Perovskite solar cell and photovoltaic power generation assembly

Abstract

The invention discloses a perovskite solar cell and a photovoltaic power generation assembly. The perovskite solar cell comprises a first transparent electrode layer, an electron transport layer, a perovskite layer, a hole transport layer and a second transparent electrode layer which are sequentially stacked and connected, and the perovskite layer comprises a perovskite main body film layer, a first perovskite sub-film layer and a second perovskite sub-film layer. The first perovskite sub-film layer and the second perovskite sub-film layer are respectively located at two sides of the perovskite main body film layer, and the material content of the first perovskite sub-film layer and the material content of the second perovskite sub-film layer are respectively smaller than the material content of the perovskite main body film layer. The Fermi level of the first perovskite sub-film layer is lower than the Fermi level of the perovskite main body film layer, and the Fermi level of the second perovskite sub-film layer is higher than the Fermi level of the perovskite main body film layer. The whole perovskite layer can form an energy gradient, photo-induced electrons in the perovskite layer can be driven to the electron transport layer by an internal electric field, and the efficiency of a large-area cell is improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a perovskite solar cell and a photovoltaic power generation component. Background Art

[0002] Photovoltaic power generation technology has attracted much attention and is expected to become an important part of the energy structure. Perovskite cells are low-cost, can form stacked cells, and have higher power generation efficiency. Perovskite cells are developing rapidly and have huge room for improvement. The industrialization direction of perovskite cells is inseparable from vacuum coating. Vacuum coating can not only form a vacuum environment to prevent water and oxygen erosion during the production process, but also achieve accurate material ratio monitoring and thickness monitoring. In traditional technology, perovskite cells add passivation layers or materials that help transmission on both sides of the perovskite film. In the large-scale preparation of perovskite cells, due to the irregular energy transfer inside the perovskite and the adaptability of the interface between the perovskite and other functional layers can only be adjusted in a single direction, resulting in the current perovskite cell efficiency is difficult to improve. Summary of the invention

[0003] Based on this, it is necessary to provide a perovskite solar cell. The perovskite solar cell of the present invention forms a potential energy by adding perovskite cells with different band gaps on both sides, which helps to improve the efficiency of large-area cells.

[0004] An embodiment of the present application provides a perovskite solar cell.

[0005] A perovskite solar cell comprises a first transparent electrode layer, an electron transport layer, a perovskite layer, a hole transport layer and a second transparent electrode layer which are sequentially stacked and connected, wherein the perovskite layer comprises a perovskite main film layer, a first perovskite sub-film layer and a second perovskite sub-film layer, the first perovskite sub-film layer and the second perovskite sub-film layer are respectively located on both sides of the perovskite main film layer, the material content of the first perovskite sub-film layer and the material content of the second perovskite sub-film layer are respectively less than the material content of the perovskite main film layer, the Fermi energy level of the first perovskite sub-film layer is lower than the Fermi energy level of the perovskite main film layer, and the Fermi energy level of the second perovskite sub-film layer is higher than the Fermi energy level of the perovskite main film layer.

[0006] In some embodiments, the main component of the perovskite main film layer is Cs y0 FA 1-y0 Pb(I 1-x Br x )3, the main component of the first perovskite sub-film layer is Cs y1 FA 1-y1 Pb(I 1-x Br x)3, the main component of the second perovskite sub-film layer is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y1<y0, y2>y0.

[0007] In some embodiments, the thickness of the first perovskite sub-film layer and the thickness of the second perovskite sub-film layer are respectively smaller than the thickness of the perovskite main film layer.

[0008] In some of the embodiments, the thickness of the perovskite main film layer is 330nm~380nm.

[0009] In some embodiments, the thickness of the first perovskite sub-film layer is 10 nm to 30 nm.

[0010] In some embodiments, the thickness of the second perovskite sub-film layer is 10 nm to 30 nm.

[0011] In some embodiments, the perovskite solar cell further includes a first interface modification layer, and the first interface modification layer is disposed between the perovskite layer and the electron transport layer.

[0012] In some embodiments, the perovskite solar cell further includes a second interface modification layer, and the second interface modification layer is disposed between the perovskite layer and the hole transport layer.

