Perovskite solar cell, preparation method thereof and power utilization device

Abstract

The invention belongs to the technical field of cells, and provides a perovskite solar cell, a preparation method thereof and a power utilization device. The perovskite solar cell comprises a first electrode, a second electrode and a functional layer located between the first electrode and the second electrode. The functional layer comprises a hole transport layer, a hole passivation layer and a perovskite absorption layer which are sequentially stacked, the material of the hole passivation layer comprises self-assembly molecules, and the self-assembly molecules comprise organic salt and optional organic acid. The perovskite solar cell has the characteristics of high photoelectric conversion efficiency and the like.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically provides a perovskite solar cell and a preparation method and an electrical device thereof. Background Art

[0002] Perovskite solar cells have a simple layer structure, and the perovskite used is a synthetic material with a simple synthesis method and is easy to apply. Therefore, perovskite cells have the characteristics of simple preparation process. In addition, perovskite solar cells have also attracted much attention due to their adjustable band gap, high light absorption efficiency and charge collection efficiency. However, when the incident light acts on the various functional layers of perovskite solar cells, it will cause the loss of light and materials, resulting in problems such as low photoelectric conversion efficiency and low stability of this type of cell. Summary of the invention

[0003] In view of the above-mentioned problems, the purpose of the present application is to provide a perovskite solar cell and a preparation method and an electrical device thereof. The perovskite solar cell has high photoelectric conversion efficiency and high stability.

[0004] The first aspect of the present application provides a perovskite solar cell, comprising a first electrode, a second electrode and a functional layer located therebetween, wherein the functional layer comprises a hole transport layer, a hole passivation layer and a perovskite absorption layer stacked in sequence; the material of the hole passivation layer comprises a self-assembled molecule, wherein the self-assembled molecule comprises an organic salt and an optional organic acid, wherein the organic salt and the organic acid each independently comprise an organic anion and a cation;

[0005] The structure of the organic anion is shown in Formula 1:

[0006] ZL-Ar Formula 1

[0007] In Formula 1, Z represents a head group and includes a negatively charged group formed by the loss of hydrogen from a hydroxyl-containing acidic group:

[0008] L represents a linking group and includes a single bond, or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; each substituent in L independently includes deuterium, halogen or cyano;

[0009] Ar represents a tail group, and includes a substituted or unsubstituted aryl group having 6-50 carbon atoms, a substituted or unsubstituted heteroaryl group having 7-50 carbon atoms, a substituted or unsubstituted diarylamine group having 12-30 carbon atoms, or a substituted or unsubstituted triarylamine group having 18-50 carbon atoms; each substituent in Ar independently includes deuterium, halogen, cyano, hydroxyl, carboxyl, acyloxy, alkyl group having 1-6 carbon atoms, alkoxy group having 1-6 carbon atoms, haloalkyl group having 1-6 carbon atoms, aryl group having 6-12 carbon atoms, haloaryl group having 6-12 carbon atoms, heteroaryl group having 5-18 carbon atoms, dialkylamine group having 2-10 carbon atoms, or diarylamine group having 6-18 carbon atoms;

[0010] The cation in the organic acid is a hydrogen ion.

[0011] In the perovskite solar cell of the present application, a hole passivation layer including self-assembled molecules of organic salts is introduced into the functional layer. On the one hand, it can passivate the adjacent hole transport layer, prevent the degradation of the perovskite due to the hole transport material, and improve the stability of the battery. On the other hand, the introduced organic salt can also prevent the decomposition of the hole transport material due to water and oxygen, reduce the recombination of carriers at the interface, inhibit the influence of water and oxygen on the perovskite absorption layer, and improve the photoelectric conversion efficiency of the battery.

[0012] In some embodiments of the present application, the cations in the organic salt include monovalent metal cations, divalent metal cations, trivalent metal cations, NH4 + or at least one of monovalent organic amine cations. Optionally, the cations in the organic salt include alkali metal cations, alkaline earth metal cations, divalent transition metal cations, Sn 2+ NH4 + or at least one of monovalent organic amine cations having 1 to 5 carbon atoms. Thus, the cations in the organic salt can more effectively compensate for the site defects that occur during the crystallization of the perovskite, promote carrier mobility, and improve the photoelectric conversion efficiency of the battery. Further, the cations in the organic salt include Cs + , K + , Rb + 、Ru + Mg 2+ , Ca 2+ , Pb 2+ , Sr 2+ ,Ge 2+ Sn 2+ , Cu 2+ 、Ni 2+ NH4 + 、MA + ,EA + or FA +At least one of .

[0013] In some embodiments of the present application, in Formula 1, L includes a substituted or unsubstituted straight-chain alkylene group having 1 to 6 carbon atoms, and each substituent in L independently includes deuterium, fluorine, bromine, chlorine or cyano. Thus, while reducing the steric hindrance of the entire self-assembled molecule, the energy level can be effectively regulated and the device stability can be improved.

[0014] In some embodiments of the present application, in Formula 1, Ar includes a substituted or unsubstituted aryl group having 6-25 carbon atoms, a substituted or unsubstituted fused heteroaryl group having 7-40 carbon atoms, a substituted or unsubstituted diarylamine group having 12-20 carbon atoms, or a substituted or unsubstituted triarylamine group having 18-45 carbon atoms, and the heteroatom in the fused heteroaryl group includes at least one of N, S or O; each substituent in Ar independently includes deuterium, fluorine, bromine, chlorine, hydroxyl, carboxyl, acyloxy, phenyl, carbazolyl, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy, ethoxy or diphenylamine. Thus, the quality of the self-assembled molecule can be controlled, and the stability and solubility of the molecule can be improved.

[0015] In some embodiments of the present application, in Formula 1, Ar is selected from a substituted or unsubstituted fused heteroaryl group having 7 to 40 carbon atoms or a substituted or unsubstituted triarylamine group having 18 to 45 carbon atoms. Thus, the self-assembled molecule can more effectively extract holes and improve the photoelectric conversion efficiency of the battery.

[0016] In some embodiments of the present application, in Formula 1, Ar includes a substituted or unsubstituted group W; wherein the unsubstituted group W is selected from any one of the following groups:

[0017]

[0018]

[0019] The substituted group W is a connecting bond, and each substituent independently includes deuterium, bromine, fluorine, chlorine, hydroxyl, carboxyl, acyloxy, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy or ethoxy. Thus, the material synthesis cost is reduced while the applicability is improved.

[0020] In some embodiments of the present application, Ar includes any one of the following groups:

[0021] As a result, the energy levels of the self-assembled molecules and the adjacent layers are more matched, thereby improving the photoelectric conversion efficiency and stability of the battery.

[0022] In some embodiments of the present application, the hydroxyl-containing acidic group includes at least one of a carboxyl group, a boric acid group, a sulfonic acid group or a phosphonic acid group. Thus, the solubility of the self-assembled molecule can be improved, and the binding ability with the hole transport material can be improved.

[0023] In some embodiments of the present application, the self-assembling molecule is the organic salt. Thus, using the organic salt as the self-assembling molecule can further improve the hole extraction ability, enhance the wettability of perovskite, compensate for the defects of perovskite, and thus improve the overall performance of the battery.

[0024] In some embodiments of the present application, the self-assembling molecule includes the organic salt and the organic acid, and the mass ratio of the organic salt to the organic acid is 1:(0.01-0.2). Thus, by introducing a small amount of organic acid into the self-assembling molecule, the combination with the hole transport material can be promoted.

[0025] In some embodiments of the present application, the material of the hole transport layer includes nickel oxide. The introduction of nickel oxide is conducive to improving the stability of the battery. More importantly, nickel oxide cooperates with self-assembly molecules, so that the trivalent nickel on the surface of nickel oxide is passivated by the self-assembly molecules including the organic salt, which can reduce the reaction between high-valent nickel and perovskite A-site cations, so that there is no halide residue at the interface, reduce the non-radiative recombination of the interface, and improve the opening voltage of the perovskite solar cell.

[0026] In some embodiments of the present application, in the perovskite absorption layer, the chemical formula of the perovskite is ABX3 or A2CDX6, wherein A is a monovalent cation, B is a divalent metal cation, C is a monovalent metal cation, D is a trivalent metal cation, and X is a monovalent anion.

[0027] In some embodiments of the present application, one of the first electrode and the second electrode is a transparent electrode, and a material of the transparent electrode includes at least one of FTO, ITO, AZO, BZO or IZO.

[0028] In some embodiments of the present application, the functional layer further includes an electron transport layer, and the electron transport layer is located on a side of the perovskite absorption layer away from the hole passivation layer.

[0029] In some embodiments of the present application, the material of the electron transport layer includes at least one of zinc oxide, fullerene or fullerene derivatives, wherein the fullerene includes C60 and / or C70, and the fullerene derivative includes (6,6)-phenyl-C61-butyric acid methyl ester and / or (6,6)-phenyl-C71-butyric acid methyl ester. Thus, the carrier extraction capability can be improved and the opening voltage loss can be reduced.

