmission path, and enable large-angle light to be utilized, thereby improving the light intensity.

[0058] On the other hand, by limiting the parameters of the patterned structure, the electron transport layer 20 is made to form a surface with a regular microstructure that conforms to crystal growth on the side close to the perovskite layer 30. This makes the crystal initiation growth line of the perovskite crystal extend along the direction of the repeating unit when the perovskite crystal is formed, thereby improving the arrangement order of the perovskite crystal, thus improving the crystal quality of the perovskite film, reducing the perovskite crystal grain boundaries, reducing the carrier recombination loss caused by grain boundary defects, increasing the carrier lifetime, reducing the carrier binding loss, and ultimately improving the photoelectric conversion efficiency of the perovskite solar cell.

[0059] In one embodiment, such as Figure 2 , Figure 3 As shown, the patterned structure includes protrusions and / or grooves, the protrusions and grooves having light refraction or reflection surfaces, and the refractive index of the transparent electrode is less than the refractive index of the electron transport layer.

[0060] Specifically, such as Figure 2 As shown, the protrusion / groove structure can form a repeating unit S shape with repeated distribution; after light is incident, it can be reflected and / or scattered multiple times on the surface of the protrusion or groove with a predetermined inclination, so that most of the light can reach the perovskite layer 30, which can concentrate the light intensity and thus improve the light utilization rate.

[0061] Wherein, d is the size of the repeating unit S or the gap between two adjacent repeating units S.

[0062] Meanwhile, because the size of the patterned structure matches the size of the perovskite cell, when the perovskite crystal is formed through the annealing step, the perovskite crystal can form grain boundaries along the patterned structure (the edges of the protrusions / grooves) and grow sequentially. This improves the order of the perovskite crystal, reduces the grain boundary area of ​​the perovskite crystal, reduces grain boundaries, avoids carrier recombination loss caused by grain boundary defects, increases carrier lifetime, reduces carrier recombination loss, and improves the light absorption, charge transport and stability of perovskite solar cells.

[0063] Understandably, in order to prevent light leakage, the refractive index of the transparent electrode 10 is less than that of the electron transport layer 20. Since the refractive index of the transparent electrode 10 is less than that of the electron transport layer 20, the internal light is not easily transmitted outward. This method can optimize the transmission and utilization efficiency of light energy. By selecting the refractive index, the internal light is prevented from escaping outward, and more light is guided to the perovskite layer, thereby improving the absorption efficiency of light energy.

[0064] In one embodiment, the aspect ratio of the protrusion or groove structure can be (1.3-1.6):1;

[0065] It is understandable that by adopting the above aspect ratio, on the one hand, in the direction perpendicular to the perovskite layer, a suitable aspect ratio makes it less likely that light transmitted in the convex part will be transmitted outward from the convex part again, thus more effectively capturing and scattering incident light. On the other hand, by adopting the above ratio, perovskite crystals with high order can also be formed on the connecting surface between the upper and lower edges of the concave and convex structure, which can further improve the transmission ability while improving the light energy utilization rate.

[0066] In one embodiment, such as Figure 4 and Figure 5 As shown, the patterned structure includes repeating units surrounded by protrusions, and the repeating units include regular polygons.

[0067] Specifically, the regular polygon includes, but is not limited to, equilateral triangles, squares, or hexagons, with regular hexagons being preferred.

[0068] Understandably, forming a regular patterned structure can enhance the strength of the transparent electrode, and compared to the traditional striped structure, it can effectively prevent moisture intrusion and reduce the lifespan of perovskite solar cells.

[0069] In one embodiment, such as Figure 4 and Figure 5 As shown, the protrusions of the patterned structure include a dam-like structure B, which has an inclined surface. The inclined surface and the horizontal plane of the transparent electrode have an acute angle α, and 30° < α < 70°.

[0070] It is understandable that when the angle between the inclined surface and the horizontal plane of the transparent electrode is close to 0° or 90°, its adjustment effect on the light path is smaller and it cannot play a significant role in concentrating the light path.

[0071] In one embodiment, a seed layer is provided between the electron transport layer 20 and the perovskite layer 30, wherein the material of the seed layer includes CsPbI3 or RbPbI3.

