Perovskite solar cell, preparation method thereof and photovoltaic system

Abstract

The embodiment of the invention provides a perovskite solar cell, a preparation method thereof and a photovoltaic system. The preparation method comprises the following steps: providing a substrate; forming a first transmission layer on one side of the substrate; sequentially depositing an inorganic layer, an auxiliary agent layer and an organic layer on one side, far away from the substrate, of the first transmission layer to form an intermediate layer; carrying out annealing treatment on the intermediate layer to form a perovskite layer; wherein the auxiliary agent layer is formed by evaporating an additive on the surface of one side, far away from the first transmission layer, of the inorganic layer, and the additive comprises an organic matter containing amino and / or carboxyl. According to the technical scheme provided by the embodiment of the invention, the efficient organic-inorganic wide-band gap perovskite solar cell can be prepared through evaporation of the additive, halogen migration is effectively relieved, and non-radiative recombination loss is reduced; and the evaporation method can realize uniform preparation of a large-area film, and can be applied to large-scale production.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a perovskite solar cell and a preparation method thereof, and a photovoltaic system. Background Art

[0002] Perovskite materials have excellent photovoltaic properties and can be made into perovskite solar cells through a simple solution preparation process, thereby achieving high-efficiency and low-cost solar power generation. However, perovskite solar cells are easily affected by environmental factors such as water, oxygen, and light, and have problems such as halogen migration, non-radiative recombination, and lattice expansion. In addition, the solution method is difficult to meet the needs of large-scale production in terms of repeatability and large-area preparation.

[0003] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0004] The embodiments of the present application provide a perovskite solar cell and a method for preparing the same, and a photovoltaic system to solve or alleviate one or more of the technical problems raised above.

[0005] As one aspect of an embodiment of the present application, an embodiment of the present application provides a method for preparing a perovskite solar cell, comprising: providing a substrate; forming a first transmission layer on one side of the substrate; An inorganic layer, an auxiliary agent layer and an organic layer are sequentially formed on a side of the first transmission layer away from the substrate to form an intermediate layer; wherein the auxiliary agent layer is formed by evaporating an additive on a surface of the inorganic layer away from the first transmission layer, and the additive includes an organic substance containing an amino group and / or a carboxyl group; annealing the intermediate layer to form a perovskite layer; A second transmission layer and an electrode are sequentially formed on a side of the perovskite layer away from the first transmission layer.

[0006] Optionally, the organic matter containing amino and / or carboxyl groups includes one or more of tartaric acid, ferulic acid, tartrate, ferulate, iodinated phenylethylamine, propylammonium chloride, aminoethanesulfonic acid, 4-fluorobenzamide, and proline amide.

[0007] Optionally, the tartrate includes one or more of potassium antimony tartrate, antimony tartrate, potassium tartrate, and L-carnitine tartrate; The ferulate salt includes one or more of potassium antimony ferulate, antimony ferulate, potassium ferulate, and L-carnitine ferulate.

[0008] Optionally, the melting point of the additive is 75-200°C.

[0009] Optionally, the evaporation adopts a first evaporation source, the first evaporation source includes the additive, and the evaporation rate of the first evaporation source is 0.01~0.1 Å / s and the evaporation thickness is 0.5~2nm.

[0010] Optionally, the inorganic layer is formed by the following operations: Depositing the inorganic layer on a side of the first transmission layer away from the substrate by dual-source evaporation; Among them, the dual-source evaporation uses a second evaporation source and a third evaporation source; the second evaporation source includes lead iodide, and the evaporation rate of the second evaporation source is 1~2 Å / s; the third evaporation source includes one or more of cesium bromide and cesium iodide, and the evaporation rate of the third evaporation source is 0.1~1 Å / s.

[0011] Optionally, the organic layer is formed by the following operations: Depositing an organic layer on the side of the auxiliary agent layer away from the inorganic layer by single-source evaporation; Among them, the single-source evaporation adopts a fourth evaporation source, and the fourth evaporation source includes one or more of formamidine iodide, potassium bromide, formamidine chloride, methylamine iodide, methylamine bromide, and methylamine chloride. The evaporation rate of the fourth evaporation source is 0.5~1.5 Å / s.

[0012] Optionally, the intermediate layer is subjected to annealing treatment, comprising: performing a first annealing treatment on the intermediate layer; The intermediate layer subjected to the first annealing treatment is subjected to a second annealing treatment.

[0013] Optionally, the annealing temperature of the first annealing treatment is 100-120° C., the annealing time is 5-10 min, and the annealing environment is a nitrogen atmosphere.

[0014] Optionally, the annealing temperature of the second annealing treatment is 150-200° C., the annealing time is 10-30 min, and the annealing environment is an air atmosphere with a humidity of 30-40%.

[0015] As another aspect of the embodiment of the present application, the embodiment of the present application further provides a perovskite solar cell, including: substrate; A first transmission layer, disposed on one side of the substrate; a perovskite layer, disposed on a side of the first transmission layer away from the substrate; A second transmission layer is provided on a side of the perovskite layer away from the first transmission layer; an electrode, disposed on a side of the second transport layer away from the perovskite layer; Wherein, the perovskite layer includes additives, and the additives include organic matter containing amino groups and / or carboxyl groups.