[0030] In some embodiments of the present application, the functional layer further comprises an electron passivation layer, and the electron passivation layer is located on a side of the electron transport layer away from the perovskite absorption layer. Optionally, the material of the electron passivation layer comprises BCP and / or tin dioxide, thereby facilitating improving the overall performance of the battery.

[0031] The second aspect of the present application provides a method for preparing the perovskite solar cell, comprising: sequentially forming a hole transport layer, a hole passivation layer and a perovskite absorption layer on a first electrode to prepare a functional layer; and forming a second electrode on the functional layer.

[0032] In some embodiments of the present application, the further comprising: forming an electron transport layer on the perovskite absorption layer;

[0033] In some embodiments of the present application, the method further includes: forming an electron passivation layer on the electron transport layer.

[0034] In some embodiments of the present application, the method for forming a hole passivation layer includes: coating a solution containing the self-assembled molecules on the hole transport layer. Thus, the self-assembled molecules are easily dissolved, and the hole passivation layer is formed by coating, which is easy to form a film, simple to operate, and low in cost.

[0035] In some embodiments of the present application, in the solution containing the self-assembling molecules, the solvent in the solution includes at least one of water, methanol, isopropanol, ethanol or chlorobenzene. Optionally, in the solution, the concentration of the self-assembling molecules is 0.1 mg / mL-10 mg / mL.

[0036] The third aspect of the present application provides an electrical device, comprising the perovskite solar cell described in the first aspect.

[0037] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used to illustrate the preferred embodiments and are not to be considered as limiting the present application. In the accompanying drawings:

[0039] Figure 1 It is a schematic structural diagram of a perovskite solar cell according to one embodiment of the present application.

[0040] Description of reference numerals:

[0041] 100: Perovskite solar cell; 1: first electrode; 2: hole transport layer; 3: hole passivation layer; 4: perovskite absorption layer; 5: electron transport layer; 6: electron passivation layer; 7: second electrode. DETAILED DESCRIPTION

[0042] The present application is further described below in conjunction with specific implementations. It should be understood that these specific implementations are only used to illustrate the present application and are not used to limit the scope of the present application.

[0043] In this application, the reference to "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0044] "Scope" disclosed in the present application is defined in the form of lower limit and / or upper limit, and a given range is defined by selecting a lower limit and / or an upper limit, and the selected lower limit and / or the rear upper limit define the boundary of a special range. The scope defined in this way can be including or excluding end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a scope that is not clearly recorded, and any lower limit can be combined with other lower limits to form a scope that is not clearly recorded, and any upper limit can be combined with any other upper limit to form a scope that is not clearly recorded. In addition, each separately disclosed point or single numerical value itself can be used as a lower limit or upper limit and any other point or single numerical value combination or with other lower limits or upper limits to form a scope that is not clearly recorded.

[0045] If not otherwise specified, all embodiments and optional embodiments of the present application may be combined with each other to form new technical solutions, and such technical solutions should be deemed to be included in the disclosure of the present application.

[0046] Unless otherwise specified, all technical features and optional technical features of the present application may be combined with each other to form a new technical solution, and such a technical solution should be deemed to be included in the disclosure of the present application.

[0047] Unless otherwise specified, the terms "include", "comprising", "including", "containing", and "having" mentioned in this application may be open-ended or closed-ended. For example, the terms "include", "comprising", "containing", "containing", and "having" may indicate that other components not listed may also be included or contained, or may only include or contain the listed components. In addition, in this application, the terms "plurality", "multiple", and "at least one" refer to more than two. "Above" and "below" include the number itself. For example, "more than two" includes two itself, such as two, three, four or more.

[0048] If there is no special explanation, in this application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0049] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and any variations thereof are intended to cover non-exclusive inclusions. Unless otherwise specified, the terms used in this application have the well-known meanings commonly understood by those skilled in the art. Unless otherwise specified, the numerical values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the embodiments of this application).

[0050] In the present application, the term "substituted or unsubstituted" means that the functional group recorded after the term may or may not have a substituent (for ease of description, the substituents are collectively referred to as Rs below). For example, "substituted or unsubstituted aryl" refers to an aryl or unsubstituted aryl having a substituent Rs. The substituent Rs can be, for example, deuterium, halogen, cyano, heteroaryl, aryl, alkyl, haloalkyl, alkoxy, diphenylamine, carboxyl, hydroxyl, acyloxy, etc. In the present application, a "substituted" functional group means that at least one hydrogen on the functional group is replaced by a non-hydrogen group (Rs). In other words, the "substituted" functional group includes at least one substituent, for example, 1, 2, 3 or more. When the number of substituents Rs in the "substituted" functional group is greater than 1, each substituent may be the same or different.

[0051] In this application, the number of carbon atoms in a substituted or unsubstituted functional group refers to the total number of carbon atoms. For example, if Ar is a substituted aryl group with 12 carbon atoms, the total number of carbon atoms in the aryl group and the substituents thereon is 12. For another example: Ar is Then its carbon number is 10.

[0052] In the present application, aryl refers to a monovalent functional group or substituent derived from an aromatic carbocyclic ring. Aryl can be a monocyclic aryl (e.g., phenyl) or a polycyclic aryl. In other words, aryl can be a monocyclic aryl, a condensed ring aryl, two or more monocyclic aryl connected by carbon-carbon bond conjugation, a monocyclic aryl and a condensed ring aryl connected by carbon-carbon bond conjugation, two or more condensed ring aryl connected by carbon-carbon bond conjugation. Wherein, condensed ring aryl can, for example, include a dicyclic condensed aryl (e.g., naphthyl), a tricyclic condensed aryl (e.g., phenanthrenyl, fluorenyl, anthracenyl), etc. Aryl does not contain heteroatoms such as B, N, O, S, P, Se, and Si. Specific examples of aryl can include, but are not limited to, phenyl, naphthyl, biphenyl, anthracenyl, phenanthrenyl, etc.

[0053] In the present application, the arylene group refers to a divalent group formed by further losing a hydrogen atom from an aryl group.

[0054] In the present application, heteroaryl refers to a monovalent aromatic ring or a derivative thereof containing 1, 2, 3, 4, 5 or more heteroatoms in the ring, and the heteroatoms may be one or more of B, O, N, P and S. The heteroaryl may be a monocyclic heteroaryl or a polycyclic heteroaryl. In other words, the heteroaryl may be a single aromatic ring system or a plurality of aromatic ring systems conjugated by carbon-carbon bonds, and any aromatic ring system is an aromatic monocyclic ring or an aromatic condensed ring. For example, the heteroaryl may include thienyl, pyrrolyl, imidazolyl, oxazolyl, oxadiazolyl, pyridyl, bipyridyl, pyrimidyl, acridinyl, quinolyl, thienopyrrolyl, dithienopyrrolyl, phenothiazinyl, phenoxazinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, N-phenylcarbazolyl, etc., without limitation thereto.

[0055] In the present application, the general chemical formula of the diarylamine group can be expressed as: The general chemical formula of the triarylamine group can be expressed as Wherein, Ar1, Ar2, Ar4, Ar5 are the same or different, and each independently includes an aryl group, such as but not limited to, phenyl, naphthyl, biphenyl, etc.; Ar3 includes an arylene group, such as but not limited to, phenylene. A substituted diarylamine group means that the hydrogen of at least one of Ar1 and Ar2 is replaced by a substituent Rs. Similarly, a substituted triarylamine group means that the hydrogen of at least one of Ar3, Ar4, Ar5 is replaced by a substituent Rs. Optionally, in the substituted triarylamine group and the substituted diarylamine group, each substituent independently includes deuterium, an alkyl group having 1-6 carbon atoms, a haloalkyl group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms, a halogen, a hydroxyl group, a carboxyl group, or an acyloxy group.

[0056] In the present application, the number of carbon atoms of the alkyl group may be 1-10, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, and the alkyl group may include a straight-chain alkyl group and a branched-chain alkyl group. Specific examples of the alkyl group include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, heptyl, n-octyl, 2-ethylhexyl, nonyl, decyl, 3,7-dimethyloctyl, etc. Alkylene refers to a divalent group formed by further losing a hydrogen atom of an alkyl group, and the number of carbon atoms of the alkylene group may also be 1-10, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0057] In the present application, "alkoxy" refers to a group with the structure -OR, R is an alkyl group, that is, the alkyl group R as defined above is connected to the adjacent group via an oxygen atom. Examples of alkoxy include, but are not limited to, methoxy (-OCH3), ethoxy (-O-CH2CH3), etc.

[0058] In the present application, halogen may include fluorine, iodine, bromine, and chlorine.

[0059] In the present application, the number of carbon atoms of the aryl group as a substituent may be 6-12, and specific examples include, but are not limited to, phenyl, naphthyl, and the like.