[0072] Specifically, the seed layer is made of a readily crystallizable material, which preferentially forms on the electron transport layer to control the growth of perovskite crystals in a specific direction. At the same time, it enables the perovskite material to form α-phase perovskite crystals during the crystallization process and stabilizes the crystal phase of perovskite under various conditions, thereby preparing a long-term stable perovskite thin film layer and improving the efficiency and stability of solar cells.

[0073] A method for fabricating a perovskite solar cell, comprising:

[0074] S1. Provide a transparent electrode 10 including a transparent insulating layer 101 and a transparent conductive layer 102;

[0075] The specific cleaning method involves sequentially ultrasonicating the transparent electrode 10 in deionized water, glass cleaner, acetone, and ethanol, followed by plasma treatment for 1 minute.

[0076] Specifically, the thickness of the transparent electrode 10 is 50nm-200nm; preferably 120nm.

[0077] S2. A patterned structure including repeating units S is formed in the transparent conductive layer 102;

[0078] Specifically, the patterned structure can be obtained by laser etching;

[0079] Specifically, the depth of the patterned structure can be 10nm-80nm;

[0080] The size of the repeating unit S or the gap between the repeating units S can be any one of 15.37nm, 23.06nm, 26.90nm, 30.74nm, 38.43nm or 76.86nm;

[0081] Specifically, the size of the repeating unit S ranges from 5 to 100 nm, preferably from 10 nm to 80 nm, and further preferably from 15 to 50 nm.

[0082] S3. An electron transport layer 20 is formed on the transparent electrode 10, and the material of the electron transport layer 20 covers the surface of the transparent electrode 10.

[0083] Specifically, a TiO2 seed layer is formed on the transparent electrode 10 by spin coating.

[0084] The specific operation is as follows: Tetrabutyl titanate, ethanol, acetylacetone, and glacial acetic acid are mixed in a volume ratio of 0.5:4:0.5:1, and 0.5 parts of deionized water are added. The mixture is stirred at room temperature for 8-10 hours to obtain a TiO2 precursor solution. The TiO2 precursor solution is spin-coated onto a transparent electrode. The transparent electrode 10 is heated in air at 125°C and then heated at 450°C to obtain a conductive substrate with a dense TiO2 seed layer deposited on it.

[0085] A porous TiO2 film is formed on the TiO2 seed layer.

[0086] A porous membrane slurry was obtained by diluting the acidic slurry with ethanol. This porous membrane slurry was then coated onto the surface of a TiO2 seed layer by spin coating. After completion, the film was transferred to a hot plate and heated to 500 degrees Celsius to evaporate the solvent, thus obtaining the electron transport layer.

[0087] Specifically, the thickness of the electron transport layer 20 is preferably 20-200 nm, and more preferably 100 nm.

[0088] S4. A perovskite layer 30, a hole transport layer 40, and a metal electrode 50 are formed on the electron transport layer 20.

[0089] Specifically, the perovskite precursor PbI2 (concentration 463 mg / ml) was dissolved in DMSO, and the solution was coated onto the surface of the perovskite film by spin coating for 40 seconds. Immediately after the spin coating was completed, the film was transferred to a hot plate preheated to 70 degrees Celsius and heated for 30 minutes.

[0090] Then, after cooling to room temperature, it was spin-coated with an isopropanol solution of CH3NH3I (concentration 10 mg / ml) at a speed of 2800 rpm for 50 seconds. The mixture was then heated on a hot plate at 70 degrees Celsius for 30 minutes to obtain a perovskite layer 30.

[0091] Specifically, the perovskite layer 30 can also be formed by processing the perovskite solution through any of the following methods: spin coating, blade coating, slot continuous coating, or spray coating, and coating it onto the surface of a substrate with an electron transport layer to obtain a perovskite film. The film is then annealed to obtain the perovskite layer.

[0092] Specifically, the thickness of the perovskite layer 30 is 200 nm to 700 nm; preferably 450 nm.

[0093] A hole transport material is spin-coated onto the surface of the brownish-black film at a speed of 3000 rpm for 30 seconds. After spin-coating, the film is left to stand for 24 hours to allow the hole transport material to fully penetrate. The thickness of the hole transport layer is 20 nm-200 nm, preferably 80 nm. The hole transport material can be spiro-OMeTAD at a concentration of 0.17 mol / L, and the solvent is chlorobenzene.