[0016] Optionally, the perovskite layer is formed by annealing an intermediate layer, the intermediate layer exists before annealing and forms the perovskite layer after annealing, and the intermediate layer includes: an inorganic layer, disposed on a side of the first transmission layer away from the substrate; An auxiliary agent layer, disposed on a side of the inorganic layer away from the first transmission layer; An organic layer is disposed on a side of the auxiliary agent layer away from the inorganic layer; Wherein, the auxiliary agent layer includes the additive, and the thickness of the auxiliary agent layer is 0.5~2nm.

[0017] Optionally, the organic compound containing amino and / or carboxyl groups includes one or more of tartaric acid, ferulic acid, tartrate, ferulate, iodinated phenylethylamine, propylammonium chloride, aminoethanesulfonic acid, 4-fluorobenzamide, and proline amide; Among them, the tartrate includes one or more of potassium antimony tartrate, antimony tartrate, potassium tartrate, and L-carnitine tartrate; the ferulate includes one or more of potassium antimony ferulate, antimony ferulate, potassium ferulate, and L-carnitine ferulate.

[0018] As another aspect of the embodiments of the present application, the embodiments of the present application also provide a photovoltaic system, including any of the above-mentioned perovskite solar cells.

[0019] The above technical solution adopted in the embodiment of the present application may have the following advantages: In the embodiment of the present application, an inorganic layer, an auxiliary agent layer and an organic layer are prepared in sequence by evaporation, and an annealing treatment is performed to obtain a perovskite layer, which is stacked with the prepared substrate, the first transmission layer, the second transmission layer and the electrode to form a perovskite solar cell. The additives for forming the auxiliary agent layer may include organic substances containing amino groups and / or carboxyl groups. The carboxyl group (-COO-) or the amino group (-NH 2 ) can dynamically adjust the growth of perovskite crystals during annealing, increase the grain size, promote directional crystallization, and enhance crystal stability; it can inhibit halogen migration and light-induced lattice expansion; it can also interact with perovskite, change the electronic structure of perovskite and adjust the band structure of perovskite. It can be seen that the embodiment of the present application can produce an efficient organic-inorganic wide-bandgap perovskite solar cell by evaporating additives, which can effectively alleviate the non-radiative recombination loss caused by halogen migration. And the evaporation method can achieve uniform preparation of large-area thin films, which can be applied to large-scale perovskite solar cell production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0021] Figure 1 The flowchart of the method for preparing a perovskite solar cell according to the first embodiment of the present application is schematically shown.

[0022] Figure 2 The flowchart of preparing the inorganic layer and the auxiliary agent layer according to the first embodiment of the present application is schematically shown.

[0023] Figure 3 It is a schematic diagram of the structure of a perovskite solar cell provided according to Example 2 of the present application.

[0024] Description of reference numerals: 1 Substrate 2 First Transport Layer 3 Perovskite layer 4 Second Transport Layer 5 Electrodes 6 Buffer layer 31 Inorganic layer 32 additive layer 33 organic layer. DETAILED DESCRIPTION

[0025] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0026] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not mean that the present disclosure necessarily has the first element, component, region, layer or part.

[0027] In this application, 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 this application can be understood according to specific circumstances.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] The embodiment of the present application provides a perovskite solar cell and its preparation method and photovoltaic system. In this technical solution: (1) the organic layer and the inorganic layer are evaporated separately to avoid the reaction of organic and inorganic components in the chamber on the crystal oscillator during co-evaporation, which affects the actual thickness of the film; (2) the organic layer is evaporated on the inorganic layer, and the perovskite layer is obtained after annealing to avoid the low photoelectric conversion efficiency caused by the large number of internal defects of pure inorganic perovskite solar cells; (3) the perovskite layer is prepared by evaporation, which can achieve uniform preparation of large-area thin films and can be applied to large-scale perovskite solar cell production; (4) by evaporating the additive potassium antimony tartrate APTA, an efficient organic-inorganic wide-bandgap perovskite solar cell can be obtained, which can effectively alleviate the non-radiative recombination loss caused by halogen migration. See below for details.

[0030] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0031] Embodiment 1 Figure 1 The flowchart of the method for preparing a perovskite solar cell according to the first embodiment of the present application is schematically shown.

[0032] like Figure 1 As shown, the method for preparing the perovskite solar cell may include steps S100 to S108, wherein: Step S100 , providing a substrate.

[0033] Step S102 , forming a first transmission layer on one side of the substrate.

[0034] Step S104 , an inorganic layer, an auxiliary layer and an organic layer are sequentially deposited on a side of the first transmission layer away from the substrate to form an intermediate layer; wherein the auxiliary layer is formed by evaporating an additive on a surface of the inorganic layer away from the first transmission layer, and the additive includes potassium antimony tartrate.

[0035] Step S106 , the intermediate layer is annealed to form a perovskite layer.

[0036] Step S108 A second transport layer and an electrode are sequentially formed on a side of the perovskite layer away from the first transport layer.