[0013] In some embodiments, the hole transport layer includes [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz) and its derivatives, [2-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz) and its derivatives, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Sprio-OMeTAD), polyethylene terephthalate (PTAA), 3-hexylthiophene polymer (P3HT), PEDOT:PSS, NiO x and one or more of CuSCN.

[0014] In some embodiments, the electron transport layer includes PCBM, SnO2, ZnO2, Al2O3, C 60 and one or more of ICBA.

[0015] An embodiment of the present application also provides a photovoltaic power generation component.

[0016] A photovoltaic power generation component comprises the perovskite solar cell.

[0017] In some embodiments, the photovoltaic power generation component includes a packaging component and a first substrate and a second substrate that are relatively arranged. The first substrate and the second substrate are sealed and connected around the packaging component, so that a closed chamber is formed between the first substrate and the second substrate, and the perovskite solar cell is encapsulated in the closed chamber.

[0018] The above-mentioned perovskite solar cell, by adding the first perovskite sub-film layer and the second perovskite sub-film layer with different band gaps on both sides of the perovskite main film layer, forms a potential energy between the first perovskite sub-film layer, the perovskite main film layer, and the second perovskite sub-film layer, which helps to improve the efficiency of large-area batteries. Due to the different material content composition ratios of the first perovskite sub-film layer and the second perovskite sub-film layer on both sides of the perovskite main film layer, the adaptability of the interface between the perovskite main film layer and other functional layers will be easier to achieve. By adding the first perovskite sub-film layer and the second perovskite sub-film layer with different material contents on both sides of the perovskite main film layer, an energy gradient can be formed on the whole perovskite layer, and due to the change in the Fermi level, the energy band is bent, and the photogenerated electrons inside the perovskite layer can be driven to the electron transport layer by the internal electric field, thereby improving the efficiency of large-area batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0020] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings. In the following description, the same reference numerals represent the same parts.

[0021] FIG1 is a schematic diagram of a perovskite solar cell according to an embodiment of the present invention.

[0022] Description of Reference Numerals

[0023] 10. Perovskite solar cell; 100. First transparent electrode layer; 200. Electron transport layer; 300. Perovskite layer; 301. Perovskite main film layer; 302. First perovskite sub-film layer; 303. Second perovskite sub-film layer; 400. Hole transport layer; 500. Second transparent electrode layer; 600. First interface modification layer; 700. Second interface modification layer. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0026] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0029] In this article, unless otherwise stated, each reaction step may be carried out in the order described herein or may not be carried out in the order described herein. For example, other steps may be included between each reaction step, and the order of the reaction steps may also be appropriately swapped. This can be determined by the technician based on common knowledge and experience. Preferably, the reaction method herein is carried out sequentially.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0031] The embodiment of the present application provides a perovskite solar cell 10 to solve the problem that in the conventional technology, in the large-area preparation of perovskite cells, the efficiency of the current perovskite cells is difficult to improve due to the irregularity of energy transfer inside the perovskite and the adaptability of the interface between the perovskite and other functional layers can only be adjusted in a single direction. The perovskite solar cell 10 will be described below in conjunction with the accompanying drawings.

[0032] The perovskite solar cell 10 provided in the embodiment of the present application is exemplified as shown in FIG1 , which is a schematic diagram of the structure of the perovskite solar cell 10 provided in the embodiment of the present application. The perovskite solar cell 10 of the present application forms a potential energy by adding perovskite cells with different band gaps on both sides, which helps to improve the power generation efficiency of the large-area perovskite solar cell 10.

[0033] In order to more clearly illustrate the structure of the perovskite solar cell 10 , the perovskite solar cell 10 will be introduced below with reference to the accompanying drawings.

