Perovskite battery, laminated solar cell, photovoltaic module, photovoltaic power generation system and electrical device

Abstract

A perovskite battery, a laminated solar cell, a photovoltaic module, a photovoltaic power generation system and an electrical device, belonging to the technical field of photovoltaics. The perovskite battery comprises a perovskite light absorption layer and an electron transport layer comprising at least two transport sub-layers. The material of the transport sub-layers comprises metal oxide MxOy, M representing a metal element. The ratio of the number of metal atoms to the number of oxygen atoms in the transport sub-layers is x / y, and in the direction from the perovskite light absorption layer to the electron transport layer, the value of x / y of the transport sub-layers successively increases. Regulating the ratio of the number of metal atoms to the number of oxygen atoms of the metal oxide in the multiple transport sub-layers of the perovskite battery can successively decrease the energy level structure in the electron transport layer in the direction from the perovskite light absorption layer to the electron transport layer, improve the transport capability of carriers in the electron transport layer, and increase the current of the perovskite battery, allowing the perovskite battery to have relatively high photovoltaic energy conversion efficiency.

Description

Perovskite cells, stacked solar cells, photovoltaic modules, photovoltaic power generation systems and electrical equipment

[0001] Cross-references

[0002] This application claims priority to Chinese patent application No. 202410008007.1 filed on January 2, 2024, entitled “Perovskite cells, stacked solar cells, photovoltaic modules, photovoltaic power generation systems and electrical equipment,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of photovoltaic technology, and more specifically, to a perovskite cell, a stacked solar cell, a photovoltaic module, a photovoltaic power generation system, and electrical equipment. Background Art

[0004] Perovskite cells have attracted widespread attention and have great application potential due to their many advantages, such as good optical absorption coefficient, luminescence quantum efficiency, high defect state tolerance, long-range charge transport and low-cost manufacturing process.

[0005] The current photoelectric energy conversion efficiency of perovskite cells is relatively low, which seriously hinders the industrialization of perovskite cells.

[0006] Summary of the Invention

[0007] In response to the deficiencies in the prior art, the present application provides a perovskite cell, a stacked solar cell, a photovoltaic module, a photovoltaic power generation system and electrical equipment to improve the photoelectric energy conversion efficiency of the perovskite cell.

[0008] In a first aspect, the present application provides a perovskite battery, which includes a perovskite light absorbing layer and an electron transport layer, and the electron transport layer includes at least two transport sublayers; the material of the transport sublayer includes a metal oxide M x O y , M represents a metal element; the ratio of the number of metal atoms to oxygen atoms in the transport sublayer is x / y, and the value of x / y of the transport sublayer increases successively along the direction from the perovskite light absorption layer to the electron transport layer.

[0009] In the perovskite battery provided in the present application, the electron transport layer has at least two transport sublayers. The present application regulates the ratio of the number of metal atoms of the metal oxide to the number of oxygen atoms in the multi-layer transport sublayer, and sets the ratio of the number of metal atoms of the metal oxide to the number of oxygen atoms in the transport sublayer to increase successively along the direction from the perovskite light absorption layer to the electron transport layer. The energy level structure in the electron transport layer can be regulated so that the energy level structure in the electron transport layer decreases successively along the direction from the perovskite light absorption layer to the electron transport layer, which can improve the carrier transport capacity in the electron transport layer, thereby improving the current of the perovskite battery, so that the perovskite battery has a higher photoelectric energy conversion efficiency.

[0010] In some embodiments, along the direction from the perovskite light-absorbing layer to the electron transport layer, the thickness ratio of at least two transport sublayers is (2 to 5):1; this can increase the carrier transport capacity in the electron transport layer, thereby enabling the perovskite cell to have a higher photoelectric energy conversion efficiency.

[0011] In some embodiments, along the direction from the perovskite light-absorbing layer to the electron transport layer, the thicknesses of at least two transport sublayers are 13 nm to 30 nm and 5 nm to 15 nm, respectively; this allows for a higher carrier transport capacity in the electron transport layer, and enables the perovskite battery to have a higher photoelectric energy conversion efficiency.

[0012] In some embodiments, y:x≤0.5×z, where z is the highest oxidation state of M.

[0013] In some embodiments, 0.4×z≤y:x≤0.5×z. When the ratio of the number of metal atoms to the number of oxygen atoms in the metal oxide in the transport sublayer satisfies the above range, it is beneficial to fully collect electrons or holes generated by the perovskite light absorption layer absorbing photons under light conditions, thereby further improving the carrier transport capacity of the electron transport layer, further improving the energy level matching between the electron transport layer and the perovskite light absorption layer, and reducing the optical loss of the electron transport layer.

[0014] In some embodiments, when the ratio y:x in a transport sublayer is 0.5×z, the thickness of the transport sublayer with a ratio of y:x of 0.5×z in the electron transport layer accounts for ≤75%. When the ratio of the number of metal atoms of the metal oxide to the number of oxygen atoms in one of the transport sublayers is 1:(0.5×z) (z is the highest oxidation state of the metal element), by regulating the thickness ratio of the transport sublayer in the entire electron transport layer, it is beneficial to further improve the carrier transport capacity in the electron transport layer, thereby increasing the current of the perovskite cell, so that the perovskite cell has a higher photoelectric energy conversion efficiency.

[0015] In some embodiments, the metal element in the metal oxide includes at least one of Sn, Ti, Zn, W, Nb, In, Zr, Ce, Cr, Ba, Sr, Fe, and Li. The metal element in the metal oxide is selected from the above elements to effectively block the migration of spacers, thereby preventing film degradation or deterioration caused by ion migration in the perovskite cell, thereby improving the service life of the perovskite cell.

[0016] In some embodiments, the metal element in the metal oxide includes at least one of Zn, Ti, and Sn.

[0017] In some embodiments, the energy levels of the transport sublayers decrease in the direction from the perovskite light-absorbing layer toward the electron transport layer. This arrangement can improve the carrier transport capability of the electron transport layer, thereby increasing the current of the perovskite cell and resulting in a higher photoelectric energy conversion efficiency.

[0018] In some embodiments, the energy level difference between two adjacent transport sublayers is ≤0.2 eV. The energy level difference between two adjacent transport sublayers within the above range is beneficial for improving the carrier extraction efficiency, thereby improving the photoelectric energy conversion efficiency of the perovskite cell.

[0019] In some embodiments, an intermediate layer is disposed between the perovskite light-absorbing layer and the electron transport layer; the intermediate layer is made of a conductive material containing carbon. The intermediate layer can passivate surface defects in the perovskite light-absorbing layer, improving the interfacial energy level matching between the perovskite light-absorbing layer and the electron transport layer in perovskite cells (particularly trans-structured perovskite cells), thereby preventing the hysteresis effect in perovskite cells, enhancing carrier transport, and improving the photoelectric energy conversion efficiency of perovskite cells.

