Electron transporting self-assembled monolayer compound for use in optoelectronic and / or photoelectrochemical device and method for manufacturing the same

Abstract

To provide novel electron transporting naphthalene diimide and naphthalene imide based compounds containing phosphonic or phosphoric acid as anchor groups, and optoelectronic and photoelectrochemical devices, their uses, and methods for their preparation.SOLUTION: A compound of the formula (I), (IV) or (V) selected from specific structures minimizes thickness at low temperatures and has appropriate energy levels to allow covalent bonding to transparent conductive oxide surfaces.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention generally relates to new self-assembled monolayer compounds and their use as electron transport materials in optoelectronic devices and / or photoelectrochemical devices, particularly photovoltaic devices, and methods for their manufacture.

Background Art

[0002] Over the past few decades, there has been a strong interest in renewable energy sources, particularly the sun, which is the most powerful of these energy sources. The conversion of solar energy into electricity using thin-film third-generation photovoltaics (PV) has been widely investigated in the last 20 years. Sandwich / monolithic-type PV devices consisting of an organic / inorganic light absorber, a redox electrolyte / solid hole conductor, and a mesoporous photoanode with a counter electrode have attracted great interest because they are easy to manufacture, flexible in material selection, and have low production costs.

[0003] Organic-inorganic metal halide perovskite solar cells (PSC) have seen rapid development in recent years, and their power conversion efficiency (PCE) has remarkably improved from 3.8% in 2009 to 26.1% in 2023 [1] ; such values now rival those of established solar cell technologies in the market, such as crystalline silicon (c-Si) and copper indium gallium diselenide (CIGS). Furthermore, PSCs can be manufactured at low cost, are scalable, and can be produced using simple solution processing techniques, further highlighting the promise of PSCs as a future mainstream technology. [2]Furthermore, when combined with either c-Si, CIGS, organic, or another PSC as bottom cell technology, the PSC can also be integrated as a top cell in a tandem, resulting in a PCE far exceeding that of the sub-cells and opening the way to highly efficient PV at affordable prices. [3] Despite the perovskite solar cell demonstrating remarkable power generation efficiency, there are still significant hurdles to overcome before this technology can be commercialized. The most important of these is the insufficient stability of the device, which is mainly due to the perovskite absorber decomposing when exposed to the ambient environment.

[0004] A typical PSC device consists of two electrodes, a perovskite light absorber, an n-type electron transport layer (ETL), and a p-type hole transport layer (HTL). [4] The perovskite layer is sandwiched between the ETL and HTL for efficient charge transport. External electrodes, including transparent conductive glass covered with a transparent conducting oxide (TCO) such as indium tin oxide (ITO) or fluorine-doped tin oxide (FTO), and a counter electrode (Au, Ag, or carbon), are used for charge collection. Three types of device configurations are commonly used in the manufacture of PSCs, including a mesoporous n-i-p structure, a planar n-i-p structure, and a planar p-i-n structure, where n represents the ETL, p represents the HTL, and i represents the perovskite layer, respectively (Figure 1). The n-i-p structure has consistently demonstrated superior performance to its p-i-n counterpart to date. [5] 。

[0005] To design a stable and efficient PSC, similar to perovskite materials, the selection of the electron transport layer and the hole transport layer is very important. The ETL composed of metal oxides (TiO2, ZnO, SnO2) promotes the collection of photo-generated electrons from the perovskite layer to the corresponding electrode in a normal PSC, and promotes hydrophobic [6,6]-phenyl-C61-butyric acid methyl ester ([6,6]-phenyl-C61-butyric acid methyl ester: PCBM) or its derivatives in an inverted PSC. [6] . On the other hand, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-MeOTAD) is the most commonly used hole transport material (HTM) in normal PSCs. In the case of inverted PSCs, various HTLs (hole transport materials) have been developed, from copper (CuI, CuCrO2) and nickel (NiOx) compounds, and polymers such as (poly(3,4-ethylenedioxythiophene)polystyrene sulfonate: (PEDOT:PSS) and poly[bis(4-phenyl)(2,5,6-trimethyl-phenyl)amine]:PTAA) to various organic small molecules including self-assembled monolayers (SAMs). [7] .

[0006] Self-assembled monolayers (SAMs) have recently emerged as a promising alternative to conventional charge transport layers in PSCs. [8] . In particular, SAM molecules based on carbazole groups and phosphonic acid groups, usually called nPACz (n is the aliphatic chain length), have attracted great interest as hole-selective contacts. The carbazole group is a strong electron-donating moiety and thus has hole selectivity, while the phosphonic acid group can covalently bond to the surface of a transparent conductive oxide (TCO) to form a monolayer. [7-9]Thanks to their efficient hole extraction and good electron passivation at the SAM / perovskite interface, perovskite-based p-i-n single-junction solar cells and monolithic perovskite / silicon tandem solar cells achieved remarkable PCEs of about 26.1% and 32.5%, respectively. [1] 。

[0007] While new SAMs are being actively investigated for hole collection in various perovskite light absorbers, reports on the design of novel electron-selective SAM molecules remain scarce. This is thought to be due to the relatively limited availability of suitable electron acceptors used in the synthesis of electron-selective materials and the need for efforts towards the identification and application of non-fullerene derivatives as electron-selective materials in PSCs. [11,12] 。Generally, the class of organic ETLs is dominated by fullerene derivatives including C60 and its functionalized analogs (e.g., PC 61 BM, PC 71 BM, etc.). [6,11,12] However, the application of fullerene-based ETLs to solution processing is limited by the insufficient solubility of unmodified fullerenes in organic solvents. Also, the synthesis and purification of modified fullerenes, especially C70 derivatives, are difficult and require complex and costly multi-step processes.

[0008] As non-fullerene alternatives, naphthalene-diimide (NDI)-based small molecules offer favorable ETL properties such as simple synthetic procedures, high electron affinity, relatively high electron mobility, and photochemical stability. [6,13-15] Initially, to improve the performance of p-i-n type PSCs, NDI-based SAMs, such as N,N'-bis(1-n-hexylpyridinium-4-ylmethyl)-1,4,5,8-naphthalenetetracarboxydiimide, and ammonium-bearing NDI polymers were applied as intermediate layers between PC 61 BM and the top-contact metal electrodes. [13,16,17]Thereafter, an NDI-based SAM containing a carboxylic acid anchor group was directly coated on an indium tin oxide (ITO) substrate to change their work functions, enabling electron collection in n-i-p type PSCs.