[0034] For example, please refer to FIG. 1, which is a schematic diagram of the structure of a perovskite solar cell 10 provided in an embodiment of the present application. A perovskite solar cell 10 comprises a first transparent electrode layer 100, an electron transport layer 200, a perovskite layer 300, a hole transport layer 400 and a second transparent electrode layer 500 which are sequentially stacked and connected. Among them, the perovskite layer 300 comprises a perovskite main film layer 301, a first perovskite sub-film layer 302 and a second perovskite sub-film layer 303. The first perovskite sub-film layer 302 and the second perovskite sub-film layer 303 are respectively located on both sides of the perovskite main film layer 301. The material content of the first perovskite sub-film layer 302 and the material content of the second perovskite sub-film layer 303 are respectively less than the material content of the perovskite main film layer 301. The Fermi level of the first perovskite sub-film layer 302 is lower than the Fermi level of the perovskite main film layer 301. The Fermi level of the second perovskite sub-film layer 303 is higher than the Fermi level of the perovskite main film layer 301 .

[0035] In some embodiments, the main component of the perovskite main film layer 301 is Cs y0 FA 1-y0 Pb(I 1-x Br x )3, the main component of the first perovskite sub-film layer 302 is Cs y1 FA 1-y1 Pb(I 1-x Br x )3. The main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y1<y0, y2>y0.

[0036] In some of the embodiments, y0=(y1+y2) / 2, y0 ranges from 0.15 to 0.25, y1=y0-(0.01 to 0.05), y2=y0+(0.01 to 0.05), and x ranges from 0.2 to 0.3.

[0037] In some embodiments, the thickness of the first perovskite sub-film layer 302 and the thickness of the second perovskite sub-film layer 303 are respectively smaller than the thickness of the perovskite main film layer 301 .

[0038] In some of the embodiments, the thickness of the perovskite main film layer 301 is 330 nm-380 nm.

[0039] In some embodiments, the thickness of the first perovskite sub-layer 302 is 10 nm to 30 nm.

[0040] In some embodiments, the thickness of the second perovskite sub-layer 303 is 10 nm to 30 nm.

[0041] When preparing the perovskite solar cell 10, after confirming the composition ratio of the perovskite main film layer 301, the composition ratio of the first perovskite sub-film layer 302, and the composition ratio of the second perovskite sub-film layer 303, the composition ratio is adjusted by evaporation to form a first perovskite sub-film layer 302 of 10nm~30nm, and the Fermi level of the first perovskite sub-film layer 302 is lower than that of the perovskite main layer. The perovskite main film layer 301 is then evaporated, and the evaporation ratio is adjusted to form a second perovskite sub-film layer 303 of 10nm~30nm, and the Fermi level of the second perovskite sub-film layer 303 is higher than that of the perovskite main film layer 301.

[0042] In some embodiments, the perovskite solar cell 10 further includes a first interface modification layer 600 . The first interface modification layer 600 is disposed between the perovskite layer 300 and the electron transport layer 200 .

[0043] In some embodiments, the perovskite solar cell 10 further includes a second interface modification layer 700 . The second interface modification layer 700 is disposed between the perovskite layer 300 and the hole transport layer 400 .

[0044] In some embodiments, the hole transport layer 400 includes [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz) and its derivatives, [2-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz) and its derivatives, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Sprio-OMeTAD), polyethylene terephthalate (PTAA), 3-hexylthiophene polymer (P3HT), PEDOT:PSS, NiO x and one or more of CuSCN.

[0045] In some embodiments, the electron transport layer 200 includes PCBM, SnO2, ZnO2, Al2O3, C 60 and one or more of ICBA.

[0046] An embodiment of the present application also provides a photovoltaic power generation component.

[0047] A photovoltaic power generation component includes a perovskite solar cell 10.

[0048] In some embodiments, the photovoltaic power generation assembly includes a packaging component and a first substrate and a second substrate disposed opposite to each other. The first substrate and the second substrate are connected by a sealing ring through the packaging component. Thus, a sealed chamber is formed between the first substrate and the second substrate. The perovskite solar cell 10 is packaged in the sealed chamber.

[0049] In some embodiments, the first substrate and the second substrate are glass substrates respectively.

[0050] Example 1

[0051] This embodiment provides a perovskite solar cell 10 .

[0052] A perovskite solar cell 10 includes a first transparent electrode layer 100, an electron transport layer 200, a first interface modification layer 600, a perovskite layer 300, a second interface modification layer 700, a hole transport layer 400 and a second transparent electrode layer 500 which are sequentially stacked and connected.