[0060] In the present application, the carbon number of the heteroaryl group as a substituent may be 5-18, and specific examples of the carbon number are 5, 8, 9, 10, 12, 15, etc. Specific examples include, but are not limited to, pyridyl, quinolyl, carbazolyl, etc.

[0061] In this application, Indicates a linker, which can be a positional linker or an unpositioned linker. When a positional linker is involved, it refers to a linker extending from the carbon position of the group. (like, ). When referring to non-localized bonds, this refers to the bonds that extend from the ring system. Indicates that one end of the connecting bond can be connected to any position in the ring system that the bond passes through, and the other end is connected to the rest of the molecule. For example, as shown in the following formula (V), the naphthyl represented by formula (V) is connected to other positions of the molecule through a non-positioning connecting bond extending from the middle of one side of the benzene ring, which includes any connection mode shown in formula (V-1) and formula (V-2). In other words, the group shown by formula (V) includes both the two positionally connected groups of formula (V-1) and formula (V-2):

[0062]

[0063] The non-positional substituent in the present application refers to a substituent connected by a single bond extending from the ring system, which means that the substituent can be connected to any possible position in the ring system. For example, as shown in the following formula I, the substituent Rs in formula I is connected to the benzene ring through a non-positional connecting bond, and the meaning represented includes any possible connection mode shown in formula I-1 to formula I-3:

[0064]

[0065] In the present application, the organic amine cation may include aliphatic amine cations, specific examples of which include, but are not limited to, methylamine ion (CH3NH3 + , M.A. + ), ethylamine cation (CH3CH2NH3 + , E.A. + ), formamidinium ion (HC(NH2)2 + , F.A. + )wait.

[0066] As the main functional layer in perovskite solar cells, the hole transport layer can collect and transport hole charges, and at the same time reduce the influence of water and oxygen on the perovskite absorption layer in the functional layer, which plays an important role in the photoelectric performance of the battery. However, the properties of hole transport materials such as inorganic materials are unstable, and they are easily decomposed or oxidized, reacting with perovskite materials to form new recombination centers, increasing the charge recombination at the interface, reducing the opening voltage of perovskite solar cells, and having a significant impact on the stability of the battery. For this reason, a passivation material can be introduced between the hole transport material and the perovskite to form a hole passivation layer. Traditional passivation materials still have the problem of easily reacting with hole transport materials, resulting in their partial decomposition. At the same time, the products (such as water) produced by the reaction of the passivation material with the hole transport material will also affect the perovskite, so that the photoelectric performance and stability of the device still need to be improved.

[0067] Accordingly, the first aspect of the present application provides a perovskite solar cell, comprising a first electrode, a second electrode and a functional layer located therebetween, the functional layer comprising a hole transport layer, a hole passivation layer and a perovskite absorption layer stacked in sequence; wherein the material of the hole passivation layer comprises self-assembled molecules, and the self-assembled molecules comprise organic salts and optional organic acids.

[0068] In the present application, the self-assembling molecules include an organic salt and an optional organic acid, and "optional" means that the self-assembling molecules may include the organic acid or may not include the organic acid.

[0069] In the present application, the organic salt and the organic acid each independently include an organic anion and a cation. The cation of the organic acid is a hydrogen ion.

[0070] In some embodiments, the cations in the organic salt include monovalent metal cations, divalent metal cations, trivalent metal cations, ammonium ions (NH4 + ) or at least one of monovalent organic amine cations. The monovalent metal cations include, for example, alkali metal cations and monovalent rare earth metal cations; the divalent metal cations include, for example, alkaline earth metal cations and divalent transition metal cations.

[0071] In some embodiments, the cations in the organic salt include alkali metal cations, alkaline earth metal cations, divalent transition metal cations, Sn 2+ NH4 + Or at least one of monovalent organic amine cations with a carbon number of 1 to 5. Thus, the cations in the organic salt can more effectively compensate for the site defects that occur during the crystallization of perovskite, promote carrier movement, and improve the photoelectric conversion efficiency of the battery.

[0072] Optionally, the cation in the organic salt is Cs + , K + , Rb + 、Ru + Mg 2+ , Ca 2+ , Pb 2+ , Sr 2+ ,Ge 2+ Sn 2+ , Cu 2+ 、Ni 2+ NH4 + 、MA + ,EA + or FA + At least one of .

[0073] In the present application, the organic anions in the organic acid and the organic salt may be the same or different, and each independently has a structure shown in Formula 1:

[0074] ZL-Ar Formula 1

[0075] wherein Z represents a head group and includes a negatively charged group formed by the loss of hydrogen from an acidic group containing a hydroxyl group;

[0076] L represents a linking group and includes a single bond, or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; each substituent in L independently includes deuterium (D), halogen or cyano (CN);

[0077] Ar represents a tail group and includes a substituted or unsubstituted aryl group having 6-50 carbon atoms, a substituted or unsubstituted heteroaryl group having 7-50 carbon atoms, a substituted or unsubstituted diarylamine group having 12-30 carbon atoms, or a substituted or unsubstituted triarylamine group having 18-50 carbon atoms; each substituent in Ar independently includes deuterium, halogen, cyano, hydroxyl, carboxyl, acyloxy, alkyl group having 1-6 carbon atoms, alkoxy group having 1-6 carbon atoms, haloalkyl group having 1-6 carbon atoms, aryl group having 6-12 carbon atoms, haloaryl group having 6-12 carbon atoms, heteroaryl group having 5-18 carbon atoms, dialkylamine group having 2-10 carbon atoms, or diarylamine group having 6-18 carbon atoms.

[0078] It can be understood that the head group refers to the active binding site with the positive ion of the hole transport material in the self-assembled molecule. Taking the hole transport material as nickel oxide as an example, the head group carries an anion, which can be covalently or ionically bonded to the trivalent nickel of the hole transport layer in the process of forming the passivation layer. The tail group is also called the parent, which refers to the side away from the hole transport layer. In addition, the number of negative charges carried by Z matches the valence of the cation. For example, when the cation is a monovalent cation, Z is a negatively charged group formed by the loss of one hydrogen from the hydroxyl-containing acidic group, and the corresponding organic anion is a monovalent organic anion; when the cation is a divalent cation, Z is a negatively charged group formed by the loss of two hydrogens from the hydroxyl-containing acidic group, and the corresponding organic anion is a divalent organic anion.

[0079] In some embodiments, in Formula 1, L includes a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, and each substituent in L independently includes deuterium, fluorine, bromine, chlorine or cyano. Thus, while reducing the steric hindrance of the entire self-assembled molecule, the energy level can be effectively regulated and the stability can be improved.

[0080] In some embodiments, in Formula 1, Ar includes a substituted or unsubstituted aryl group having 6-25 carbon atoms, a substituted or unsubstituted fused heteroaryl group having 7-40 carbon atoms, a substituted or unsubstituted diarylamine group having 12-20 carbon atoms, or a substituted or unsubstituted triarylamine group having 18-45 carbon atoms, and the heteroatom in the fused heteroaryl group includes at least one of N, S or O; each substituent in Ar independently includes deuterium, fluorine, bromine, chlorine, hydroxyl, carboxyl, acyloxy, phenyl, carbazolyl, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy, ethoxy or diphenylamine. Thus, the quality of the self-assembled molecule can be controlled, and the stability and solubility of the molecule can be improved.

[0081] Optionally, in Formula 1, Ar is selected from a substituted or unsubstituted fused heteroaryl group having 7 to 40 carbon atoms or a substituted or unsubstituted triarylamine group having 18 to 45 carbon atoms. Thus, the assembled molecule can more effectively extract holes and improve the photoelectric conversion efficiency of the battery.

[0082] In some specific embodiments, in Formula 1, Ar includes a substituted or unsubstituted fused heteroaryl group having 7 to 40 carbon atoms, and L is a substituted or unsubstituted straight-chain alkylene group having 2 to 6 carbon atoms. In other specific embodiments, in Formula 1, Ar includes a substituted or unsubstituted triarylamine group having 7 to 40 carbon atoms, and L is a substituted or unsubstituted straight-chain alkylene group having 1 to 5 carbon atoms. Thus, the overall performance of the battery can be improved.

[0083] In some embodiments, in Formula 1, Ar includes a substituted or unsubstituted group W; wherein the unsubstituted group W is selected from any one of the following groups:

[0084]

[0085] In the substituted group W, each substituent independently includes deuterium, bromine, fluorine, chlorine, hydroxyl, carboxyl, acyloxy, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy or ethoxy. Thus, while reducing the material synthesis cost, the applicability is improved.

[0086] Optionally, the substituted or unsubstituted group W includes any one of the following groups:

[0087]

[0088]

[0089] wherein Z1 to Z8 are the same or different, and each group independently comprises deuterium, bromine, fluorine, chlorine, hydroxyl, carboxyl, acyloxy, methyl, ethyl, n-propyl, isopropyl, tert-butyl or methoxy.

[0090] Further, the substituted group W includes any one of the following groups:

[0091]

[0092] In other embodiments, Ar includes any of the following groups:

[0093] As a result, the energy levels of the adjacent layers are better matched, thereby improving the photoelectric conversion efficiency and stability of the battery.