[18] These NDI-based devices demonstrated a PCE of 16% with a fill factor (FF) of 70%. Although these results are promising, they do not reach the highest performance of conventional n-i-p type PSCs that usually rely on metal oxide ETLs (such as TiO2 or SnO2). In particular, solution-processed conventional metal oxide ETLs require additional surface modification with organic or inorganic materials to minimize interfacial charge loss, which makes the scalability of PSCs difficult.

[0009] The present invention provides an electron-transporting NDI-based compound functionalized with a phosphonic acid group or a phosphate group for direct immobilization on a transparent conductive oxide (such as ITO, FTO) with a minimum thickness. In contrast to conventional low-temperature processed metal oxide ETLs that usually require high-temperature treatment (≥150°C), these new electron-selective SAMs enable solution processing that requires a moderate temperature (usually about 100°C) and can be beneficial for specific applications of n-i-p type PSCs with improved efficiency and stability. Furthermore, additional surface modification with organic or inorganic materials to minimize interfacial charge loss and reduce material consumption has become an existing problem that needs to be solved recently, especially regarding the provision of scalable technologies. Moreover, such organic semiconductors are also attractive for the development of low-cost and high-performance optoelectronic devices such as light-emitting diodes, phototransistors, and photovoltaic cells, in addition to photovoltaic power generation.

Summary of the Invention

[0010] The object of the present invention is to provide new organic electron transport naphthalenediimide-based compounds and naphthalimide-based compounds that contain phosphonic acid or phosphoric acid as an anchor group, minimize thickness at low temperatures, and enable covalent bonding to the surface of a transparent conductive oxide at an appropriate energy level. Such compounds also passivate the sensitizer layer (such as perovskite) of a photovoltaic device more efficiently. Advantageously, when used in optoelectronic devices and / or photoelectrochemical devices, the compounds of the present invention provide multiple advantages, such as simultaneously reducing light reflectance and energy loss compared to the conventionally used SnO2 ETL. Furthermore, the compounds of the present invention can be directly coated on a TCO substrate (e.g., an ITO substrate), and can be used as an alternative to, or in place of, conventional metal oxide (i.e., SnO2, ZnO, and TiO2) ETLs, for example, in an n-i-p type PSC.

[0011] This disclosure also provides new electron transport materials that offer higher power conversion efficiency and stability.

[0012] Further aspects and preferred embodiments are detailed below in this specification and in the appended claims. Further features and advantages will become apparent to those skilled in the art from the following description of the preferred embodiments.

Brief Description of the Drawings

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Figure 1

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Figure 13a

Figure 13b

Mode for Carrying Out the Invention

[0026] The main subject of the present disclosure is a compound of formula (I), (IV) or (V):

Chemical formula

Chem.

Chem.

Chem.

[0027] In the embodiment where the compound of formula (I) contains X selected from C1-C 10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, when the alkyl, alkenyl, alkynyl moieties contain 3 or more carbons, they can be linear, branched or cyclic. The compound of formula (I) is C1-C 10In embodiments comprising X selected from alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C4-C10 aryl, C4-C20 alkylaryl, C4-C20 alkenylaryl, and C4-C20 alkynylaryl, the alkyl, alkenyl, alkynyl, aryl, alkylaryl, alkenylaryl, alkynylaryl may be unsubstituted or substituted by C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C1-C10 heteroalkyl, C4-C1 aryl, C2-C10 heteroalkenyl, C2-C10 heteroalkynyl, C4-C10 heteroaryl, or one or more heteroatoms selected from N, S, and O.

[0028] In embodiments where the compound of formula (I) comprises L, L and L1 are independently selected from C1-C9-alkylene, C4-C20 arylene, C4-C20 heteroarylene, C4-C20 alkylarylene, C4-C20 alkenearylene, C4-C20 heteroalkylarylene, C4-C20 heteroalkenearylene, where the heteroatom is from O, N, S, Se, Si, or the structure:

Chemical formula

Chemical formula

[0029] As used herein, the term "alkylene" represents a saturated divalent hydrocarbon group derived from a straight-chain or branched-chain saturated hydrocarbon by removal of two hydrogen atoms, and is exemplified by methylene, ethylene, and isopropylene. Accordingly, as used herein, "arylene", "heteroarylene", "alkylarylene", "alkenearylene", "heteroalkylarylene" each represent a respective divalent group (aryl, heteroaryl, alkylaryl, alkenearyl, heteroalkylaryl, respectively) derived by removal of two hydrogen atoms. As used herein, the term "C4-C20 heteroalkenearylene" includes structures such as

Chemical formula

[0030] According to another embodiment, the naphthalenediimide-based compound of formula (I) includes a phosphonic acid as an anchor group that enables covalent bonding to a transparent conductive oxide surface, and is an electron-transporting material selected from, but not limited to, compounds according to any one of formulas (1)-(35), (37)-(82).

[0031] In some embodiments, the naphthalenediimide-based compound of formula (I) includes a phosphoric acid as an anchor group, and includes, for example, the compound of formula (36).

[0032] Symmetric structure of an exemplary compound of formula (I):

Chemical formula

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

Chem.

[0033] In some embodiments, compounds of formula (I) are provided in which each of R, R, R, R is H and / or each of A, A is phosphonic acid. In such cases, the compound can further include L, L independently selected from C3-C9-alkylene, C4-C20-arylene, C4-C20-heteroarylene, C4-C20-alkylarylene, C4-C20-heteroalkylarylene, C4-C20-heteroalkenearylene, where the heteroatom is selected from O, N, S, Se, Si. In particular, for example, when the compound of formula (I) includes each of R, R, R, R that is H, A, A are phosphonic acid and L, L are not methylene or ethylene.

[0034] In some embodiments, compounds of formula (I) are provided, wherein: X is selected from -L1-A1, R1, R2, R3, R4 are independently selected from H, CN, Cl, Br, F, CF3, NO2, C1-C20-alkyl, C2-20-perfluoroalkyl, C5-20-aryl, C5-20-heteroaryl; A, A1, A2 are anchor groups, phosphonic acid, monoalkyl ether of phosphonic acid, phosphoric acid, monoalkyl ether of phosphoric acid:

Chemical formula

Chemical formula

Chemical formula

[0035] In some embodiments, such compounds include A, A1, A2 which are phosphonic acid.