[0053] The perovskite layer 300 includes a perovskite main film layer 301, a first perovskite sub-film layer 302, and a second perovskite sub-film layer 303. The first perovskite sub-film layer 302 and the second perovskite sub-film layer 303 are respectively located on both sides of the perovskite main film layer 301. The main component of the perovskite main film layer 301 is Cs y0 FA 1-y0 Pb(I 1-x Br x )3, the main component of the first perovskite sub-film layer 302 is Cs y1 FA 1-y1 Pb(I 1-x Br x )3. The main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, wherein y0=0.2, x=0.2, y1=0.15, y2=0.25, that is, y1<y0, y2>y0. The thickness of the perovskite main film layer 301 is 380nm. The thickness of the first perovskite sub-film layer 302 is 10nm. The thickness of the second perovskite sub-film layer 303 is 10nm. The total thickness of the perovskite layer 300 is 400nm. The Fermi level of the first perovskite sub-film layer 302 is lower than the Fermi level of the perovskite main film layer 301. The Fermi level of the second perovskite sub-film layer 303 is higher than the Fermi level of the perovskite main film layer 301. The perovskite main film layer 301, the first perovskite sub-film layer 302, and the second perovskite sub-film layer 303 are prepared by evaporation respectively. The hole transport layer 400 is NiO x The electron transport layer 200 includes SnO 2 .

[0054] Example 2

[0055] This embodiment provides a perovskite solar cell 10 .

[0056] The structure of the perovskite solar cell in Example 2 is substantially the same as that in Example 1, except that in Example 2, the main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y0=0.2, x=0.2, y1=0.19, y2=0.21, that is, y1<y0, y2>y0.

[0057] Example 3

[0058] This embodiment provides a perovskite solar cell 10 .

[0059] The structure of the perovskite solar cell in Example 3 is substantially the same as that in Example 1, except that in Example 3, the main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y0=0.2, x=0.2, y1=0.17, y2=0.23, that is, y1<y0, y2>y0.

[0060] Example 4

[0061] This embodiment provides a perovskite solar cell 10 .

[0062] The structure of the perovskite solar cell in Example 4 is substantially the same as that in Example 1, except that in Example 4, the main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y0=0.15, x=0.2, y1=0.14, y2=0.16, that is, y1<y0, y2>y0.

[0063] Example 5

[0064] This embodiment provides a perovskite solar cell 10 .

[0065] The structure of the perovskite solar cell in Example 5 is substantially the same as that in Example 1, except that in Example 5, the main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y0=0.15, x=0.2, y1=0.12, y2=0.18, that is, y1<y0, y2>y0.

[0066] Example 6

[0067] This embodiment provides a perovskite solar cell 10 .

[0068] The structure of the perovskite solar cell in Example 6 is substantially the same as that in Example 1, except that in Example 6, the main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y0=0.15, x=0.2, y1=0.1, y2=0.2, that is, y1<y0, y2>y0.

[0069] Example 7

[0070] This embodiment provides a perovskite solar cell 10 .

[0071] The structure of the perovskite solar cell in Example 7 is substantially the same as that in Example 1, except that in Example 7, the main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y0=0.25, x=0.3, y1=0.24, y2=0.26, that is, y1<y0, y2>y0.

[0072] Example 8

[0073] This embodiment provides a perovskite solar cell 10 .

[0074] The structure of the perovskite solar cell in Example 8 is substantially the same as that in Example 1, except that in Example 8, the main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y0=0.25, x=0.3, y1=0.22, y2=0.28, that is, y1<y0, y2>y0.

[0075] Example 9

[0076] This embodiment provides a perovskite solar cell 10 .

[0077] The structure of the perovskite solar cell in Example 9 is substantially the same as that in Example 1, except that in Example 9, the main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x)3, where y0=0.25, x=0.3, y1=0.2, y2=0.3, that is, y1<y0, y2>y0.

[0078] Comparative Example 1

[0079] This comparative example 1 provides a perovskite solar cell.

