Additive for hole transport layer and perovskite solar cell

Abstract

The application relates to an additive for a hole transport layer and a perovskite solar cell, the additive being a compound with the following formula (I). The triphenylamine derivative with an unsaturated bond (carbon-carbon double bond or carbon-carbon triple bond) can effectively regulate the photoelectric properties of a hole transport layer bulk phase and an interface in a perovskite photovoltaic device when the triphenylamine derivative is used as an additive of the hole transport layer: the extraction and transport capacity of carriers in the hole transport layer are promoted; the surface defects on a perovskite layer are passivated, non-radiative recombination is effectively reduced; the binding force of the hole transport layer and an opposite electrode interface is improved, and ion migration at the interface is inhibited; the preparation process is simple, the efficiency of an assembled solar cell is high, the repeatability is good, the stability is obviously improved, and the additive has good industrial application value.

Description

Technical Field

[0001] This application relates to the field of solar cells, and in particular to the field of perovskite solar cells. Background Technology

[0002] Perovskite solar cells (PSCs) are rapidly becoming strong competitors in the photovoltaic field due to their advantages such as low manufacturing cost, ability to be fabricated in stacked layers, and ability to be fabricated on rigid or flexible substrates, achieving a photoelectric conversion efficiency of 26.1%. The performance of PSCs is essentially related to the interface contact, therefore, good interface contact is particularly important.

[0003] In both nip and pin-mounted solar cells, hole transport layers (HTLs) effectively transfer holes and block electrons, transporting positive charges to the cathode while preventing negative charges from reaching it, thereby improving device efficiency and stability. The optoelectronic and materials science properties of HTLs, including interface energy levels, chemical compatibility, thin film morphology, hole extraction / transport efficiency, and ion migration barriers, largely determine the performance of solar cells. By carefully designing and optimizing the materials and structure of HTLs to facilitate the extraction of photogenerated charges to their respective electrodes and achieve charge transfer / accumulation at the interface, the photovoltaic performance and stability of solar cells can be significantly improved.

[0004] Currently used organic hole transport materials (such as spiro-OMeTAD) suffer from low hole mobility, low conductivity, and high cost, hindering their application in large-scale components. While doping strategies have proven effective in improving charge extraction / transport characteristics, commonly used additives can easily lead to decreased device stability. For example, lithium salts are hygroscopic, causing perovskite structure collapse, and lithium ions easily migrate within the device, leading to performance degradation; 4-tert-butylpyridine is volatile, causing porosity in the HTL, severely affecting the long-term stability of the device. Furthermore, in nip structures, the HTL provides more than just hole transport; it also needs to act as a physical shield to prevent direct contact between the perovskite layer and the electrode. When the perovskite material interacts with the counter electrode (especially a metal electrode), unexpected interfacial reactions may occur, such as biphasic redox reactions, the formation of interfacial dipoles, and changes in polar molecular orientation. These reactions severely hinder carrier transport. Even in the presence of the HTL, metal atoms can gradually diffuse into the device under operating conditions, leading to device failure. Striking a balance between managing complex interface effects and avoiding the resulting reduction in interfacial contact is a significant challenge in hole transport layer fabrication. Therefore, it is necessary to develop novel hole dopant to achieve both efficiency and stability in the device. Summary of the Invention

[0005] This application provides an additive for a hole transport layer, which is a compound having the following formula (I):

[0006]

[0007] Among them, R1, R2, and R3 are each independently hydrogen and C. 1-6 Alkyl group, -CH=CH2, -CH=CHR 21 , -C≡CH, -R-CH=CH2, -RC≡CH, -NR 11 R 12 There are 0-1 R's that can be replaced. 10 C 6-12 Aryl;

[0008] Where R is C 6-12 Alpha-aryl;

[0009] R 10 Each independently is hydrogen, C 1-6 Alkyl, -CH=CH2, -C≡CH or -NR 11 R 12 ;

[0010] R 11 and R 12 Each can independently replace 0-1 R. 20 C 6-12 Aryl;

[0011] R 21 Each can independently replace 0-1 R. 20 C 6-12 Aryl;

[0012] R 20 Each independently is hydrogen, C 1-6 Alkyl group, -CH=CH2 or -C≡CH;

[0013] The compound has at least one terminal alkenyl or terminal alkyne group.

[0014] Secondly, this application provides the use of the above-mentioned compound as an additive for the hole transport layer.

[0015] Thirdly, this application provides a hole transport layer comprising the compound and hole transport material described above.

[0016] Fourthly, this application provides a solar cell comprising: a conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a back electrode, wherein the hole transport layer comprises the aforementioned compound and hole transport material of this application.

