Perovskite solar cell and preparation method thereof

Abstract

The invention discloses a perovskite solar cell and a preparation method thereof. The perovskite solar cell may include: a substrate; the hole transport layer, the perovskite layer and the electron transport layer are stacked on the substrate in the thickness direction of the substrate; at least one phenyl compound is introduced into the hole transport layer and / or the perovskite layer, a benzene ring of the phenyl compound comprises three substituent groups, one substituent group is one of a sulfonic acid group, a phosphate group, sulfonate and phosphate, and the other two substituent groups are one of a hydroxyl group, a carboxyl group and a carbonyl group respectively. According to the perovskite solar cell, the wettability between the perovskite layer and the hole transport layer can be obviously improved, and the film-forming property of the perovskite layer and the energy level matching between the hole transport layer and the perovskite layer can be effectively improved, so that the photoelectric conversion efficiency and the stability of the perovskite solar cell are improved.

Description

Technical Field

[0001] The present invention relates to a perovskite solar cell and a preparation method thereof. Background Art

[0002] Regarding perovskite solar cells, due to their advantages such as simple process and low manufacturing cost, as well as the gradually increasing photoelectric conversion efficiency, they have received more and more attention. Further improving the performance of perovskite solar cells helps to enhance their competitive advantage in the field of photovoltaic cells.

[0003] It has been found that for P-i-N structure perovskite cells, due to the defects of the hole transport layer, the defects of the perovskite layer, and the poor wettability between the materials contained in the hole transport layer and the materials contained in the perovskite layer, the film-forming property of the perovskite layer is poor, resulting in the mismatch of the interface energy levels between the hole transport layer and the perovskite layer and the poor performance of the perovskite solar cell. Summary of the Invention

[0004] In view of this, the present invention provides a perovskite solar cell and a preparation method thereof. The perovskite solar cell can significantly improve the wettability between the perovskite layer and the hole transport layer, effectively improve the film-forming property of the perovskite layer and the energy level matching between the hole transport layer and the perovskite layer, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a perovskite solar cell, including:

[0007] A substrate;

[0008] A hole transport layer, a perovskite layer, and an electron transport layer stacked on the substrate in the thickness direction of the substrate;

[0009] At least one phenyl compound is introduced into the hole transport layer and / or the perovskite layer:

[0010] The phenyl compound is shown in the following structural formula (I):

[0011]

[0012] Among them, R1 represents one of a sulfonic acid group, a phosphoric acid group, a sulfonate, and a phosphate; R2 represents one of a hydroxyl group, a carboxyl group, and a carbonyl group; R3 represents one of a hydroxyl group, a carboxyl group, and a carbonyl group.

[0013] In a second aspect, an embodiment of the present invention provides a preparation method for the perovskite solar cell according to the first aspect embodiment, including:

[0014] Step 1: Prepare a stacked hole transport layer, perovskite layer, and electron transport layer on the substrate in the thickness direction of the substrate; wherein,

[0015] The solution used to prepare the hole transport layer and / or the perovskite precursor solution used to prepare the perovskite layer includes at least one of the following phenyl compounds:

[0016] The phenyl compound is represented by the following structural formula (I):

[0017]

[0018] wherein, R1 represents one of a sulfonic acid group, a phosphoric acid group, a sulfonate, and a phosphate; R2 represents one of a hydroxyl group, a carboxyl group, and a carbonyl group; R3 represents one of a hydroxyl group, a carboxyl group, and a carbonyl group.

[0019] The technical solution of the first aspect of the above invention has the following advantages or beneficial effects:

[0020] The perovskite solar cells provided by the embodiments of the present invention have three structures. The first structure is to introduce at least one phenyl compound of structural formula (I) only into the hole transport layer; the second structure is to introduce at least one phenyl compound of structural formula (I) only into the perovskite layer; the third structure is to introduce at least one phenyl compound of structural formula (I) into both the hole transport layer and the perovskite layer. For the first and third structures, by introducing at least one phenyl compound of structural formula (I) into the hole transport layer, one of the sulfonic acid group, phosphoric acid group, sulfonate and phosphate contained in the phenyl compound of structural formula (I) can interact with the substrate, and one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) cooperates with the interaction with other materials in the hole transport layer, which can not only make the hole transport layer firmly adhere to the substrate, but also make the phenyl compound of structural formula (I) firmly stay in the hole transport layer and at the interface between the hole transport layer and the perovskite layer, avoiding the migration of the phenyl compound of structural formula (I) and ensuring the stability of the structure and function of the hole transport layer. In addition, one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) introduced into the hole transport layer can interact with the perovskite material in the perovskite precursor solution, forming a Lewis structure at the interface between the hole transport layer and the perovskite layer, improving the wettability of the perovskite precursor solution on the surface of the hole transport layer, that is, there is relatively good wettability between the hole transport layer and the perovskite layer. Since the perovskite layer can be well infiltrated in the hole transport layer, the perovskite layer can form a complete film layer on the surface of the hole transport layer, effectively improving the film-forming property of the perovskite layer. In addition, introducing one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) into the hole transport layer to interact with other materials in the hole transport layer can improve the electron distribution state of the materials in the hole transport layer, thereby achieving the effect of improving the energy level of the hole transport layer, enhancing the energy level matching between the hole transport layer and the perovskite layer, helping to reduce the interfacial steric hindrance between the hole transport layer and the perovskite layer, improving perovskite crystallization, being beneficial to carrier transport, and thus enhancing the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0021] For the second and third structures, by introducing at least one phenyl compound of structural formula (I) into the perovskite layer, the groups in the phenyl compound of structural formula (I) can interact with the components in the perovskite through coordination and hydrogen bonding to slow down perovskite crystallization, improve crystallization compactness and grain size. At the same time, it will passivate defects, improve the film-forming quality of the perovskite layer on the hole transport layer and the wettability between the perovskite layer and the hole transport layer, fill the defects in the perovskite layer and the interfacial defects between the perovskite layer and the hole transport layer, help to reduce the interfacial steric hindrance between the hole transport layer and the perovskite layer, enhance the stability of the perovskite layer and the carrier transport ability between the perovskite layer and the hole transport layer, and thus enhance the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0022] Further, on one hand, the phenyl group in the phenyl compound can endow the phenyl compound with a relatively appropriate molecular size, preventing the phenyl compound from entering the lattice and ensuring the integrity of the lattices of both the perovskite layer and the hole transport layer. Since the phenyl group is a conjugated structure, the carrier cloud can accumulate at its center, which is conducive to the carrier transport at the interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic cross-sectional structure diagram of the first structure of the perovskite solar cell according to an embodiment of the present invention;

[0024] Figure 2 is a schematic cross-sectional structure diagram of the second structure of the perovskite solar cell according to an embodiment of the present invention;

[0025] Figure 3 is a schematic cross-sectional structure diagram of the third structure of the perovskite solar cell according to an embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of the main process of the preparation method of the perovskite solar cell according to an embodiment of the present invention;

[0027] Figure 5 is a J-V curve diagram of the perovskite solar cell provided according to the embodiments and comparative examples of the present invention;

[0028] Figure 6 is a film formation diagram of the perovskite layer according to Example 1 and the comparative example.