[0080] The structure of the perovskite solar cell in Comparative Example 1 is substantially the same as that in Example 1, except that the perovskite layer in Comparative Example 1 includes a perovskite main film layer 301, and does not contain a first perovskite sub-film layer 302 and a second perovskite sub-film layer 303. The main component of the perovskite main film layer 301 is Cs y0 FA 1-y0 Pb(I 1-x Br x )3, wherein y0=0.2, x=0.2, and the perovskite layer is a one-layer structure. The total thickness of the perovskite layer of Comparative Example 1 is 400 nm.

[0081] Comparative Example 2

[0082] This comparative example 2 provides a perovskite solar cell.

[0083] The structure of the perovskite solar cell in this comparative example 2 is basically the same as that in Example 1, except that the perovskite layer in this comparative example 2 includes a perovskite main film layer and a first perovskite sub-film layer. The first perovskite sub-film layer is located on one side of the perovskite main film layer. The main component of the perovskite main film layer is Cs y0 FA 1-y0 Pb(I 1-x Br x )3, the main component of the first perovskite sub-film layer is Cs y1 FA 1-y1 Pb(I 1-x Br x )3. Wherein, y0=0.2, x=0.2, y1=0.15. The thickness of the main perovskite film layer is 390nm. The thickness of the first perovskite sub-film layer is 10nm. The total thickness of the perovskite layer is 400nm.

[0084] Comparative Example 3

[0085] This comparative example 3 provides a perovskite solar cell.

[0086] The structure of the perovskite solar cell in this comparative example 3 is basically the same as that in Example 1, except that the perovskite layer in this comparative example 3 includes a perovskite main film layer and a second perovskite sub-film layer. The second perovskite sub-film layer is located on one side of the perovskite main film layer. The main component of the perovskite main film layer is Csy0 FA 1-y0 Pb(I 1-x Br x )3, the main component of the second perovskite sub-film layer is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, wherein, wherein, y0=0.2, x=0.2, y2=0.25. The thickness of the main perovskite film layer is 390nm. The thickness of the second perovskite sub-film layer is 10nm. The total thickness of the perovskite layer is 400nm.

[0087] Comparative Example 4

[0088] This comparative example 4 provides a perovskite solar cell.

[0089] The structure of the perovskite solar cell in Comparative Example 4 is substantially the same as that in Example 1, except that in Comparative Example 4, the first perovskite sub-film layer 302 and the second perovskite sub-film layer 303 are respectively located on both sides of the perovskite main film layer 301. The main component of the perovskite main film layer 301 is Cs y0 FA 1-y0 Pb(I 1-x Br x )3, the main component of the first perovskite sub-film layer 302 is Cs y1 FA 1-y1 Pb(I 1-x Br x )3. The main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, wherein y0=0.2, x=0.2, y1=0.15, y2=0.15, i.e., y1<y0, y2<y0. The thickness of the main perovskite film layer is 380nm. The thickness of the first perovskite sub-film layer is 10nm. The thickness of the second perovskite sub-film layer is 10nm. The total thickness of the perovskite layer is 400nm.

[0090] Comparative Example 5

[0091] This comparative example 5 provides a perovskite solar cell.

[0092] The structure of the perovskite solar cell in Comparative Example 5 is substantially the same as that in Example 1, except that in Comparative Example 5, the first perovskite sub-film layer 302 and the second perovskite sub-film layer 303 are respectively located on both sides of the perovskite main film layer 301. The main component of the perovskite main film layer 301 is Cs y0 FA 1-y0 Pb(I1-x Br x )3, the main component of the first perovskite sub-film layer 302 is Cs y1 FA 1-y1 Pb(I 1-x Br x )3. The main component of the second perovskite sub-film layer 303 is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, wherein y0=0.2, x=0.2, y1=0.25, y2=0.25, i.e., y1>y0, y2>y0. The thickness of the main perovskite film layer is 380nm. The thickness of the first perovskite sub-film layer is 10nm. The thickness of the second perovskite sub-film layer is 10nm. The total thickness of the perovskite layer is 400nm.

[0093] The performance tests were performed on the perovskite solar cell in Example 1 and the perovskite solar cells in Comparative Examples 1 to 5, and the test results are shown in Table 1.