[0020] In some embodiments, the material of the intermediate layer includes at least one of fullerenes and their derivatives, imide compounds, quinone compounds, pyrrolidone compounds, isoindigo compounds, indigo compounds, benzobisthiadiazole compounds, hexaazine compounds, indenothiophene compounds, tetraphenylethylene compounds, and conjugated polymers. Including the aforementioned materials in the intermediate layer helps prevent the hysteresis effect in perovskite cells and improves the photoelectric energy conversion efficiency of the perovskite cell.

[0021] In some embodiments, the energy level M1 of the intermediate layer is less than the energy level M2 of the transport sublayer adjacent to the intermediate layer, and M2-M1 ≤ 0.2 eV. This can improve the interface energy level matching between the perovskite light-absorbing layer and the electron transport layer in perovskite cells (especially trans-structured perovskite cells), help avoid the hysteresis effect in perovskite cells, improve the carrier transport capability, and improve the photoelectric energy conversion efficiency of perovskite cells.

[0022] In some embodiments, the thickness ratio of the intermediate layer to the electron transport layer is (0.01-50):1; this can enable the perovskite cell to have a higher photoelectric energy conversion efficiency.

[0023] In some embodiments, the thickness ratio of the intermediate layer to the electron transport layer is (1-3): 1. This can give full play to the advantages of the intermediate layer and the electron transport layer, which is conducive to further improving the photoelectric energy conversion efficiency of the perovskite cell.

[0024] In some embodiments, a perovskite cell comprises a transparent substrate layer, a hole transport layer, a perovskite light absorbing layer, an intermediate layer, an electron transport layer, and an electrode layer, arranged in sequence; or, a perovskite cell comprises a transparent substrate layer, an electron transport layer, an intermediate layer, a perovskite light absorbing layer, a hole transport layer, and an electrode layer, arranged in sequence. In such a trans-structured or regular-structured perovskite cell, the interface energy level matching between the perovskite light absorbing layer and the electron transport layer is high, which can improve the photoelectric energy conversion efficiency of the trans-structured or regular-structured perovskite cell.

[0025] In a second aspect, the present application provides a tandem solar cell, which comprises a perovskite cell as provided in any one of the first aspects.

[0026] In a third aspect, the present application provides a photovoltaic module, which includes the perovskite cell provided by any one of the first aspects or the stacked solar cell provided by the second aspect.

[0027] In a fourth aspect, the present application provides a photovoltaic power generation system, which includes a plurality of electrically connected photovoltaic components provided by the third aspect above.

[0028] In a fifth aspect, the present application provides an electrical device, which includes several electrically connected photovoltaic power generation systems provided in the fourth aspect above.

[0029] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0031] FIG1 is a schematic structural diagram of a first perovskite battery provided in some embodiments of the present application;

[0032] FIG2 is a schematic structural diagram of a second perovskite battery provided in some embodiments of the present application;

[0033] FIG3 is a schematic structural diagram of a photovoltaic module provided in some embodiments of the present application.

[0034] icon:

[0035] 1000-PV panels;

[0036] 1100-cell string; 1200-front glass; 1300-front encapsulation film; 1400-back encapsulation film; 1500-back glass;

[0037] 100-perovskite battery;

[0038] 110 - transparent substrate layer; 120 - hole transport layer; 130 - perovskite light absorption layer; 140 - intermediate layer; 150 - electron transport layer; 151 - transport sublayer; 160 - electrode layer. DETAILED DESCRIPTION

[0039] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0041] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0042] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0043] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0044] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0045] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0046] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0047] Solar cells, as green energy sources, are currently seeing increasing market adoption. They are not only used in photovoltaic power generation systems like solar power plants, but are also increasingly being incorporated into electrical devices like electric vehicles. As the application of solar cells continues to expand, market demand is also growing.

[0048] Perovskite cells have become the most widely studied and applied solar cells in recent years due to their many advantages, such as good optical absorption coefficient, luminescence quantum efficiency, high defect state tolerance, long-range charge transport and low-cost manufacturing process.

[0049] Perovskite cells typically include functional layers such as a transparent substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and an electrode layer. The perovskite light-absorbing layer is primarily composed of perovskite materials. When exposed to sunlight, the perovskite light-absorbing layer first absorbs photons to generate electron-hole pairs (excitons). Under the action of the pn junction electric field, the excitons are first separated into electrons and holes and transported to the cathode and anode, respectively. Photogenerated holes flow to the p-region, and photogenerated electrons flow to the n-region. When the circuit is connected, current is generated.

[0050] However, the current perovskite cell's relatively low photoelectric energy conversion efficiency has seriously hindered its industrialization. The inventors have discovered that the relatively low photoelectric energy conversion efficiency of perovskite cells is due to the obstruction of carrier transport in the electron transport layer. This relatively low carrier transport capacity in the electron transport layer results in a low current in the perovskite cell, which in turn affects the photoelectric energy conversion efficiency of the perovskite cell.

[0051] Based on the above considerations, in order to improve the photoelectric energy conversion efficiency of the perovskite cell, the present application designs a perovskite cell, which includes a perovskite light absorbing layer and an electron transport layer, and the electron transport layer includes at least two transport sublayers; the material of the transport sublayer includes metal oxide M x O y , M represents a metal element; the ratio of the number of metal atoms to oxygen atoms in the transport sublayer is x / y, and the value of x / y of the transport sublayer increases successively along the direction from the perovskite light absorption layer to the electron transport layer.

[0052] In the perovskite cell provided in the present application, the electron transport layer has at least two transport sublayers. The present application regulates the ratio of the number of metal atoms of the metal oxide to the number of oxygen atoms in the multi-layer transport sublayer, and sets the ratio of the number of metal atoms of the metal oxide to the number of oxygen atoms in the transport sublayer to increase successively along the direction from the perovskite light absorption layer to the electron transport layer. This can regulate the energy level structure in the electron transport layer so that the energy level structure in the electron transport layer decreases successively along the direction from the perovskite light absorption layer to the electron transport layer, thereby improving the carrier transport capacity in the electron transport layer, thereby improving the current of the perovskite cell, and making the perovskite cell have a higher photoelectric energy conversion efficiency.

[0053] Hereinafter, the technical solution of the present application will be exemplarily described with reference to embodiments.

[0054] Referring to Figures 1 and 2, the present application provides a perovskite cell 100, which includes a perovskite light absorption layer 130 and an electron transport layer 150, and the electron transport layer 150 includes at least two transport sublayers 151; the material of the transport sublayer 151 includes a metal oxide; along the direction from the perovskite light absorption layer 130 to the electron transport layer 150, the ratio of the number of metal atoms of the metal oxide to the number of oxygen atoms in the transport sublayer 151 increases successively.

[0055] The perovskite cell 100 is a perovskite solar cell, which generally includes functional layers such as a transparent substrate layer 110 , a hole transport layer 120 , a perovskite light absorbing layer 130 , an electron transport layer 150 , and an electrode layer 160 .

[0056] The perovskite cell 100 provided in the embodiment of the present application can be a regular structure perovskite cell 100 or a trans structure perovskite cell 100, both of which can improve the device efficiency (i.e., photoelectric energy conversion efficiency) and commercial value of the corresponding perovskite cell 100.