[0036] In some embodiments, such compounds include A, A1 which are phosphoric acid.

[0037] In some embodiments, when the compound of formula (I) includes X selected from -L1-A1, the linking fragments L and L1 are the same.

[0038] In some embodiments, the compound of formula (I) comprises X which is -L1-A1, R1, R2, R3, and R4 are independently selected from H, CN, Cl, Br, F, CF3, NO2, C1-C20-alkyl, C2-20-perfluoroalkyl, C5-20-aryl, and C5-20-heteroaryl, The linking fragments L and L1 are the same and are selected from C1-C9-alkylene, C4-C20-arylene, C4-C20-heteroarylene, C4-C20-alkylarylene, C4-C20-alkenearylene, C4-C20-heteroalkylarylene, C4-C20-heteroalkenearylene, where the heteroatom is from O, N, S, Se, Si, or the structure:

Chemical formula

[0039] In a further embodiment, a compound according to formula (I) is provided, wherein X is selected from H, NH2, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C4-C10 aryl, C4-C20 alkylaryl, C4-C20 alkenylaryl, and C4-C20 alkynylaryl, each of which is optionally substituted with one or more heteroatoms selected from C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C1-C10 heteroalkyl, C4-C10 aryl, C2-C10 heteroalkenyl, C2-C10 heteroalkynyl, C4-C10 heteroaryl, or N, S, and O. Such compounds can have the additional advantage of increased solubility in organic solvents and are thus more convenient to handle. Exemplary compounds of such a structure are the compounds of Structures 40-78.

[0040] In some embodiments, compounds of formula (I) are provided, wherein X is selected from C4-C20 alkylaryl optionally substituted with C1-C10 alkyl. Such compounds, when used in a photovoltaic device, can provide an improvement in the interaction with the sensitizer layer of the photovoltaic device. For example, such compounds can have structures such as those provided in Structures 41, 43, 45, 47, 49, 51, 59, 61, 63, 64, 66, 72.

[0041] Tables 1 and 2 show some further non-limiting examples of compounds of formula (I) of the present invention.

[0042] Table 1. Examples of symmetric compounds of formula (I) of the present invention [Table 1] JPEG2025112277000023.jpg151154Table 2. Examples of asymmetric compounds of formula (I) of the present invention [Table 2] JPEG2025112277000025.jpg128155JPEG2025112277000026.jpg152157JPEG2025112277000027.jpg136157In Tables 1 and 2, each row numbered with a specific number represents an exemplary compound or group of compounds of formula (I) having specific values of X, R1, R2, R3, R4, A, A1, A2, L, L1. For example, row "number 90" represents a compound of formula (I) wherein both R1 and R4 are H, R2 and R3 are both F, A, A1, A2 are phosphonic acids, L and L1 are the same and are selected from C1-C9-alkylene, C4-C20 arylene, C4-C20 heteroarylene, C4-C20 alkylarylene, C4-C20 heteroalkylarylene, C4-C20 heteroalkenarylene, where the heteroatom is selected from O, N, S, Se, Si, or the structure.

[0043] Similarly, for example, row "Number 150" indicates a compound where X is 2-ethylhexyl, both R1 and R4 are H, both R2 and R3 are phenyl, A and A2 are phosphonic acids, L and L1 are the same, and are selected from C1-C9-alkylene, C4-C20 arylene, C4-C20 heteroarylene, C4-C20 alkylarylene, C4-C20 heteroalkylarylene, C4-C20 heteroalkenarylene, where the heteroatom is selected from O, N, S, Se, Si, or the structure. It will be understood.

[0044] Examples of the structure of the compound of formula (IV) or (V):

Chemical formula

[0045] In some embodiments, a composition comprising one or more compounds of formula (I) is provided.

[0046] In a further embodiment, the present invention provides an electron transport material comprising one or more of the compounds of formula (IV) or (V) described above. In some embodiments, a composition comprising one or more compounds of formula (IV) or (V) is provided.

[0047] In some embodiments, the composition further comprises a filler molecule (FM), where FM is an anchor group, an alkyl chain of N carbon atoms (N ranges from 1 to 18), and at least one functional group selected from the group consisting of a methyl functional group, a halogen functional group, an amino functional group, a bromide functional group, an ammonium functional group, and a sulfur functional group.

[0048] In a further embodiment, there is provided an optoelectronic device and / or a photoelectrochemical device comprising an electron transport layer comprising a compound of formula (I). In other embodiments, there is provided an optoelectronic device and / or a photoelectrochemical device comprising an electron transport layer comprising a composition comprising one or more compounds of formula (I).

[0049] As provided herein, the optoelectronic device and / or the photoelectrochemical device can be selected from a photovoltaic device, an organic photovoltaic device, a solid-state photovoltaic device, an organic solar cell, a solid-state solar cell, a perovskite solar cell, a tandem solar cell, a light-emitting electrochemical cell, and an OLED. As further examples of such devices, a p-n heterojunction, a dye-sensitized solar cell can be provided.

[0050] In some embodiments, the photovoltaic device comprising an electron transport material comprising a compound of formula (I) is a tandem solar cell, and preferably, the tandem solar cell comprises at least one perovskite solar cell. A tandem solar cell is a photovoltaic device comprising a plurality (two or more) of stacked photovoltaic sub-cells, which may be individual cells (mechanically stacked) or integrated into one device electrically interconnected. At least one of the sub-cells is a perovskite solar cell (based on a perovskite semiconductor). Examples are: perovskite / silicon; perovskite / CIGS; perovskite / perovskite; organic / perovskite, etc. A tandem comprising two photovoltaic sub-cells can be 4-terminal, 2-terminal and 3-terminal. The purpose of forming a tandem device is to more efficiently utilize the solar spectrum by optimized complementary absorption of electromagnetic radiation by different semiconductors. As provided herein, the compounds of the present invention or compositions comprising such compounds can function as an electron transport material in at least one of the perovskite sub-cells of a tandem solar cell.

