Perovskite solar cell

Abstract

The utility model discloses a perovskite solar cell. The perovskite solar cell comprises a perovskite layer used for absorbing light and generating electron-hole pairs; the electron transport layer and the hole transport layer are respectively located at two sides of the perovskite layer and are used for respectively transmitting the electrons and the holes; the first passivation layer is located between the electron transport layer and the perovskite layer, and the first passivation layer comprises a boron-doped carbon nitride nanosheet; and the first electrode layer and the second electrode layer are respectively positioned on two sides of the electron transport layer and the hole transport layer and are used for leading out photo-generated current. Through the perovskite cell, electron transfer and separation can be promoted, the interface defect between the perovskite layer and the electron transport layer is passivated, and the open-circuit voltage and the fill factor of the cell are improved, so that a high-quality solar cell is obtained.

Description

Technical Field

[0001] The utility model relates to the technical field of solar cells, in particular to a perovskite solar cell. Background Art

[0002] Recently, the power conversion efficiency of perovskite solar cells has increased from the initial 3.8% to the current 25.7%. The rapid increase in efficiency has guaranteed confidence in the commercial application of perovskite solar cells. For perovskite solar cells, the energy level mismatch between the perovskite layer and the electron transport layer may lead to severe energy loss during electron transfer, reducing the power conversion efficiency of the device. Therefore, improving the quality of perovskite films, optimizing energy band matching, and reducing the uncoordinated Pb 2+ Defects are an effective way to improve its performance.

[0003] In recent years, interface engineering involving two-dimensional carbon nitride nanosheets has been widely used to improve the performance of perovskite solar cells (PSCs). For example, using carbon nitride nanosheets to modify the interface between the electron transport layer and the MAPbI3 layer can improve energy level alignment and thus enhance the open circuit voltage. At the same time, carbon nitride materials, as a typical Lewis base, can react with unsaturated Pb 2+ Combined with reducing the defect density, the film quality of the perovskite layer is improved, thereby improving the power conversion efficiency.

[0004] However, carbon nitride nanoparticles still have shortcomings such as insufficient charge separation, insufficient visible light absorption, and slow carrier transport, which is also the main reason for the poor performance of current perovskite solar cells.

[0005] In order to solve the above-mentioned problems existing in the prior art, the field urgently needs an improved perovskite solar cell technology that can promote electron transfer and separation, passivate the interface defects between the perovskite layer and the electron transport layer, and improve the open circuit voltage and fill factor of the battery, thereby obtaining high-quality solar cells. Utility Model Content

[0006] The following is a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that will be provided later.

[0007] In order to overcome the above-mentioned defects of the prior art, the utility model provides a perovskite solar cell, which can promote electron transfer and separation, passivate the interface defects between the perovskite layer and the electron transport layer, and improve the open circuit voltage and fill factor of the battery, thereby obtaining a high-quality solar cell.

[0008] Specifically, the perovskite solar cell provided according to the first aspect of the present invention includes: a perovskite layer, which is used to absorb light and generate electron-hole pairs; an electron transport layer and a hole transport layer, which are respectively located on both sides of the perovskite layer, and are used to transport the electrons and the holes, respectively; a first passivation layer, which is located between the electron transport layer and the perovskite layer, and the first passivation layer includes boron-doped carbon nitride nanosheets; and a first electrode layer and a second electrode layer, which are respectively located on both sides of the electron transport layer and the hole transport layer, and are used to derive photogenerated current.

[0009] Furthermore, in some embodiments of the present invention, the first passivation layer is a composite film layer of boron-doped carbon nitride nanosheets and gold nanoparticles.

[0010] Furthermore, in some embodiments of the present invention, the perovskite solar cell has a formal structure, the first electrode layer is a transparent electrode layer, and is located below the electron transport layer, for receiving sunlight and receiving the electrons transmitted from the electron transport layer, the second electrode layer is a metal electrode layer, and is located above the hole transport layer, for receiving the holes transmitted from the hole transport layer.

[0011] Furthermore, in some embodiments of the present invention, the perovskite solar cell has an inverted structure, the second electrode layer is a transparent electrode layer, and is located below the hole transport layer, for receiving sunlight and receiving the holes transmitted by the hole transport layer, and the first electrode layer is a metal electrode layer, and is located above the electron transport layer, for receiving the electrons transmitted by the electron transport layer.

[0012] Furthermore, in some embodiments of the present invention, the metal electrode layer is any one of a copper electrode layer, an aluminum electrode layer and a silver electrode layer.

[0013] Furthermore, in some embodiments of the present invention, the electron transport layer includes a fullerene thin film layer.