[0017] When triphenylamine derivatives with unsaturated bonds (carbon-carbon double or triple bonds) are used as additives in the hole transport layer, they can effectively regulate the photoelectric properties of the bulk phase and interface of the hole transport layer in perovskite photovoltaic devices: promoting the extraction and transport capabilities of charge carriers in the hole transport layer; passivating surface defects in the perovskite layer and effectively reducing non-radiative recombination; improving the bonding force between the hole transport layer and the counter electrode interface and suppressing interface ion migration; and the preparation process is simple, the assembled solar cells have high efficiency, good repeatability, and significantly improved stability, making them valuable for industrial applications. Attached Figure Description

[0018] Figure 1 The JV curves of the single-junction cells in Example 1 and Comparative Example 1 are shown.

[0019] Figure 2 The hole mobility of the spiro-OMeTAD films in Example 1 and Comparative Example 1 is shown.

[0020] Figure 3 The SCLC test curves of the perovskite films in Example 1 and Comparative Example 1 are shown.

[0021] Figure 4 High-resolution XPS spectra of the gold electrode Au 4f in Example 1 and Comparative Example 1 are shown.

[0022] Figure 5 The JV curves of the single-junction cells in Example 2 and Comparative Example 2 are shown.

[0023] Figure 6 The stability output test curves of the single-junction cells packaged in Example 2 and Comparative Example 2 are shown.

[0024] Figure 7 The efficiency evolution curve of the packaged module is shown under conditions of 85°C and 85% relative humidity. Detailed Implementation

[0025] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0026] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0027] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0028] definition

[0029] The chemical nomenclature used in this paper is a modified version of the IUPAC nomenclature system, employing ACD Nomenclature version 9.07 and / or ChemDraw Professional version 17.0.0.206 (CambridgeSoft). For complex chemical names used herein, substituents are typically named before the groups they are attached to. For example, cyclopropylethyl comprises an ethyl backbone with cyclopropyl substituents. Unless otherwise described below, all bonds are identified in the chemical structure diagrams presented herein, but it is assumed that all bonds on some carbon atoms are bonded to a sufficient number of hydrogen atoms to complete the valence.

[0030] Unless the context otherwise requires, throughout the specification and claims, the word “comprise” and its variations (e.g., “comprises” and “comprising”) are interpreted as having an open-ended, inclusive meaning, that is, as “including, but not limited to”.

[0031] In this specification, any concentration range, percentage range, ratio range, or integer range shall be understood to be any integer value included within the range, and, where appropriate, to include fractions (e.g., one-tenth and one-hundredth of an integer), unless otherwise stated. As used herein, the terms “about” and “approximately” mean ±20%, ±10%, ±5%, or ±1% of the range, value, or structure indicated, unless otherwise stated. It should be understood that the terms “a” and “an” as used herein refer to “one or more” of the enumerated components. The use of alternatives (e.g., “or”) shall be understood to mean one or both of the alternatives or any combination thereof.

[0032] Throughout this specification, the phrase "in one embodiment" or "in an embodiment" means that a specific feature, structure, or characteristic described with respect to that embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0033] "Optional" or "optionally" means that the event described below may or may not occur, and that the description includes examples of both the occurrence and non-occurrence of said event or situation. For example, "optionally substituted aryl" means that the aryl group may or may not be substituted, and that the description includes substituted aryl groups and unsubstituted aryl groups.

[0034] The term "alkyl" refers to a saturated aliphatic hydrocarbon group that is optionally substituted, either straight-chain or branched, and is connected to the rest of the molecule by a single bond. As used herein, "alkyl" may have 1-8 carbon atoms, for example, 1-6 carbon atoms, 1-4 carbon atoms, or 1-3 carbon atoms. The “alkyl” examples in this document include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, etc., as well as longer alkyl groups such as heptyl and octyl. When the term "alkyl" as defined in this article is used in a numerical range, such as "C1-C8 alkyl," it refers to an alkyl group that can be composed of 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms. Similarly, "C1-C4 alkyl" refers to an alkyl group that can be composed of 1, 2, 3, or 4 carbon atoms. The term "alkyl" in this article also includes cases where no numerical range is specified.

[0035] The term "alkenyl" refers to a monovalent hydrocarbon group, optionally substituted straight-chain or optionally substituted branched, having at least one C=C double bond. The alkenyl group has, but is not limited to, 2-8 carbon atoms, such as 2-6 carbon atoms or 2-4 carbon atoms. The double bond in these groups can be in either cis or trans conformation and should be understood to include both isomers. Examples of alkenyl groups include, but are not limited to, vinyl (CH=CH2), 1-propenyl (CH2CH=CH2), isopropenyl (C(CH3)=CH2), butenyl, and 1,3-butadienyl. When an alkenyl group as defined herein includes a numerical range, such as "C2-C8 alkenyl," it refers to an alkenyl group that can be composed of 2, 3, 4, 5, 6, 7, or 8 carbon atoms. The use of alkenyl groups herein also includes cases where no numerical range is specified.