[0051] In some embodiments, the optoelectronic device and / or the photoelectrochemical device is a photovoltaic device, and preferably, the device is a photovoltaic cell. In some embodiments, there is provided a photovoltaic device, e.g., a photovoltaic cell, comprising a conductive support layer covered with an electron transport layer, a sensitizer layer, a hole transport layer, and a counter electrode, wherein the electron transport layer comprises a compound according to formula (I). In some embodiments, the electron transport layer comprises a composition comprising one or more compounds according to formula (I) and optionally filler molecules. In some embodiments, the optoelectronic device and / or the photoelectrochemical device is a photovoltaic device, and preferably, the device is a photovoltaic cell. In some embodiments, there is provided a photovoltaic device, e.g., a photovoltaic cell, comprising a conductive support layer covered with an electron transport layer, a sensitizer layer, a hole transport layer, and a counter electrode, wherein the electron transport layer comprises a compound according to formula (IV) or (V). In some embodiments, the electron transport layer comprises a composition comprising one or more compounds according to formula (IV) or (V) and optionally filler molecules.

[0052] In some embodiments, the photovoltaic device comprises an electron transport layer composed of a compound according to formula (I). In some embodiments, the photovoltaic device comprises only an electron transport layer composed of a compound according to formula (I). That is, in such a device, an electron transport material or an electron transport layer other than the compound of the present invention may not be necessary, and the compound of the present invention can be directly applied onto a TCO substrate and used as an alternative to or instead of a conventional metal oxide (i.e., SnO2, ZnO, and TiO2) ETL. In some embodiments, the photovoltaic device comprises an electron transport layer consisting of a compound according to formula (I). In some embodiments, the electron transport layer consists of a composition comprising one or more compounds according to formula (I) and optionally filler molecules.

[0053] The conductive support layer of the photovoltaic device is preferably substantially transparent. "Transparent" means being transparent to at least a part, preferably a large part, of visible light. Preferably, the conductive support layer is substantially transparent to all wavelengths or types of visible light. Further, the conductive support layer may be transparent to non-visible light such as UV and IR radiation, for example. The conductive support layer preferably functions as and / or includes a current collector that collects the current obtained from the photovoltaic solid device. The conductive support layer can include a conductive material selected from indium-doped tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), metal, and / or other conductors, and is preferably coated on a transparent substrate such as plastic or glass. In this case, the plastic or glass provides the support structure of the layer, and the conductive material mentioned above provides conductivity. Such support layers are generally recognized as conductive glass and conductive plastic, respectively, and are preferred conductive support layers according to the present invention.

[0054] According to some embodiments, the sensitizer layer of the photovoltaic device includes at least one pigment selected from organic pigments, inorganic pigments, organometallic pigments, organic-inorganic pigments, or combinations thereof. The sensitizer is preferably a compound or material that absorbs light. Preferably, the sensitizer is a pigment, and most preferably, the sensitizer is an organic-inorganic pigment.

[0055] According to a preferred embodiment, the electron transport layer containing the compound of formula (I) is coated with a layer containing a sensitizer. Preferably, the sensitizer layer contains an organic-inorganic perovskite.

[0056] In some embodiments, the electron transport layer comprising a compound of formula (IV) or (V) is coated by a layer comprising a sensitizer. According to a preferred embodiment, the sensitizer or the sensitizer layer comprises, consists of, or is made of an organic-inorganic perovskite. The organic-inorganic perovskite is provided under a film of one perovskite pigment, or a mixed perovskite pigment, or a perovskite pigment mixed with a further dye or sensitizer.

[0057] According to a further embodiment, the sensitizer layer comprises, in addition to the organic-inorganic perovskite pigment, another pigment selected from an organic pigment, an organometallic pigment, or an inorganic pigment.

[0058] According to another embodiment, the optoelectronic device and / or the photoelectrochemical device is a dye sensitized solar cell (DSC) comprising a compound of formula (I) as an electron transport material and a pigment selected from an organic pigment, an organometallic pigment, an inorganic pigment, or a combination thereof as a sensitizer.

[0059] For the purposes of this specification, the term "perovskite" refers to a "perovskite structure" and does not specifically refer to the perovskite material CaTiO3. For the purposes of this specification, "perovskite" encompasses any material having the same type of crystal structure as calcium titanate, and any material in which a divalent cation has been replaced by two individual monovalent cations, preferably in relation thereto. The perovskite structure has the general stoichiometry AMX3, where "A" and "M" are cations and "X" is an anion. The "A" cation and the "M" cation can have different charges. For example, in the original perovskite mineral (CaTiO3), the A cation is divalent and the M cation is tetravalent.

[0060] In a further embodiment, the organic-inorganic perovskite layer material has the perovskite structure of formula (II): AMX3 (II) and comprises In the formula, A is an alkali metal ion, preferably Li + , Na + , K + , Rb + , Cs + ; an ammonium ion or an amidinium ion, where one or more hydrogens are substituted by an alkyl group or an acyl group. The ammonium ion includes mono-, di-, tri- and tetraalkylammonium ions, where one or more hydrogens are substituted by an alkyl group. Preferably, the substituent is an alkyl group or a group independently selected from C1-C6, preferably a methyl group or an ethyl group. The ammonium ion, N-alkylamidinium ion and imidinium ion, where one or more hydrogens are substituted by an alkyl group. Preferably, the amidinium ion or imidinium ion is selected from a C1-C6 carboxamide group, preferably a formamidinium group or an acetamidinium group. The hydrogen atom in the organic cation A may be substituted by a halogen selected from F, Cl, I and Br, preferably F or Cl.

[0061] Preferably, A is Cs + or methylammonium ion (MA + ), or formamidinium ion (FA + ).

[0062] M is a divalent metal cation selected from the group consisting of Cu 2+ , Ni 2+ , Co 2+ , Fe 2+ , Mn 2+ , Cr 2+ , Pd 2+ , Cd 2+ , Ge 2+ , Sn 2+ , Pb 2+ , Eu 2+ , or Yb 2+ ; preferably Pb 2+ , Sn 2+ .

[0063] X is Cl - , Br - , I - , NCS - , CN - , and NCO - and is a monovalent anion independently selected from the group consisting of; preferably Cl - , Br - or I - . X may be the same or different.

[0064] According to a preferred embodiment, examples of organic-inorganic perovskites are methylammonium lead halides, such as methylammonium lead iodide (CH3NH3PbI3); methylammonium lead halide mixtures, such as CH3NH3PbClI2; formamidinium lead halides, such as HC(NH2)2PbI3, HC(NH2)2PbBr3 or HC(NH2)2PbCl2I; cesium lead iodide (CsPbI3), cesium tin iodide (CsSnI3).