[0057] Please refer to Figure 1. In the inverted structure perovskite cell 100, the transparent substrate layer 110, the hole transport layer 120, the perovskite light absorbing layer 130, the electron transport layer 150 and the electrode layer 160 are arranged in sequence; please refer to Figure 2. In the formal structure perovskite cell 100, the transparent substrate layer 110, the electron transport layer 150, the perovskite light absorbing layer 130, the hole transport layer 120 and the electrode layer 160 are arranged in sequence.

[0058] In the perovskite cell 100 provided in the embodiment of the present application, in addition to improving the electron transport layer 150 , the specifications and material types of other functional layers can be selected or designed as needed.

[0059] The transparent substrate layer 110 serves as an electrode with high conductivity and high visible light transmittance, and is an output terminal of the perovskite cell 100. The types of the transparent substrate layer 110 include, but are not limited to, FTO (fluorine-doped SnO2 transparent conductive glass), ITO (indium tin oxide transparent conductive glass), AZO (aluminum-doped zinc oxide transparent conductive glass), BZO (benzodiazepine transparent conductive glass), and IZO (indium zinc oxide transparent conductive glass).

[0060] The hole transport layer 120 is an important component of the perovskite cell 100. Its main function is to collect and transport holes, realize effective separation of electrons and holes, and protect the perovskite light absorbing layer 130 from the erosion of oxygen and water vapor, which has an important impact on the efficiency and stability of the perovskite cell 100. The hole transport material in the hole transport layer 120 is, for example, at least one of the following materials, their derivatives, and materials obtained by doping or passivation: poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA), poly 3-hexylthiophene, triphenylamine with triptycene as the core (H101), 3,4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N- (4-phenylamino) carbazole-spirobifluorene (CzPAF-SBF), poly (3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT:PSS), polythiophene, nickel oxide (NiO x ), molybdenum oxide (MoO3), cuprous iodide (CuI), cuprous oxide (CuO), 2,2',7,7'tetrakis (N,N-p-methoxyanilino) 9,9' spirobifluorene, methoxytriphenylamine fluoroformamidine, poly (3,4-ethylenedioxythiophene), polystyrene sulfonic acid, triphenylamine with triptylide as the core, phosphoric acid-based monomers, carboxylic acid-based monomers, carbazolyl monomers, sulfonic acid-based monomers, triphenylamine-based monomers, aromatic monomers, metal oxides, cuprous thiocyanate, etc.; wherein the metal element in the metal oxide selected in the hole transport material includes at least one of Ni, Mo and Cu.

[0061] As an example, the thickness of the hole transport layer 120 is, for example, 5500 nm, and may be 1020 nm.

[0062] The perovskite light absorbing layer 130 is the core component of the perovskite cell 100, which is used to absorb the photon energy of sunlight and generate electrons.

[0063] The holes are collected by the transparent electrode through the hole transport layer 120, and the electrons are collected by the electrode layer 160. The transparent electrode and the electrode layer 160 are connected to form a circuit to generate photocurrent.

[0064] The chemical formula of the perovskite material in the perovskite light absorbing layer 130 satisfies ABX3, wherein A is an inorganic, organic, or organic-inorganic mixed cation, B is an inorganic, organic, or organic-inorganic mixed cation, and X is an inorganic, organic, or organic-inorganic mixed anion. A is selected from CH3NH3 + (abbreviated as MA + ), CH(NH2) 2+ (abbreviated as FA + )、Li + 、Na + , K +, Rb + and Cs + At least one of; optionally, M is selected from CH3NH3 + 、CH(NH2) 2+ and Cs + At least one of. B is selected from Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Fe 2+ 、Co 2+ and Ni 2+ At least one of; optionally, B is selected from Pb 2+ 、Sn 2+ One or two of X is selected from Cl - Br - and I - At least one of; optionally, X is selected from Cl - Br - and I - At least one of .

[0065] As an example, perovskite materials include but are not limited to CH3NH3PbI3 (abbreviated as MAPbI3), CH(NH2)2PbI3 (abbreviated as FAPbI3), Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 )3 (abbreviated as CsFAMA), CsPbI3, CsPbI2Br, and CsPbIBr2.

[0066] As an example, the band gap of the perovskite light absorbing layer 130 is between 1.20 eV and 2.30 eV. The band gap measurement method includes, for example, obtaining an ultraviolet absorption curve through ultraviolet absorption spectroscopy testing and then calculating the perovskite band gap using the Tauc equation. The thickness of the perovskite light absorbing layer 130 is between 100 nm and 1000 nm, for example, but not limited to, any point value among 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, and 1000 nm, or a range of values ​​between any two thereof; wherein the thickness of the perovskite light absorbing layer 130 refers to the dimension of the perovskite light absorbing layer 130 in the thickness direction of the perovskite cell 100, and the thickness direction of the perovskite cell 100 also refers to the direction in which the functional layers are stacked in sequence.

[0067] Electrode layer 160 serves as the other output terminal of perovskite cell 100. Electrode layer 160 is an organic, inorganic, or organic-inorganic hybrid conductive material, wherein the conductive material is at least one of an organic conductive material and an inorganic conductive material. The organic conductive material may be a conductive polymer, including but not limited to at least one of polyethylenedioxythiophene (PEDOT), polythiophene, and polyacetylene. The inorganic conductive material includes but is not limited to at least one of a transparent conductive oxide, a metal, and a carbon derivative. Specific examples of the inorganic conductive material include Ag, Cu, C, Au, Al, ITO, AZO, BZO, and IZO.

[0068] As an example, the thickness of the electrode layer 160 is, for example, 10 nm to 1000 nm.

[0069] The electron transport layer 150 collects electrons or holes generated by photons absorbed by the perovskite light-absorbing layer 130 under illumination, playing an important role in transporting electrons and preventing electron-hole recombination. The electron transport layer 150 plays a crucial role in the perovskite cell 100, and its performance directly impacts the cell's performance.

[0070] In the present application, the electron transport layer 150 includes at least two transport sublayers 151; the material of the transport sublayer 151 includes metal oxide M x O y , M represents a metal element; the ratio of the number of metal atoms to oxygen atoms in the transport sublayer is x / y, and the value of x / y of the transport sublayer increases successively along the direction from the perovskite light absorption layer to the electron transport layer.

[0071] Among them, "M x O y "O" in " is oxygen, "M x O y" " and "y" represent the number of metal atoms and the number of oxygen atoms in the metal oxide, respectively.

[0072] “The x / y values ​​of the transport sublayer 151 increase successively along the direction from the perovskite light absorption layer 130 to the electron transport layer 150” means that the “ratio x / y of the number of metal atoms to the number of oxygen atoms in the metal oxide” in all transport sublayers 151 is different from each other, and along the direction from the perovskite light absorption layer 130 to the electron transport layer 150, the “x / y values” corresponding to the transport sublayer 151 increase successively.

[0073] The present application does not limit the number of transport sublayers 151 in the electron transport layer 150 , and the number may be 2, 3 or more.

[0074] It should be noted that the ratio of the number of metal atoms to oxygen atoms in each transport sublayer 151 in the electron transport layer 150 is x / y, which can be analyzed and determined by time-of-flight secondary ion mass spectrometry (TOF-SIMS).