[0037] In this embodiment, an inorganic layer, an auxiliary agent layer and an organic layer are prepared in sequence by evaporation, and an annealing treatment is performed to obtain a perovskite layer, and the prepared substrate, the first transmission layer, the second transmission layer and the electrode are stacked to form a perovskite solar cell. Among them, the additives forming the auxiliary agent layer may include organic matter containing amino groups and / or carboxyl groups. The organic matter containing amino groups and / or carboxyl groups may include organic matter containing only amino groups but not carboxyl groups, organic matter containing only carboxyl groups but not amino groups, and organic matter containing both amino groups and carboxyl groups. The carboxyl group (-COO-) or the amino group (-NH2) can dynamically adjust the growth of perovskite crystals during annealing, increase the grain size, promote directional crystallization, and enhance crystal stability; it can inhibit halogen migration and light-induced lattice expansion; it can also interact with perovskite, change the electronic structure of perovskite and adjust the band structure of perovskite. It can be seen that the embodiment of the present application can prepare an efficient organic-inorganic wide-bandgap perovskite solar cell by evaporating additives, which can effectively alleviate the non-radiative recombination loss caused by halogen migration. Moreover, the evaporation method can achieve uniform preparation of large-area thin films and can be applied to large-scale perovskite solar cell production.

[0038] In an optional embodiment, the organic matter containing amino and / or carboxyl groups may include one or more of tartaric acid, ferulic acid, tartrate, ferulate, iodinated phenylethylamine, propylammonium chloride, aminoethanesulfonic acid, 4-fluorobenzamide, and proline amide.

[0039] Exemplarily, both ferulic acid / salt and tartaric acid / salt contain carboxyl groups, which can passivate uncoordinated halides through hydrogen bonds, promote the increase of grain size, effectively reduce the stress inside the perovskite film, and optimize the crystal structure of the perovskite layer. It should be noted that trans-ferulic acid can also be used. Exemplarily, iodinated phenylethylamine, propylammonium chloride, aminoethanesulfonic acid, 4-fluorobenzamide, and proline amide all contain amino groups, which can passivate uncoordinated metal ions in the perovskite layer, thereby regulating the crystal and nucleation and growth process, and effectively optimizing the crystal structure of the perovskite layer.

[0040] In optional embodiments, the tartrate may include one or more of potassium antimony tartrate, antimony tartrate, potassium tartrate, and L-carnitine tartrate; the ferulate may include one or more of potassium antimony ferulate, antimony ferulate, potassium ferulate, and L-carnitine ferulate.

[0041] In an optional embodiment, the melting point of the additive may be 75-200°C.

[0042] The following uses potassium antimony tartrate and L-carnitine tartrate as examples to illustrate the working principle of the additives.

[0043] Potassium antimony tartrate (APTA) has a low melting point (75-100°C) and is suitable for evaporation to prepare perovskite solar cells. Its carboxyl group (-COO-) can dynamically regulate the growth of perovskite crystals during annealing, increase the grain size, and promote directional crystallization. The carboxyl group can also bind lead ions (Pb 2+ ) coordination, reducing the binding energy of lead ions and enhancing crystal stability. The potassium ions (K + ) can inhibit halogen migration and light-induced lattice expansion. The antimony element (Sb) in APTA can interact with perovskite, change the electronic structure of perovskite and adjust the band structure of perovskite. It can be seen that the embodiment of the present application can produce an efficient organic-inorganic wide-bandgap perovskite solar cell by evaporating the additive potassium antimony tartrate APTA, which can effectively alleviate the non-radiative recombination loss caused by halogen migration; and the evaporation method can achieve uniform preparation of large-area thin films, which can be applied to large-scale perovskite solar cell production. L-carnitine tartrate has a low melting point (169~175℃), and is also suitable for evaporation to prepare perovskite solar cells, which will not be repeated here.

[0044] In some embodiments, the additive may also include pemilastat potassium, wherein the potassium ion (K + ) can suppress halogen migration and light-induced lattice expansion.

[0045] Combine the following Figure 1 , each step in step S100~step S108 and other optional steps are explained in detail.

[0046] Step S100 , providing a substrate.

[0047] The substrate can be a transparent conductive substrate, or a silicon cell, a perovskite cell or other types of cells, such as copper indium gallium selenide (CIGS), gallium nitride (GaN), etc. Among them, the transparent conductive substrate can be one or more of transparent glass or plastic substrates, fluorine-doped tin oxide (FTO), indium tin oxide (ITO), indium zinc oxide (IZO), tungsten-doped indium oxide (IWO), and aluminum-doped zinc oxide (AZO). Transparent conductive substrates can be used to prepare single-junction perovskite solar cells. Cell substrates such as silicon cells can be used to prepare stacked perovskite solar cells, such as perovskite-silicon stacked cells, and the photoelectric conversion efficiency of the cell can be further improved through stacking technology.

[0048] Step S102 , forming a first transmission layer on one side of the substrate.