[0094] In some specific embodiments, in Formula 1, Ar includes any one of the following groups:

[0095]

[0096]

[0097] In some specific embodiments, the organic salt comprises at least one of the following compounds:

[0098]

[0099]

[0100]

[0101]

[0102] In some specific embodiments, the organic acid comprises at least one of the following compounds:

[0103]

[0104]

[0105] In some embodiments, in the hole passivation layer, the self-assembling molecule is the organic salt. Thus, using the organic salt as the self-assembling molecule can further improve the hole extraction ability, enhance the wettability of perovskite, compensate for the defects of perovskite, and thus improve the overall performance of the battery.

[0106] In other embodiments, the self-assembling molecule includes the organic salt and the organic acid, and the mass ratio of the organic salt to the organic acid is 1:(0.01-0.2). Thus, by introducing a small amount of organic acid into the self-assembling molecule, the solubility of the material can be improved, and the combination with the hole transport material can be promoted.

[0107] In some embodiments, the hole passivation layer may have a thickness of 0.1 nm-5 nm, for example, 0.1 nm, 0.5 nm, 0.5 nm, 1 nm, 1.5 nm, 2 nm, 3 nm, 4 nm, 5 nm, etc.

[0108] In some embodiments, the material of the hole transport layer includes nickel oxide, and nickel oxide has higher stability than other inorganic materials. The nickel oxide can be expressed as NiOx, where x represents the ratio of oxygen atoms (O) to nickel atoms (Ni), and x satisfies 1≤x≤2. Typically, the nickel oxide may include one or more of nickel oxide, nickel trioxide, and other nickel oxides. Optionally, the nickel oxide includes nickel oxide (NiO). It can be understood that the hole transport layer is formed with nickel oxide, such as oxygen in the environment can oxidize divalent nickel to trivalent nickel, so that the hole transport layer contains both divalent nickel and trivalent nickel. By passivating the trivalent nickel on the surface of nickel oxide by self-assembled molecules including the organic salt, the reaction of high-valent nickel with the A-site cation of the perovskite can be reduced, so that there is no halide residue at the interface, the non-radiative recombination of the interface is reduced, and the opening voltage of the perovskite solar cell is increased.

[0109] In some embodiments, the thickness of the hole transport layer is 1 nm-50 nm, for example, 1 nm, 3 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 40 nm, 45 nm, 50 nm, etc.

[0110] In some embodiments, in the perovskite absorption layer, the chemical formula of the perovskite is ABX3 or A2CDX6, wherein A is a monovalent cation, such as an alkali metal cation, a monovalent rare earth metal cation, and an organic amine cation having a carbon atom number of 1-5; B is a divalent metal cation, such as a transition metal cation; X is a monovalent anion, such as a halogen anion; C is a monovalent cation, such as an alkali metal cation, a monovalent rare earth metal cation, a silver ion, etc.; and D is a trivalent metal cation.

[0111] Optionally, A includes MA + ,EA + , FA + , Rb + or Cs + At least one of .

[0112] Optionally, B includes Pb 2+ Sn 2+ , Fe 2+ , Mn 2+ 、Ni 2+ ,Ge 2+ , Cu 2+ 、Ni 2+ 、Co 2+or Sb 2+ At least one of .

[0113] Optionally, C includes Ag + , Cs + , K + Or Ru + At least one of .

[0114] Optionally, D includes Bi 3+ 、Ni 3+ , Fe 3+ , Sb 3+ or In 3+ At least one of .

[0115] Optionally, X includes I - Br - or Cl - At least one of .

[0116] Typically, the thickness of the perovskite absorption layer can be 200nm-800nm, for example, 200nm, 220nm, 250nm, 300nm, 350nm, 380nm, 400nm, 420nm, 450nm, 500nm, 550nm, 600nm, 700nm, 800nm, etc.

[0117] In some embodiments, one of the first electrode and the second electrode is a transparent electrode. It is understood that the perovskite solar cell containing a hole transport layer of nickel oxide is particularly suitable for a transverse cell, that is, the hole transport layer is closer to the transparent electrode than the hole passivation layer.

[0118] The other of the first electrode and the second electrode may be an electrode layer. Typically, the thickness of the electrode layer may be 40 nm-100 nm, such as 40 nm, 45 nm, 50 nm, 60 nm, 70 nm, 80 nm, 85 nm, 90 nm, 100 nm, etc.

[0119] In some specific embodiments, the material of the transparent electrode may include at least one of FTO (fluorine tin oxide), ITO (indium tin oxide), AZO (aluminum zinc oxide), BZO (boron zinc oxide) or IZO (indium zinc oxide). Generally, the thickness of the transparent electrode may be 300nm-700nm, such as 300nm, 400nm, 450nm, 500nm, 600nm, 700nm, etc.

[0120] In the present application, the material of the electrode layer may include, for example, one or more of a carbon material, a metal, a metal oxide, or other conductive material, and the present application has no particular limitation thereto. As an example, the material of the electrode layer may include at least one of Ag, Cu, C, Au, Al, ITO, AZO, BZO, or IZO.

[0121] In some embodiments, the functional layer further comprises an electron transport layer, which is located on a side of the perovskite absorption layer away from the hole passivation layer. The electron transport layer can transport electrons and block holes, thereby promoting the recombination of charges in the absorption layer to form excitons and improving the photoelectric efficiency.

[0122] In some embodiments, the material of the electron transport layer includes at least one of zinc oxide, fullerene or fullerene derivatives, wherein the fullerene includes C60 and / or C70, and the fullerene derivative includes (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) and / or (6,6)-phenyl-C71-butyric acid methyl ester. Thus, the ability to extract carriers can be improved and the opening voltage loss can be reduced.

[0123] In some embodiments, the functional layer further comprises an electron passivation layer, which is disposed on a side of the electron transport layer away from the perovskite absorption layer. The electron passivation layer can prevent the recombination of carriers caused by hole migration. It can be understood that the "electron passivation layer" can also be referred to as an "electron buffer layer" or "electron insertion layer". Typically, the thickness of the electron passivation layer can be 1nm-20nm, for example 1nm, 5nm, 7nm, 10nm, 12nm, 18nm, 20nm, etc.

[0124] Optionally, the material of the electronic passivation layer includes BCP (bathocuproine) and / or tin dioxide (SnO2). This is beneficial to improving the overall performance of the device.

[0125] In some embodiments, the perovskite solar cell comprises Figure 1 The structure shown, Figure 1 In the embodiment, the perovskite solar cell 100 includes a first electrode 1 and a second electrode 7, and a hole transport layer 2, a hole passivation layer 3, a perovskite absorption layer 4, an electron transport layer 5 and an electron passivation layer 6 which are sequentially stacked therebetween; and equivalent to the hole passivation layer 3, the hole transport layer 2 is closer to the first electrode 1. Optionally, the first electrode 1 is a transparent electrode.

[0126] In a second aspect, the present application provides a method for preparing the perovskite solar cell, comprising: sequentially forming a hole transport layer, a hole passivation layer and a perovskite absorption layer on a first electrode to prepare a functional layer; and forming a second electrode on the functional layer.

[0127] The present application does not particularly limit the method for forming the hole transport layer. For example, the hole transport layer including nickel oxide can be formed by sputtering or sol-gel method. The hole transport layer can also be formed by dispersing the hole transport material in a solvent and then coating it. The coating method includes but is not limited to spin coating, scraper coating, slit coating, etc.

[0128] As an example, a method for forming a hole transport layer includes: spin coating a dispersion of nickel oxide nanoparticles (solvent such as water) on a transparent electrode, and then removing the solvent by, for example, vacuuming or annealing to form a hole transport layer. The annealing temperature may be 90° C.-120° C., and the annealing time may be 0.2 h-1 h.

[0129] In some embodiments, the hole passivation layer can be formed on the hole transport layer by coating. Optionally, the method for forming the hole passivation layer includes: coating a solution containing the self-assembled molecules on the hole transport layer. In addition, the solvent in the solution can be removed by volatilization or by an operation such as annealing or vacuum to form a hole passivation layer. The annealing temperature can be 90°C-120°C, and the annealing time can be 5min-30min.

[0130] The solvent used in the solution containing the self-assembling molecules can be any solvent that can dissolve the self-assembling molecules, such as water and / or an organic solvent. Further, the solvent includes at least one of water, methanol, isopropanol, ethanol or chlorobenzene.

[0131] In the solution of the self-assembling molecules, the concentration of the self-assembling molecules can be 0.1 mg / mL-10 mg / mL, such as 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 2 mg / mL, 5 mg / mL, 8 mg / mL, 10 mg / mL, etc. In order to improve the coating efficiency and film formation uniformity, the concentration of the self-assembling molecules in the solution can be 0.5 mg / mL-5 mg / mL.