[0075] The present application regulates the ratio of the number of metal atoms of the metal oxide to the number of oxygen atoms in the transport sublayer 151 in the electron transport layer 150, and sets the ratio of the number of metal atoms of the metal oxide to the number of oxygen atoms in the transport sublayer 151 to increase successively along the direction from the perovskite light absorption layer 130 to the electron transport layer 150. This can regulate the energy level structure in the electron transport layer 150 so that the energy level structure in the electron transport layer 150 decreases successively along the direction from the perovskite light absorption layer 130 to the electron transport layer 150, thereby improving the carrier transport capacity in the electron transport layer 150, thereby improving the current of the perovskite battery 100, and making the perovskite battery 100 have a higher photoelectric energy conversion efficiency.

[0076] In some embodiments, along the direction from the perovskite light absorbing layer 130 to the electron transport layer 150, the thickness ratio of at least two transport sublayers 151 is (2 to 5):1; this can make the carrier transport capacity in the electron transport layer 150 higher, so that the perovskite battery 100 has a higher photoelectric energy conversion efficiency.

[0077] Among them, "the thickness ratio of at least two transmission sublayers 151 along the direction pointing from the perovskite light absorption layer 130 to the electron transport layer 150" refers to the ratio of the thickness of "the transmission sublayer 151 (denoted as the first sublayer) close to the perovskite light absorption layer 130 among the at least two transmission sublayers 151" and the thickness of "the transmission sublayer 151 adjacent to the aforementioned first sublayer and located on the side away from the perovskite light absorption layer 130 among the at least two transmission sublayers 151".

[0078] As an example, along the direction from the perovskite light absorbing layer 130 to the electron transport layer 150, the thickness ratio of at least two transport sublayers 151 can be any value among 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1 and 5:1 or a range value between any two of them.

[0079] In some embodiments, along the direction from the perovskite light absorbing layer 130 to the electron transport layer 150, the thicknesses of at least two transport sublayers 151 are 13 nm to 30 nm and 5 nm to 15 nm, respectively; this allows the electron transport layer 150 to have a higher carrier transport capacity, so that the perovskite battery 100 has a higher photoelectric energy conversion efficiency.

[0080] Among them, "along the direction of the perovskite light absorption layer 130 pointing to the electron transport layer 150, the thicknesses of at least two transport sublayers 151 are 13nm~30nm and 5nm~15nm respectively" means: "Among the at least two transport sublayers 151, the transport sublayer 151 close to the perovskite light absorption layer 130 (denoted as the first sublayer)" has a thickness of 13nm~30nm, and "Among the at least two transport sublayers 151, the transport sublayer 151 adjacent to the aforementioned first sublayer and located on the side away from the perovskite light absorption layer 130" has a thickness of 5nm~15nm.

[0081] As an example, the thickness of "the transmission sublayer 151 (denoted as the first sublayer) among the at least two transmission sublayers 151, which is close to the perovskite light absorbing layer 130" can be any value among 13nm, 13.3nm, 15nm, 17.5nm, 20nm, 22.5nm, 25nm, 27.5nm and 30nm, or a range value between any two of them; the thickness of "the transmission sublayer 151 (denoted as the first sublayer) among the at least two transmission sublayers 151, which is adjacent to the aforementioned first sublayer and located on the side away from the perovskite light absorbing layer 130" can be any value among 5nm, 5.5nm, 6nm, 6.5nm, 7nm, 7.5nm, 8nm, 8.5nm, 9nm, 9.5nm, 10nm, 10.5nm, 11nm, 11.5nm, 12nm, 12.5nm, 13nm, 13.5nm, 14nm, 14.5nm and 15nm, or a range value between any two of them.

[0082] In some embodiments, the metal oxide is expressed as M x O y , M represents a metal element, y:x≤0.5×z, z is the highest oxidation state of M.

[0083] Here, “the highest oxidation state of M” means that the valence state corresponding to the metal element corresponding to M is the highest oxidation state when all valence electrons are lost or transferred (electron pairs deviate from the atom).

[0084] The "×" in "0.5×z" is a multiplication sign. The value corresponding to "0.5×z" is 0.5 times the value corresponding to "z". All "×" mentioned below are multiplication signs.

[0085] In some embodiments, 0.4×z≤y:x≤0.5×z. x O y The ratio y:x of "y" and "x" in the above range is beneficial to fully collect the electrons or holes generated by the perovskite light absorption layer 130 absorbing photons under light conditions, which is beneficial to further improve the carrier transmission capacity in the electron transport layer 150, and can also further improve the energy level matching between the electron transport layer 150 and the perovskite light absorption layer 130, and can also reduce the optical loss of the electron transport layer 150.

[0086] As an example, M x O y The ratio y:x of "y" and "x" can be any point value among 0.4×z, 0.42×z, 0.425×z, 0.43×z, 0.44×z, 0.45×z, 0.46×z, 0.47×z, 0.48×z, 0.49×z and 0.5×z, or any range value between two of them.

[0087] In some embodiments, when the electron transport layer 150 includes a transport sublayer 151 with a y:x ratio of 0.5×z, the thickness of the transport sublayer 151 with a y:x ratio of 0.5×z in the electron transport layer 150 accounts for ≤75%.

[0088] It is understandable that in other feasible embodiments, there may also be a transport sublayer 151 in the electron transport layer 150 that does not have "y:x is 0.5×z", that is, the y:x of the transport sublayer 151 in the electron transport layer 150 is less than 0.5×z.

[0089] When the ratio of the number of metal atoms of the metal oxide to the number of oxygen atoms in one of the transport sublayers 151 is 1:(0.5×z) (z is the highest oxidation state of the metal element), by regulating the thickness of the transport sublayer 151 in the entire electron transport layer 150 to ≤75%, it is beneficial to further improve the carrier transport capacity in the electron transport layer 150, thereby increasing the current of the perovskite battery 100, so that the perovskite battery 100 has a higher photoelectric energy conversion efficiency.

[0090] As an example, when the electron transport layer 150 has a transport sublayer 151 with "y:x of 0.5×z", the thickness of the transport sublayer 151 with y:x of 0.5×z in the electron transport layer 150 can be any value among 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% and 75%, or any range value between two of them.

[0091] In some embodiments, compared to when the y:x of all transport sublayers 151 is less than 0.5×z, when the y:x of one transport sublayer 151 is 0.5×z, it is beneficial to further improve the carrier transport capacity in the electron transport layer 150, thereby increasing the current of the perovskite battery 100, so that the perovskite battery 100 has a higher photoelectric energy conversion efficiency.

[0092] In some embodiments, the metal element in the metal oxide includes at least one of Sn, Ti, Zn, W, Nb, In, Zr, Ce, Cr, Ba, Sr, Fe, and Li. This can effectively block the migration of spacers, thereby preventing film degradation or deterioration caused by ion migration in the perovskite cell 100, and improving the service life of the perovskite cell 100.

[0093] In some embodiments, the metal element in the metal oxide includes at least one of Zn, Ti, and Sn.