[0029] Reference Numerals:

[0030] 10 - Substrate; 20 - Hole Transport Layer; 30 - Perovskite Layer; 40 - Electron Transport Layer; 50 - Transparent Conductive Layer; 60 - Isolation Layer; 70 - Top Conductive Layer DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] On one hand, the perovskite solar cell has the advantages of low manufacturing cost, simple process, and a wide variety of selectable substrate types (such as flexible substrates, transparent substrates, etc.), endowing it with great commercial potential. On the other hand, the photoelectric conversion efficiency of the perovskite solar cell has been increased from less than 4% to more than 26%, showing relatively high application value. Therefore, the perovskite solar cell has received increasing attention and has become a research hotspot in photovoltaic cells.

[0032] Perovskite solar cells mainly have a heterojunction structure. Heterojunction perovskite solar cells are mainly divided into two types: normal structure (N-i-P type) perovskite solar cells and inverted structure (P-i-N type) perovskite solar cells. Among them, the N-i-P type perovskite solar cell sequentially stacks an electron transport layer, a perovskite layer, and a hole transport layer in the thickness direction of the substrate; the P-i-N type perovskite solar cell sequentially stacks a hole transport layer, a perovskite layer, and an electron transport layer in the thickness direction of the substrate. It should be noted that whether it is an N-i-P type perovskite solar cell or a P-i-N type perovskite solar cell, more film layers can be provided between the substrate and the electron transport layer or the hole transport layer, between the electron transport layer and the perovskite layer, or between the perovskite layer and the hole transport layer.

[0033] Through research, it is found that whether it is an N-i-P type perovskite solar cell or a P-i-N type perovskite solar cell, by improving the defects and interface states of the functional layers (hole transport layer, perovskite layer, or electron transport layer) and passivating the functional layers, the photoelectric conversion efficiency and stability can be significantly improved. In addition, passivation can also effectively reduce non-radiative recombination, improve the carrier transport efficiency and the durability of the functional layers. In particular, for P-i-N type perovskite solar cells, the self-assembled monolayers (SAMs) formed by most of the currently selected materials as the currently most excellent hole transport layer still face various problems, such as energy level mismatch with the perovskite layer and poor wettability.

[0034] In order to further improve the performance of perovskite solar cells such as photoelectric conversion efficiency, stability, reliability, and durability, an embodiment of the present invention provides a perovskite solar cell and a preparation method thereof. Among them, Figure 1 Exemplarily shows the structure of a perovskite solar cell with a phenyl compound introduced into the hole transport layer 20; Figure 2 Exemplarily shows the structure of a perovskite solar cell with a phenyl compound introduced into the perovskite layer 30; Figure 3 Exemplarily shows the structure of a perovskite solar cell with a phenyl compound introduced into both the hole transport layer 20 and the perovskite layer 30.

[0035] It should be noted that the perovskite solar cell targeted by the embodiment of the present invention is a heterojunction perovskite solar cell. Preferably, the perovskite solar cell targeted by the embodiment of the present invention is a P-i-N type heterojunction perovskite solar cell.

[0036] In the embodiments of the present invention, another structure stacked on one structure does not specifically refer to direct contact between the one structure and the other structure, and other structures may be included between the two structures. Exemplarily, a hole transport layer 20 stacked on a substrate 10 may have other film layers such as a fluorine-doped tin oxide (FTO) film layer or an indium-tin oxide (ITO) film layer between the main surface of the substrate 10 and the hole transport layer 20. For another example, other functional layers such as a passivation layer may exist between the hole transport layer 20 and the perovskite layer 30 or between the perovskite layer 30 and the electron transport layer 40.

[0037] The phenyl compound involved in the embodiments of the present invention generally refers to a compound having a single benzene ring, and a polar functional group exists at the meta position of the phenyl compound.

[0038] In addition, introducing at least one phenyl compound into a structure or a functional layer in the embodiments of the present invention generally means that the phenyl compound is introduced during the formation of the structure or the functional layer, and after the formation of the structure or the functional layer, the main structure of the phenyl compound such as a phenyl group, other functional groups (such as a sulfonic acid group or a phosphoric acid group, a hydroxyl group, a carboxyl group or a carbonyl group) or the main part of other functional groups (such as a sulfonyl group, a phosphoryl group, an acyl group or an oxy group) still exists. Therefore, for the perovskite solar cell provided in the embodiments of the present invention, by performing reverse engineering or component analysis on it, it can be obtained that the phenyl compound provided in the embodiments of the present invention is introduced during the formation of the structure or the functional layer, and after the formation of the structure or the functional layer, the main structure of the phenyl compound such as a phenyl group, other functional groups (such as a sulfonic acid group or a phosphoric acid group, a hydroxyl group, a carboxyl group or a carbonyl group) or the main part of other functional groups (such as a sulfonyl group, a phosphoryl group, an acyl group or an oxy group) still exists.

[0039] Therefore, introducing at least one phenyl compound into the hole transport layer 20 and / or the perovskite layer 30 in the embodiments of the present invention does not specifically refer to the phenyl compound existing in the hole transport layer 20 and / or the perovskite layer 30 in its own chemical structure, but means that the phenyl compound is introduced into the solution for forming the hole transport layer 20 and / or the solution for forming the perovskite layer 30 during the formation of the hole transport layer 20 and / or the perovskite layer 30.

[0040] Specifically, the embodiments of the present invention provide a perovskite solar cell. As Figures 1 to 3 shown, the structure of the perovskite solar cell may include:

[0041] A substrate 10;

[0042] In the thickness direction of the substrate 10, a hole transport layer 20, a perovskite layer 30, and an electron transport layer 40 stacked on the substrate 10;

[0043] At least one phenyl compound is introduced into the hole transport layer 20 and / or the perovskite layer 30:

[0044] The phenyl compound is represented by the following structural formula (I):

[0045]

[0046] Wherein, R1 represents one of a sulfonic acid group, a phosphoric acid group, a sulfonate and a phosphate; R2 represents one of a hydroxyl group, a carboxyl group and a carbonyl group; R3 represents one of a hydroxyl group, a carboxyl group and a carbonyl group.

[0047] It can be understood that the hole transport layer 20, the perovskite layer 30 and the electron transport layer 40 stacked on the substrate 10 are located on the main surface of the substrate 10.

[0048] The main surface of the substrate 10 can be a planar structure or a matte surface structure. In the case where the main surface of the substrate 10 is a matte surface structure, the hole transport layer 20, the perovskite layer 30 and the electron transport layer 40 stacked on the substrate 10 are also preferably all matte surface structures.

[0049] In addition, as Figures 1 to 3 shown, a transparent conductive layer 50 is further provided on the substrate 10, and the above-mentioned hole transport layer 20, perovskite layer 30 and electron transport layer 40 are stacked on the transparent conductive layer 50. Preferably, the transparent conductive layer 50 is a film layer formed by fluorine-doped tin oxide, that is, an FTO film layer.