[0049] According to the different directions of charge transfer, perovskite solar cells can be divided into the formal structure nip type and the trans structure pin type. Among them, n represents the electron transport layer, i represents the perovskite layer, and p represents the hole transport layer. Taking the preparation of the trans structure pin type perovskite solar cell as an example, a first transport layer can be formed on one side or the conductive side of the substrate. The first transport layer is a hole transport layer, which can be used to extract and transport holes while blocking the migration of electrons and carrier recombination. Correspondingly, if a formal structure pin type perovskite solar cell is prepared, the first transport layer is an electron transport layer, which can be used to extract and transport photogenerated electrons to form an electric current. In some embodiments, the preparation method of the first transport layer includes but is not limited to solution spin coating, spray coating, sol-gel method, vacuum evaporation, and physical vapor deposition.

[0050] Step S104 , an inorganic layer, an auxiliary layer and an organic layer are sequentially deposited on a side of the first transmission layer away from the substrate to form an intermediate layer; wherein the auxiliary layer is formed by evaporating an additive on a surface of the inorganic layer away from the first transmission layer, and the additive includes potassium antimony tartrate.

[0051] In practical applications, inorganic salts (such as lead iodide, cesium bromide) can be deposited on the side of the first transport layer away from the substrate to form an inorganic layer, which can be directly used as the perovskite layer of the perovskite solar cell. However, the pure inorganic perovskite layer has many internal defects and low photoelectric conversion efficiency. In order to improve the performance of the battery, an organic layer can also be prepared on the basis of the inorganic layer, and an organic-inorganic perovskite solar cell is formed after annealing. Since perovskite solar cells are easily affected by environmental factors such as water, oxygen, and light, problems such as halogen migration, non-radiative recombination, and lattice expansion occur. In order to further improve the performance and stability of the battery, an auxiliary layer can also be prepared to change the electronic structure of the perovskite and adjust the energy band structure, thereby forming an organic-inorganic wide bandgap perovskite solar cell. In order to promote the reaction between the organic layer and the inorganic layer, an auxiliary layer can be prepared on the surface of the inorganic layer, and an organic layer can be prepared on the surface of the auxiliary layer.

[0052] It should be noted that the preparation methods of the inorganic layer, the auxiliary agent layer, and the organic layer can be selected according to actual needs, including but not limited to spin coating, evaporation, slit coating, blade coating, spraying, screen printing, inkjet printing, etc. The following takes evaporation as an example to introduce how to prepare the inorganic layer, the auxiliary agent layer, and the organic layer.

[0053] In an optional embodiment, if Figure 2 As shown, the inorganic layer can be formed on the side of the first transmission layer away from the substrate by dual-source evaporation. The dual-source evaporation can use a second evaporation source and a third evaporation source. The second evaporation source can include lead iodide (PbI 2), the evaporation rate may be 1-2 Å / s. The third evaporation source may include one or more of cesium bromide (CsBr) and cesium iodide (CsI), and the evaporation rate of the third evaporation source may be 0.1-1 Å / s.

[0054] In this embodiment, a variety of different inorganic salts are deposited together through dual-source evaporation to form a high-quality, uniform inorganic layer. The deposition rates of various materials can also be precisely controlled, thereby effectively regulating the structure and properties of the inorganic layer.

[0055] In an optional embodiment, if Figure 2 As shown, an auxiliary agent layer can be formed on the side of the inorganic layer away from the first transport layer by evaporation. The evaporation can use a first evaporation source, which can include any one of the aforementioned additives or a combination of multiple additives. The evaporation rate can be 0.01-0.1 Å / s, and the evaporation thickness can be 0.5-2 nm, preferably 0.5-1.5 nm.

[0056] In this embodiment, a uniform auxiliary agent layer can be formed between the inorganic layer and the organic layer by evaporation. The thickness of the auxiliary agent layer can also be precisely controlled by evaporation to avoid affecting the annealing effect due to the auxiliary agent layer being too thick, and failing to passivate the perovskite defects due to the auxiliary agent layer being too thin.

[0057] In an optional embodiment, the organic layer may be formed on the side of the auxiliary agent layer away from the inorganic layer by single-source evaporation. The single-source evaporation may use a fourth evaporation source, which may include one or more of formamidine iodide (FAI), potassium amidine bromide (FABr), formamidine chloride (FACl), methylamine iodide (MAI), methylamine bromide (MABr), and methylamine chloride (MACl), and the evaporation rate may be 0.5-1.5 Å / s.

[0058] In this embodiment, the composition and purity of the organic layer can be precisely controlled through single-source evaporation, thereby ensuring the quality and performance uniformity of the organic layer.

[0059] The above-mentioned embodiments describe how to prepare an inorganic layer, an auxiliary agent layer, and an organic layer to form an intermediate layer (prefabricated perovskite layer) together. The following will provide an exemplary introduction to how to prepare a perovskite layer.

[0060] Step S106 , the intermediate layer is annealed to form a perovskite layer.

[0061] Annealing can make the organic layer, additive layer and inorganic layer fully react, eliminate or reduce the internal defects of the inorganic layer, adjust the band structure of the perovskite, and thus improve the photoelectric properties of the perovskite layer. Annealing can be carried out directly in the air, or in multiple steps and under multiple conditions (different annealing environments, temperatures, and times) to regulate the quality of the perovskite layer.