[0094] Table 1

[0095]

[0096] From the data in Table 1, it can be seen that, in Example 1, y0=0.2, x=0.2, y1=0.15, y2=0.25 are compared with Example 2, y0=0.2, x=0.2, y1=0.19, y2=0.21 are compared with Example 3, and y0=0.2, x=0.2, y1=0.17, y2=0.23 are compared with Example 1. It can be seen that compared with Example 1, y1 and y2 in Example 2 are closer to y0. Therefore, the energy gradient formed by the perovskite layer 300 as a whole in Examples 2 and 3 is smaller than that in Example 1. Therefore, the various test data in Example 1 are better than those in Example 3, and the various test data in Example 3 are better than those in Example 2. Similarly, the various test data in Example 6 are better than those in Example 5, and the various test data in Example 5 are better than those in Example 4. Similarly, the various test data in Example 9 are better than those in Example 8, and the various test data in Example 5 are better than those in Example 7.

[0097] It can be seen from the data in Table 1 that in Examples 1 to 9, the perovskite layers are basically the same, so the opening voltage Voc values ​​are not much different. The increase in the x value of the perovskite layer and the decrease in the y value will lead to significant changes in the opening voltage, FF and current, but the decrease in FF will increase the current. Therefore, the gradient between y1, y2 and y0 cannot be too large, otherwise the energy band gap is too large and the current cannot be increased. Therefore, in this application, y0 ranges from 0.15 to 0.25, y1=y0-(0.01 to 0.05), y2=y0+(0.01 to 0.05), and x ranges from 0.2 to 0.3.

[0098] Furthermore, it can be seen from the data in Table 1 that when Example 1 is compared with Comparative Example 1, Comparative Example 1 does not contain the first perovskite sub-film layer 302 and the second perovskite sub-film layer 303. Therefore, the perovskite solar cell in Comparative Example 1 cannot form a potential energy, and the perovskite layer 300 as a whole cannot form an energy gradient, so the battery efficiency cannot be effectively improved.

[0099] When Example 1 is compared with Comparative Example 2, the first perovskite sub-film layer is arranged on one side of the perovskite main film layer in Comparative Example 2, and the second perovskite sub-film layer is not contained on the other side of the perovskite main film layer. Therefore, in Comparative Example 2, only a potential energy is formed between the perovskite main film layer and the first perovskite sub-film layer, and the battery efficiency is limited compared with Example 1, but the battery efficiency can be slightly improved compared with Comparative Example 1. Similarly, when Example 1 is compared with Comparative Example 3, Comparative Example 3 does not contain the second perovskite sub-film layer, and only a potential energy is formed between the perovskite main film layer and the second perovskite sub-film layer in Comparative Example 3, and the battery efficiency is limited compared with Example 1, but the battery efficiency can be slightly improved compared with Comparative Example 1.

[0100] When Example 1 is compared with Comparative Example 4, although Comparative Example 4 contains the first perovskite sub-film layer 302 and the second perovskite sub-film layer 303, y1<y0 and y2<y0 in Comparative Example 4, therefore, the perovskite solar cell in Comparative Example 4 cannot form a gradient potential energy, and the perovskite layer 300 as a whole cannot form an energy gradient, therefore, compared with Example 1, Comparative Example 4 cannot effectively improve the cell efficiency. Similarly, when Example 1 is compared with Comparative Example 5, although Comparative Example 5 contains the first perovskite sub-film layer 302 and the second perovskite sub-film layer 303, y1>y0 and y2>y0 in Comparative Example 5, therefore, the perovskite solar cell in Comparative Example 5 cannot form a potential energy, and the perovskite layer 300 as a whole cannot form an energy gradient, therefore, the cell efficiency cannot be effectively improved.