[0036] The term "alkynyl" refers to an optionally substituted straight-chain or branched monovalent hydrocarbon group having at least one C≡C triple bond. The alkynyl group has, but is not limited to, 2-8 carbon atoms, for example 2-6 carbon atoms, or 2-4 carbon atoms. Examples of alkynyl groups described herein include, but are not limited to, acetylenyl, 2-propynyl, 2-butynyl, and 1,3-butadiynyl. When a numerical range is specified for alkynyl groups as defined herein, such as "C2-C8 alkynyl," it refers to an alkynyl group that can consist of 2, 3, 4, 5, 6, 7, or 8 carbon atoms. The use of alkynyl groups herein also includes cases where no numerical range is specified.

[0037] The term "aryl" refers to an optionally substituted aromatic hydrocarbon group having 6 to 20, such as 6 to 12 or 6 to 10 cyclic carbon atoms, which can be monocyclic, bicyclic, or more cyclic aryl. Bicyclic or more cyclic aryl groups can be a monocyclic aryl group fused with other independent rings, such as alicyclic, heterocyclic, aromatic, or aromatic-heterocyclic rings. Non-limiting examples of monocyclic aryl groups include monocyclic aryl groups with 6 to 12, 6 to 10, or 6 to 8 cyclic carbon atoms, such as phenyl; bicyclic aryl groups, such as naphthyl; and polycyclic aryl groups, such as phenanthryl, anthracene, or azulel.

[0038] The term "aryl" refers to a divalent aryl group (aryl is defined as above), such as phenylene, naphthylene, etc.

[0039] In a first aspect, this application relates to an additive for a hole transport layer, which is a compound having the following formula (I):

[0040]

[0041] Among them, R1, R2, and R3 are each independently hydrogen and C. 1-6 Alkyl group, -CH=CH2, -CH=CHR 21 , -C≡CH, -R-CH=CH2, -RC≡CH, -NR 11 R 12 There are 0-1 R's that can be replaced. 10 C 6-12 Aryl;

[0042] Where R is C 6-12 Alpha-aryl;

[0043] R 10 Each independently is hydrogen, C 1-6 Alkyl, -CH=CH2, -C≡CH or -NR 11 R 12 ;

[0044] R 11 and R 12 Each can independently replace 0-1 R.20 C 6-12 Aryl;

[0045] R 21 Each can independently replace 0-1 R. 20 C 6-12 Aryl;

[0046] R 20 Each independently is hydrogen, C 1-6 Alkyl group, -CH=CH2 or -C≡CH;

[0047] The compound has at least one terminal alkenyl or terminal alkyne group.

[0048] The main structure of the compounds described in this application is a triphenylamine molecule, which has at least one terminal alkenyl or terminal alkynyl group. In the compounds of this application, a terminal alkenyl or terminal alkynyl group means that the compound contains "-CH=CH2" or "-C≡CH", that is, a carbon-carbon double bond or a carbon-carbon triple bond is located at the end. The compounds described in this application will be referred to as TPA (Triphenylamine) derivatives below.

[0049] When used as an additive in the hole transport layer, this triphenylamine derivative with unsaturated bonds (carbon-carbon double or triple bonds) effectively improves the hole mobility of the hole transport layer. Furthermore, the terminal unsaturated bonds (carbon-carbon double or triple bonds) form coordination bonds with free metal vacancy ions on the perovskite surface, passivating perovskite surface defects and improving the interfacial stability between the perovskite and the hole transport layer. The unsaturated bonds also interact strongly with metal-containing electrode interfaces, or the benzene ring interacts strongly with carbon black, graphene, etc., effectively suppressing ion migration at the electrode interface. The addition of this hole additive improves both efficiency and stability, thereby comprehensively enhancing device performance.

[0050] In one implementation, R 11 and R 12 Each can independently replace 0-1 R. 20 phenyl; R 20 Each independently is hydrogen, C 1-3 Alkyl group, -CH=CH2 or -C≡CH.

[0051] In one embodiment, R1, R2, and R3 are each independently hydrogen, C, and C. 1-3 Alkyl, phenyl, or -CH=CH2, and at least one of R1, R2, and R3 is -CH=CH2.

[0052] In one embodiment, R1, R2, and R3 are each independently hydrogen or... And at least one of R1, R2, and R3 is

[0053] In one embodiment, R1, R2, and R3 are each independently hydrogen, C, and C. 1-3 Alkyl, -NR 11 R 12 Or -CH=CH2, and at least one of R1, R2, and R3 is -CH=CH2;

[0054] Among them, R 11 and R 12 Each can independently replace 0-1 R. 20 phenyl, R 20 Each independently is hydrogen, C 1-3 Alkyl or -CH=CH2.

[0055] In one embodiment, R1, R2, and R3 are each independently hydrogen, C, and C. 1-3 Alkyl or -C≡CH, and at least one of R1, R2, and R3 is -C≡CH.

[0056] In one embodiment, the TPA derivative is selected from one of the following compounds.