[0014] Furthermore, in some embodiments of the present invention, the perovskite solar cell further includes: a hole blocking layer located between the electron transport layer and the first electrode layer, wherein the hole blocking layer is a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline thin film layer.

[0015] Furthermore, in some embodiments of the present invention, the hole transport layer includes a polytriarylamine thin film layer, or a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) thin film layer.

[0016] Furthermore, in some embodiments of the present invention, the perovskite layer includes a CsFAPbI3 thin film layer, a MAPbI3 thin film layer, a CsPbI3 thin film layer, and a Cs x FA 1-x Pb(I y Br 1-y ) Any one of the 3 thin film layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or characteristics may have the same or similar reference numerals.

[0018] Figure 1 A schematic structural diagram of a perovskite solar cell provided according to some embodiments of the present utility model is shown.

[0019] Reference numerals:

[0020] 100 Perovskite Solar Cells;

[0021] 110 perovskite layer;

[0022] 120 electron transport layer;

[0023] 121 first passivation layer;

[0024] 130 hole transport layer;

[0025] 140 first electrode layer; and

[0026] 150 second electrode layer. DETAILED DESCRIPTION

[0027] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and functions of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this utility model are limited to this implementation. On the contrary, the purpose of introducing the utility model in conjunction with the implementation is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide an in-depth understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0028] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0029] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood to refer to the orientations depicted in that section and the accompanying drawings. These relative terms are used solely for convenience of description and do not necessarily imply that the devices described herein must be manufactured or operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0030] It is understood that although the terms "first," "second," "third," etc. may be used herein to describe various components, regions, layers, and / or portions, these components, regions, layers, and / or portions should not be limited by these terms, and these terms are merely used to distinguish different components, regions, layers, and / or portions. Thus, a first component, region, layer, and / or portion discussed below may be referred to as a second component, region, layer, and / or portion without departing from some embodiments of the present invention.

[0031] As mentioned above, the interface between the electron transport layer and the MAPbI3 layer is modified by carbon nitride nanosheets, which can improve the energy level alignment and thus enhance the open circuit voltage. At the same time, carbon nitride materials, as a typical Lewis base, can react with unsaturated Pb 2+This, combined with the reduction of defect density, improves the film quality of the perovskite layer, thereby increasing power conversion efficiency. However, carbon nitride nanoparticles still suffer from shortcomings such as insufficient charge separation, insufficient visible light absorption, and slow carrier transport, which are the main reasons for the poor performance of current perovskite solar cells.

[0032] In order to solve the above-mentioned problems existing in the prior art, the utility model provides a perovskite solar cell, which can promote electron transfer and separation, passivate the interface defects between the perovskite layer and the electron transport layer, and improve the open circuit voltage and fill factor of the battery, thereby obtaining a high-quality solar cell.

[0033] The following describes some examples of perovskite solar cells. Those skilled in the art will appreciate that these examples are merely non-limiting implementations of the present invention, intended to clearly illustrate the main concepts of the present invention and provide some specific solutions for easy implementation by the public, and are not intended to limit the entire structure of the perovskite solar cell.

[0034] Please see Figure 1 , Figure 1 A schematic structural diagram of a perovskite solar cell provided according to some embodiments of the present utility model is shown.

[0035] like Figure 1 As shown, in some embodiments of the present invention, the perovskite solar cell 100 may include a perovskite layer 110 for absorbing light and generating electron-hole pairs; an electron transport layer 120 and a hole transport layer 130, respectively located on both sides of the perovskite layer 110, for transporting electrons and holes, respectively; a first passivation layer 121, located between the electron transport layer 120 and the perovskite layer 110, and a first electrode layer 140 and a second electrode layer 150, respectively located on both sides of the electron transport layer 120 and the hole transport layer 130, for extracting photocurrent.

[0036] The perovskite layer 110 may include a CsFAPbI3 thin film layer, a MAPbI3 thin film layer, a CsPbI3 thin film layer, and a Cs x FA 1-x Pb(I y Br 1-y ) Any one of the 3 thin film layers.

[0037] The first passivation layer 121 may include boron-doped carbon nitride nanosheets. Since the doping of the carbon nitride nanosheets with boron atoms helps increase the supply of free electrons, it can promote charge transfer and separation. Boron-doped carbon nitride nanosheets have excellent stability and faster electron transfer capabilities, and their advantages depend on their π-π stacking interaction and electrostatic force. In an embodiment of the present invention, the first passivation layer 121, which serves as the upper interface of the perovskite layer 110, can passivate the defects of the perovskite interface and improve the performance of the solar cell.