[0101] In summary, the above-mentioned perovskite solar cell 10 forms a potential energy between the first perovskite sub-film layer 302, the perovskite main film layer 301, and the second perovskite sub-film layer 303 by adding the first perovskite sub-film layer 302 and the second perovskite sub-film layer 303 with different band gaps on both sides of the perovskite main film layer 301, which helps to improve the efficiency of large-area cells. Due to the different material content composition ratios of the first perovskite sub-film layer 302 and the second perovskite sub-film layer 303 on both sides of the perovskite main film layer 301, the adaptability of the interface between the perovskite main film layer 301 and other functional layers will be easier to achieve. A first perovskite sub-layer 302 and a second perovskite sub-layer 303 with thinner thickness and different content materials are added on both sides of the perovskite main film layer 301, so that the perovskite layer 300 as a whole can form an energy gradient, and due to the band bending caused by the change of the Fermi level, the photogenerated electrons inside the perovskite layer 300 can be driven toward the electron transport layer 200 by the internal electric field, thereby improving the efficiency of large-area batteries.

[0102] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0103] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0104] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A perovskite solar cell, characterized in that: It includes a first transparent electrode layer, an electron transport layer, a perovskite layer, a hole transport layer and a second transparent electrode layer which are sequentially stacked and connected, wherein the perovskite layer includes a perovskite main film layer, a first perovskite sub-film layer and a second perovskite sub-film layer, the first perovskite sub-film layer and the second perovskite sub-film layer are respectively located on both sides of the perovskite main film layer, the material content of the first perovskite sub-film layer and the material content of the second perovskite sub-film layer are respectively less than the material content of the perovskite main film layer, the Fermi energy level of the first perovskite sub-film layer is lower than the Fermi energy level of the perovskite main film layer, and the Fermi energy level of the second perovskite sub-film layer is higher than the Fermi energy level of the perovskite main film layer.

2. The perovskite solar cell according to claim 1, characterized in that: The main component of the perovskite main film layer is Cs y0 FA 1-y0 Pb(I 1-x Br x )3, the main component of the first perovskite sub-film layer is Cs y1 FA 1-y1 Pb(I 1-x Br x )3, the main component of the second perovskite sub-film layer is Cs y2 FA 1-y2 Pb(I 1-x Br x )3, where y1<y0, y2>y0.

3. The perovskite solar cell according to claim 1, characterized in that: The thickness of the first perovskite sub-film layer and the thickness of the second perovskite sub-film layer are respectively smaller than the thickness of the perovskite main film layer.

4. The perovskite solar cell according to any one of claims 1 to 3, characterized in that: The thickness of the perovskite main film layer is 330nm~380nm.

5. The perovskite solar cell according to any one of claims 1 to 3, characterized in that: The thickness of the first perovskite sub-film layer is 10nm~30nm.

6. The perovskite solar cell according to any one of claims 1 to 3, characterized in that: The thickness of the second perovskite sub-film layer is 10nm~30nm.

7. The perovskite solar cell according to any one of claims 1 to 3, characterized in that: The perovskite solar cell further includes a first interface modification layer, and the first interface modification layer is disposed between the perovskite layer and the electron transport layer.

8. The perovskite solar cell according to any one of claims 1 to 3, characterized in that: The perovskite solar cell further includes a second interface modification layer, and the second interface modification layer is disposed between the perovskite layer and the hole transport layer.

9. The perovskite solar cell according to any one of claims 1 to 3, characterized in that: The hole transport layer includes [2-(9H-carbazole-9-yl)ethyl]phosphonic acid and its derivatives, [2-(9H-carbazole-9-yl)butyl]phosphonic acid and its derivatives, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, polyethylene terephthalate, polymer of 3-hexylthiophene, PEDOT:PSS, NiO x and one or more of CuSCN.

10. The perovskite solar cell according to any one of claims 1 to 3, characterized in that: The electron transport layer includes PCBM, SnO2, ZnO2, Al2O3, C 60 and one or more of ICBA.

11. A photovoltaic power generation assembly, characterized in that: Comprising the perovskite solar cell according to any one of claims 1 to 10.

12. The photovoltaic power generation assembly according to claim 11, characterized in that: The photovoltaic power generation component includes a packaging component and a first substrate and a second substrate that are arranged opposite to each other. The first substrate and the second substrate are connected in a circumferential and sealed manner through the packaging component, so that a closed chamber is formed between the first substrate and the second substrate, and the perovskite solar cell is packaged in the closed chamber.

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