[0057] 1) Triphenylamine derivatives containing a single terminal alkenyl group

[0058]

[0059] 2) Triphenylamine derivatives containing multiple terminal alkenyl groups

[0060]

[0061] 3) Triphenylamine derivatives containing terminal alkyne groups

[0062]

[0063] This application also relates to the use of the above-mentioned TPA derivatives as additives for hole transport layers.

[0064] Secondly, this application relates to a hole transport layer, which includes this application as the aforementioned TPA derivative and hole transport material.

[0065] The aforementioned TPA derivatives can be added to hole transport materials in a solution-mixing manner for doping, and then a hole transport layer can be formed using conventional methods, such as spin coating, blade coating, slot coating, and dip-coating, with a thickness of 10-300 nm. When mixing the TPA derivatives, one TPA derivative or a combination of several TPA derivatives can be used. For example, it can be a combination of several different TPA derivatives with one or more terminal alkenyl groups, a combination of several different TPA derivatives with one or more terminal alkyne groups, or even a combination of one or more TPA derivatives with one or more terminal alkenyl groups and one or more TPA derivatives with one or more terminal alkyne groups. Preferably, the TPA derivative used for the hole transport layer is tris(4-acetylenylphenyl)amine.

[0066] Typically, in hole transport layers, the mass ratio of TPA derivative to hole transport material is 1:(100-1800), with upper limits of 1:1500, 1:1200, or 1:900, and lower limits of 1:200, 1:300, or 1:500. When the ratio of TPA derivative to hole transport material is lower than 1:1800, the mobility and conductivity of the hole transport layer are insufficient, resulting in low electrical performance. When the ratio of TPA derivative to hole transport material is higher than 1:100, poor solubility makes effective doping difficult, and the doped hole transport layer is unstable under humid and thermal conditions at the cost of reduced PCE (Power Conversion Efficiency).

[0067] The hole transport material used in this application can be selected from p-type inorganic or organic semiconductor materials, such as cuprous iodide (CuI), cuprous thiocyanate (CuSCN), phthalocyanine metal compounds, 2,2′,7,7′-tetratetra(N,N-di-p-methoxyphenylamine)-9,9′-spirodifluorene (spiro-OMeTAD), poly(3-hexylthiophene) (P3HT), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and combinations thereof. Preferably, the hole transport material is spiro-OMeTAD or zinc phthalocyanine (ZnPc).

[0068] This application utilizes TPA derivatives to effectively modulate the bulk and interfacial photoelectric properties of the hole transport layer, offering multiple functionalities: TPA derivatives effectively enhance the conductivity of the hole transport layer, promoting carrier extraction and transport; the terminal unsaturated bonds form coordination bonds with free metal vacancy ions on the perovskite surface, passivating perovskite surface defects and improving the interfacial stability between the perovskite and hole transport layer; and the unsaturated bonds, benzene rings, and electrode interfaces generate strong interactions, effectively suppressing ion migration at the electrode interface. This doping method can be widely used to improve the bulk and interfacial properties of the hole transport layer, thereby obtaining perovskite solar modules with high transport efficiency and stable output under extreme conditions.

[0069] Therefore, in a third aspect, this application relates to a solar cell comprising: a conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a back electrode, wherein the hole transport layer comprises the aforementioned TPA derivative and a hole transport material.

[0070] The solar cell of this application can be a front-mounted solar cell (i.e., nip-type) or an inverted solar cell (i.e., pin-type), meaning the positions of the electron transport layer and the hole transport layer can be interchanged. In a front-mounted solar cell (i.e., nip-type), it can sequentially include a conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a back electrode. In an inverted solar cell (i.e., pin-type), it can sequentially include a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and a back electrode.

[0071] The layers of a solar cell can be formed according to methods known in the art. The layers can be formed as needed, and the TPA derivative of this application can be incorporated into the hole transport layer during its fabrication. Further details regarding these aspects are omitted here.

[0072] In one embodiment, the electron transport layer may comprise an n-type inorganic or organic semiconductor material, preferably PCBM, TiO2, ZnTiO3, SnO2, ZnO, ZnO-ZnS, or combinations thereof. In one embodiment, the thickness of the electron transport layer is 10-120 nm.

[0073] According to this application, the perovskite layer may include AMX3, wherein A is selected from C4H. 11 N + CH3NH3 + HC(NH2)2 + Cs + and Rb + and its combinations; M is selected from Pb 2+ and Sn 2+X represents a halide ion or a halide-like ion or a combination thereof. Halide ions may include chloride ions, bromide ions, and iodide ions. Halide-like ions may include thiocyanate ions, cyanide ions, etc. In one embodiment, the thickness of the perovskite layer is 200-900 nm.

[0074] According to this application, the hole transport layer is the doped hole transport layer of this application, that is, a hole transport layer comprising the above-mentioned TPA derivative and hole transport material. In one embodiment, the thickness of the hole transport layer is 10-300 nm.