[0065] In a further embodiment, the organic-inorganic perovskite layer material comprises a mixed perovskite structure, where A is a mixture of two or more cations as defined above, and X is a mixture of two or more anions as defined above. Preferably, A is a mixture of two cations, M is Pb, and X is a mixture of two anions. Formula (II) is the following formula (III): A 1 1-y A 2 y PbX 1 3-z X 2 z (III) can be represented by wherein: A 1 and A 2 are the organic monovalent cations as defined above for A; X 1 and X 2 are Cl - , Br - , I- , NCS - , CN - and NCO - and may be the same or different monovalent anions selected from the group consisting of; y ranges between 0.1 and 0.9; z ranges between 0.2 and 2.

[0066] The sensitizer layer is coated by a layer containing a hole transport layer (HTL), which can contain an inorganic hole transport material and / or an organic hole transport material. The inorganic hole transport material can contain at least one selected from nickel oxide (NiO x ), CuSCN, CuCrO2, and CuI.

[0067] Examples of organic hole transporting materials include carbazole derivatives, polyarylalkane derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorene derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidine compounds, porphyrin compounds, phthalocyanine compounds, polythiophene derivatives, polypyrrole derivatives, polyparaphenylenevinylene derivatives, pentacene, coumarin 6, 3-(2-benzothiazolyl)-7-(diethylamino)coumarin, ZnPC (zinc phthalocyanine), CuPC (copper phthalocyanine), TiOPC (titanium oxide phthalocyanine), Spiro-MeOTAD (2,2',7,7'-tetrakis(N,N-p-dimethoxyphenylamino)-9,9'-spirobifluorene), F16CuPC (copper(II) 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine), SubPc (boron subphthalocyanine chloride), and N3 (cis-di(thiocyanato)-bis(2,2'-bipyridyl-4,4'-dicarboxylic acid)-ruthenium(II), P3HT (poly[3-hexylthiophene]), MDMO-PPV (poly[2-methoxy-5-(3',7'-dimethyloctyloxy)]-1,4-phenylenevinylene), MEH-PPV (poly[2-methoxy-5-(2"-ethylhexyloxy)-p-phenylenevinylene]), P3OT (poly(3-octylthiophene)), POT (poly(octylthiophene)), P3DT (poly(3-decylthiophene)), P3DDT (poly(3-dodecylthiophene)), PPV (poly(p-phenylenevinylene)), TFB (poly(9,9'-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine), polyaniline, Spiro-MeOTAD ([2,22',7,77'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9,9'-spirobifluorene]), CuSCN, CuI, PCPDTBT (poly[2,1,3-benzothiadiazole-4,7-diyl[4,4-bis(2-ethylhexyl-4H-cyclopenta[2,1-b:3,4-b']dithiophene-2,6-diyl, Si-PCPDTBT (poly[(4,4'-bis(2-ethylhexyl)dithieno[3,2-b:2',3'-d]silole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl]), PBDTTPD (poly((4,8-diethylhexyloxy)), PFDTBT (poly[2,7-(9-(2-ethylhexyl)-9-hexyl-fluorene)-alt-5,5-(4',7-di-2-thienyl1-2',1',3'-benzothiadiazole)]), PFO-DBT (poly[2,7-.9,9-(dioctylfluorene)-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]), PSiFDTBT (poly[(2,7-dioctylsilafluorene)-2,7-diyl-alt-(4,7-bis(2-thienyl)-2,1,3-benzothiadiazole)-5,5'-diyl]), PCDTBT (poly[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl]), PFB (poly(9,9'-dioctylfluorene-co-bis(N,N'-(4-butylphenyl))bis(N,N'-phenyl-1,4-phenylene)diamine), F8BT (poly(9,9'-dioctylfluorene-cobenzothiadiazole), PEDOT (poly(3,4-ethylenedioxythiophene)), PEDOT:PSS poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), PTAA (poly(triarylamine)), 2-PACz, and / or MeO-2PACz, 4-PACz can be mentioned.,

[0068] Also provided herein is a method for preparing an electron transport layer using the compound of the present invention. Various methods can be used to form and manufacture an electron transport layer containing one or more compounds of the present invention. Suitable coating methods for providing a thin monolayer of the electron transport layer can be selected from various solution-based coating methods disclosed herein, such as those provided below.,

[0069] For example, a spin coating method for forming a self-assembled monolayer on a TCO substrate for use in a perovskite solar cell may comprise the following steps: 1) Providing a substrate covered with an oxide layer (TCO); for example, providing a glass substrate covered with ITO (i.e., a conductive support layer); 2) Optionally, cleaning the substrate covered with the oxide layer by ultrasonic treatment; for example, the ultrasonic treatment may be performed in an ultrasonic treatment bath in acetone and / or isopropyl alcohol (IPA); for example, the ultrasonic treatment may be performed for 15 minutes; 3) Optionally, treating the substrate covered with TCO by UV ozone or plasma treatment; for example, the treatment can be applied for 15 minutes; 4) Providing a solution containing a solvent and a compound according to formula (I); for example, a solution of the compound of formula (I) at a concentration of 0.1 mg / ml to 10 mg / ml dissolved in chlorobenzene may be used, preferably a solution at a concentration of about 1 mg / ml may be used; 5) Spin coating the compound according to formula (I) in the solution onto the substrate; for example, rotating at 5,000 r.p.m. for 30 seconds; 6) Thermally annealing the compound on the substrate covered with TCO; for example, heating at 100 °C for 10 minutes to 60 minutes, preferably for 10 minutes; 7) Optionally, cleaning the resulting coated substrate; the cleaning is performed to remove unbound molecules, for example, the cleaning is performed using a solvent by dynamic spin coating at 5,000 r.p.m. for 30 seconds.

[0070] In a preferred embodiment, the spin coating method for forming a self-assembled monolayer on a TCO substrate comprises the step of 3) treating the substrate covered with TCO by UV ozone or plasma treatment.