[0132] As an example, the method of forming the perovskite absorption layer includes:

[0133] providing a perovskite precursor solution;

[0134] The perovskite precursor solution is coated on the hole passivation layer and annealed. The annealing temperature is, for example, 90° C. to 150° C. and the annealing time is 0.5 h to 2 h.

[0135] In the perovskite precursor solution, the precursor composition can be selected according to the selected perovskite material. As an example, the perovskite is a CsFAMA system, and the precursor can include lead iodide, iodoformamidine, cesium iodide, methylamine bromide and lead bromide.

[0136] In some embodiments, the process of preparing the functional layer also includes: forming an electron transport layer on the perovskite absorption layer. The present application does not particularly limit the method for forming the electron transport layer. For example, the material of the electron transport layer can be dissolved or dispersed in a solvent to obtain a coating solution, and a film is formed by spin coating, spraying, scraping or slit coating, and then the solvent is removed by annealing or vacuum, thereby forming the electron transport layer. As an example, the solvent can be at least one of toluene, chlorobenzene or dichloromethane, and the concentration of the electron transport material in the coating solution can be 15mg / mL-80mg / mL, such as 15mg / mL, 20mg / mL, 25mg / mL, 30mg / mL, 50mg / mL, 60mg / mL, etc.

[0137] In some embodiments, the process of preparing the functional layer also includes: forming an electron passivation layer on the electron transport layer. The present application does not particularly limit the method for forming the electron passivation layer. For example, the solution containing the electron passivation material can be applied to the electron transport layer in the form of spin coating, spray coating, scraping or slit coating, and then the solvent is removed by annealing or vacuum to form the electron passivation layer. As an example, in the solution containing the electron passivation material, the solvent used may include at least one of isopropanol, ethanol or methanol, and the concentration of the electron passivation material therein may be 0.1 mg / mL-5 mg / mL, such as 0.2 mg / mL, 0.5 mg / mL, 1 mg / mL, 2 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, etc.

[0138] In some embodiments, the second electrode is an electrode layer, which can be formed on the functional layer by evaporating an electrode material, for example.

[0139] Optionally, the method further includes: performing an edge clearing test after forming the electrode layer.

[0140] In some specific embodiments, the method for preparing the perovskite solar cell comprises the following steps:

[0141] etching and cleaning the transparent electrode;

[0142] preparing a nickel oxide hole transport layer on a transparent electrode;

[0143] coating a solution containing self-assembled molecules on the hole transport layer, removing the solvent by annealing or vacuuming to obtain a hole passivation layer;

[0144] preparing a perovskite absorption layer on the hole passivation layer;

[0145] preparing an electron transport layer on the perovskite absorption layer;

[0146] preparing an electron passivation layer on the electron transport layer;

[0147] An electrode layer is prepared on the electronic passivation layer, and an edge clearing test is performed.

[0148] In a third aspect, the present application provides an electrical device, comprising the perovskite solar cell described in the first aspect of the present application. The perovskite solar cell can be used as a power source for the electrical device, or as an energy storage unit for the electrical device.

[0149] In some embodiments, the power-consuming device may include a mobile device, such as, but not limited to, a mobile phone, a laptop computer, an electric vehicle, an electric train, a ship, a satellite, an energy storage system, etc.

[0150] As an example, the electrical device may be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.

[0151] As another example, the power-consuming device may be a mobile phone, a tablet computer, a laptop computer, etc.

[0152] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. In addition, the synthesis examples are used to illustrate the preparation methods of organic salts and organic acids. If no specific techniques or conditions are specified in the following embodiments and synthesis examples, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0153] Synthesis Example 1: Synthesis of Compounds A-1 and B-1

[0154] (1) Preparation of ethyl p-bromophenylvalerate

[0155] After mixing 24g of p-bromophenylvaleric acid with 200mL of ethanol, 9mL of concentrated sulfuric acid (98wt%) was added dropwise, and then heating was started, the temperature was raised to 85°C, and the reaction was continued for 10h. After the reaction was completed, the product was concentrated, the solvent was removed, and then diluted with ether, and a saturated NaHCO3 aqueous solution was slowly added dropwise until no bubbles were generated, and the aqueous phase was extracted with ether for 3 times, the organic phases were mixed, and the organic phases were washed with saturated brine, and the organic phase was dehydrated with anhydrous magnesium sulfate, and then filtered, rotary evaporated, and placed in a vacuum oven at 60°C overnight to obtain ethyl bromophenylvaleric acid.

[0156] (2) Synthesis of intermediate IM 1-1

[0157]

[0158] To a reaction flask equipped with a condenser, raw material Sub 1-1 (diphenylamine, 14.7 g, 86.8 mmol), raw material Sub 1-2 (ethyl p-bromophenylvalerate, 25 g, 87.7 mmol), Pd2(dba)3 (1.6 g, 1.75 mmol), toluene solution of tri-tert-butylphosphine (1 mol / L, 7 mL), cesium carbonate (57 g, 175 mmol) and 300 mL of toluene were added. Under nitrogen protection, the reaction flask was placed in an oil bath and heated to 120° C., stirred overnight for reflux reaction. During the reaction, the reaction degree was monitored by a spot plate method until one of the reactants was completely reacted. The developing solvent was (ethyl acetate: n-hexane = 1: 20, v / v). After the reaction was completed, it was cooled to room temperature, filtered, dried, and concentrated. The crude product was purified by column, and the mobile phase was (ethyl acetate: n-hexane = 1: 10, v / v) to obtain intermediate IM 1-1 (5-(4-(diphenylamino)phenyl)pentanoic acid ethyl ester, 25g, yield 77%).

[0159] (3) Synthesis of intermediate IM 2-1

[0160]

[0161] IM 1-1 (15 g, 40.2 mmol) and 50 mL of ethanol were added to the reaction bottle. IM 1-1 was dissolved in ethanol by magnetic stirring. During the stirring process, an aqueous solution of NaOH (formed by dissolving 30 g of NaOH in 100 mL of water) was added dropwise. After the addition was completed, the temperature was raised to 70° C. and stirred for 6 h. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a crude product of the intermediate IM 2-1 (sodium 5-(4-(diphenylamino)phenyl)pentanoate), which was directly used in the next step of the reaction.

[0162] (4) Synthesis of Compound B-1

[0163]

[0164] The crude product of IM 2-1 was dissolved in 50 mL of water, and hydrochloric acid was added dropwise until the pH of the solution was adjusted to 3. The product was extracted with ethyl acetate, and the oil phase was washed with saturated brine. The oil phase was collected and distilled under reduced pressure to remove the solvent. The obtained solid product was dissolved in ethanol and added dropwise to water to obtain a large amount of white solid. The solid was filtered and recrystallized repeatedly with ethanol and water to obtain compound B-1 (5-(4-(diphenylamino)phenyl)pentanoic acid, 12.5 g, yield 90%).

[0165] (5) Synthesis of Compound A-1

[0166]

[0167] Compound B-1 (10 g, 28.9 mmol) was dissolved in 50 mL of water to obtain an aqueous solution of B-1. Cesium carbonate (4 g, 12.3 mmol) was dissolved in 20 mL of water and then added dropwise to the aqueous solution of B-1. The mixture was heated to 60°C and stirred overnight. The mixture was filtered and the filter cake was rinsed with clean water and then with ether and dried to obtain compound A-1 (cesium 5-(4-(diphenylamino)phenyl)pentanoate, 11.2 g, yield 95%). The NMR of compound A-1 was 1 H-NMR (CDCl3, 400MHz) δppm: 1.40-1.57 (4H, 1.46 (tt, J = 7.6, 7.4Hz), 1.51 (quint, J=7.5Hz)),2.13(2H,t,J=7.6Hz),2.60(2H,t,J=7.5Hz),6.98-7.18(4H,7.04(ddd ,J=8.1,1.3,0.5Hz),7.11(ddd,J=8.1,1.3,0.5Hz)),7.18-7.43(10H,7.24(tt,J= 7.7,1.3Hz),7.25(dtd,J=7.9,1.3,0.5Hz),7.36(dddd,J=7.9,7.7,1.9,0.5Hz)).

[0168] Synthesis example 2-8

[0169] The compounds listed in Table 1 were synthesized according to the method for compound A-1 (steps (2) to (5)), except that the raw material Sub a was used instead of Sub 1-1, the raw material Sub b was used instead of Sub 2-1, and the raw material Sub c was used instead of cesium carbonate in step (4).

[0170] Table 1

[0171]

[0172]

[0173] Synthesis Example 9: Preparation of Compounds B-3 and A-9

[0174] (1) Synthesis of Compound B-3

[0175]

[0176] Add raw materials Sub 2-1 (carbazole, 6 g, 35.9 mmol), NaOH (5 g, 125 mmol) and DMSO50 mL to the reaction bottle, heat to 80 ° C and stir for 1 h, then add Sub 2-2 (ethyl 4-bromobutyrate, 10 mL, 81.6 mmol), continue to stir at 80 ° C overnight, after the reaction is completed, cool to room temperature, add 20 mL of ice water and stir until the ice melts, then add hydrochloric acid and adjust the pH to 3. A large amount of white solid precipitates, filter, dissolve the filter cake in ethanol, and add water to precipitate it. Repeat the recrystallization process 3 times, filter, and dry to obtain compound B-3 (4-(9H-carbazole-9-yl)butyric acid, 7.3 g, yield 81%).