[0094] The thin film obtained in the previous step is vacuum-deposited with metal, and the thickness of the metal electrode 50 is 80 nm.

[0095] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.

[0096] Example 1

[0097] A perovskite solar cell comprising:

[0098] A transparent electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode are stacked in sequence.

[0099] The transparent electrode is an ITO glass plate with a thickness of 120 nm;

[0100] The patterned structure consists of multiple equally spaced grooves arranged along one direction. The grooves are 38.43 nm deep, have a sidewall inclination angle of 60°, a bottom width of 76.86 nm, and a spacing of 307 nm between adjacent grooves.

[0101] The electron transport layer is TiO2, which includes a dense layer and a porous layer. The thickness of the dense film layer is 50 nm, and the thickness of the porous film layer is 100 nm.

[0102] The perovskite layer is made of MAPbI3 and has a thickness of 450 nm.

[0103] Hole transport layer, Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene), with a thickness of 80 nm;

[0104] The metal electrode is a Cu electrode with a thickness of 80 nm.

[0105] Example 2

[0106] A perovskite solar cell comprising:

[0107] A transparent electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode are stacked in sequence.

[0108] The transparent electrode is an ITO glass plate with a thickness of 120 nm;

[0109] The patterned structure consists of multiple equally spaced grooves arranged along one direction. The grooves are 38.43 nm deep, have a sidewall inclination angle of 60°, a bottom width of 76.86 nm, and a spacing of 307 nm between adjacent grooves.

[0110] The electron transport layer is TiO2, which includes a dense layer and a porous layer. The thickness of the dense film layer is 50 nm, and the thickness of the porous film layer is 100 nm.

[0111] The seed layer is made of CsPbI3 and has a thickness of 5 nm.

[0112] The perovskite layer is made of MAPbI3 and has a thickness of 450 nm.

[0113] Hole transport layer, Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene), with a thickness of 80 nm;

[0114] The metal electrode is a Cu electrode with a thickness of 80 nm.

[0115] Example 3

[0116] A perovskite solar cell comprising:

[0117] A transparent electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode are stacked in sequence.

[0118] The transparent electrode is an ITO glass plate with a thickness of 120 nm;

[0119] like Figure 4 As shown, the patterned structure is an array of regular hexagonal structures surrounding a dam. The dam is 50 nm high, has a sidewall inclination angle of 60°, and the spacing between the upper edges of the dam is 26.90 nm.

[0120] The electron transport layer is TiO2, which includes a dense layer and a porous layer. The thickness of the dense film layer is 50 nm, and the thickness of the porous film layer is 100 nm.

[0121] The perovskite layer is made of MAPbI3 and has a thickness of 450 nm.

[0122] Hole transport layer, Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene), with a thickness of 80 nm;

[0123] The metal electrode is a Cu electrode with a thickness of 80 nm.

[0124] Example 4

[0125] A perovskite solar cell comprising:

[0126] A transparent electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode are stacked in sequence.

[0127] The transparent electrode is an ITO glass plate with a thickness of 120 nm;

[0128] The patterned structure consists of multiple equally spaced grooves arranged along one direction. The grooves are 38.43 nm deep, have a sidewall inclination angle of 45°, a bottom width of 38.43 nm, and a spacing of 38.43 nm between adjacent grooves.

[0129] The electron transport layer is TiO2, which includes a dense layer and a porous layer. The thickness of the dense film layer is 50 nm, and the thickness of the porous film layer is 100 nm.

[0130] The perovskite layer is made of MAPbI3 and has a thickness of 450 nm.

[0131] Hole transport layer, Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene), with a thickness of 80 nm;

[0132] The metal electrode is a Cu electrode with a thickness of 80 nm.

[0133] Comparative Example 1

[0134] It has the same film stack and materials as Example 1, except that there is no patterned structure on the transparent electrode.

[0135] Comparative Example 2

[0136] It has the same film stack and material as Example 1, except that the patterned structure is a plurality of equally spaced grooves arranged in one direction. The grooves are 20 nm deep, have a sidewall inclination angle of 90°, a bottom width of 20 nm, and a spacing of 20 nm between adjacent grooves.