[0071] For example, an immersion / impregnation method for forming a self-assembled monolayer on a TCO substrate for use in a perovskite solar cell may comprise the following steps: 1) providing a substrate covered with an oxide layer (TCO); for example, providing a glass substrate covered with ITO (i.e., a conductive support layer); 2) optionally, cleaning the substrate covered with the oxide layer by ultrasonic treatment; for example, the ultrasonic treatment may be performed in an ultrasonic treatment bath in acetone and / or isopropyl alcohol (IPA); for example, the ultrasonic treatment may be performed for 15 minutes; 3) optionally, treating the substrate covered with TCO by UV ozone or plasma treatment; for example, the treatment can be applied for 15 minutes; 4) providing a solution containing a solvent and a compound according to formula (I); for example, a solution of the compound of formula (I) at a concentration of 0.1 mg / ml to 10 mg / ml dissolved in chlorobenzene may be used, preferably a solution at a concentration of about 1 mg / ml may be used; 5) immersing the substrate covered with TCO in the solution containing the compound according to formula (I); for example, the immersion can be carried out for 10 minutes to 24 hours, preferably about 1 hour; 6) thermally annealing the compound on the substrate covered with TCO; for example, heating at 100 °C for 10 minutes to 60 minutes, preferably for 10 minutes; 7) optionally, cleaning the resulting coated substrate; the cleaning is carried out to remove unbound molecules, for example, the cleaning is carried out using a solvent by dynamic spin coating at 5,000 r.p.m. for 30 seconds.

[0072] In a preferred embodiment, the dipping / impregnation method for forming a self-assembled monolayer on a TCO substrate comprises 3) treating the substrate covered with TCO by UV ozone or plasma treatment.

[0073] For the formation of self-assembled monolayers on TCO substrates, other solution-based coating methods such as spray coating, slot die coating, inject printing, doctor blade printing, screen printing, etc. may be suitable in some cases. When used, such methods can have the same steps as the spin coating method provided above, and instead of the spin coating step, depending on the method used, a spray coating, slot die coating, inject printing, doctor blade printing, or screen printing step can be performed respectively.

[0074] When the formation of self-assembled monolayers (SAMs) on TCO substrates is achieved by the methods as described above, in order to remove the solvent, a further step of thermal annealing (e.g., at 80 °C for about 5 minutes) can be performed.

[0075] Alternatively, the SAM can also be formed on the TCO substrate by thermal evaporation. For example, the evaporation can be carried out in a thermal evaporation system. In this case, the formed SAM film can be deposited at a pressure of about 5×10 -6 mbar and a rate of 0.15 - 0.25 Å / s, and can be carried out at a maximum rate of 0.6 Å / s -1 -1 . Thereafter, the thermally annealed or deposited film can be spin-coated in a one-step program (e.g., 3,000 rpm, 40 seconds) and washed using, for example, ethanol.

[23]

[0076] In some embodiments, for example, a method for forming a self-assembled monolayer on a TCO substrate for use in perovskite solar cells can include the step of simultaneously forming a SAM ETL and a perovskite layer containing a compound of formula (I). In such a method, for example, the SAM layer and the perovskite layer can be formed by a single processing step using a single solution containing additives of both the compound of formula (I) and the perovskite precursor. This method can be, for example, 1) preparing a solution comprising a perovskite precursor, a solvent, and a compound of formula (I); 2) applying the solution to a substrate to form a liquid layer on the substrate; and 3) treating the liquid layer to form a perovskite layer disposed adjacent to a first layer containing molecules may be provided with.

Example

[0077] Information on examples of actual embodiments is provided below, which describes the preparation formats and properties of exemplary compounds (V1612, V1625, V1486, V1624, V1635). This information is provided for illustrative purposes only and is not limiting.

[0078] [Example 1] General synthetic scheme of the compound of general formula (I): Symmetrical structure of an electron transport naphthalenediimide-based SAM compound.

Chemical formula

[0079] Electron transport naphthalenediimide-based compounds V1612, V1625, and V1486, which contain phosphonic acid anchor groups and correspond to general formula (I), were prepared by the two-step synthetic route shown in Scheme 1.

[0080] The first step was to reflux commercially available 1,4,5,8-naphthalenetetracarboxylic dianhydride (1a, TCI Europe) or 2,6-dibromo-naphthalene-1,4,5,8-tetracarboxylic dianhydride (1b, TCI Europe) with (aminomethyl)phosphonic acid (abcr GmbH) or (aminoethyl)phosphonic acid (abcr GmbH) in acetic acid to form intermediates 2a-c with symmetric ether groups (Scheme 1). The next step was to hydrolyze intermediates 2a-c using bromotrimethylsilane at room temperature (Method A) or refluxing with concentrated hydrochloric acid (Method B). The target product was obtained as beige crystals.

[0081] N,N'-Bis[diethyl(methyl)]-1,4,5,8-naphthalenetetracarboxylic diimidodiphosphonate (2a):

Chem.

[0082] N,N'-Bis(methyl)-1,4,5,8-naphthalenetetracarboxylic diimide diphosphonic acid (V1612)

Chem.

[0083] Method B. N,N'-Bis[diethyl(methyl)]-1,4,5,8-naphthalenetetracarboxylic diimide (2a, 2.87 g, 5.06 mmol) and concentrated hydrochloric acid (80 ml) were refluxed for 24 h. The formed beige solid was filtered off and washed with 100 ml of distilled water and THF (80 ml). The product was obtained as 2.22 g of beige crystals (96% yield); melting point >405 °C. Anal. calcd. for C 16 H 12 N2O 10 P2: C 42.31; H 2.66; N 6.17; found: C 42.22; H 2.5; N 6.05. MS(ESI, pos.mode), m / z: 453 (M - 1).

[0084] [Example 2] N,N'-Bis[diethyl(ethyl)]-1,4,5,8-naphthalenetetracarboxylic diimide diphosphonate (2b)

Chem.

[0085] N,N'-Bis(ethyl)-1,4,5,8-naphthalenetetracarboxylic diimidodiphosphonic acid (V1625)

Chem.