[0038] Specifically, the preparation process of boron-doped carbon nitride nanosheets may include: first, dissolving 0.5g of boric acid in 10ml of deionized water, and then adding 10g of urea. The solution is heated at room temperature overnight in the temperature range of 60°C to 70°C to generate a white precursor powder. Then, the precursor powder is placed in a covered crucible for sintering, wherein the sintering heating rate is preferably maintained in the range of 2°C / min to 5°C / min, and the sintering is heated to 510°C and maintained for 60 minutes. Finally, it is cooled to room temperature to obtain boron-doped carbon nitride nanosheets.

[0039] Furthermore, in some preferred embodiments, the first passivation layer 121 can also be a composite thin film layer of boron-doped carbon nitride nanosheets and gold nanoparticles. The addition of gold atoms provides the first passivation layer 121 with greater stability and stronger electron transfer, thereby further increasing the conductivity of the first passivation layer 121 and ultimately improving battery performance.

[0040] Specifically, the preparation process of the composite film layer of boron-doped carbon nitride nanosheets and gold nanoparticles can include: first, dissolving 10 mg of chloroauric acid powder in 1 ml of pure water (H2O) to prepare a 1% chloroauric acid solution, and shaking to dissolve. Then, freshly preparing a 0.2 mol / L sodium borohydride (NaBH4) solution can include: dissolving 0.0757 g of NaBH4 powder in 10 ml of H2O, and shaking to dissolve. It is worth noting that the sodium borohydride solution needs to be prepared freshly to ensure that the reducing effect of NaBH4 can be stably exerted. The concentration range of NaBH4 is preferably 0.1 to 0.5 mol / L, so that the obtained first passivation layer 121 has a better interface passivation effect on the perovskite layer 110. Subsequently, dissolving 100 mg of boron carbon nitride powder in 5 ml of H2O. Then, adding 1 ml of 1% chloroauric acid and 1 ml of 0.2 mol / L NaBH4 to the solution containing the boron carbon nitride powder, and stirring continuously for 40 minutes. Finally, the mixture was centrifuged and washed three times with water and ethanol respectively, and then dried in an oven to obtain a boron-doped carbon nitride nanosheet and gold nanoparticle composite.

[0041] In some optional embodiments, the perovskite solar cell 100 may be an inverted structure. Figure 1 As shown, the second electrode layer 150 can be a transparent electrode layer and is located below the hole transport layer 130 to receive sunlight. The first electrode layer 140 can be a metal electrode layer and is located above the electron transport layer 120. Sunlight enters from the transparent second electrode layer 150 and is first received by the hole transport layer 130. It then enters the perovskite layer 110. After absorbing light, the perovskite layer 110 generates electron-hole pairs. The holes are collected by the hole transport layer and transported to the second electrode layer 150, while the electrons are transported to the metal second electrode layer 150 through the first passivation layer 121 and the electron transport layer 120, forming and conducting photocurrent.

[0042] In some other optional embodiments, the perovskite solar cell 100 may also be a formal structure. Figure 1 On the basis of the above, the positions of the electron transport layer 120 and the hole transport layer 130 in the formal structure are interchanged. The electron transport layer 120 can be located below the perovskite layer 110, while the hole transport layer 130 is located above it. The first electrode layer 140 can be a transparent electrode layer and is located below the electron transport layer 120 for receiving sunlight. The second electrode layer 150 can be a metal electrode layer and is located above the hole transport layer 130. Sunlight enters from one side of the transparent first electrode layer 140, passes through the electron transport layer 120 and reaches the perovskite layer 110. After the perovskite layer 110 absorbs light, electron-hole pairs are generated. The electrons are collected and transported to the transparent first electrode layer 140 through the first passivation layer 121 and the electron transport layer 120, while the holes pass through the hole transport layer 130 to the metal second electrode layer 150, forming and conducting photocurrent.

[0043] Optionally, the transparent electrode layer may be made primarily of indium tin oxide (ITO) or fluorine-doped tin oxide (FTO). The metal electrode layer may be any of a copper electrode layer, an aluminum electrode layer, and a silver electrode layer. The hole transport layer may be a polytriarylamine (PTAA) thin film layer or a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT / PSS) thin film layer.

[0044] Furthermore, preferably, the perovskite solar cell 100 may further include a hole blocking layer ( Figure 1 (not shown). A hole blocking layer may be located between the electron transport layer 120 and the first electrode layer 140 to transport photogenerated electrons and block holes. Optionally, the hole blocking layer may be a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) thin film layer.

[0045] In order to more clearly introduce the above-mentioned perovskite solar cell 100 provided by the present invention, the following will be combined with Figure 1 , describing the preparation process of the inverted structured perovskite solar cell 100.