[0177] (2) Synthesis of Compound A-9

[0178]

[0179] Compound B-3 (5 g, 19.74 mmol) was dissolved in 30 mL of ethanol, and then an ethanol solution of methylamine (concentration 33% wt, 4 g) was added, and stirred at 60 ° C overnight. The solvent was removed by rotary evaporation, and the obtained solid product was washed with ethyl acetate, filtered and dried to obtain compound A-9 (4-(9H-carbazole-9-yl)butyric acid methylamine, 5.42 g, yield 96%).

[0180] Synthesis Example 10-15

[0181] The compounds listed in Table 2 were synthesized according to the method for preparing compound A-9, except that the raw material Sub d was used instead of Sub 2-1, the raw material Sub e was used instead of Sub 2-2, and the raw material Sub f was used instead of methylamine.

[0182] Table 2

[0183]

[0184] Synthesis Example 16: Synthesis of Compounds B-9 and A-16

[0185] (1) Synthesis of intermediate IM 3-1

[0186]

[0187] The raw material Sub 2-1 (carbazole, 1.672 g, 10.0 mmol) was dissolved in the raw material Sub 3-1 (1,2-dibromoethane, 25 mL, 290 mmol), and then tetrabutylammonium bromide (0.5 g, 1.5 mmol) and 3 mL of 50 wt% KOH aqueous solution were added. The temperature was raised to 50°C and the reaction was stopped after stirring for 72 h. The obtained product was extracted with dichloromethane, and the organic phase was dried over anhydrous MgSO4. Then, the solvent was removed by rotary evaporation to obtain a crude product. The crude product was purified by column (the mobile phase was acetone: n-hexane = 1:10, v / v) to obtain the intermediate IM 3-1 (9-(2-bromoethyl)-9H-carbazole, 2.2 g, yield 84%).

[0188] (2) Synthesis of intermediate IM 3-2

[0189]

[0190] IM 3-1 (2 g, 7.3 mmol) was dissolved in the raw material Sub 4-1 (triethyl phosphite, 15 mL, 86.9 mmol), heated to reflux and reacted for 24 h. After the reaction, the excess Sub 4-1 was removed by rotary evaporation, and the product was purified by column (the mobile phase was acetone: n-hexane = 1:4, v / v) to obtain the intermediate IM 3-2 (2-(9H-carbazole-9-ethyl)phosphonic acid diethyl ester, 2.17 g, yield 90%).

[0191] (3) Synthesis of Compound B-9

[0192]

[0193] IM3-2 (2g, 6.0mmol), added 20mL of 1,4-dioxane and 10mL of trimethylsilyl bromide, passed nitrogen protection, stirred at room temperature for 12h, and the reaction stopped. The solvent was removed by rotary evaporation, 5mL of methanol was added to dissolve the product, and water was slowly added dropwise, 50mL, stirred at room temperature, the solution gradually became turbid, and then solid appeared, filtered, and dried to obtain compound B-9 (1.59g, yield 96%)

[0194] (4) Synthesis of Compound A-16

[0195]

[0196] Compound B-9 (1 g, 3.6 mmol) was dissolved in 30 mL of water to obtain an aqueous solution of B-9; cesium carbonate (3 g, 9.2 mmol) was dissolved in 20 mL of water; the obtained cesium carbonate aqueous solution was added dropwise to the aqueous solution of B-9, stirred at 60 °C overnight, filtered, and the obtained filter cake was rinsed with clean water, then rinsed with ethyl acetate, and dried to obtain compound A-16 (cesium 2-(9H-carbazole-9-yl)ethyl)phosphonate, 1.92 g, yield 98%).

[0197] Synthesis Example 17-20

[0198] The compounds listed in Table 3 were synthesized according to the method for compound A-16, except that the raw material Sub g was used instead of Sub2-1, the raw material Sub h was used instead of Sub 3-1, and the raw material Sub i was used instead of cesium carbonate.

[0199] Table 3

[0200]

[0201] Synthesis Example 21: Synthesis of Compound A-21

[0202] (1) Synthesis of Compound B-18

[0203]

[0204] 4-R-4H-dithieno[3,2-B:2',3'-D]pyrrole (7.17 g, 40 mmol), 4.5 g sodium hydroxide, 5 mL ethyl 4-bromobutyrate and 30 mL DMSO were added to the reaction bottle and stirred overnight at 85°C. Subsequently, 1 mL of water was added, followed by 200 mL of ice-water mixture, and hydrochloric acid was added to adjust the pH to 3. A large amount of white solid appeared, which was filtered and washed with water to obtain compound B-18 (10 g, yield 94%).

[0205] (2) Synthesis of Compound A-21

[0206]

[0207] Add 50 mL of water to the reaction bottle, add compound B-18 (10 g, 37.7 mmol) and cesium carbonate (6 g, 18.4 mmol) in sequence, stir at room temperature for 4 h, extract with dichloromethane to remove unreacted acid, then evaporate the water phase to remove water, and dry at 70 ° C for 24 h to obtain compound A-21 (14.2 g, yield 95%). NMR of compound A-21, 1H-NMR (CDCl3, 400MHz) δppm: 2.01 (2H, quint, J = 7.4Hz), 2.35 (2H, t, J = 7.4Hz), 4.02 (2H, t, J = 7.5Hz), 7.08 (2H, d, J = 6.4Hz), 7.58 (2H, d, J = 6.4Hz).

[0208] Synthesis Example 22: Synthesis of Compound A-22

[0209]

[0210] Compound A-22 was synthesized by referring to the method of compound A-21, except that 4-R-4H-dithieno[3,2-b:2',3'-d]pyrrole was replaced by 11H-bis[1]benzothieno[3,2-b:2',3'-d]pyrrole Thus, compound A-22 was obtained. The NMR of compound A-22, 1 H-NMR (CDCl3, 400MHz) δppm: 2.27-2.42 (4H, 2.33 (tt, J = 6.5, 6.3Hz), 2.36 (t, J = 6.5Hz)), 4.46 (2H, t, J = 6.3Hz), 7.27 (2H, ddd, J = 8 .5,7.4,1.3Hz),7.48(2H,ddd,J=8.1,7.4,1.4Hz),7.85-8.09(4H,7.91(ddd,J=8.5,1.4,0.5Hz),8.03(ddd,J=8.1,1.3,0.5Hz)).

[0211] Synthesis Example 23: Synthesis of Compound A-23

[0212] (1) Synthesis of intermediate IM 4-1

[0213]

[0214] Carbazole (1.67 g, 10 mmol), 1,6-dibromohexane (48 g, 0.2 mol), tetrabutylammonium bromide (0.29 g, 0.9 mmol) and 50 wt% aqueous potassium hydroxide solution (2.5 mL, 22.44 mmol) were added to the reaction flask, heated to 60 ° C and stirred overnight, then extracted with dichloromethane, the organic phase was dried over anhydrous magnesium sulfate, distilled under reduced pressure, and purified by column chromatography, the eluent was n-hexane / dichloromethane = 4 / 1 (v / v), and the intermediate IM 4-1 (2.9 g, yield 89%) was obtained.

[0215] (2) Synthesis of Compound B-19

[0216]

[0217] IM 4-1 (2.1 g, 6.4 mmol) was dissolved in 40 mL of anhydrous THF, the resulting mixture was cooled to -78 ° C, 2 M n-butyl lithium (3.2 mL, 6.48 mmol) was slowly dripped into the mixture and stirred at -78 ° C for 30 min. Trimethyl borate (2.22 mL, 20 mmol) was slowly added to the mixture and stirring was continued for 4 h. The resulting mixture was gradually heated to room temperature. The reaction was quenched with water. The organic layer was extracted with ethyl acetate and water. The organic layer was dried over anhydrous MgSO4. The organic layer was filtered and the solvent was evaporated. The residue was purified by recrystallization from hexane to obtain compound B-19 (0.8 g, yield 40%).

[0218] (3) Synthesis of Compound A-23

[0219]

[0220] Dissolve B-19 (1.5 g, 5 mmol) in 50 mL of water, add lead oxide (2.3 g, 10 mmol), react at room temperature and stir for 12 h, filter to remove unreacted lead oxide, extract with ethyl acetate to remove unreacted second-step product, distill to remove water, and dry the product in an oven at 70 ° C for 24 h to obtain compound A-23 (1.1 g, yield 45%). NMR of compound A-23, 1 H-NMR (CDCl3, 400MHz) δppm: 1.07 (2H, t, J = 7.8Hz), 1.14-1.37 (6H, 1.20 (tt, J = 7.8) ,7.1Hz),1.28(quint,J=7.8Hz),1.30(tt,J=7.1,6.5Hz)),1.92(2H,tt,J=7.4,6.5 Hz), 4.46 (2H, t, J = 7.4Hz), 7.13 (2H, ddd, J = 8.0, 7.6, 2.3Hz), 7.30 (2H, ddd, J = 8.0 ,7.6,1.6Hz),7.52(2H,ddt,J=8.0,2.3,0.5Hz),7.68(2H,ddd,J=8.0,1.6,0.5Hz).