[0075] In one embodiment, the back electrode may be a conductive electrode, which may include a metal electrode or a non-metal electrode, preferably selected from gold, silver, copper, ITO, IWO, ICO, AZO, carbon electrodes, graphene electrodes, and combinations thereof. In one embodiment, the thickness of the back electrode is 10-100 nm.

[0076] Example 1

[0077] The perovskite solar cell of this embodiment includes a transparent conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a back electrode stacked sequentially. This perovskite solar cell structure achieves optimal energy level matching and effectively conducts charge.

[0078] In this embodiment, tris(4-acetylenylphenyl)amine was used to dope the hole transport material to study the performance difference of perovskite solar cells before and after tris(4-acetylenylphenyl)amine treatment.

[0079] As a preferred option, the electron transport layer material is ZnO-ZnS. ZnO-ZnS has good energy level matching with the perovskite light-absorbing layer and excellent interfacial stability.

[0080] Preferably, the perovskite layer has a composition of Cs. 0.03 FA 0.97 PbI3. This component of perovskite has few defects, a stable structure, high photoelectric conversion efficiency, and good repeatability, which helps to obtain efficient and stable perovskite devices.

[0081] The preparation method in this embodiment is as follows:

[0082] S1. Substrate preparation: The substrate composed of conductive glass / dense ZnO-ZnS layer is annealed at 450℃ for 60 min. After cooling to room temperature, the substrate is transferred to a glove box.

[0083] S2. Preparation of the perovskite layer: PbI2, CsI, FAI (formamidine iodoformin), MACl (chloromethylamine), and NMP (N-methylpyrrolidone) were dissolved in DMF (N,N-dimethylformamide) at a molar ratio of 1:0.03:0.97:0.3:1. The solution was stirred continuously for 1 hour until completely dissolved to prepare the FA layer. 0.97 Cs 0.03 A PbI3 perovskite precursor solution with a concentration of 1.67 mol / L was prepared and deposited onto the substrate by dynamic spin coating at a speed of 6000 r / min for 30 s. 1 mL of diethyl ether was added dropwise at the 27th s mark. Afterward, the substrate was annealed at 110 °C for 30 min and then at 130 °C for 30 min under a N2 atmosphere to generate a black perovskite phase.

[0084] S3. Preparation of Hole Transport Layer Solution: In this embodiment, a tri(4-acetylenylphenyl)amine-doped spiro-OMeTAD-based hole transport additive layer is used. 1 mg of tri(4-acetylenylphenyl)amine is dissolved in 1 mL of chlorobenzene solution and shaken for 5 min to ensure complete dissolution, obtaining a tri(4-acetylenylphenyl)amine solution. 90 mg of spiro-OMeTAD is dissolved in 1 mL of chlorobenzene solution, and 17.5 μL of Li-TFSI (lithium bis(trifluoromethanesulfonylimide), dissolved in acetonitrile, concentration 520 mg / mL) and 28.8 μL of tBP (tetra-tert-butylpyridine) are added, and the mixture is shaken for 1 h to ensure complete dissolution, obtaining a spiro-OMeTAD solution. The prepared tri(4-acetylenylphenyl)amine solution and spiro-OMeTAD solution are mixed at a volume ratio of 1:20 and shaken for 3 min to ensure complete dissolution.

[0085] S4. Hole transport layer preparation: The spiro-OMeTAD solution containing tris(4-ethynylphenyl)amine was spin-coated onto the prepared perovskite film at a rotation speed of 3500 r / min for 30 s.

[0086] S5. Using a thermal evaporation method, a gold back electrode layer is deposited on a perovskite thin film coated with spiro-OMeTAD holes containing tris(4-ethynylphenyl)amine.

[0087] S6. In this embodiment, the electron transport layer has a thickness of 40 nm, the perovskite film has a thickness of 500 nm, the hole transport material layer has a thickness of 100 nm, and the gold electrode layer has a thickness of 60 nm.

[0088] S7. The above preparation processes are all carried out in an atmosphere with a humidity of 10%-15%.

[0089] S8. The assembled solar cell was subjected to performance testing, and its photoelectric conversion efficiency was 23.32% (see...). Figure 1 ).

[0090] Comparative Example 1

[0091] Similar to Example 1, the perovskite solar cell of this comparative example includes a transparent conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a back electrode stacked sequentially.

[0092] The preparation process is the same as in Example 1, except that:

[0093] In Comparative Example 1, spiro-OMeTAD without tris(4-ethynylphenyl)amine additive was used as the hole transport material in step S3.

[0094] The assembled solar cells were tested for performance, and their photoelectric conversion efficiency was 22.11% (see [link to test results]). Figure 1 ).

[0095] Table 1 lists the performance test results of the solar cells of Example 1 and Comparative Example 1. As can be seen from the table, the various performance parameters of the solar cells prepared by the method described in this invention, such as V... oc J sc The FF and PCE are all superior to the perovskite solar cells in the comparative example that did not have a hole transport layer pre-added with tris(4-acetylenylphenyl)amine.

[0096] Table 1. Test results of battery performance in Example 1 and Comparative Example 1.