[0050] Among them, the hole transport layer 20, the perovskite layer 30 and the electron transport layer 40 stacked on the substrate 10 can be, as Figure 1 shown, an inverted structure (P-i-N) perovskite solar cell, that is, from one main surface of the substrate 10, the hole transport layer 20, the perovskite layer 30 and the electron transport layer 40 are sequentially stacked in a direction away from the substrate 10 (that is, the hole transport layer 20 is located between the perovskite layer 30 and the substrate 10, and compared with the hole transport layer 20 and the perovskite layer 30, the electron transport layer 40 is the farthest from the substrate 10), or it can be a normal structure (N-i-P) perovskite solar cell, that is, from one main surface of the substrate 10, the electron transport layer 40, the perovskite layer 30 and the hole transport layer 20 are sequentially stacked in a direction away from the substrate 10 (that is, the electron transport layer 40 is located between the perovskite layer 30 and the substrate 10, and compared with the electron transport layer 40 and the perovskite layer 30, the hole transport layer 20 is the farthest from the substrate 10). Preferably, the solar cell provided by the embodiment of the present invention is an inverted structure (P-i-N) perovskite solar cell.

[0051] Among them, at least one phenyl compound is introduced into the hole transport layer 20 and / or the perovskite layer 30, which can be as Figure 1As shown, at least one phenyl compound is introduced into the hole transport layer 20; Figure 2 As shown, at least one phenyl compound is introduced into the perovskite layer 30; Figure 3 As shown, at least one phenyl compound is introduced into both the hole transport layer 20 and the hole transport layer 20. That is, the heterojunction solar cell provided by the embodiment of the present invention has three structures. The first structure is to introduce at least one phenyl compound of structural formula (I) only into the hole transport layer; the second structure is to introduce at least one phenyl compound of structural formula (I) only into the perovskite layer; the third structure is to introduce at least one phenyl compound of structural formula (I) into both the hole transport layer and the perovskite layer.

[0052] It can be understood that introducing at least one phenyl compound into a structure (such as the hole transport layer 20 or the perovskite layer 30) may refer to introducing one or more phenyl compounds into the structure. Introducing one phenyl compound into the structure means that the molecular structures of the phenyl compounds introduced into the structure are the same; introducing multiple phenyl compounds into the structure means that the molecular structures of the phenyl compounds introduced into the structure are multiple, and the difference between the multiple molecular structures is that the functional groups introduced into the phenyl groups are different.

[0053] For the three types of perovskite solar cells provided in the embodiments of the present invention, for the first structure (in the first structure, at least one phenyl compound of structural formula (I) is introduced only into the hole transport layer 20) and the third structure (in the third structure, at least one phenyl compound of structural formula (I) is introduced into both the hole transport layer 20 and the perovskite layer 30), by introducing at least one phenyl compound of structural formula (I) into the hole transport layer 20, one of the sulfonic acid group, phosphoric acid group, sulfonate and phosphate contained in the phenyl compound of structural formula (I) can interact with the substrate, and one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) cooperates with the interaction with other materials in the hole transport layer. This can not only make the hole transport layer firmly fixed on the substrate, but also make the phenyl compound of structural formula (I) firmly fixed in the hole transport layer 20 and at the interface between the hole transport layer 20 and the perovskite layer 30, avoiding the migration of the phenyl compound of structural formula (I) and ensuring the stable structure and function of the hole transport layer 20. In addition, one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) introduced into the hole transport layer 20 can interact with the perovskite material in the perovskite precursor solution, forming a Lewis structure at the interface between the hole transport layer 20 and the perovskite layer 30, improving the wettability of the perovskite precursor solution on the surface of the hole transport layer 20, that is, there is relatively good wettability between the hole transport layer 20 and the perovskite layer 30. Since the perovskite layer 30 can be well wetted in the hole transport layer 20, the perovskite layer 30 can form a complete film layer on the surface of the hole transport layer 20, effectively improving the film-forming property of the perovskite layer 30. In addition, introducing one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) into the hole transport layer 20 to interact with other materials in the hole transport layer 20 can improve the electron distribution state of the materials in the hole transport layer 20, thereby achieving the effect of improving the energy level of the hole transport layer 20, enhancing the energy level matching between the hole transport layer 20 and the perovskite layer 30, helping to reduce the interfacial steric hindrance between the hole transport layer 20 and the perovskite layer 30, improving perovskite crystallization, being beneficial to carrier transport, and thus enhancing the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0054] For the second structure (the second structure is to introduce at least one phenyl compound of structural formula (I) only in the perovskite layer 30) and the third structure (the third structure is to introduce at least one phenyl compound of structural formula (I) in both the hole transport layer 20 and the perovskite layer 30), at least one phenyl compound of structural formula (I) is introduced in the perovskite layer 30. The groups in the phenyl compound of structural formula (I) interact with the components in the perovskite through coordination and hydrogen bonds to slow down the crystallization of the perovskite, improve the crystal density and grain size, and at the same time blunt the The defects of the perovskite layer 30 and the interface defects between the perovskite layer 30 and the hole transport layer 20 are filled, which helps to reduce the interface steric hindrance between the hole transport layer 20 and the perovskite layer 30, improve the stability of the perovskite layer 30 and the carrier transport capacity between the perovskite layer 30 and the hole transport layer 20, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0055] Furthermore, the phenyl group in the phenyl compound can, on the one hand, make the phenyl compound have a more suitable molecular size, prevent the phenyl compound from entering the crystal lattice, and ensure that the lattices of the perovskite layer 30 and the hole transport layer 20 can remain intact. Since the phenyl group is a conjugated structure, the carrier cloud can gather at its center, which is beneficial to the carrier transport at the interface.

[0056] In order to clearly illustrate the phenyl compound of the above structure (I), the following are several examples to explain in detail that the phenyl compound satisfying the above structure (I) may be:

[0057]

[0058] It can be understood that the above-mentioned compounds are not an exhaustive list of the phenyl compounds of structural formula (I) applicable to the embodiments of the present invention. For example, the above-mentioned sulfonic acid group or phosphoric acid group can also be replaced by sulfonate or phosphate, the above-mentioned carboxyl group can also be replaced by hydroxyl or carbonyl, the carbonyl group can be replaced by carboxyl or hydroxyl, and the hydroxyl group can be replaced by carboxyl or carbonyl.

[0059] The various functional layers in perovskite solar cells will be explained below.

[0060] Specifically, for the perovskite solar cell structure provided in the embodiment of the present invention in which at least one phenyl compound is introduced only in the hole transport layer 20 (i.e., the first structure described above) and the perovskite solar cell structure in which at least one phenyl compound is introduced in the hole transport layer 20 and the perovskite layer 30 (i.e., the third structure described above), exemplarily, Figure 1 and Figure 3In the structure shown, the solution for forming the hole transport layer 20 at least includes a phenyl compound of structural formula (I) and Me-4PACz. The Me-4PACz is [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid.