[0094] In some embodiments, when the metal element in the metal oxide includes Sn, the highest oxidation state of Sn is 4, and the corresponding Sn x O y The ratio of "y" to "x" in y:x≤2 (i.e. 0.5×4); further, Sn x O y The ratio of "y" to "x" satisfies: 1.7≤y:x≤2.

[0095] As an example, when the metal element in the metal oxide includes Sn, the metal oxide Sn in each transmission sublayer 151 x O y The ratio y:x of "y" and "x" in the above formula can be any value among 2, 1.9, 1.8, 1.7, 1.6 and 1.5 or any range between them; for example, the metal oxide Sn in each transmission sublayer 151 x O y Can be SnO2, SnO 1.9 、SnO 1.8 、SnO 1.7 or SnO 1.6 etc.

[0096] In some embodiments, in addition to the metal oxide, the transport sublayer 151 may also contain other electron transport materials, such as at least one of the following materials, their derivatives, and materials obtained by doping or passivation: imine compounds, quinone compounds, fullerenes and their derivatives, silicon oxide, strontium titanate, calcium titanate, lithium fluoride, and calcium fluoride; as an example, the other electron transport material can be selected from [6,6]-phenyl C61 butyric acid methyl ester (PC61BM), [6,6]-phenyl C71 butyric acid methyl ester (PC71BM), fullerene C 60 , fullerene C 61 , fullerene C 70 , Yutongling, etc.

[0097] As an example, the thickness of the electron transport layer 150 may be, for example, 5 to 200 nm, or optionally 20 to 50 nm.

[0098] In some embodiments, the energy level of the transport sublayer 151 decreases sequentially along the direction from the perovskite light absorbing layer 130 to the electron transport layer 150. This configuration improves the carrier transport capability of the electron transport layer 150, thereby increasing the current of the perovskite cell 100 and enabling the perovskite cell 100 to have a higher photoelectric energy conversion efficiency.

[0099] In some embodiments, the energy level difference between two adjacent transport sublayers 151 is ≤0.2 eV, which is beneficial to improving the carrier extraction efficiency and thus improving the photoelectric energy conversion efficiency of the perovskite cell 100 .

[0100] As an example, the energy level difference between two adjacent transmission sublayers 151 can be any value among 0.01eV, 0.02eV, 0.05eV, 0.07eV, 0.1eV, 0.12eV, 0.15eV, 0.17eV and 0.2eV, or a range of values ​​between any two of them.

[0101] In some embodiments, an intermediate layer 140 is disposed between the perovskite light absorbing layer 130 and the electron transport layer 150 ; the intermediate layer 140 is made of a conductive material containing carbon.

[0102] Here, "conductive material containing carbon elements" means that the material contains carbon atoms and has the ability to extract or transfer electrons.

[0103] Because the perovskite light-absorbing layer 130 is a polycrystalline thin film, its surface inevitably contains numerous defects, primarily uncoordinated ions and dangling bonds at grain boundaries and crystal surfaces. These surface defects in the perovskite light-absorbing layer 130 can cause hysteresis in the perovskite cell 100.

[0104] The hysteresis effect refers to the presence of a certain lag between the output current of the perovskite cell 100 and the input light intensity. Specifically, when light intensity changes from low to high, the output current of the perovskite cell 100 does not immediately follow the change, but rather there is a certain delay. This phenomenon results in a certain nonlinear relationship between the output current of the perovskite cell 100 and the input light intensity, thereby affecting the performance and efficiency of the solar cell.

[0105] The present application provides an intermediate layer 140 between the perovskite light-absorbing layer 130 and the electron transport layer 150, which can passivate the defects on the surface of the perovskite light-absorbing layer 130, thereby improving the interface energy level matching between the perovskite light-absorbing layer 130 and the electron transport layer 150 in the perovskite cell 100 (especially the trans-structured perovskite cell 100), which is beneficial to avoiding the hysteresis effect of the perovskite cell 100, improving the carrier transmission capacity, and improving the photoelectric energy conversion efficiency of the perovskite cell 100.

[0106] In some embodiments, the material of the intermediate layer 140 includes at least one of fullerene and its derivatives, imide compounds, quinone compounds, pyrrolidone compounds, isoindigo compounds, indigo compounds, benzobisthiadiazole compounds, hexaazine compounds, indenothiophene compounds, tetraphenylethylene compounds, and conjugated polymers. The conjugated polymer includes at least one of PFN-2TNDI, PBDT-PDI, NDP-V, P(NDI2DT-TTCN), PN-F, and PF-PDI.

[0107] The material of the intermediate layer 140 includes the above-mentioned substances, which is beneficial to avoiding the hysteresis effect of the perovskite cell 100 and improving the photoelectric energy conversion efficiency of the perovskite cell 100.

[0108] In some embodiments, the energy level M1 of the intermediate layer 140 is less than the energy level M2 of the transport sublayer 151 adjacent to the intermediate layer 140, and M2-M1≤0.2eV. The above configuration can improve the interface energy level matching between the perovskite light absorbing layer 130 and the electron transport layer 150 in the perovskite cell 100 (especially the trans-structured perovskite cell 100), which helps to avoid the hysteresis effect of the perovskite cell 100, improve the carrier transport capability, and improve the photoelectric energy conversion efficiency of the perovskite cell 100.

[0109] As an example, M2-M1 can be any value among 0.01eV, 0.02eV, 0.05eV, 0.07eV, 0.1eV, 0.12eV, 0.15eV, 0.17eV and 0.2eV, or a range of values ​​between any two of them.

[0110] In some embodiments, the thickness ratio of the intermediate layer 140 to the electron transport layer 150 is (0.01-50):1, which can enable the perovskite cell to have a higher photoelectric energy conversion efficiency.

[0111] Here, “the thickness ratio of the intermediate layer 140 to the electron transport layer 150 ” refers to the ratio of the thickness of the intermediate layer 140 to the thickness of the entire electron transport layer 150 .

[0112] As an example, the thickness ratio of the intermediate layer 140 to the electron transport layer 150 can be any value among 0.01:1, 1:1, 5:1, 10:1, 20:1, 30:1, 40:1 and 50:1, or a range of values ​​therebetween.

[0113] In some embodiments, the thickness ratio of the intermediate layer 140 to the electron transport layer 150 is (1-3):1.

[0114] The thickness ratio of the intermediate layer 140 to the electron transport layer 150 is (1-3):1, which can give full play to the advantages of the intermediate layer 140 and the electron transport layer 150 and is conducive to further improving the photoelectric energy conversion efficiency of the perovskite cell 100.

[0115] As an example, the thickness ratio of the intermediate layer 140 to the electron transport layer 150 can be any value among 1:1, 1.2:1, 1.5:1, 1.7:1, 2:1, 2.2:1, 2.5:1, 2.7:1 and 3:1, or a range between any two values.

[0116] As an example, the thickness of the intermediate layer 140 may be, for example, 5 nm to 100 nm.