[0097]

[0098] To demonstrate the effect of tris(4-acetylenylphenyl)amine as a hole additive in Comparative Example 1 and Example 1, we first quantitatively characterized the effect of tris(4-acetylenylphenyl)amine as an additive on the bulk hole mobility of the hole transport layer (see...). Figure 2 The effect of adding tris(4-acetylenephenyl)amine to the hole transport layer was investigated. With the same hole transport layer thickness, the electrical conductivity of the material was effectively improved. Secondly, the defect state density at the perovskite layer-hole transport layer interface was explored using space charge confinement current (SCLC) curves (see...). Figure 3 The impact of ) V. TFL To fill the saturation voltage of the defect state limit, V TFL Substituting into the defect state calculation formula: N trap =2ε·ε0·V TFL / (e·L 2 The defect state density can be calculated (see Table 2).

[0099] Table 2 Defect state density parameters of Example 1 and Comparative Example 1

[0100]

[0101] In Example 1, tris(4-ethynylphenyl)amine was introduced as a hole additive, which could passivate the lower interface of the hole transport layer, reduce the defect state density at the perovskite layer-hole transport layer interface, thereby suppressing carrier nonradiative recombination and promoting hole extraction and transport.

[0102] Meanwhile, experiments using X-ray photoelectron spectroscopy (XPS) to test the chemical state of the lower interface of the gold electrode showed that, compared to Comparative Example 1, the Au 4f peak position at the lower interface of the gold electrode in Example 1 shifted towards a lower binding energy direction (see...). Figure 4 This verifies the strong interaction between tris(4-acetylenylphenyl)amine and gold.

[0103] In summary, the introduction of tris(4-ethynylphenyl)amine as a hole additive can reduce defects on the perovskite surface, improve the extraction and transport capabilities of the hole transport layer, and enhance the bonding ability between the hole transport layer and the gold electrode interface, thereby significantly improving the efficiency and stability of the battery.

[0104] Example 2 and Comparative Example 2

[0105] To advance the commercialization of perovskite solar cells, stability tests were conducted on multi-junction modules prepared by replacing the unstable spiro-OMeTAD with zinc phthalocyanine (ZnPc) in Example 2 and Comparative Example 2.

[0106] The preparation process is the same as in Example 1, except that:

[0107] In step S3 of Comparative Example 2, ZnPc was used as the hole transport material. ZnPc was dissolved in chlorobenzene at a concentration of 10 mg / mL and shaken for 5 min to ensure complete dissolution. The ZnPc solution was then spin-coated onto a perovskite film at a speed of 4000 r / min for 30 s.

[0108] In step S3 of Example 2, a ZnPc solution containing tris(4-ethynylphenyl)amine was used as the hole transport material. A tris(4-ethynylphenyl)amine solution (1 mg / mL) dissolved in chlorobenzene was mixed with a ZnPc solution at a volume ratio of 1:10 and shaken for 3 min until completely dissolved. The ZnPc-based hole transport solution with added tris(4-ethynylphenyl)amine was spin-coated onto a perovskite film at a speed of 4000 r / min for 30 s.

[0109] The performance of the solar cells in Example 2 and Comparative Example 2 was also tested, and the results are as follows: Figure 5 As shown in Table 3.

[0110] Table 3. Performance test results of single-junction cells in Example 2 and Comparative Example 2

[0111]

[0112] Compared to solar cells using ZnPc as the hole transport layer, solar cells fabricated with a ZnPc-based hole transport layer containing tris(4-acetylenylphenyl)amine exhibit superior performance parameters, such as V0. oc J sc Both FF and PCE have seen significant improvements.

[0113] In Example 2, the single-junction device using tris(4-acetylenylphenyl)amine as an additive not only exhibited higher photoelectric conversion efficiency but also better stability. The packaged device demonstrated significantly better stability under harsh operating conditions compared to Comparative Example 2 (see Example 2). Figure 6 Under test conditions of 85°C and 40%-50% relative humidity, the maximum power output of the packaged device in Example 2 remained stable for 2500 min, while the device in Comparative Example 2 experienced a 20% decrease in initial efficiency within 1500 min.

[0114] In summary, the introduction of tris(4-acetylenephenyl)amine as a hole additive can significantly improve the efficiency and stability of single-junction devices. Similarly, the hole transport layer with added tris(4-acetylenephenyl)amine also significantly improves the efficiency of multi-junction modules (see Table 4).

[0115] Table 4. Performance test results of the multi-junction module in Example 2 and Comparative Example 2

[0116]

[0117] After being subjected to continuous light irradiation (85°C, 60% relative humidity) for up to 1000 hours, the device in Example 2 retained 85.57% of its initial efficiency, while the device in Comparative Example 2 experienced a rapid decline in efficiency (see...). Figure 7 In summary, the addition strategy of tris(4-acetylenylphenyl)amine helps to prepare multi-junction solar modules with good wet, thermal and light stability, showing great potential in practical applications.