[0061] By introducing the phenyl compound of structural formula (I) into the solution for forming the hole transport layer 20, one of the sulfonic acid group, phosphoric acid group, sulfonate and phosphate contained in the phenyl compound of structural formula (I) can interact with the substrate, and one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) coordinates with the methyl group of Me-4PACz. This can not only make the hole transport layer 20 firmly adhere to the substrate, but also make the phenyl compound of structural formula (I) firmly stay in the hole transport layer 20 and at the interface between the hole transport layer 20 and the perovskite layer 30, preventing the migration of the phenyl compound of structural formula (I) and ensuring the stability of the structure and function of the hole transport layer 20. In addition, one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) introduced into the hole transport layer 20 can interact with the perovskite material in the perovskite precursor solution, forming a Lewis structure at the interface between the hole transport layer 20 and the perovskite layer 30, improving the wettability of the perovskite precursor solution on the surface of the hole transport layer 20, that is, there is good wettability between the hole transport layer 20 and the perovskite layer 30. Since the perovskite layer 30 can be well wetted on the hole transport layer 20, the perovskite layer 30 can form a complete film layer on the surface of the hole transport layer 20, effectively improving the film-forming property of the perovskite layer 30.

[0062] In addition, one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) introduced into the hole transport layer 20 coordinates with the methyl group of Me-4PACz in the hole transport layer 20, improving the electron distribution state of Me-4PACz, thereby improving the energy level of the hole transport layer 20, enhancing the energy level matching between the hole transport layer 20 and the perovskite layer 30, helping to reduce the interfacial steric hindrance between the hole transport layer 20 and the perovskite layer 30, improving perovskite crystallization, and being beneficial to further enhancing the carrier transport ability, thus improving the performance of the perovskite solar cell.

[0063] Furthermore, for the perovskite solar cell structure provided in the embodiments of the present invention, in which at least one phenyl compound is introduced only into the hole transport layer 20, and the perovskite solar cell structure in which at least one phenyl compound is introduced into the hole transport layer 20 and the perovskite layer 30, in the solution used to form the hole transport layer 20, the mass ratio of the phenyl compound of formula (I) to Me-4PACz can be 1:10 to 5:3. For example, the mass ratio of the phenyl compound of formula (I) to Me-4PACz can be 1:10, 1:8, 1:5, 1:1, 2:1, 3:1.7, 4:2.3 or 5:3, etc. Preferably, in the solution used to form the hole transport layer 20, the mass ratio of the phenyl compound of formula (I) to Me-4PACz can be 1:6 to 3:4. Exemplarily, the mass ratio of the phenyl compound of formula (I) to Me-4PACz can be 1:6, 1:5, 1:3, 1:1, 2:2.7 or 3:4, etc. By controlling the mass ratio of the phenyl compound of formula (I) to Me-4PACz in the solution used to form the hole transport layer 20, the defects of the hole transport layer 20 can be effectively reduced, the electron distribution state of Me-4PACz can be improved, so as to better improve the energy level of the hole transport layer 20, further enhance the energy level matching between the hole transport layer 20 and the perovskite layer 30, and can improve the wettability of the interface of the hole transport layer 20 to the perovskite layer 30, and can reduce the waste of the phenyl compound of formula (I), effectively controlling the production cost of the perovskite solar cell.

[0064] More specifically, in the solution used to form the hole transport layer 20, the mass concentration of the phenyl compound of formula (I) can be 0.1 g / L to 0.5 g / L. For example, the mass concentration of the phenyl compound of formula (I) in the solution used to form the hole transport layer 20 can be 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L or 0.5 g / L, etc.

[0065] Preferably, in the solution used to form the hole transport layer 20, the mass concentration of the phenyl compound of formula (I) can be 0.1 g / L to 0.3 g / L. For example, the mass concentration of the phenyl compound of formula (I) in the solution used to form the hole transport layer 20 can be 0.1 g / L, 0.2 g / L or 0.3 g / L, etc.

[0066] Wherein, the mass concentration of the phenyl compound of formula (I) refers to the mass of the phenyl compound of formula (I) contained in the solution used to form the hole transport layer 20 per unit volume.

[0067] By controlling the mass concentration of the phenyl compound of the structural formula (I) in the solution used for the hole transport layer 20, while ensuring the function of the hole transport layer 20, the uniformity, film-forming property of the hole transport layer 20 can be ensured, and the formation of coordination between the phenyl compound of the structural formula (I) and Me-4PACz is matched with the film-forming process of the hole transport layer 20, so as to obtain a hole transport layer 20 with better performance.

[0068] Furthermore, for the perovskite solar cell structure provided in the embodiment of the present invention that only introduces at least one phenyl compound into the perovskite layer 30 (i.e., the above-mentioned second structure) and the perovskite solar cell structure that introduces at least one phenyl compound into the hole transport layer 20 and the perovskite layer 30 (i.e., the above-mentioned third structure), exemplarily, such as Figure 2 and Figure 3 For the structure shown, the solvent of the perovskite precursor solution for forming the perovskite layer 30 may include N,N-dimethylformamide (DMF) and / or dimethyl sulfoxide (DMSO). Furthermore, the perovskite precursor solution for forming the perovskite layer 30 further includes at least the phenyl compound of the structural formula (I), lead halide, cesium halide, formamidinium halide, and methylammonium halide. Exemplarily, the lead halide may be lead iodide and / or lead bromide and / or lead chloride, etc., the cesium halide may be cesium iodide and / or cesium bromide and / or cesium chloride, etc., the formamidinium halide may be formamidinium iodide or formamidinium bromide, etc., and the methylammonium halide may be methylammonium iodide, methylammonium bromide, or methylammonium chloride, etc.

[0069] Preferably, DMF and / or DMSO are coordinated with the phenyl compound of the structural formula (I), lead halide, cesium halide, formamidinium halide, and methylammonium halide included in the perovskite precursor solution.

[0070] Compared with only DMF and / or DMSO in the solvent, by introducing a phenyl compound of structural formula (I) with a higher boiling point into the perovskite precursor solution, the boiling point of the perovskite precursor solution for forming the perovskite layer 30 can be increased, the volatility of the perovskite precursor solution for forming the perovskite layer 30 can be reduced, the volatilization of DMF and / or DMSO can be slowed down, thereby reducing the crystallization rate of the perovskite precursor solution for forming the perovskite layer 30, improving the compactness of the crystallization formed in the perovskite layer 30, being beneficial to improving the compactness of the crystallization particles, reducing the vacancy defects in the perovskite layer 30, reducing the capture of carriers by the perovskite layer 30, and effectively improving the carrier transport ability of the perovskite layer 30. In addition, by introducing a phenyl compound of structural formula (I) into the perovskite precursor solution for forming the perovskite layer 30, an intermediate formation stage is added to the process of forming the perovskite layer 30. Specifically, in the process of forming the perovskite layer 30, the phenyl compound of structural formula (I) first combines with lead halide, and cesium halide, formamidinium halide and methylammonium halide are re-substituted, making the crystallization process have an additional step of the phenyl compound of structural formula (I) first combining with lead halide, reducing the crystallization rate of forming the perovskite layer 30, making the crystallization denser, being beneficial to further improving the formation of denser crystallization particles in the perovskite layer 30, and thus further filling the vacancy defects in the perovskite layer 30.