[0086] [Example 3] 2,6-Dibromo-N,N'-[diethyl(methyl)]-1,4,5,8-naphthalenetetracarboxydiimidodiphonate (2c) [Chemical formula] A mixture of 2,6-dibromonaphthalene-1,4,5,8-tetracarboxylic dianhydride (1b, 1 g, 1.16 mmol) and diethyl(aminomethyl)phosphonate (0.36 ml; 2.20 mmol) was refluxed in acetic acid (20 ml) under an argon atmosphere for 4 h. After completion of the reaction (TLC: methanol:dichloromethane, 5:245), distilled water (200 ml) was poured into the mixture. The solid that precipitated in red was filtered off and washed with water (100 ml). The crude product was purified by column chromatography (methanol:dichloromethane, 5:245) to give yellow crystals (0.522 g, (33%)); melting point >405 °C. 1 H NMR (400 MHz, CDCl3) δ: 9.00 (s, 2H), 4.68 (d, J = 12.8 Hz, 4H), 4.33 - 4.08 (m, 8H), 1.35 (t, J = 7.0 Hz, 12H) ppm. 1313C NMR (101 MHz, CDCl3) δ: 160.27, 160.04, 139.45, 128.93, 127.86, 125.28, 124.28, 63.06, 63.00, 37.27, 35.73, 16.52, 16.46 ppm. Anal. calcd. for C 24 H 26 Br2N2O 10 P2: C 39.80; H 3.62; N 3.87; found: C 40.22; H 3.7; N 3.93。

[0087] 2,6-Dibromo-N,N'-bis(ethyl)-1,4,5,8-naphthalenetetracarboxylic diimide diphosphonic acid (V1486)

Chem.

[0088] [Example 4] General synthetic scheme of the compounds of general formula (I): Asymmetric structure of the electron-transporting naphthalenediimide-based SAM compounds. [Chem.] Scheme 2. Synthetic route for the asymmetric structures of the electron-transporting naphthalenediimide-based SAM compounds V1264 and V1624.

[0089] The electron-transporting naphthalenediimide-based compounds V1264 and V1624 containing phosphonic acid anchor groups and corresponding to general formula (I) were prepared by the three-step synthetic route shown in Scheme 2. The first two steps were carried out in a one-pot operation: First, the reaction of commercially available 1,4,5,8-naphthalenetetracarboxylic dianhydride (1, TCI Europe) and diethyl(aminomethyl)phosphonate or diethyl(aminoethyl)phosphonate (abcr GmbH) was carried out at 110 °C in DMF, and then the intermediate 3a,b was obtained by the imidization reaction of 2a,b and 2,5-di-tert-butylaniline (Scheme 2). As the final step, the phosphonates 3a,b were hydrolyzed using bromotrimethylsilane at room temperature (Method A) or by refluxing with concentrated hydrochloric acid (Method B). The target products were obtained as greenish-yellow crystals.

[0090] N-(2,5-Di-tert-butyl-phenyl)-N'-[diethyl(methyl)]-1,4,5,8-naphthalenetetracarboxylic diimide phosphonate (3a) [Chem.] 1,4,5,8-Naphthalenetetracarboxylic dianhydride (1, 0.5 g, 1.86 mmol) was dissolved in anhydrous DMF (50 ml), and diethyl (aminomethyl) phosphonate (0.337 g, 1.86 mmol) was added dropwise. The solution was stirred at 110 °C for 4 hours under an argon atmosphere. Then (TLC: acetone: n-hexane, 1:4, TLC was developed with 1% ninhydrin solution), 2,5-di-tert-butylaniline (0.458 g, 2.23 mmol) was added, and the reaction mixture was heated to 140 °C and the reaction was carried out for an additional 24 hours. After completion of the reaction (TLC: acetone: n-hexane, 1:4), the reaction mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous Na2SO4 and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography (acetone: n-hexane, 1:4) to give the product as a greenish-yellow powder (0.359 g, 32%); melting point 217 - 218 °C. 1 1H NMR (400 MHz, CDCl3) δ: 8.82 (s, 4H), 7.60 (d, J = 8.6 Hz, 1H), 7.48 (d, J = 10.8 Hz, 1H), 7.00 (s, 1H), 4.71 (d, J = 12.8 Hz, 2H), 4.30 - 4.19 (m, 4H), 1.36 (t, J = 7.1 Hz, 6H), 1.32 (s, 9H), 1.26 (s, 9H) ppm. 13 13C NMR (101 MHz, CDCl3) δ: 163.87, 162.33, 150.51, 143.82, 132.09, 131.56, 131.52, 129.13, 127.66, 127.07, 126.82, 126.60, 62.99, 62.93, 36.96, 35.69, 34.41, 31.84, 31.32, 16.55, 16.49 ppm. Anal. calcd. for C 33 H 37 N2O7P: C 65.55; H 6.17; N 4.63; found: C 65.29; H 5.91; N 4.34.

[0091] N-(2,5-Di-tert-butyl-phenyl)-N'-(methyl)-1,4,5,8-naphthalenetetracarboxylic diimide phosphonic acid (V1264)

Chemical formula

[0092] Method II. N-(2,5-Di-tert-butyl-phenyl)-N'-[diethyl(methyl)]-1,4,5,8-naphthalenetetracarboxylic diimide phosphonate (3a) (0.200 g, 0.36 mmol) and concentrated hydrochloric acid (25 ml) were refluxed for 24 h. The yellow solid formed was filtered off and washed with 200 ml of distilled water. The product was dissolved in THF (50 ml) and recrystallized from diethyl ether (250 ml). The crystals were filtered off and washed with diethyl ether (50 ml) to give 0.173 g (yield 95%) of yellow crystals: melting point 275 - 276 °C. 1 H NMR (400 MHz, CDCl3) δ: 8.78 (s, 4H), 7.57 (d, J = 8.6 Hz, 1H), 7.46 (d, J = 10.6 Hz, 1H), 6.99 (s, 1H), 4.53 (s, 2H), 3.49 (s, 1H), 3.48 (s, 1H), 1.26 (s, 9H), 1.22 (s, 9H) ppm. 13 C NMR (101 MHz, CDCl3) δ: 163.95, 162.73, 150.46, 143.79, 132.13, 131.91, 131.53, 129.11, 127.64, 127.50, 126.80, 126.37, 66.01, 34.38, 31.85, 31.30, 29.84 ppm. Anal.calcd.for C 29 H 29F5N2O7P: C 63.50; H 5.33; N 5.11; found: C 63.27; H 5.08; N 4.88. MS(ESI, pos.mode), m / z: 547(M+H + )。