[0117] Based on the above embodiment, the preparation process of the inverted perovskite cell 100 exemplarily includes:

[0118] Step 1: Clean the transparent base layer 110 and blow dry it for later use;

[0119] Step 2: Prepare a hole transport layer 120 on the transparent base layer 110 for later use;

[0120] Step 3: Prepare a perovskite light absorbing layer 130 on the hole transport layer 120 for later use;

[0121] Step 4: Prepare an intermediate layer 140 on the perovskite light absorbing layer 130 for later use;

[0122] Step 5: Prepare an electron transport layer 150 (including at least two transport sublayers 151 ) on the intermediate layer 140 for later use;

[0123] Step 6: Prepare the electrode layer 160 on the electron transport layer 150 and perform edge cleaning test.

[0124] In some embodiments, the intermediate layer 140 may not be prepared, and the electron transport layer 150 may be directly prepared on the perovskite light absorbing layer 130 .

[0125] The preparation process of the formal structure perovskite cell 100 exemplarily includes:

[0126] Step 1: Clean the transparent base layer 110 and blow dry it for later use;

[0127] Step 2: preparing an electron transport layer 150 (including at least two transport sublayers 151 ) on the transparent substrate layer 110 for later use;

[0128] Step 3: Prepare an intermediate layer 140 on the electron transport layer 150 for later use;

[0129] Step 4: Prepare a perovskite light absorbing layer 130 on the intermediate layer 140 for later use;

[0130] Step 5: Prepare a hole transport layer 120 on the perovskite light absorbing layer 130 for later use;

[0131] Step 6: Prepare the electrode layer 160 on the hole transport layer 120 and perform edge cleaning test.

[0132] In some embodiments, the intermediate layer 140 may not be prepared, and the perovskite light absorbing layer 130 may be directly prepared on the electron transport layer 150 .

[0133] In this embodiment, the transparent substrate layer 110, the hole transport layer 120, the perovskite light absorbing layer 130, the intermediate layer 140, the electron transport layer 150 and the electrode layer 160 have a suitable arrangement order, which facilitates the formation of each layer structure and makes the process convenient.

[0134] It can be understood that the preparation methods of the above-mentioned layers include but are not limited to chemical bath deposition, electrochemical deposition, chemical vapor deposition, physical epitaxial growth, thermal evaporation co-evaporation, atomic layer deposition, magnetron sputtering, precursor coating, precursor slit coating, precursor scraping, etc., and those skilled in the art can make a choice according to actual needs. In addition to the above-mentioned setting method, a mechanical pressing method can also be used to form at least two interconnected functional layers at one time.

[0135] Optionally, each layer is prepared by a thermal evaporation method or a precursor liquid coating method, wherein the precursor liquid coating method can be a spin coating method.

[0136] As an example, the method of the inverted perovskite cell 100 includes: depositing a hole transport layer 120 on the surface of a transparent substrate by a magnetron sputtering method; spin-coating a perovskite light absorption layer 130 slurry on the surface of the hole transport layer 120 at a rotation speed of 3000 rpm to 4500 rpm, and then drying it on a constant temperature hot stage at, for example, 100 to 200 ° C to obtain the perovskite light absorption layer 130; and then using a vacuum evaporation method in a vacuum thermal evaporation device at 4×10 4 Pa vacuum conditions, the intermediate layer 140 is deposited on the surface of the perovskite light absorbing layer 130; the electron transport layer 150 (including at least two transport sublayers 151) is deposited on the surface of the intermediate layer 140 by atomic deposition method; and then the vacuum coating machine is used to coat the electrons in the vacuum coating machine at 5×10 4 Under a vacuum condition of 0.04 Pa, the electrode layer 160 is evaporated on the surface of the electron transport layer 150 .

[0137] As an example, the method of the formal structure of the perovskite cell 100 includes: depositing an electron transport layer 150 (including at least two transport sublayers 151) on the surface of a transparent substrate by an atomic deposition method; then using a vacuum evaporation method to deposit an electron transport layer 150 (including at least two transport sublayers 151) in a vacuum thermal evaporation device at 4×10 4 Pa, depositing the intermediate layer 140 on the surface of the electron transport layer 150; spin coating the perovskite light absorption layer 130 slurry on the surface of the intermediate layer 140 at a rotation speed of 3000 rpm to 4500 rpm, and then drying it on a constant temperature hot stage at, for example, 100 to 200 ° C to obtain the perovskite light absorption layer 130; depositing the hole transport layer 120 on the surface of the perovskite light absorption layer 130 by a magnetron sputtering method; and then in a vacuum coating machine, at 5×10 4 Under a vacuum condition of 1.5 Pa, the electrode layer 160 is evaporated on the surface of the hole transport layer 120 .

[0138] According to some embodiments of the present application, the present application further provides a tandem solar cell comprising the perovskite cell 100 provided by any of the above solutions. Referring to FIG3 , according to some embodiments of the present application, the present application further provides a photovoltaic module 1000 comprising the perovskite cell 100 provided by any of the above solutions.

[0139] Photovoltaic module 1000 refers to a solar cell module, i.e., an integrated assembly comprising multiple perovskite cells 100. This assembly includes multiple cell strings 1100, each of which comprises multiple perovskite cells 100 connected in series via connectors such as solder ribbons. The term "several" refers to an integer of one, two, or more.

[0140] In the photovoltaic module 1000, in addition to the cell string 1100, it can also include front glass 1200, front packaging film 1300, back packaging film 1400, back glass 1500, etc. As an example, the photovoltaic module 1000 includes the front glass 1200, the front packaging film 1300, the cell string 1100, the back packaging film 1400 and the back glass 1500 stacked in sequence along the thickness direction.

[0141] According to some embodiments of the present application, the present application further provides a photovoltaic assembly 1000, which includes the stacked solar cell provided above.

[0142] According to some embodiments of the present application, the present application further provides a photovoltaic power generation system, which includes a plurality of electrically connected photovoltaic components 1000 .

[0143] Several refers to a number of one, two or more integers.

[0144] Photovoltaic power generation system refers to a power generation system that uses the photovoltaic effect to directly convert solar radiation energy into electrical energy. It is divided into a stand-alone photovoltaic power generation system (Stand alone PV System) and a grid-connected photovoltaic power generation system (Grid connected PV System). A stand-alone photovoltaic power generation system consists of a solar photovoltaic array consisting of 1000 photovoltaic modules, a battery pack, a charge controller, a power electronic converter (inverter), a load, etc. A grid-connected photovoltaic power generation system consists of a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter), and a system monitoring system.

[0145] According to some embodiments of the present application, the present application further provides an electrical device, which includes the photovoltaic power generation system provided by the above solution, and the photovoltaic power generation system is used to provide electrical energy to the electrical device.

[0146] Electrical equipment can be in various forms, such as electric cars, ships, spacecraft, solar water heaters, solar energy, etc.

[0147] The power supply method for the electrical equipment can be solely powered by the photovoltaic module 1000, or it can be powered by the photovoltaic module 1000 and the energy storage battery. That is, the electrical equipment is equipped with both the photovoltaic module 1000 and the energy storage battery. The energy storage battery is not limited to primary batteries and secondary batteries, and can be, for example, but not limited to, lithium-ion secondary batteries and sodium-ion secondary batteries.