[0062] An exemplary annealing treatment scheme is provided below.

[0063] In an optional embodiment, annealing the intermediate layer may include: performing a first annealing treatment on the intermediate layer; performing a second annealing treatment on the intermediate layer subjected to the first annealing treatment. The annealing temperature of the first annealing treatment may be 100-120°C, the annealing time may be 5-10 minutes, and the annealing environment may be a nitrogen atmosphere. The annealing temperature of the second annealing treatment may be 150-200°C, the annealing time may be 10-30 minutes, and the annealing environment may be an air atmosphere with a humidity of 30-40%.

[0064] In this embodiment, the annealing treatment is carried out in two steps: first, the annealing treatment is carried out in a nitrogen environment to promote the reaction of the organic layer, the auxiliary layer and the inorganic layer to pre-form a perovskite film; then the film is transferred to the air for annealing treatment. The moisture in the air can dissolve part of the FAI in the organic layer, increase the diffusion of FAI, and further promote the reaction of the organic layer, the auxiliary layer and the inorganic layer. The annealing temperature of 150~200℃ is the optimal temperature for perovskite film formation, so that a high-quality, uniform, and defect-free perovskite layer can be formed.

[0065] The above embodiment introduces how to prepare a perovskite layer. The following is an exemplary introduction to other preparation steps of a perovskite solar cell.

[0066] Step S108 A second transport layer and an electrode are sequentially formed on a side of the perovskite layer away from the first transport layer.

[0067] Taking the preparation of an inverted pin-type perovskite solar cell as an example, a second transport layer can be formed on the side of the perovskite layer away from the first transport layer. The second transport layer is an electron transport layer, which can be used to extract and transport photogenerated electrons to form an electric current. Correspondingly, if a formal pin-type perovskite solar cell is prepared, the second transport layer is a hole transport layer. An electrode can be formed on the side of the second transport layer away from the perovskite layer, which can be used to collect electrons and transmit them to an external circuit. In some embodiments, the preparation method of the electron transport layer includes but is not limited to solution spin coating, sol-gel method, physical vapor deposition, and vacuum deposition. The preparation method of the electrode includes but is not limited to physical vapor deposition, solution spin coating, vacuum evaporation, and solution printing.

[0068] Embodiment 2 like Figure 3 As shown, the embodiment of the present application further provides a perovskite solar cell. The perovskite solar cell may include: a substrate 1 , a first transmission layer 2 , a perovskite layer 3 , a second transmission layer 4 and an electrode 5 .

[0069] It should be noted that Figure 3Only a single-junction perovskite solar cell with an inverted structure is schematically shown. In an optional embodiment, the perovskite solar cell may be a single-junction perovskite solar cell or a stacked perovskite solar cell. A single-junction perovskite solar cell has only one PIN junction. A stacked perovskite solar cell may be a perovskite stacked with a perovskite, a crystalline silicon or other battery, so as to have multiple light-absorbing layers (multiple PIN junctions). Since various materials have different band gaps, different material stacks can absorb light of different spectra respectively, further improving the photoelectric conversion efficiency. Of course, two perovskites with different band gaps can also be stacked to improve the cell efficiency. In an optional embodiment, the stacked perovskite solar cell may be a two-terminal stacked perovskite solar cell, a three-terminal stacked perovskite solar cell or a four-terminal stacked perovskite solar cell. In an optional embodiment, the perovskite solar cell may also be divided into a formal structure (nip type) and an inverted structure (pin type) according to different charge transfer directions.

[0070] The structure of each layer of the perovskite solar cell and its coordination with other layers will be further introduced as an example below.

[0071] The substrate 1 may be a transparent conductive substrate, or a silicon cell, a perovskite cell, or other types of cells, such as copper indium gallium selenide (CIGS), gallium nitride (GaN), etc., for preparing a single-junction or stacked perovskite solar cell. In some embodiments, the thickness of the substrate 1 may be 1 to 5 mm.

[0072] The first transmission layer 2 may be arranged on one side or the conductive side of the substrate 1, the perovskite layer 3 may be arranged on the side of the first transmission layer 2 away from the substrate 1, and the second transmission layer 4 may be arranged on the side of the perovskite layer 3 away from the first transmission layer 2. Wherein, the perovskite layer 3 may include potassium antimony tartrate, through the action of potassium antimony tartrate, the defects of the perovskite layer can be effectively passivated, the electronic structure of the perovskite can be improved, and the energy band structure can be adjusted, so as to achieve the purpose of improving the performance of the battery. Exemplarily, the perovskite layer 3 may be formed by annealing the intermediate layer. The intermediate layer may include an inorganic layer 31, an auxiliary layer 32, and an organic layer 33. Wherein, the auxiliary layer 32 may include an additive, and the additive may include an organic substance containing an amino group and / or a carboxyl group. In an optional embodiment, the organic substance containing an amino group and / or a carboxyl group may include one or more of tartaric acid, ferulic acid, tartrate, ferulate, iodinated phenylethylamine, propylammonium chloride, aminoethanesulfonic acid, 4-fluorobenzamide, and proline amide. Among them, the tartrate may include one or more of potassium antimony tartrate, antimony tartrate, potassium tartrate, and L-carnitine tartrate; the ferulate may include one or more of potassium antimony ferulate, antimony ferulate, potassium ferulate, and L-carnitine ferulate.