[0137] Detection Examples

[0138] The testing method is as follows:

[0139] The open-circuit voltage test method, short-circuit current density test method, fill factor test method, battery efficiency test method, and battery active area test method all use a solar simulator.

[0140] The test method for the active area of ​​the battery uses a photomask.

[0141] Table 1 shows the test parameters for Examples 1-4 and Comparative Examples 1-2.

[0142]

[0143] The substrate formed using the above-mentioned different perovskite thin films has a size of 5.7*5.7cm. 2 The device was tested under conditions ranging from 1.2V to 0V. After adjusting the interface morphology of the transparent electrode layer, the device efficiency increased from 18.71% to 20.91%. It can be seen that setting a patterned structure can not only increase the light utilization rate, but also guide the crystallization of perovskite crystals, forming high-quality perovskite crystals and thus increasing the battery efficiency. Adding a seed layer can further promote the crystallization morphology of perovskite crystals and enhance the stability of the device.

[0144] The above provides a detailed description of a perovskite solar cell and its fabrication method provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A perovskite solar cell, characterized in that, include: A transparent electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode are stacked in sequence. The transparent electrode has a patterned structure on the side near the electron transport layer; the transparent electrode side is the light incident side, and the patterned structure includes multiple repeating units; The size of the repeating unit is an integer multiple of the cell parameter of the perovskite material in the perovskite layer; or The gap between two adjacent repeating units is an integer multiple of the cell parameter of the perovskite material in the perovskite layer; The integer multiples are 30-200 times.

2. The perovskite solar cell as described in claim 1, characterized in that, The patterned structure includes protrusions and / or grooves, the protrusions and grooves having light refraction or reflection surfaces, and the refractive index of the transparent electrode is less than the refractive index of the electron transport layer.

3. The perovskite solar cell as described in claim 2, characterized in that, The patterned structure includes repeating units surrounded by protrusions, and the repeating units include regular polygons.

4. The perovskite solar cell according to claim 2, characterized in that, The protrusions of the patterned structure include a dam-like structure with an inclined surface. The inclined surface has an acute angle α with the horizontal plane of the transparent electrode, and 30° < α < 70°.

5. The perovskite solar cell according to claim 1, characterized in that, The size of the repeating unit, or the gap between two adjacent repeating units, ranges from 10nm to 200nm.

6. The perovskite solar cell according to claim 1, characterized in that, A seed layer is provided between the electron transport layer and the perovskite layer, and the material of the seed layer includes CsPbI3 or RbPbI3.

7. The perovskite solar cell according to claim 6, characterized in that, The electron transport layer is made of materials including tin dioxide (SnO2), titanium dioxide (TiO2), zinc oxide (ZnO), and [6,6]-phenyl C. 61 Isomethyl butyrate (PC) 61 BM) and fullerene (C 60 Any one of them.

8. The perovskite solar cell according to claim 1, characterized in that, The transparent electrode is made of one of the following materials: indium zinc oxide (IZO), indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped tin oxide (AZO), indium tungsten oxide (IWO), and cesium indium oxide (ICO).

9. The perovskite solar cell according to claim 1, characterized in that, The perovskite layer comprises a perovskite material, wherein the perovskite material comprises ABX3, and A comprises CH3NH3. + CH(NH2) 2+ CH(NH2)2 + 、Cs + 、Rb + At least one of them, B includes Pb 2+ Sn 2+ 、Ge 2+ At least one of them, X includes Cl-, Br - I - At least one of them.

10. A method for fabricating a perovskite solar cell, characterized in that, include: Provides a transparent electrode comprising a transparent insulating layer and a transparent conductive layer; A patterned structure is formed on the transparent conductive layer, the patterned structure comprising a plurality of repeating units; An electron transport layer is formed on the transparent electrode, and the material of the electron transport layer covers the surface of the transparent electrode. A perovskite layer, a hole transport layer, and a metal electrode are sequentially formed on the electron transport layer. Wherein, the size of the repeating unit is an integer multiple of the cell parameter of the perovskite material in the perovskite layer; or The gap between two adjacent repeating units is an integer multiple of the cell parameter of the perovskite material in the perovskite layer; The integer multiples are 30-200 times.

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