[0148] Next, one or more embodiments will be described in more detail with reference to the following examples. Of course, these examples do not limit the scope of one or more embodiments.

[0149] Example 1

[0150] The perovskite cell 100 shown in FIG1 , wherein the preparation method thereof comprises:

[0151] (1) Preparation of transparent base layer 110:

[0152] The surface of FTO conductive glass with a size of 2.0 cm×2.0 cm was cleaned twice with acetone and isopropyl alcohol in sequence, immersed in deionized water for ultrasonic treatment for 10 minutes, dried in a forced air drying oven, and placed in a glove box (N2 atmosphere) to serve as the transparent base layer 110.

[0153] (2) Preparation of hole transport layer 120:

[0154] Nickel oxide was deposited on the surface of the conductive glass by magnetron sputtering to form a hole transport layer 120 with a thickness of 15 nm.

[0155] (3) Preparation of perovskite light absorbing layer 130:

[0156] A mixed DMF solution of 5 mg / mL CuInP2S6 nanocolloid and 1.5 mol / L FAPbI3 was spin-coated on the obtained hole transport layer 120 at a speed of 4000 rpm. The layer was then moved to a constant temperature hot plate and heated at 100°C for 30 minutes. After cooling to room temperature, a perovskite light absorption layer 130 with a thickness of 500 nm was formed.

[0157] Preparation of the intermediate layer 140:

[0158] The device prepared above was placed in a vacuum thermal evaporation device and vacuumed to 4×10 -4 Pa, a 30nm material C is deposited on the surface of the perovskite light absorbing layer 130. 60 The middle layer 140.

[0159] (5) Preparation of electron transport layer 150:

[0160] Two transmission sublayers 151 made of tin oxide are sequentially deposited on the surface of the intermediate layer 140 using an atomic layer deposition method. The ratio of tin atoms to oxygen atoms (Sn / O) in the tin oxide of the two transmission sublayers 151 is 1:2.0 and 1:1.7, respectively. The thicknesses of the two transmission sublayers 151 are 20 nm and 10 nm, respectively.

[0161] (6) Preparation of electrode layer 160:

[0162] The device prepared above was placed in a vacuum coating machine and -4 Under a vacuum condition of 1.5 Å Pa, a Cu electrode was evaporated on the surface of the electron transport layer 150 at a deposition rate of 0.1 Å / s to form an electrode layer 160 with a thickness of 80 nm.

[0163] Example 2

[0164] The perovskite cell 100 shown in FIG2 , wherein the preparation method includes:

[0165] (1) Preparation of transparent base layer 110:

[0166] The surface of FTO conductive glass with a size of 2.0 cm×2.0 cm was cleaned twice with acetone and isopropyl alcohol in sequence, immersed in deionized water for ultrasonic treatment for 10 minutes, dried in a forced air drying oven, and placed in a glove box (N2 atmosphere) to serve as the transparent base layer 110.

[0167] (2) Preparation of electron transport layer 150:

[0168] Two transmission sublayers 151 made of tin oxide are sequentially deposited on the surface of the transparent base layer 110 using an atomic layer deposition method. The ratio of tin atoms to oxygen atoms (Sn / O) in the tin oxide of the two transmission sublayers 151 is 1:1.7 and 1:2.0, respectively. The thicknesses of the two transmission sublayers 151 are 10 nm and 20 nm, respectively.

[0169] (3) Preparation of the intermediate layer 140:

[0170] The device prepared above was placed in a vacuum thermal evaporation device and vacuumed to 4×10 -4 Pa, a 30 nm layer of C is deposited on the surface of the electron transport layer 150. 60 The middle layer 140.

[0171] (4) Preparation of perovskite light absorbing layer 130:

[0172] A mixed DMF solution of 5 mg / mL CuInP2S6 nanocolloid and 1.5 mol / L FAPbI3 was spin-coated on the obtained intermediate layer 140 at a speed of 4000 rpm, and then moved to a constant temperature hot stage and heated at 100°C for 30 minutes. After cooling to room temperature, a perovskite light absorption layer 130 with a thickness of 500 nm was formed.

[0173] (5) Preparation of hole transport layer 120:

[0174] A chlorobenzene solution of 73 mg / mL Spiro-OMeTAD was spin-coated on the surface of the perovskite light absorption layer 130 at a speed of 3000 rpm using a magnetron sputtering method to form a hole transport layer 120 with a thickness of 30 nm.

[0175] (6) Preparation of electrode layer 160:

[0176] The device prepared above was placed in a vacuum coating machine and -4Under a vacuum condition of 1.5 Å Pa, a Cu electrode was evaporated on the surface of the hole transport layer 120 at a rate of 0.1 Å / s to form an electrode layer 160 with a thickness of 80 nm.

[0177] Examples 3 to 26 and Comparative Examples 1 to 8

[0178] The differences between Examples 3 to 14 and Comparative Examples 1 to 4 and Example 1 are shown in Tables 1 and 2. The differences between Examples 15 to 26 and Comparative Examples 5 to 8 and Example 2 are shown in Tables 1 and 2.

[0179] Table 1 Parameters of the electron transport layer of perovskite cells.

[0180] In Table 1, “ / ” means that there is no corresponding parameter. In Comparative Examples 2 and 6, “SnO2 and SnO 1.7 The mass ratio is 2:1" means that the transport sublayer contains SnO2 and SnO with a mass ratio of 2:1. 1.7 The mixture of TiO2 and TiO 1.7 The mass ratio is 2:1" means that the transmission sublayer is composed of TiO2 and TiO 1.7 mixture.

[0181] Table 2 Parameters of perovskite cells

[0182] In Table 2, PCBM refers to [6,6]-phenyl-C61 butyric acid methyl ester, and “ / ” means that there is no corresponding parameter.

[0183] The energy conversion efficiency of the perovskite cells prepared in Examples 1 to 26 and Comparative Examples 1 to 8 was measured, and the results are shown in Table 3. The test conditions for the energy conversion efficiency are as follows:

[0184] Under atmospheric conditions, the sunlight simulation light source uses the AM1.5G standard light source, and a four-channel digital source meter (Keithley2440) is used to measure the volt-ampere characteristic curve of the battery under the light source to obtain the battery operating output power Pout (unit: mW / cm 2 ), and the energy conversion efficiency Eff (Efficiency) of the battery is calculated from this; where, for the AM1.5G standard light source, the incident light power Popt is 100mW / cm 2 .

[0185] The energy conversion efficiency is calculated as follows: Eff = (Pout / Popt) x 100%.

[0186] Table 3 Test results of perovskite battery 100

[0187] As can be seen from Table 3, the energy conversion efficiency of the trans-structured perovskite batteries prepared in Example 1 and Examples 3 to 14 is higher than that of the trans-structured perovskite batteries prepared in Comparative Examples 1 to 4, and the energy conversion efficiency of the regular-structured perovskite batteries prepared in Example 2 and Examples 15 to 26 is higher than that of the regular-structured perovskite batteries prepared in Comparative Examples 5 to 8; this indicates that: along the direction from the perovskite light-absorbing layer to the electron transport layer, the ratio of the number of metal atoms of the metal oxide in the transport sublayer to the number of oxygen atoms increases successively, which can improve the photoelectric energy conversion efficiency of the perovskite battery.