[0221] Synthesis Example 24: Synthesis of Compound A-24

[0222] (1) Synthesis of intermediate IM 5-1

[0223]

[0224] Sub 1-1 (20.29 g, 0.12 mol), 4-bromophenylbutyl bromide (34.8 g, 0.12 mol), sodium tert-butoxide (22 g, 0.23 mol), Pd2(dba)3 (2.1 g, 2.3 mmol), tri-tert-butylphosphine tetrafluoroborate (2.7 g, 9.3 mmol) and toluene 500 mL were added to the reaction bottle, and the temperature was raised to 60 ° C for reaction for 12 h. After the reaction was completed, the temperature was cooled to room temperature, filtered, concentrated by rotary evaporation, and purified by column chromatography (n-hexane: dichloromethane = 20: 1, v / v) to obtain intermediate IM 5-1 (23.65 g, yield 52%).

[0225] (2) Synthesis of Compound A-24

[0226]

[0227] Add IM 5-1 (22.75 g, 60 mmol), ammonium bisulfite (31.2 g, 0.3 mol), 150 mL of ethanol and 100 mL of deionized water to the reaction flask, and heat and reflux for 60 h. After the reaction is completed, cool to room temperature, filter, and rinse with water and ethanol to obtain compound A-24 (16.24 g, yield 68%).

[0228] Synthesis Example 25: Synthesis of Compound A-25

[0229]

[0230] Add 7-phenylheptanoic acid (10.3 g, 0.05 mol), cesium carbonate (7.5 g, 0.023 mol) and 50 mL of deionized water to the reaction bottle, stir and react at room temperature for 4 h, extract with dichloromethane to remove unreacted acid, then rotary evaporate the aqueous phase to remove water, and finally dry in an oven at 70 ° C for 24 h to obtain compound A-25 (15.2 g, yield 97.7%).

[0231] Example 1

[0232] Take a 2.0 cm × 2.0 cm FTO conductive glass (FTO thickness 500 nm), remove 0.35 cm of FTO at both ends by laser etching, and expose the glass substrate; then ultrasonically clean the etched FTO conductive glass with water, acetone, and isopropanol in turn;

[0233] The FTO conductive glass was blown dry of solvent under a nitrogen gun and placed in a UV ozone machine for further cleaning;

[0234] After spin coating a 10 mg / mL dispersion of nickel oxide nanoparticles (water as solvent) on the FTO substrate treated with UV ozone at a rate of 4000 rpm, the substrate was annealed on a hot plate at 100° C. for 30 min to obtain a hole transport layer with a thickness of 20 nm.

[0235] Dissolve compound A-1 in methanol to obtain a methanol solution of compound A-1 with a concentration of 1 mg / mL; spin-coat the solution on the hole transport layer at 3000 rpm, and anneal at 100° C. for 10 min to obtain a hole passivation layer with a thickness of 1 nm;

[0236] 1.2 g of lead iodide, iodoformamidine, cesium iodide, lead bromide, and methyl bromide were dissolved in 1 mL of a mixed solution of DMF and DMSO (v / v=4:1) at a molar ratio of 0.83:0.78:0.05:0.17:0.17, stirred for 3 hours, and filtered with a 0.22 μm organic filter membrane to obtain a perovskite precursor solution. The perovskite precursor solution was spin-coated on the hole passivation layer at 3000 rpm, annealed at 100°C for 30 minutes, and cooled to room temperature to obtain a perovskite absorption layer with a thickness of 500 nm, wherein the active material of the perovskite absorption layer is a CsFAMA system (chemical formula Cs 0.05 FA 0.78 MA 0.17 PbI 2.49 Br 0.51 ).

[0237] On the perovskite absorption layer, a chlorobenzene solution of PCBM (PCBM concentration is 20 mg / mL) was spin-coated at 1500 rpm, annealed at 100° C. for 10 min, and cooled to room temperature to obtain an electron transport layer with a thickness of 60 nm.

[0238] On the electron transport layer, an isopropanol solution of BCP (BCP concentration is 0.5 mg / mL) was spin-coated at 5000 rpm and annealed at 120° C. for 30 min to obtain an electron passivation layer with a thickness of 5 nm.

[0239] Cu was vacuum-deposited on the electronic passivation layer to form a copper electrode layer with a thickness of 80 nm.

[0240] Thereby, the preparation of the perovskite solar cell is completed, and the prepared cell is recorded as C1.

[0241] Example 2-29

[0242] Perovskite solar cells were prepared according to the method of Example 1, except that when forming the hole passivation layer, the compound listed in Table 4 ("self-assembling molecules" column) replaced the compound A-1 of Example 1. The prepared cells were respectively denoted as C2 to C29.

[0243] Comparative Example 1

[0244] A perovskite solar cell was prepared according to the method of Example 1, except that no hole passivation layer was formed. The prepared cell was denoted as D1.

[0245] Comparative Example 2

[0246] A perovskite solar cell was prepared according to the method of Example 1, except that when forming the hole passivation layer, compound B-9 was used instead of compound A-1 in Example 1. The prepared cell was recorded as D2.

[0247] Performance Testing

[0248] The IV performance of cells C1~C29 and D1~D2 is tested using Guangyan's solar simulator, which complies with the national standard IEC61215. Crystalline silicon solar cells are used to calibrate the light intensity to reach the intensity of one sun. The cells are connected to a digital source meter and their photoelectric conversion efficiency is measured under illumination. The efficiency on the 3rd day can reflect the photoelectric conversion capacity of the battery, and the performance on the 30th day can reflect the stability of the battery. The specific test methods are as follows:

[0249] Energy conversion efficiency test: In the atmospheric environment, the sunlight simulation light source uses the AM1.5G standard light source, and a four-channel digital source meter (Keithley 2440) is used to measure the volt-ampere characteristic curve of the battery under the irradiation of the light source to obtain the open circuit voltage Voc, short circuit current density Jsc, and fill factor FF (Fill Factor) of the battery, thereby calculating the energy conversion efficiency Eff (Efficiency) of the battery.

[0250] The energy conversion efficiency is calculated as follows: Eff = Pout / Popt = Voc×Jsc×(Vmpp×Jmpp) / (Voc×Jsc) = Voc×Jsc×FF

[0251] Among them, Pout, Popt, Vmpp, and Jmpp are the battery operating output power, incident light power, battery maximum power point voltage, and maximum power point current, respectively.

[0252] The test results are shown in Table 4.

[0253] Table 4

[0254] serial number Self-assembling molecules Open circuit voltage / V Day 3 efficiency / % Efficiency on day 30 / % Example 1 Compound A-1 1.12 18.25 18.31 Example 2 Compound A-2 1.14 18.52 18.62 Example 3 Compound A-3 1.09 17.94 17.98 Example 4 Compound A-4 1.06 15.78 15.85 Example 5 Compound A-5 1.15 19.22 19.15 Example 6 Compound A-6 1.13 17.89 18.02 Example 7 Compound A-7 1.14 18.49 18.26 Example 8 Compound A-8 1.07 17.76 17.99 Example 9 Compound A-9 1.11 18.08 18.11 Example 10 Compound A-10 1.04 15.72 15.81 Embodiment 11 Compound A-11 1.12 18.50 18.45 Example 12 Compound A-12 1.13 18.22 18.07 Example 13 Compound A-13 1.16 19.34 19.46 Embodiment 14 Compound A-14 1.14 18.76 18.62 Embodiment 15 Compound A-15 1.12 18.29 18.33 Example 16 Compound A-16 1.13 18.11 18.25 Embodiment 17 Compound A-17 1.05 18.01 18.08 Embodiment 18 Compound A-18 1.12 18.75 18.64 Embodiment 19 Compound A-19 1.08 17.71 17.66 Embodiment 20 Compound A-20 1.10 17.98 18.05 Embodiment 21 Compound A-21 1.12 18.26 18.37 Embodiment 22 Compound A-22 1.16 18.94 19.02 Embodiment 23 Compound A-23 1.01 16.68 16.56 Embodiment 24 Compound A-24 1.12 18.17 18.27 Embodiment 25 Compound A-25 1.02 15.65 15.52 Embodiment 26 A-1 / B-1(100:10) 1.13 18.23 18.31 Embodiment 27 A-2 / B-1(100:10) 1.15 18.49 18.61 Embodiment 28 A-9 / B-3(100:5) 1.09 17.88 17.62 Embodiment 29 A-16 / B-9 (100:15) 1.12 17.97 18.15 Comparative Example 1 none 0.85 10.65 10.76 Comparative Example 2 B-9 1.02 16.26 15.04

[0255] Note: The ratio of compounds in Table 4 is by mass.