[0071] Furthermore, in the process of the perovskite layer 30 forming denser crystallization particles, the phenyl compound of structural formula (I) will be squeezed to the grain boundaries of the perovskite layer 30, increasing the probability of the phenyl compound of structural formula (I) combining with defects, better filling the defects, improving the passivation effect of the perovskite layer 30, and thus effectively improving the carrier transport ability of the perovskite layer 30.

[0072] Further, in the perovskite precursor solution used to form the perovskite layer 30, the molar ratio of the phenyl compound of structural formula (I) to the perovskite material may be 1:900 to 1:75. Exemplarily, the molar ratio of the phenyl compound of structural formula (I) to the perovskite material may be 1:900, 1:850, 1:800, 1:650, 1:500, 1:450, 1:300, 1:250, 1:200, 1:150, 1:100, 1:85 or 1:75, etc. Preferably, in the perovskite precursor solution used to form the perovskite layer 30, the molar ratio of the phenyl compound of structural formula (I) to the perovskite material is 1:900 to 1:375. Exemplarily, the molar ratio of the phenyl compound of the structural formula (I) to the perovskite material can be 1:900, 1:850, 1:800, 1:650, 1:500, 1:450, 1:400 or 1:375, etc. Wherein, the perovskite material in the perovskite precursor solution is a composition formed by a phenyl compound, a lead halide, a cesium halide, a methylammonium halide and a methylamine halide. By controlling the molar ratio of the phenyl compound of the structural formula (I) to the perovskite material, it is possible to ensure that the phenyl compound of the structural formula (I) is matched with the perovskite material, ensure the crystal density of the perovskite layer 30, better fill the defects of the perovskite layer and the interface defects between the perovskite layer and the hole transport layer, and obtain a perovskite layer 30 with excellent performance.

[0073] Furthermore, for the perovskite solar cell structure provided in the embodiment of the present invention in which at least one phenyl compound is introduced only into the perovskite layer 30 (the second structure) and the perovskite solar cell structure in which at least one phenyl compound is introduced into the hole transport layer 20 and the perovskite layer 30 (the third structure), in the perovskite precursor solution used to form the perovskite layer 30, the mass concentration of the phenyl compound of structural formula (I) can be 0.5 g / L to 5 g / L; for example, the perovskite precursor solution used to form the perovskite layer 30 can be 0.5 g / L to 5 g / L. The mass concentration of the phenyl compound of structural formula (I) in the perovskite precursor solution used in the mineral layer 30 may be 0.5 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L, 1 g / L, 1.5 g / L, 1.8 g / L, 2 g / L, 2.4 g / L, 2.5 g / L, 2.7 g / L, 3 g / L, 3.3 g / L, 3.7 g / L, 4 g / L, 4.3 g / L, 4.5 g / L, 4.8 g / L or 5 g / L, etc. Preferably, in the perovskite precursor solution used to form the perovskite layer 30, the mass concentration of the phenyl compound of structural formula (I) may be 0.1 g / L to 1 g / L. For example, the mass concentration of the phenyl compound of structural formula (I) in the perovskite precursor solution used to form the perovskite layer 30 may be 0.5 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L or 1 g / L.

[0074] By controlling the mass concentration of the phenyl compound of structural formula (I) in the solution used to form the perovskite layer 30, it is ensured that the perovskite layer 30 forms dense grains, fills the defects of the perovskite layer 30, and passivates the interface, while avoiding the waste of the phenyl compound of structural formula (I), so as to effectively control the production cost of the perovskite solar cell.

[0075] Furthermore, in the perovskite precursor solution, the mass concentration of the phenyl compound of structural formula (I) matches the perovskite in the perovskite precursor solution, so that the reaction rate between the phenyl compound of structural formula (I) and the perovskite is consistent with the film formation rate of the perovskite layer 30, so as to effectively improve the structural consistency of the formed perovskite layer 30.

[0076] Furthermore, if Figures 1 to 3 As shown, the structure of the above-mentioned perovskite solar cell may further include: an insulating layer 60 and a top conductive layer 70 stacked on a side of the electron transport layer 40 away from the perovskite layer 30 .

[0077] Furthermore, an embodiment of the present invention also provides a method for preparing a perovskite solar cell. The method for preparing a perovskite solar cell may include the following steps:

[0078] In the thickness direction of the substrate 10, a stacked hole transport layer 20, a perovskite layer 30 and an electron transport layer 40 are prepared on the substrate 10, wherein:

[0079] The solution used to prepare the hole transport layer 20 and / or the solution used to prepare the perovskite layer 30 includes at least one of the following phenyl compounds:

[0080] The phenyl compound is shown in the following structural formula (I):

[0081]

[0082] Among them, R1 represents one of sulfonic acid group, phosphoric acid group, sulfonate and phosphate; R2 represents one of hydroxyl group, carboxyl group and carbonyl group; R3 represents one of hydroxyl group, carboxyl group and carbonyl group.

[0083] In the preparation method of the above-mentioned perovskite solar cell provided by an embodiment of the present invention, by introducing at least one phenyl compound of structural formula (I) into the solution used to prepare the hole transport layer 20, one of the sulfonic acid group, phosphoric acid group, sulfonate and phosphate contained in the phenyl compound of structural formula (I) can interact with the substrate, and one of the hydroxyl group, carboxyl group and carbonyl group contained in the phenyl compound of structural formula (I) can interact with the material forming the hole transport layer 20. This can not only stabilize the hole transport layer 20 on the substrate 10, but also stabilize the phenyl compound of structural formula (I) in the hole transport layer 20 and the interface between the hole transport layer 20 and the perovskite layer 30, thereby avoiding the migration of the phenyl compound of structural formula (I) and ensuring the stability of the structure and function of the hole transport layer 20. In addition, one of the hydroxyl, carboxyl and carbonyl groups contained in the phenyl compound of structural formula (I) introduced into the hole transport layer 20 can interact with the perovskite material in the perovskite precursor solution, so that the interface between the hole transport layer 20 and the perovskite layer 30 forms a Lewis structure, thereby improving the wettability of the perovskite precursor solution on the surface of the hole transport layer 20, that is, the hole transport layer 20 and the perovskite layer 30 have relatively good wettability. Since the perovskite layer 30 can be relatively well infiltrated into the hole transport layer 20, the perovskite layer 30 can form a complete film layer on the surface of the hole transport layer 20, thereby effectively improving the film-forming property of the perovskite layer.