[0073] In an optional embodiment, the thickness of the auxiliary agent layer 32 can be 0.5-2 nm, preferably 0.5-1.5 nm. If the auxiliary agent layer is too thick, the annealing effect will be affected, and if it is too thin, the perovskite defects cannot be passivated. In some embodiments, the thickness of the inorganic layer 31 can be 200-300 nm, and the thickness of the organic layer 33 can be 180-250 nm.

[0074] For the first transmission layer 2 and the second transmission layer 4: Figure 3 As shown, in the trans-structure pin-type perovskite solar cell, the first transport layer 2 corresponds to the hole transport layer, and the second transport layer 4 corresponds to the electron transport layer. In the regular structure pin-type perovskite solar cell, the first transport layer 2 corresponds to the electron transport layer, and the second transport layer 4 corresponds to the hole transport layer. Through the first transport layer 2 and the second transport layer 4, the electrons and holes generated by the perovskite layer 3 after light absorption can be effectively separated and transported, thereby generating current.

[0075] In an alternative embodiment, the hole transport layer may include nickel oxide (NiO x ) and a self-assembled material (SAM). The self-assembled material (SAM) includes one or more of [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz)), [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid (4PADCB), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (TAPC). In some embodiments, the thickness of the hole transport layer may be 20 to 40 nm.

[0076] In an alternative embodiment, the electron transport layer may include tin oxide (such as SnO 2 ), titanium oxide (TiO 2 ), fullerene (C 60 ) and its derivatives. In some embodiments, the thickness of the electron transport layer can be 12 to 30 nm.

[0077] In an optional embodiment, if Figure 3 As shown, the inverted pin-type perovskite solar cell may further include a buffer layer 6, which is disposed between the electron transport layer and the electrode 5 to adjust electron transport, optimize interface properties and improve stability, thereby further improving battery performance. The buffer layer 6 may include bathocuproine (BCP), atomic layer deposited tin dioxide (SnO 2In some embodiments, the buffer layer 6 may have a thickness of 5-15 nm.

[0078] The electrode 5 may be disposed on a side of the second transport layer 4 away from the perovskite layer 3 for collecting and transporting carriers. The electrode 5 may include: a metal electrode; or a transparent conductive electrode. The metal electrode may include one of silver (Ag), copper (Cu), and aluminum (Al), and the transparent conductive electrode may include one of indium tin oxide (ITO), indium zinc oxide (IZO), tungsten-doped indium oxide (IWO), and aluminum-doped zinc oxide (AZO). In some embodiments, the thickness of the electrode may be 100 to 400 nm.

[0079] The present application will be further described below in conjunction with specific embodiments, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0080] [Example 1] like Figure 3 As shown, the specific structure of a perovskite solar cell (taking a trans-structure pin-type single junction as an example) can be: The substrate 1, the first transport layer (hole transport layer) 2, the perovskite layer 3, the second transport layer (electron transport layer) 4, the buffer layer 6, and the electrode 5 are stacked in sequence.

[0081] A specific preparation process of a perovskite solar cell can be: S200, depositing NiO on the transparent conductive substrate 1 by magnetron sputtering X , thickness is 25nm.

[0082] S201, NiO X The self-assembled material Me-4PACz was deposited on the surface. The Me-4PACz was dissolved in ethanol at a concentration of 0.5 mg / mL. The spin coating speed was 3000 rpm / s and annealed at 100° C. for 10 min to obtain a SAM layer to form a hole transport layer (the first transport layer 2).

[0083] S202, PbI is co-evaporated on the surface of the SAM layer by evaporation method 2 , CsBr forms an inorganic layer 31, PbI 2 The evaporation rate is 2Å / s and the thickness is 180nm. The evaporation rate of CsBr is 0.4Å / s and the thickness is 36nm.

[0084] S203, using a vapor deposition method to deposit the additive APTA on the surface of the inorganic layer to form an auxiliary agent layer 32, the vapor deposition rate is 0.05Å / s, and the thickness is 1.5nm.

[0085] S204, depositing an organic layer 33 on the surface of the inorganic layer 31 (auxiliary agent layer 32) on which the additive has been deposited by evaporation, with an evaporation rate of 1 Å / s and a thickness of 220 nm, to obtain a prefabricated perovskite layer (intermediate layer).

[0086] S205, the prefabricated perovskite layer is subjected to step-wise annealing treatment, the annealing temperature in the glove box (nitrogen atmosphere) is 100°C, and the annealing time is 10 minutes. Then, it is transferred to an air atmosphere with a humidity of 30-40%, the annealing temperature is 150°C, and the annealing time is 20 minutes to obtain the perovskite layer 3.