[0118] Example 3

[0119] To verify the practicality of triphenylamine hole transport additives with unsaturated bonds, this embodiment obtained triphenylamine molecular derivatives by modifying the R1 group with double bonds. N,N-diphenyl-4-vinylaniline (CAS: 25069-74-3) was used to dope the hole transport material, and the performance difference of perovskite solar cells before and after N,N-diphenyl-4-vinylaniline treatment was investigated.

[0120] The preparation process is the same as in Example 1, and the performance of the prepared single-junction perovskite solar cells is shown in Table 5.

[0121] The difference is:

[0122] In step S3 of Example 3, a spiro-OMeTAD solution containing N,N-diphenyl-4-vinylaniline was used as the hole transport material. A solution of N,N-diphenyl-4-vinylaniline dissolved in chlorobenzene (1 mg / mL) was mixed with a spiro-OMeTAD solution of 90 mg / mL at a volume ratio of 1:10 and shaken for 3 min until completely dissolved. The spiro-OMeTAD hole transport solution with added N,N-diphenyl-4-vinylaniline was spin-coated onto a perovskite film at a speed of 4000 rpm for 30 s.

[0123] Example 4

[0124] To verify the practicality of triphenylamine hole transport additives with unsaturated bonds, this embodiment obtained triphenylamine molecular derivatives by modifying the R3 group with phenylene double bonds. The hole transport material was doped with 4-[2-(4-vinylphenyl)vinyl]-N,N-diphenylaniline (CAS: 134060-87-0), and the performance difference of perovskite solar cells before and after treatment with 4-[2-(4-vinylphenyl)vinyl]-N,N-diphenylaniline was investigated.

[0125] The preparation process is the same as in Example 1, and the performance of the prepared single-junction perovskite solar cells is shown in Table 5.

[0126] The difference is:

[0127] In step S3 of Example 4, a spiro-OMeTAD solution containing 4-[2-(4-vinylphenyl)vinyl]-N,N-diphenylaniline was used as the hole transport material. A 1 mg / mL solution of 4-[2-(4-vinylphenyl)vinyl]-N,N-diphenylaniline dissolved in chlorobenzene was mixed with a 90 mg / mL spiro-OMeTAD solution at a volume ratio of 1:10 and shaken for 3 min until completely dissolved. The spiro-OMeTAD hole transport solution with added 4-[2-(4-vinylphenyl)vinyl]-N,N-diphenylaniline was spin-coated onto a perovskite film at a speed of 4000 rpm for 30 s.

[0128] Example 5

[0129] To verify the practicality of triphenylamine hole transport additives with unsaturated bonds, this embodiment obtained triphenylamine molecular derivatives by simultaneously modifying the double bonds of the R1, R2, and R3 groups. Tri(4-vinylphenyl)amine (CAS: 190334-75-9) was used to dope the hole transport material, and the performance difference of perovskite solar cells before and after tri(4-vinylphenyl)amine treatment was studied.

[0130] The preparation process is the same as in Example 1, and the performance of the prepared single-junction perovskite solar cells is shown in Table 5.

[0131] The difference is:

[0132] In step S3 of Example 5, a spiro-OMeTAD solution containing tris(4-vinylphenyl)amine was used as the hole transport material. A solution of tris(4-vinylphenyl)amine dissolved in chlorobenzene (1 mg / mL) was mixed with a spiro-OMeTAD solution of 90 mg / mL at a volume ratio of 1:10 and shaken for 3 min until completely dissolved. The spiro-OMeTAD hole transport solution with added tris(4-vinylphenyl)amine was spin-coated onto a perovskite film at a speed of 4000 rpm for 30 s.

[0133] Example 6

[0134] To verify the practicality of triphenylamine hole transport additives with unsaturated bonds, this embodiment modifies the R1 group to obtain triphenylamine molecular derivatives. 4-ethynyltriphenylamine (CAS: 205877-26-5) is used to dope the hole transport material, and the performance differences of perovskite solar cells before and after 4-ethynyltriphenylamine treatment are investigated.

[0135] The preparation process is the same as in Example 1, and the performance of the prepared single-junction perovskite solar cells is shown in Table 5.

[0136] The difference is:

[0137] In step S3 of Example 6, a spiro-OMeTAD solution containing 4-ethynyltriphenylamine was used as the hole transport material. A 1 mg / mL solution of 4-ethynyltriphenylamine dissolved in chlorobenzene was mixed with a 90 mg / mL spiro-OMeTAD solution at a volume ratio of 1:10 and shaken for 3 min to completely dissolve the mixture. The spiro-OMeTAD hole transport solution with added 4-ethynyltriphenylamine was then spin-coated onto a perovskite film at a speed of 4000 rpm for 30 s.