[0084] In addition, introducing one of the hydroxyl, carboxyl and carbonyl groups contained in the phenyl compound of structural formula (I) into the hole transport layer 20 interacts with other materials in the hole transport layer 20, thereby improving the electron distribution state of the material in the hole transport layer 20, thereby achieving the effect of improving the energy level of the hole transport layer 20, improving the energy level matching between the hole transport layer 20 and the perovskite layer 30, helping to reduce the interface steric hindrance between the hole transport layer 20 and the perovskite layer 30, improving perovskite crystallization, and facilitating carrier transport, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0085] Furthermore, in the above preparation method, a phenyl compound of structural formula (I) can be introduced into the solution used to prepare the perovskite layer 30 to introduce at least one phenyl compound of structural formula (I) into the perovskite layer. The groups in the phenyl compound of structural formula (I) interact with the components in the perovskite through coordination and hydrogen bonds to slow down the crystallization of the perovskite, improve the crystal density and grain size, and passivate defects, thereby improving the film formation quality of the perovskite layer 30 on the hole transport layer 20 and the wettability between the perovskite layer 30 and the hole transport layer 20, filling the defects of the perovskite layer 30 and the interface defects between the perovskite layer 30 and the hole transport layer 20, helping to reduce the interface steric hindrance between the hole transport layer 20 and the perovskite layer 30, improving the stability of the perovskite layer 30 and the carrier transport capacity between the perovskite layer 30 and the hole transport layer 20, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0086] Furthermore, the phenyl group in the phenyl compound introduced into the solution used to prepare the hole transport layer 20 and / or the solution used to prepare the perovskite layer 30 can, on the one hand, make the phenyl compound have a more suitable molecular size, avoid the phenyl compound from entering the crystal lattice, and ensure that the lattices of the perovskite layer 30 and the hole transport layer 20 can remain intact. Since the phenyl group is a conjugated structure, the carrier cloud can gather at its center, which is beneficial to the carrier transport at the interface.

[0087] Specifically, Figure 4 As shown, the specific implementation of preparing the stacked hole transport layer 20, the perovskite layer 30 and the electron transport layer 40 on the substrate 10 may include the following steps:

[0088] Step S401 : preparing a hole transport layer 20 on a substrate 10 .

[0089] It can be understood that for a structure in which a FTO film layer 50 is formed on a substrate 10 , this step is to prepare a hole transport layer 20 on the FTO film layer 50 .

[0090] The hole transport layer 20 can be formed by coating methods such as spin coating, blade coating or spray coating.

[0091] In this step, the solution used to prepare the hole transport layer 20 may include at least the phenyl compound of structural formula (I) and Me-4PACz; the solution used to prepare the hole transport layer 20 may also include Me-4PACz but not the phenyl compound of structural formula (I).

[0092] Further, in this step, the coated solution comprising at least the phenyl compound of structural formula (I) and Me-4PACz is annealed at 90°C to 110°C for 5min to 15min. Exemplarily, the annealing temperature of this step may be 90°C, 93°C, 95°C, 98°C, 100°C, 103°C, 105°C, 108°C or 110°C, etc., and the annealing time of this step may be 5min, 7min, 8min, 9min, 10min, 12min, 14min or 15min, etc. By controlling the annealing temperature and annealing time for preparing the hole transport layer 20, damage to the hole transport layer 20 can be avoided.

[0093] Preferably, in this step, for the solution comprising at least the phenyl compound of structural formula (I) and Me-4PACz, the mass ratio of the phenyl compound of structural formula (I) to Me-4PACz may be 1:10 to 5:3, for example, the mass ratio of the phenyl compound of structural formula (I) to Me-4PACz may be 1:10, 1:8, 1:5, 1:1, 2:1, 3:1.7, 4:2.3 or 5:3, etc. Preferably, in the solution used to form the hole transport layer 20, the mass ratio of the phenyl compound of structural formula (I) to Me-4PACz may be 1:6 to 3:4, illustratively, the mass ratio of the phenyl compound of structural formula (I) to Me-4PACz may be 1:6, 1:5, 1:3, 1:1, 2:2.7 or 3:4, etc. By controlling the mass ratio of the phenyl compound of structural formula (I) and Me-4PACz in the solution used to form the hole transport layer 20, the defects of the hole transport layer 20 can be effectively reduced, the wettability of the interface of the hole transport layer 20 to the perovskite layer 30 can be improved, and the waste of the phenyl compound of structural formula (I) can be reduced, thereby effectively controlling the production cost of perovskite solar cells.

[0094] More specifically, in the solution for preparing the hole transport layer 20, the mass concentration of the phenyl compound of structural formula (I) may be 0.1 g / L to 0.5 g / L. For example, the mass concentration of the phenyl compound of structural formula (I) in the solution used to form the hole transport layer 20 may be 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L or 0.5 g / L. Preferably, in the solution for preparing the hole transport layer 20, the mass concentration of the phenyl compound of structural formula (I) may be 0.1 g / L to 0.3 g / L. For example, the mass concentration of the phenyl compound of structural formula (I) in the solution may be 0.1 g / L, 0.2 g / L or 0.3 g / L.

[0095] When the hole transport layer 20 is prepared by spin coating, the spin coating rate may be 3000 rpm to 5000 rpm. For example, the spin coating rate may be 3000 rpm, 3400 rpm, 3500 rpm, 4000 rpm, 4500 rpm or 5000 rpm.

[0096] Step S402 : preparing a perovskite layer 30 on a side of the hole transport layer 20 away from the substrate 10 .

[0097] The perovskite layer 30 in this step may also be formed by coating methods such as spin coating, blade coating or spray coating.

[0098] In this step, the solvent in the perovskite precursor solution used to prepare the perovskite layer 30 may include DMF and / or DMSO, and the perovskite precursor solution used to prepare the perovskite layer 30 may include at least a phenyl compound of structural formula (I), lead halide, cesium halide, guanidine halide and methylamine halide; the solution used to prepare the perovskite layer 30 may also include lead halide, cesium halide, guanidine halide and methylamine halide but not include a phenyl compound of structural formula (I).

[0099] Furthermore, in this step, the coated solution comprising at least the phenyl compound of structural formula (I), lead halide, cesium halide, methylammonium halide, methylamine halide, DMF and / or DMSO is generally annealed at 100° C. to 150° C. for 10 min to 60 min. Exemplarily, the annealing temperature of this step may be 100°C, 103°C, 105°C, 108°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C or 150°C, etc., and the annealing time of this step may be 10min, 12min, 14min, 15min, 20min, 25min, 30min, 40min, 50min or 60min, etc. By controlling the annealing temperature and annealing time for preparing the perovskite layer 30, damage to the perovskite layer 30 can be avoided, and the wettability and interface passivation effect of the perovskite layer 30 at the interface of the hole transport layer 20 can be improved.