[0046] First, a 100nm transparent ITO or FTO layer can be deposited as the second electrode layer 150 by magnetron sputtering. Next, a 15nm NiOx hole transport layer 130 can be deposited on top of the second electrode layer 150 by magnetron sputtering, or a 10nm PTAA thin film layer or PEDOT / PSS thin film layer can be deposited by doctor blade coating as the hole transport layer 130. Next, a 300-600nm perovskite layer 110 can be deposited on top of the hole transport layer 130 by slit coating or wire bar doctor blade coating, and the annealing temperature can be 120°C to 160°C.

[0047] For example, the specific process of preparing the 400nm perovskite layer 110 by wire bar coating method may include: configuring 0.8M concentration of Cs 0.17 FA 0.83 Pb(I 0.83 Br 0.17 )3 and dissolved it in a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), where the volume ratio of DMF / DMSO can be 4:1. It was then scraped at a rate of 10 mm / s, and then the excess solvent was removed using a nitrogen gun for 30 seconds until it turned dark yellow. It was then annealed at 150°C for 30 minutes. The scraping method is simple to operate, requires low equipment precision, and can be used for large-scale preparation. Here, verification can be done quickly and easily.

[0048] Then, the first passivation layer 121 can be prepared by a scraping method. The process may include: dissolving 1 to 5 mg / ml of a composite of boron-doped carbon nitride nanosheets and gold nanoparticles in isopropyl alcohol, scraping at a scraping rate of 8 mm / s, and then annealing at 80°C for 5 minutes. Preferably, the scraping rate of the solution of the composite of boron-doped carbon nitride nanosheets and gold nanoparticles is in the range of 5 to 10 mm / s. If the scraping rate is too low, the film of the prepared first passivation layer 121 is too thick, which will hinder light absorption and thus affect battery performance. If the scraping rate is too high, the film of the prepared first passivation layer 121 is too thin, which will also fail to absorb light better and affect battery performance.

[0049] Afterwards, a 20 nm thick fullerene (C 60) as the electron transport layer 120. Preferably, a 5 nm thick layer of BCP can be deposited by vacuum evaporation on top of the electron transport layer 120 as a hole blocking layer. Finally, a 90-100 nm thick copper, aluminum, or silver electrode can be deposited by vacuum evaporation as the first electrode layer 140.

[0050] In summary, the present invention provides a perovskite solar cell that can promote electron transfer and separation, passivate interface defects between the perovskite layer and the electron transport layer, and improve the open circuit voltage and fill factor of the cell, thereby obtaining a high-quality solar cell.

[0051] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A perovskite solar cell, characterized in that include: a perovskite layer to absorb light and generate electron-hole pairs; An electron transport layer and a hole transport layer, respectively located on both sides of the perovskite layer, for transporting the electrons and the holes respectively; a first passivation layer, located between the electron transport layer and the perovskite layer, the first passivation layer comprising boron-doped carbon nitride nanosheets; as well as The first electrode layer and the second electrode layer are respectively located on both sides of the electron transport layer and the hole transport layer, and are used to conduct photogenerated current.

2. The perovskite solar cell according to claim 1, wherein The first passivation layer is a composite film layer of boron-doped carbon nitride nanosheets and gold nanoparticles.

3. The perovskite solar cell according to claim 1, wherein The perovskite solar cell has a formal structure. The first electrode layer is a transparent electrode layer and is located below the electron transport layer, and is used to receive sunlight and the electrons transmitted from the electron transport layer. The second electrode layer is a metal electrode layer and is located above the hole transport layer, and receives the holes transmitted from the hole transport layer.

4. The perovskite solar cell according to claim 1, wherein The perovskite solar cell has an inverted structure. The second electrode layer is a transparent electrode layer and is located below the hole transport layer, and is used to receive sunlight and the holes transmitted from the hole transport layer. The first electrode layer is a metal electrode layer and is located above the electron transport layer, and receives the electrons transmitted from the electron transport layer.

5. The perovskite solar cell according to claim 3 or 4, wherein: The metal electrode layer is any one of a copper electrode layer, an aluminum electrode layer and a silver electrode layer.

6. The perovskite solar cell according to claim 1, wherein The electron transport layer includes a fullerene thin film layer.

7. The perovskite solar cell according to claim 6, wherein Also includes: The hole blocking layer is located between the electron transport layer and the first electrode layer, wherein the hole blocking layer is a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline thin film layer.

8. The perovskite solar cell according to claim 1, wherein The hole transport layer includes a polytriarylamine thin film layer or a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) thin film layer.

9. The perovskite solar cell according to claim 1, wherein The perovskite layer includes a CsFAPbI3 thin film layer, a MAPbI3 thin film layer, a CsPbI3 thin film layer, and a Cs x FA 1-x Pb(I y Br 1-y ) Any one of the 3 thin film layers.

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