[0138] Example 7

[0139] To verify the practicality of triphenylamine hole transport additives with unsaturated bonds, this embodiment modifies the triple bond of the R1 group while simultaneously modifying the alkyl groups of R2 and R3 to obtain triphenylamine molecular derivatives. The hole transport material is then doped with (4-ethynylphenyl)-di-p-toluidine (CAS: 596109-87-4), and the performance differences of perovskite solar cells before and after (4-ethynylphenyl)-di-p-toluidine treatment are investigated.

[0140] The preparation process is the same as in Example 1, and the performance of the prepared single-junction perovskite solar cells is shown in Table 5.

[0141] The difference is:

[0142] In step S3 of Example 7, a spiro-OMeTAD solution containing (4-ethynylphenyl)-di-p-toluidine was used as the hole transport material. A (4-ethynylphenyl)-di-p-toluidine solution (1 mg / mL) dissolved in chlorobenzene was mixed with a spiro-OMeTAD solution of 90 mg / mL at a volume ratio of 1:10 and shaken for 3 min until completely dissolved. The spiro-OMeTAD hole transport solution with added (4-ethynylphenyl)-di-p-toluidine was spin-coated onto a perovskite film at a speed of 4000 rpm for 30 s.

[0143] Table 5 shows the performance test results of single-junction cells prepared with different hole additives in the examples and Comparative Example 1.

[0144]

[0145] In this application, the terminal unsaturated bonds in the TPA derivative interact with the dangling bonds on the perovskite layer surface, passivating perovskite interface defects, reducing nonradiative recombination, and improving interface transport efficiency. Furthermore, this TPA derivative can enhance the extraction and transport performance of the hole transport layer and interact with the metal back electrode, improving the bonding ability between the hole transport layer interface and the metal electrode. Perovskite solar cell devices fabricated using this strategy exhibit excellent photoelectric conversion performance and good operational stability. This strategy of using TPA derivatives to modulate the hole transport layer provides an effective solution for achieving high performance and stability in perovskite solar cells, offering a valuable reference for future commercial applications.

[0146] The present application has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present application based on these embodiments, all of which fall within the protection scope of the present application.

Claims

1. The use of a compound of Formula I as an additive for a hole transport layer: (I) in, R1, R2, and R3 are each independently hydrogen, methyl, or -CH. CH2, -CH CHR 21 -C CH or substitutions have 0-1 R. 10 phenyl; Among them, R 10 For hydrogen, methyl, -CH CH2; R 21 To replace 0-1 R 20 phenyl; R 20 It is hydrogen, methyl or -CH CH2; The compound has at least one terminal alkenyl or terminal alkyne group.

2. The use according to claim 1, wherein, R1, R2, and R3 are each independently hydrogen, methyl, phenyl, or -CH. CH2, and at least one of R1, R2, and R3 is -CH CH2.

3. The use according to claim 1, wherein, R1, R2, and R3 are each independently hydrogen or And at least one of R1, R2, and R3 is .

4. The use according to claim 1, wherein, R1, R2, and R3 are each independently hydrogen, methyl, or -C. CH, and at least one of R1, R2, and R3 is -C. CH.

5. The use according to claim 1, wherein, The compound is selected from one of the following compounds: 。 6. A hole transport layer comprising a compound of formula I and a hole transport material, (I) The compound of Formula I is defined as described in any one of claims 1-5.

7. The hole transport layer according to claim 6, wherein, The mass ratio of the compound of Formula I to the hole transport material is 1:(100-1800).

8. The hole transport layer according to claim 6, wherein, Hole transport materials are selected from p-type inorganic or organic semiconductor materials.

9. The hole transport layer according to claim 7, wherein, Hole transport materials are selected from cuprous iodide, cuprous thiocyanate, phthalocyanine metal compounds, and 2,2′,7,7′-tetra( N , N -di-p-methoxyphenylamine)-9,9′-spirodifluorene, poly-3-hexylthiophene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] and combinations thereof.

10. A solar cell comprising: A conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a back electrode, wherein the hole transport layer is the hole transport layer according to any one of claims 6-9.

11. The solar cell according to claim 10, wherein, The electron transport layer comprises n-type inorganic or organic semiconductor materials.

12. The solar cell according to claim 10, wherein, The electron transport layer material is selected from PCBM, TiO2, ZnTiO3, SnO2, ZnO, ZnO-ZnS and combinations thereof.

13. The solar cell according to claim 10, wherein, The perovskite layer is composed of ABX3, where A is selected from CH3NH3. + HC(NH2)2 + Cs + and Rb + and its combinations; B is selected from Pb 2+ and Sn 2+ X is selected from halide ions and halide-like ions and their combinations.

14. The solar cell according to claim 10, wherein, The back electrode is a conductive electrode.

15. The solar cell according to claim 10, wherein, The back electrode is selected from gold, silver, copper, ITO, IWO, ICO, AZO, carbon electrode, graphene electrode, and combinations thereof.

16. The solar cell according to claim 10, wherein, The thickness of the electron transport layer is 10-120 nm; the thickness of the perovskite layer is 200-900 nm.

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