[0100] In this step, if the solution used to prepare the perovskite layer 30 contains a phenyl compound of structural formula (I), the molar ratio between the phenyl compound of structural formula (I) and the perovskite material (a composition of lead halide, cesium halide, methylammonium halide and methylamine halide) in the perovskite precursor solution used to prepare the perovskite layer 30 is 1:900 to 1:75. Exemplarily, the molar ratio of the phenyl compound of structural formula (I) to the perovskite material may be 1:900, 1:850, 1:800, 1:650, 1:500, 1:450, 1:300, 1:250, 1:200, 1:150, 1:100, 1:85 or 1:75, etc. Preferably, in the perovskite precursor solution used to form the perovskite layer 30, the molar ratio of the phenyl compound of structural formula (I) to the perovskite material is 1:900 to 1:375. Exemplarily, the molar ratio of the phenyl compound of structural formula (I) to the perovskite material may be 1:900, 1:850, 1:800, 1:650, 1:500, 1:450, 1:400 or 1:375, etc. Wherein, the perovskite material in the perovskite precursor solution is a composition formed by a phenyl compound, a lead halide, a cesium halide, a methylamidine halide and a methylamino halide. By controlling the molar ratio of the phenyl compound of structural formula (I) and the perovskite material, it is possible to ensure that the phenyl compound of structural formula (I) and the perovskite material are compatible, ensure the crystal density of the perovskite layer 30, better fill the defects of the perovskite layer and the interface defects between the perovskite layer and the hole transport layer, and obtain a perovskite layer 30 with excellent performance.

[0101] Furthermore, in this step, for introducing at least one phenyl compound into the perovskite precursor solution for preparing the perovskite layer 30, in the solution, the mass concentration of the phenyl compound of structural formula (I) may be 0.5 g / L to 5 g / L; for example, the mass concentration of the phenyl compound of structural formula (I) in the perovskite precursor solution used to form the perovskite layer 30 may be 0.5 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L, 1 g / L, 1.5 g / L, 1.8 g / L, 2 g / L, 2.4 g / L, 2.5 g / L, 2.7 g / L, 3 g / L, 3.3 g / L, 3.7 g / L, 4 g / L, 4.3 g / L, 4.5 g / L, 4.8 g / L or 5 g / L, etc. Preferably, the mass concentration of the phenyl compound of structural formula (I) in the perovskite precursor solution used to form the perovskite layer 30 may be 0.1 g / L to 1 g / L. For example, the mass concentration of the phenyl compound of structural formula (I) in the perovskite precursor solution used to form the perovskite layer 30 may be 0.5 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L or 1 g / L, etc.

[0102] In the process of preparing the perovskite layer 30 by spin coating, the spin coating rate can be 1000rpm to 5000rpm. For example, the spin coating rate can be 1000rpm, 1500rpm, 2000rpm, 2500rpm, 3000rpm, 3400rpm, 3500rpm, 4000rpm, 4500rpm or 5000rpm.

[0103] Step S403 : preparing an electron transport layer 40 on a side of the perovskite layer 30 away from the hole transport layer 20 .

[0104] In this step of preparing the electron transport layer 40 , the electron transport layer 40 can be formed by evaporating C60.

[0105] In addition, the isolation layer 60 and the top conductive layer 70 may be formed on the electron transport layer 40 by evaporation.

[0106] The following describes in detail the perovskite solar cell provided by the embodiments of the present invention with reference to several specific examples.

[0107] Embodiment 1:

[0108] Step A1: Provide a spin coater, a heating stage, and a substrate with a FTO film layer.

[0109] Step B1: Preparation of a solution for preparing a hole transport layer: Dissolve Me-4PACz and 5-sulfonyl isophthalic acid sodium salt in anhydrous ethanol at a mass ratio of 5:2, and make the mass concentration of 5-sulfonyl isophthalic acid sodium salt in the solution for preparing a hole transport layer be 0.2 g / L.

[0110] The chemical structure of 5-sulfonylisophthalic acid sodium salt is as follows:

[0111]

[0112] Step C1: Preparation of a solution for the perovskite layer: dissolve appropriate amounts of lead iodide, cesium iodide, formamidine iodine, methylamine bromide, methylamine chloride, and lead bromide in a mixed solution of DMF and DMSO.

[0113] Step D1: Spin the solution for preparing the hole transport layer onto the FTO film layer using a spin coater at 4000 rpm and anneal at 100° C. for 10 min to prepare the hole transport layer.

[0114] Step E1: The solution for preparing the perovskite layer was spin-coated on the hole transport layer at 4000 rpm using a spin coater and annealed at 120° C. for 30 min.

[0115] Step F1: C60, BCP, and silver are sequentially deposited on the perovskite layer by evaporation, and an electron transport layer, an insulating layer, and a top electrode are sequentially prepared.

[0116] Embodiment 2:

[0117] The difference from Example 1 is that in the preparation of the solution for the perovskite layer, sodium 5-sulfonate isophthalic acid is introduced, wherein the molar ratio of the perovskite material to sodium 5-sulfonate isophthalic acid is 500:1, and the mass concentration of sodium 5-sulfonate isophthalic acid in the solution of the perovskite layer is 0.8 g / L.

[0118] Embodiment 3:

[0119] The difference from Example 1 is that in the preparation of the solution for the hole transport layer, only Me-4PACz is dissolved in anhydrous ethanol, and isophthalic acid-5-sulfonate sodium salt is not introduced into the solution of the hole transport layer; in the preparation of the solution for the perovskite layer, isophthalic acid-5-sulfonate sodium salt is introduced, wherein the molar ratio of the perovskite material to the isophthalic acid-5-sulfonate sodium salt is 500:1, and the mass concentration of isophthalic acid-5-sulfonate sodium salt in the perovskite layer solution is 0.8 g / L.

[0120] Comparative Example:

[0121] The difference from Example 1 is that in the preparation of the solution for preparing the hole transport layer, only Me-4PACz is dissolved in anhydrous ethanol, and 5-sulfonyl isophthalic acid sodium salt is not introduced into the solution of the hole transport layer.

[0122] The performance of the perovskite solar cells prepared in Example 1, Example 2, Example 3 and the comparative example was tested. The test results are shown in Table 1.

[0123] Table 1

[0124] <![CDATA[V OC (V)]]> <![CDATA[J SC (mA / cm 2 )]]> FF (%) PCE (%) Example 1 1.150 26.05 83.79 25.11 Example 2 1.162 26.33 85.06 26.04 Example 3 1.123 26.03 73.38 21.46 Comparative Example 1.112 25.71 65.52 18.73

[0125] According to Table 1 and Figure 5 It can be clearly seen from the JV curves of the provided Examples 1, 2, 3 and the comparative example that, compared with the comparative example in which the solution forming the hole transport layer 20 does not add the phenyl compound of the structural formula (I), and the solution forming the perovskite layer 30 does not add the phenyl compound of the structural formula (I), in the perovskite solar cell provided by the embodiments of the present invention provided by Examples 1, 2 and 3, by adding the phenyl compound of the structural formula (I) to the solution forming the hole transport layer 20 and / or adding the phenyl compound of the structural formula (I) to the solution forming the perovskite layer 30, the open circuit voltage (V OC ), short circuit current (J SC), fill factor (FF) and photoelectric conversion efficiency (PCE). In addition, by comparing the test results of Example 1, Example 2 and Example 3, it can be seen that compared with adding the phenyl compound of structural formula (I) only in the solution for forming the hole transport layer 20 (Example 1) or adding the phenyl compound of structural formula (I) only in the solution for forming the perovskite layer 30 (Example 3), adding the phenyl compound of structural formula (I) in the solution for forming the hole transport layer 20 and adding the phenyl compound of structural formula (I) in the solution for forming the perovskite layer 30 (Example 2) at the same time, the open circuit voltage (V OC ), short circuit current (J SC ), fill factor (FF) and photoelectric conversion efficiency (PCE).