[0256] Comparing Examples 1-29 with Comparative Example 1, it can be seen that introducing an organic salt and an optional organic acid between the nickel oxide hole transport layer and the perovskite absorption layer to form a hole passivation layer can improve the photoelectric conversion efficiency and stability of the battery, while allowing the battery to have a higher open circuit voltage.

[0257] Comparing Examples 1-29 with Comparative Example 2, when the hole passivation layer is formed by self-assembled molecules with organic salts, the photoelectric stability of the battery can be further improved compared to the use of organic acids alone to form the hole passivation layer. Usually, nickel oxide contains divalent nickel and trivalent nickel during the preparation process. The trivalent nickel in the bulk phase will improve the hole extraction ability of the device, thereby improving the photocurrent of the device; while the trivalent nickel on the surface will react with perovskite, thereby causing the decomposition of the perovskite, forming a composite center, and gradually causing the device to fail; compared with organic acids, organic salts have a stronger binding ability with trivalent nickel, and metal cations can more effectively compensate for the defects of perovskite and improve the stability of the battery.

[0258] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A perovskite solar cell, characterized in that: The invention comprises a first electrode, a second electrode and a functional layer therebetween; wherein the functional layer comprises a hole transport layer, a hole passivation layer and a perovskite absorption layer which are stacked in sequence; the material of the hole passivation layer comprises self-assembled molecules, the self-assembled molecules comprise an organic salt and an optional organic acid, and the organic salt and the organic acid each independently comprise an organic anion and a cation; The structure of the organic anion is shown in Formula 1: ZL-Ar Formula 1 In Formula 1, Z represents a head group and includes a negatively charged group formed by the loss of hydrogen from a hydroxyl-containing acidic group: L represents a linking group and includes a single bond, or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; each substituent in L independently includes deuterium, halogen or cyano; Ar represents a tail group, and includes a substituted or unsubstituted aryl group having 6-50 carbon atoms, a substituted or unsubstituted heteroaryl group having 7-50 carbon atoms, a substituted or unsubstituted diarylamine group having 12-30 carbon atoms, or a substituted or unsubstituted triarylamine group having 18-50 carbon atoms; each substituent in Ar independently includes deuterium, halogen, cyano, hydroxyl, carboxyl, acyloxy, alkyl group having 1-6 carbon atoms, alkoxy group having 1-6 carbon atoms, haloalkyl group having 1-6 carbon atoms, aryl group having 6-12 carbon atoms, haloaryl group having 6-12 carbon atoms, heteroaryl group having 5-18 carbon atoms, dialkylamine group having 2-10 carbon atoms, or diarylamine group having 6-18 carbon atoms; The cation in the organic acid is a hydrogen ion.

2. The perovskite solar cell according to claim 1, characterized in that The cations in the organic salt include monovalent metal cations, divalent metal cations, trivalent metal cations, NH4 + or at least one of monovalent organic amine cations; Optionally, the cations in the organic salt include alkali metal cations, alkaline earth metal cations, divalent transition metal cations, Sn 2+ NH4 + or at least one of monovalent organic amine cations having 1 to 5 carbon atoms; Optionally, the cation in the organic salt includes Cs + , K + , Rb + 、Ru + Mg 2+ , Ca 2+ , Pb 2+ , Sr 2+ ,Ge 2+ Sn 2+ , Cu 2 + 、Ni 2+ NH4 + 、MA + ,EA + or FA + At least one of .

3. The perovskite solar cell according to claim 1 or 2, characterized in that: In Formula 1, L includes a substituted or unsubstituted straight-chain alkylene group having 1 to 6 carbon atoms, and each substituent in L independently includes deuterium, fluorine, bromine, chlorine or cyano.

4. The perovskite solar cell according to any one of claims 1 to 3, characterized in that: In Formula 1, Ar includes a substituted or unsubstituted aryl group having 6 to 25 carbon atoms, a substituted or unsubstituted fused heteroaryl group having 7 to 40 carbon atoms, a substituted or unsubstituted diarylamine group having 12 to 20 carbon atoms, or a substituted or unsubstituted triarylamine group having 18 to 45 carbon atoms, and the heteroatom in the fused heteroaryl group includes at least one of N, S or O; each substituent in Ar independently includes deuterium, fluorine, bromine, chlorine, hydroxyl, carboxyl, acyloxy, phenyl, carbazolyl, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy, ethoxy or diphenylamine; Optionally, in Formula 1, Ar includes a substituted or unsubstituted fused heteroaryl group having 7 to 40 carbon atoms or a substituted or unsubstituted triarylamine group having 18 to 45 carbon atoms.

5. The perovskite solar cell according to any one of claims 1 to 4, characterized in that: In Formula 1, Ar includes a substituted or unsubstituted group W; wherein the unsubstituted group W is selected from any one of the following groups: represents a connecting bond, and in the substituted group W, each substituent independently includes deuterium, bromine, fluorine, chlorine, hydroxyl, carboxyl, acyloxy, methyl, ethyl, n-propyl, isopropyl, tert-butyl, methoxy or ethoxy; or Ar includes any of the following groups:

6. The perovskite solar cell according to any one of claims 1 to 5, characterized in that: In Formula 1, Ar includes any one of the following groups: Indicates a connection key.

7. The perovskite solar cell according to any one of claims 1 to 6, characterized in that: The hydroxyl-containing acidic group includes at least one of a carboxyl group, a boric acid group, a sulfonic acid group or a phosphonic acid group.

8. The perovskite solar cell according to any one of claims 1 to 7, characterized in that: The organic salt comprises at least one of the following compounds: and / or The organic acid comprises at least one of the following compounds:

9. The perovskite solar cell according to any one of claims 1 to 8, characterized in that: In the hole passivation layer, the self-assembling molecules are the organic salts; or The self-assembling molecule comprises the organic salt and the organic acid, and the mass ratio of the organic salt to the organic acid is 1:(0.01-0.2).

10. The perovskite solar cell according to any one of claims 1 to 9, characterized in that: The material of the hole transport layer includes nickel oxide.

11. The perovskite solar cell according to any one of claims 1 to 10, characterized in that: In the perovskite absorption layer, the chemical formula of the perovskite is ABX3 or A2CDX6, wherein A is a monovalent cation, B is a divalent metal cation, C is a monovalent metal cation, D is a trivalent metal cation, and X is a monovalent anion; Optionally, A includes MA + ,EA + , FA + , Rb + or Cs + At least one of; Optionally, B includes Pb 2+ Sn 2+ , Fe 2+ , Mn 2+ 、Ni 2+ ,Ge 2+ , Cu 2+ 、Ni 2+ 、Co 2+ or Sb 2+ At least one of; Optionally, C includes Ag + , Cs + , K + Or Ru + At least one of; Optionally, D includes Bi 3+ 、Ni 3+ , Fe 3+ , Sb 3+ or In 3+ At least one of; Optionally, X includes I - Br - or Cl - At least one of; and / or One of the first electrode and the second electrode is a transparent electrode, and a material of the transparent electrode includes at least one of FTO, ITO, AZO, BZO, or IZO.

12. The perovskite solar cell according to any one of claims 1 to 11, characterized in that: The functional layer further comprises an electron transport layer, and the electron transport layer is located on a side of the perovskite absorption layer away from the hole passivation layer; Optionally, the material of the electron transport layer includes at least one of zinc oxide, fullerene or a fullerene derivative, wherein the fullerene includes C60 and / or C70, and the fullerene derivative includes (6,6)-phenyl-C61-butyric acid methyl ester and / or (6,6)-phenyl-C71-butyric acid methyl ester; Optionally, the functional layer further comprises an electron passivation layer, and the electron passivation layer is located on a side of the electron transport layer away from the perovskite absorption layer; Optionally, the material of the electronic passivation layer includes BCP and / or tin dioxide.

13. A method for preparing the perovskite solar cell according to any one of claims 1 to 12, characterized in that: include: forming a hole transport layer, a hole passivation layer and a perovskite absorption layer in sequence on the first electrode to prepare a functional layer; A second electrode is formed on the functional layer.

14. The method according to claim 13, characterized in that Also includes: forming an electron transport layer on the perovskite absorption layer; Optionally, the method further includes: forming an electron passivation layer on the electron transport layer.

15. The method according to claim 13 or 14, characterized in that The method for forming the hole passivation layer comprises: coating a solution containing the self-assembling molecules on the hole transport layer; Optionally, the solvent in the solution includes at least one of water, methanol, isopropanol, ethanol or chlorobenzene; Optionally, in the solution, the concentration of the self-assembling molecules is 0.1 mg / mL-10 mg / mL.

16. An electrical device comprising the perovskite solar cell according to any one of claims 1 to 12.

Images