[0087] S206 , a 20 nm thick electron transport layer (second transport layer 4 ) and a 5 nm thick BCP buffer layer 6 are deposited on the surface of the perovskite layer 3 by an evaporation method.

[0088] S207, preparing Ag metal electrode 5 with a thickness of 100 nm by thermal evaporation method, and completing battery preparation.

[0089] [Example 2] The perovskite solar cell of Example 2 was prepared by referring to the preparation steps of Example 1, except that the thickness of the APTA additive evaporated in step S203 of Example 2 was 0.5 nm.

[0090] [Example 3] The perovskite solar cell of Example 3 was prepared by referring to the preparation steps of Example 1, except that the thickness of the APTA additive evaporated in step S203 of Example 3 was 1 nm.

[0091] [Example 4] The perovskite solar cell of Example 4 was prepared by referring to the preparation steps of Example 1, except that the thickness of the APTA additive evaporated in step S203 of Example 4 was 2 nm.

[0092] [Example 5] The perovskite solar cell of Example 5 is prepared by referring to the preparation steps of Example 1, except that step S203 of Example 5 is: depositing the additive t-FA (trans-ferulic acid) on the surface of the inorganic layer by evaporation to form an auxiliary agent layer 32, with an evaporation rate of 0.05 Å / s and a thickness of 0.5 nm.

[0093] [Example 6] The perovskite solar cell of Example 6 is prepared by referring to the preparation steps of Example 1, except that step S203 of Example 6 is: depositing the additive t-FA (trans-ferulic acid) on the surface of the inorganic layer by evaporation to form an auxiliary agent layer 32, with an evaporation rate of 0.05 Å / s and a thickness of 1 nm.

[0094] [Example 7] The perovskite solar cell of Example 7 is prepared by referring to the preparation steps of Example 1, except that step S203 of Example 7 is: depositing the additive t-FA (trans-ferulic acid) on the surface of the inorganic layer by evaporation to form an auxiliary agent layer 32, with an evaporation rate of 0.05 Å / s and a thickness of 2 nm.

[0095] [Comparative Example 1] A comparative example perovskite solar cell was prepared by referring to the preparation method of the embodiment, except that step S203 was not performed in the comparative example, and step S204 was directly entered after step S202 was completed, and step S204 of the comparative example was: an organic layer 33 was deposited on the surface of the inorganic layer 31 by evaporation, the evaporation rate was 1 Å / s, and the thickness was 220 nm, to obtain a prefabricated perovskite layer (intermediate layer).

[0096] [Comparative Example 2] The perovskite solar cell of Comparative Example 2 was prepared by referring to the preparation steps of Example 1, except that the thickness of the APTA additive evaporated in step S203 of Comparative Example 2 was 3 nm.

[0097] [Comparative Example 3] The perovskite solar cell of Comparative Example 3 was prepared by referring to the preparation steps of Example 1, except that step S203 of Comparative Example 3 was: an additive t-FA (trans-ferulic acid) was deposited on the surface of the inorganic layer by evaporation to form an auxiliary agent layer 32, the evaporation rate was 0.05 Å / s, and the thickness was 3 nm.

[0098] The following is a performance test of the perovskite solar cell provided in the embodiment of the present application and the comparative example, so as to obtain the open circuit voltage V of the corresponding battery device. oc , short circuit current density J sc , fill factor FF, photoelectric conversion efficiency PCE, the test results are shown in Table 1.

[0099] Table 1 Performance test results of perovskite solar cells of embodiments and comparative examples

[0100] It can be seen from Table 1 above that, compared with the comparative example, the perovskite solar cells of Examples 1-7 of the present application have higher short-circuit current, fill factor and photoelectric conversion efficiency, that is, have better battery performance. It can be seen from Table 1 that the thickness of the auxiliary agent layer 32 can be controlled at 0.5~2nm, preferably 0.5~1.5nm. If the auxiliary agent layer 32 is too thick, it may affect the annealing effect, thereby causing the performance of the perovskite solar cell to deteriorate.

[0101] In summary, the embodiments of the present application can produce efficient organic-inorganic wide bandgap perovskite solar cells by evaporating additives, which can effectively alleviate non-radiative recombination losses caused by halogen migration; and the evaporation method can achieve uniform preparation of large-area thin films, which can be applied to large-scale perovskite solar cell production.

[0102] The embodiment of the present application may also provide a photovoltaic module (not shown), including at least one battery string, the battery string including at least two perovskite solar cells as described above, and adjacent perovskite solar cells may be connected together by serial welding.

[0103] The embodiment of the present application can also provide a photovoltaic system, including the perovskite solar cell or photovoltaic module in any of the above embodiments. The advantages of the above perovskite solar cell or photovoltaic module are also possessed by the photovoltaic system, which will not be repeated here. The above photovoltaic system has a wide range of applications, not only limited to photovoltaic power stations, such as ground power stations, rooftop power stations and water power stations, but also includes various equipment and devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars and solar buildings. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be used in all fields where solar energy is required for power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic modules. For example, multiple photovoltaic modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid and then connected to the mains network to realize solar power supply.