[0126] Furthermore, the film forming properties of the perovskite layers prepared in Example 1 and the comparative example were tested, and the test results are as follows: Figure 6 As shown. Figure 6 It can be seen that the perovskite layer prepared in the comparative example (marked as pure Me-4PACz) is not complete, indicating that the film-forming property of the perovskite layer of the technical solution provided in the comparative example is poor, while the perovskite layer prepared in Example 1 (marked as mixed Me-4PACz) forms a complete film layer, indicating that Example 1 has a relatively good perovskite layer film-forming property.

[0127] By studying each functional layer formed by the above-mentioned embodiment 1 to embodiment 3, it is found that the sodium salt of isophthalic acid-5-sulfonic acid group is in the solution, and the sodium ion dissociates and does not participate in the reaction. The only thing participating in the reaction is the carboxylate radical on the benzene ring and the sulfonate radical that loses the sodium ion, wherein, the sulfonate radical can interact with the substrate as a Lewis base due to having a lone pair of electrons, and the carboxylate radical can interact with other materials in the hole transport layer as an electron-donating group. Compared to the sulfur atom in sulfonic acid group or sulfonate, the phosphorus atom in phosphate group or phosphate is weak in electronegativity, and the oxygen atom to which it is connected has a stronger electron-donating ability, and the characteristic of the Lewis base shown is stronger, and phosphate group or phosphate can also interact with the substrate as an electron-donating group, therefore, the sodium salt of sulfonic acid group in the above-mentioned embodiment can be replaced by sulfonic acid group or phosphate group or sodium salt of phosphate group. In addition, carbonyl and hydroxyl are as electron-donating groups, and their performance is similar to carboxyl (comprising carbonyl and hydroxyl), and can interact with other materials in the hole transport layer, therefore, carboxyl can also be replaced by carbonyl or hydroxyl.

[0128] The introduction provided in the above steps is only used to help understand the structure, method and core idea of ​​the present invention. For ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also belong to the scope of protection of the claims of the present invention.

Claims

1. A perovskite solar cell, characterized in that: include: Base (10); A hole transport layer (20), a perovskite layer (30) and an electron transport layer (40) stacked on the substrate (10) in the thickness direction of the substrate (10); The hole transport layer (20) and / or the perovskite layer (30) introduces at least one phenyl compound: The phenyl compound is shown in the following structural formula (I): Among them, R1 represents one of sulfonic acid group, phosphoric acid group, sulfonate and phosphate; R2 represents one of hydroxyl group, carboxyl group and carbonyl group; R3 represents one of hydroxyl group, carboxyl group and carbonyl group.

2. The perovskite solar cell according to claim 1, characterized in that The solution for forming the hole transport layer (20) comprises at least the phenyl compound of the structural formula (I) and Me-4PACz; and / or, The perovskite precursor solution for forming the perovskite layer (30) at least comprises the phenyl compound of the structural formula (I), lead halide, cesium halide, methylammonium halide and methylamine halide.

3. The perovskite solar cell according to claim 2, characterized in that: In the solution used to form the hole transport layer (20), the mass ratio of the phenyl compound of the structural formula (I) to Me-4PACz is 1:10 to 5:3; and / or, In the perovskite precursor solution used to form the perovskite layer (30), the molar ratio of the phenyl compound of the structural formula (I) to the perovskite material is 1:900 to 1:75; and / or, The solvent of the perovskite precursor solution for forming the perovskite layer (30) includes DMF and / or DMSO.

4. The perovskite solar cell according to claim 2, characterized in that: In the solution used to form the hole transport layer (20), the mass ratio of the phenyl compound of the structural formula (I) to Me-4PACz is 1:6 to 3:4; and / or, In the perovskite precursor solution used to form the perovskite layer (30), the molar ratio of the phenyl compound of the structural formula (I) to the perovskite material is 1:900 to 1:

375.

5. The perovskite solar cell according to claim 3 or 4, characterized in that: In the solution used to form the hole transport layer (20), the mass concentration of the phenyl compound of the structural formula (I) is 0.1 g / L to 0.5 g / L; and / or, In the perovskite precursor solution used to form the perovskite layer (30), the mass concentration of the phenyl compound of the structural formula (I) is 0.5 g / L to 5 g / L.

6. The perovskite solar cell according to claim 3 or 4, characterized in that: In the solution used to form the hole transport layer (20), the mass concentration of the phenyl compound of the structural formula (I) is 0.1 g / L to 0.3 g / L; and / or, In the perovskite precursor solution used to form the perovskite layer (30), the mass concentration of the phenyl compound of the structural formula (I) is 0.5 g / L to 1 g / L.

7. The perovskite solar cell according to any one of claims 1 to 4, characterized in that: The perovskite solar cell further comprises: a transparent conductive layer (50) disposed between the substrate (10) and the hole transport layer (20); and / or, The perovskite solar cell further comprises: an insulating layer (60) and a top conductive layer (70) stacked on a side of the electron transport layer (40) away from the perovskite layer (30).

8. The method for preparing a perovskite solar cell according to any one of claims 1 to 6, characterized in that: include: Step 1: preparing a stacked hole transport layer (20), a perovskite layer (30) and an electron transport layer (40) on the substrate (10) in the thickness direction of the substrate (10); wherein: The solution used to prepare the hole transport layer (20) and / or the perovskite precursor solution used to prepare the perovskite layer (30) comprises at least one of the following phenyl compounds: The phenyl compound is shown in the following structural formula (I): Among them, R1 represents one of sulfonic acid group, phosphoric acid group, sulfonate and phosphate; R2 represents one of hydroxyl group, carboxyl group and carbonyl group; R3 represents one of hydroxyl group, carboxyl group and carbonyl group.

9. The preparation method according to claim 8, characterized in that: The solution used to prepare the hole transport layer (20) comprises at least the phenyl compound of the structural formula (I) and Me-4PACz; and / or, The perovskite precursor solution used to prepare the perovskite layer (30) at least comprises the phenyl compound of the structural formula (I), lead halide, cesium halide, methylammonium halide and methylamino halide.

10. The preparation method according to claim 9, characterized in that: Annealing the coated solution comprising at least the phenyl compound of the structural formula (I) and Me-4PACz at 90° C. to 110° C. for 5 min to 15 min; and / or, The coated perovskite precursor solution comprising at least the phenyl compound of the structural formula (I), lead halide, cesium halide, methylammonium halide and methylamine halide is annealed at 100° C. to 150° C. for 10 min to 60 min.

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