[0188] From the comparison between Example 1 and Example 3 and the comparison between Example 2 and Example 15, it can be seen that when the ratio of metal atoms to oxygen atoms in the second transport sublayer is the same, compared with the ratio y / x of the number of oxygen atoms to metal atoms in the first transport sublayer being less than 0.5×z (z is the highest valence oxidation state of the metal atom), when the ratio y / x of the number of oxygen atoms to metal atoms in the first transport sublayer is 0.5×z (z is the highest valence oxidation state of the metal atom), the energy conversion efficiency of the perovskite battery can be further improved.

[0189] From the comparison between Example 1 and Examples 4 to 5, and between Example 2 and Examples 16 to 17, it can be seen that when the ratio y / x of the number of oxygen atoms to tin atoms in the transport sublayer satisfies 1.7≤y:x≤2, it is beneficial to further improve the energy conversion efficiency of the perovskite battery.

[0190] From the comparison between Example 1 and Examples 6 to 7, and between Example 2 and Examples 18 to 19, it can be seen that when the ratio y / x of the number of oxygen atoms to metal atoms in the first transport sublayer is 0.5×z (z is the highest oxidation state of the metal atom), and the thickness of the first transport sublayer accounts for ≤75% of the total thickness of the electron transport layer, it is beneficial to further improve the energy conversion efficiency of the perovskite battery.

[0191] From the comparison between Example 1 and Example 8 and the comparison between Example 2 and Example 20, it can be seen that when "the electron transport layer has at least two transport sublayers (two or three layers), and along the direction of the perovskite light absorption layer pointing to the electron transport layer, the ratio of the number of metal atoms of the metal oxide in the transport sublayer to the number of oxygen atoms is increased successively", the energy conversion efficiency of the perovskite battery can be effectively improved.

[0192] From the comparison between Example 1 and Example 9 and the comparison between Example 2 and Example 21, it can be seen that the material of the electron transport layer is tin oxide or titanium oxide, which can effectively improve the energy conversion efficiency of the perovskite battery.

[0193] From the comparison between Example 1 and Examples 10 to 12, and the comparison between Example 2 and Examples 22 to 24, it can be seen that the thickness ratio of the electron transport layer to the intermediate layer can further affect the energy conversion efficiency of the perovskite battery; when the thickness ratio of the electron transport layer to the intermediate layer is 1:(1 to 3), it is beneficial to further improve the energy conversion efficiency of the perovskite battery.

[0194] From the comparison between Example 1 and Example 13 and the comparison between Example 2 and Example 25, it can be seen that the material of the middle layer is C 60 When [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) is used, the energy conversion efficiency of perovskite cells can be effectively improved.

[0195] From the comparison between Example 1 and Example 14 and the comparison between Example 2 and Example 26, it can be seen that when no intermediate layer is provided in the perovskite battery, the ratio of the number of metal atoms of the metal oxide in the transport sublayer to the number of oxygen atoms increases successively along the direction from the perovskite light absorption layer to the electron transport layer, which can still effectively improve the energy conversion efficiency of the perovskite battery.

[0196] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A perovskite solar cell, wherein, The perovskite solar cell includes a perovskite light-absorbing layer and an electron transport layer, and the electron transport layer includes at least two transport sub-layers; The material of the transmission sub-layer includes metal oxide M x O y , where M represents a metal element; the ratio of the number of metal atoms to the number of oxygen atoms in the transmission sub-layer is x / y, and along the direction from the perovskite light-absorbing layer to the electron transport layer, the value of x / y of the transmission sub-layer increases successively.

2. The perovskite cell according to claim 1, wherein, Along the direction from the perovskite light-absorbing layer to the electron transport layer, the thickness ratio of at least two of the transport sub-layers is (2-5):

1.

3. The perovskite cell according to claim 2, wherein, Along the direction from the perovskite light-absorbing layer to the electron transport layer, the thicknesses of at least two of the transport sub-layers are 13 nm to 30 nm and 5 nm to 15 nm respectively.

4. The perovskite cell according to claim 1, wherein, y:x ≤ 0.5×z, where z is the highest oxidation state of M.

5. The perovskite cell according to claim 4, wherein, 0.4×z ≤ y:x ≤ 0.5×z.

6. The perovskite solar cell according to claim 4, wherein, When y:x in one of the transport sub-layers is 0.5×z, the thickness ratio of the transport sub-layer with y:x of 0.5×z in the electron transport layer ≤ 75%.

7. The perovskite cell according to claim 1, wherein, The metal element in the metal oxide includes at least one of Sn, Ti, Zn, W, Nb, In, Zr, Ce, Cr, Ba, Sr, Fe, and Li; Optionally, the metal element in the metal oxide includes at least one of Zn, Ti, and Sn.

8. The perovskite cell according to claim 1, wherein, Along the direction from the perovskite light-absorbing layer to the electron transport layer, the energy levels of the transport sub-layers decrease in sequence.

9. The perovskite cell according to claim 8, wherein, The energy level difference between two adjacent transport sub-layers ≤ 0.2 eV.

10. The perovskite cell according to any one of claims 1 to 9, wherein, An intermediate layer is provided between the perovskite light-absorbing layer and the electron transport layer; the material of the intermediate layer includes a conductive material containing carbon elements; Optionally, the material of the intermediate layer includes at least one of fullerene and its derivatives, imide compounds, quinone compounds, pyrrolidone compounds, isoindigo compounds, indigo compounds, benzobisthiadiazole compounds, hexaazacoronene compounds, indeno[1,2-b]thiophene compounds, tetraphenylethylene compounds, and conjugated polymers.

11. The perovskite cell according to claim 10, wherein, The energy level M1 of the intermediate layer is less than the energy level M2 of the transport sub-layer adjacent to the intermediate layer, and M2 - M1 ≤ 0.2 eV.

12. The perovskite cell according to claim 10, wherein, The thickness ratio of the intermediate layer to the electron transport layer is (0.01-50):1; Optionally, the thickness ratio of the intermediate layer to the electron transport layer is (1-3):

1.

13. The perovskite cell according to claim 10, wherein, The perovskite solar cell includes a transparent substrate layer, a hole transport layer, the perovskite light-absorbing layer, the intermediate layer, the electron transport layer, and an electrode layer arranged in sequence; Or, the perovskite solar cell includes a transparent substrate layer, the electron transport layer, the intermediate layer, the perovskite light-absorbing layer, a hole transport layer, and an electrode layer arranged in sequence.

14. A laminated solar cell, wherein, The tandem solar cell includes the perovskite solar cell according to any one of claims 1-13.

15. A photovoltaic module, wherein, The photovoltaic module includes the perovskite solar cell according to any one of claims 1-13 or the tandem solar cell according to claim 14.

16. A photovoltaic power generation system, wherein, The photovoltaic power generation system includes a plurality of electrically connected photovoltaic modules according to claim 15.

17. An electrical device, wherein, The electrical equipment includes a plurality of electrically connected photovoltaic power generation systems according to claim 16.

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