[0104] It should be noted 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", etc. are only for the convenience of describing 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 present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0105] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0106] 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.

[0107] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing a perovskite solar cell, characterized in that: include: providing a substrate; forming a first transmission layer on one side of the substrate; An inorganic layer, an auxiliary agent layer and an organic layer are sequentially formed on a side of the first transmission layer away from the substrate to form an intermediate layer; wherein the auxiliary agent layer is formed by evaporating an additive on a surface of the inorganic layer away from the first transmission layer, and the additive includes an organic substance containing an amino group and / or a carboxyl group; annealing the intermediate layer to form a perovskite layer; A second transmission layer and an electrode are sequentially formed on a side of the perovskite layer away from the first transmission layer.

2. The preparation method according to claim 1, characterized in that: The organic matter containing amino and / or carboxyl groups includes one or more of tartaric acid, ferulic acid, tartrate, ferulate, iodinated phenylethylamine, propylammonium chloride, aminoethanesulfonic acid, 4-fluorobenzamide, and proline amide.

3. The preparation method according to claim 2, characterized in that: The tartrate includes one or more of potassium antimony tartrate, antimony tartrate, potassium tartrate, and L-carnitine tartrate; The ferulate salt includes one or more of potassium antimony ferulate, antimony ferulate, potassium ferulate, and L-carnitine ferulate.

4. The preparation method according to claim 1, characterized in that: The melting point of the additive is 75-200°C.

5. The preparation method according to claim 1, characterized in that The evaporation adopts a first evaporation source, the first evaporation source includes the additive, the evaporation rate of the first evaporation source is 0.01-0.1 Å / s, and the evaporation thickness is 0.5-2 nm.

6. The preparation method according to claim 1, characterized in that: The inorganic layer is formed by the following operations: Depositing the inorganic layer on a side of the first transmission layer away from the substrate by dual-source evaporation; Among them, the dual-source evaporation uses a second evaporation source and a third evaporation source; the second evaporation source includes lead iodide, and the evaporation rate of the second evaporation source is 1~2 Å / s; the third evaporation source includes one or more of cesium bromide and cesium iodide, and the evaporation rate of the third evaporation source is 0.1~1 Å / s.

7. The preparation method according to claim 1, characterized in that: The organic layer is formed by the following operations: Depositing an organic layer on the side of the auxiliary agent layer away from the inorganic layer by single-source evaporation; Among them, the single-source evaporation adopts a fourth evaporation source, and the fourth evaporation source includes one or more of formamidine iodide, potassium bromide, formamidine chloride, methylamine iodide, methylamine bromide, and methylamine chloride. The evaporation rate of the fourth evaporation source is 0.5~1.5 Å / s.

8. The preparation method according to any one of claims 1 to 7, characterized in that: Annealing the intermediate layer includes: performing a first annealing treatment on the intermediate layer; The intermediate layer subjected to the first annealing treatment is subjected to a second annealing treatment.

9. The preparation method according to claim 8, characterized in that: The annealing temperature of the first annealing treatment is 100-120° C., the annealing time is 5-10 min, and the annealing environment is a nitrogen atmosphere.

10. The preparation method according to claim 8, characterized in that: The annealing temperature of the second annealing treatment is 150-200° C., the annealing time is 10-30 minutes, and the annealing environment is an air atmosphere with a humidity of 30-40%.

11. A perovskite solar cell, characterized in that: include: substrate; A first transmission layer, disposed on one side of the substrate; a perovskite layer, disposed on a side of the first transmission layer away from the substrate; A second transmission layer is provided on a side of the perovskite layer away from the first transmission layer; an electrode, disposed on a side of the second transport layer away from the perovskite layer; Wherein, the perovskite layer includes additives, and the additives include organic matter containing amino groups and / or carboxyl groups.

12. The perovskite solar cell according to claim 11, characterized in that: The perovskite layer is formed by annealing the intermediate layer, the intermediate layer exists before annealing and forms the perovskite layer after annealing, and the intermediate layer includes: an inorganic layer, disposed on a side of the first transmission layer away from the substrate; An auxiliary agent layer, disposed on a side of the inorganic layer away from the first transmission layer; An organic layer is disposed on a side of the auxiliary agent layer away from the inorganic layer; Wherein, the auxiliary agent layer includes the additive, and the thickness of the auxiliary agent layer is 0.5~2nm.

13. The perovskite solar cell according to claim 11, characterized in that: The organic matter containing amino and / or carboxyl groups includes one or more of tartaric acid, ferulic acid, tartrate, ferulate, iodinated phenylethylamine, propylammonium chloride, aminoethanesulfonic acid, 4-fluorobenzamide, and proline amide; Among them, the tartrate includes one or more of potassium antimony tartrate, antimony tartrate, potassium tartrate, and L-carnitine tartrate; the ferulate includes one or more of potassium antimony ferulate, antimony ferulate, potassium ferulate, and L-carnitine ferulate.

14. A photovoltaic system, characterized in that: Comprising the perovskite solar cell according to any one of claims 11 to 13.

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