[0093] [Example 5] N-(2,5-Di-tert-butyl-phenyl)-N'-[diethyl(ethyl)]-1,4,5,8-naphthalenetetracarboxylic diimide phosphonate(3b) [Chemical formula] 1,4,5,8-Naphthalenetetracarboxylic dianhydride(1, 0.5 g, 1.86 mmol) was dissolved in anhydrous DMF(40 ml), and diethyl(2-aminoethyl)phosphonate(0.3 ml, 1.86 mmol) was added dropwise. The solution was stirred at 110 °C for 4 hours under an argon atmosphere. Then(TLC: acetone: n-hexane, 8:17) 2,5-di-tert-butylaniline(0.458 g, 2.23 mmol) was added, the reaction mixture was heated to 140 °C, and further reacted for 24 hours. After completion of the reaction(TLC: acetone: n-hexane, 8:17), the reaction mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous Na2SO4, and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography(acetone: n-hexane, 8:17), and the product was obtained as a beige powder(0.35 g, 30%); melting point 234~235 °C. 1 H NMR(400 MHz, CDCl3) δ: 8.81(s, 4H), 7.59(d, J = 8.6 Hz, 1H), 7.48(d, J = 8.5 Hz, 1H), 6.99(s, 1H), 4.57 - 4.42(m, 2H), 4.27 - 4.06(m, 4H), 2.36 - 2.22(m, 2H), 1.37(t, J = 7.0 Hz, 6H), 1.32(s, 9H), 1.25(s, 9H) ppm. 1313C NMR (101 MHz, CDCl3) δ: 163.91, 162.72, 150.48, 143.80, 131.54, 131.30, 129.12, 127.64, 127.30, 127.18, 127.11, 126.82, 68.10, 62.16, 35.67, 35.24, 34.40, 31.84, 31.32, 25.74, 16.61, 16.55 ppm. Anal. calcd. for C 34 H 39 N2O7P: C 66.01; H 6.35; N 4.53; found: C 65.91; H 6.26; N 4.55.

[0094] N-(2,5-Di-tert-butyl-phenyl)-N'-(ethyl)-1,4,5,8-naphthalenetetracarboxylic diimide phosphonic acid (V1624)

Chem.

[0095] [Example 6] N-(2,5-Di-tert-butyl-phenyl)-N'-(phenyl)-1,4,5,8-naphthalenetetracarboxylic diimide phosphonate [Chemical formula] 1,4,5,8-Naphthalenetetracarboxylic dianhydride (1, 0.5 g, 1.86 mmol) was dissolved in anhydrous DMF (40 ml), and diethyl (4-aminophenyl) phosphonate (0.427 g, 1.86 mmol) was added. The solution was stirred at 140 °C for 12 hours under an argon atmosphere. Then (TLC: acetone: n-hexane, 12:13) 2,5-di-tert-butylaniline (0.459 g, 2.23 mmol) was added, and the reaction mixture was heated to reflux and reacted for another 12 hours. After completion of the reaction (TLC: acetone: n-hexane, 9:16), the reaction mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous Na2SO4, and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography (acetone: n-hexane, 9:16) to obtain the product as beige crystals (0.131 g, 11%); melting point 165 - 166 °C. 1 1H NMR(400MHz, CDCl3) δ: 8.87 (s, 4H), 8.11 - 7.93 (m, 2H), 7.61 (d, J = 8.5 Hz, 1H), 7.48 (dd, J = 14.2, 8.2 Hz, 3H), 7.02 (s, 1H), 4.28 - 4.09 (m, 4H), 1.38 (t, J = 7.0 Hz, 6H), 1.33 (s, 9H), 1.28 (s, 9H) ppm.13 13C NMR (101 MHz, CDCl3) δ: 166.95, 163.85, 162.92, 150.56, 143.79, 138.39, 133.31, 133.20, 132.04, 131.74, 131.65, 130.80, 129.18, 129.07, 128.92, 127.63, 127.53, 127.47, 126.86, 62.58, 62.53, 35.71, 34.43, 31.87, 31.33, 30.45, 16.56, 16.49 ppm. Anal. calcd. for C 38 H 39 N2O7P: C 68.46; H 5.90; N 4.20; found: C 68.55; H 5.73; N 4.33.

[0096] N-(2,5-Di-tert-butyl-phenyl)-N'-(phenyl)-1,4,5,8-naphthalenetetracarboxylic diimide phosphonic acid (V1635)

Chem.

[0097] [Example 7] Absorption spectrum In the n-i-p structure, PSC light first passes through the ETL, so it is important to minimize the parasitic absorption of this layer. The optical properties of the electron transport SAM compound V1264 were investigated by UV / vis spectroscopy from 10 -4 M anhydrous dichloromethane (Figure 2a). Clearly, no obvious absorption is seen in the visible region. Furthermore, the results of the UV-Vis transmittance of the electron transport material SAM functionalization on the ITO surface show negligible optical losses compared to bare ITO and ITO / SnO2 films (Figure 2b, c).

[0098] [Example 8] Thermogravimetric Analysis (TGA) TGA was performed on a Q50 thermogravimetric analyzer (TA Instruments) in a nitrogen atmosphere at a scan rate of 10K min -1 as shown in Figure 3, the 95% weight loss temperature of the electron transport SAM compound V1264 is 356 °C, which is suitable for the actual use of optoelectronic devices.

[0099] [Example 9] Cyclic Voltammetry (CV) CV measurements were performed on a three-electrode assembly cell of Bio-Logic SP-150. The measurements were carried out on a glassy carbon electrode in a DMF and DCM solution containing 0.1 M tetrabutylammonium hexafluorophosphate as the electrolyte, and Pt as the counter electrode and reference electrode. Each measurement was calibrated with ferrocene (Fc), and the potential was Fc +Calculated against / Fc. Conversion factors: ferrocene in DCM vs SCE 0.46, DMF vs SCE 0.45, SCE vs SHE: 0.244, SHE vs vacuum: 4.43 (N.G. Connelly, W.E. Geiger, Chemical Reviews 1996, 96, 877; V.V. Pavlishchuk, A.W. Addison, Inorganica Chimica Acta 2000, 298, 97). Half-wave potential

Number

Number

Number

Number

Number

[0100] The voltammogram of V1264 in solution showed a reversible reduction wave during the scan and was typical of NDI derivatives (Figure 4). The reversible process indicates that the material exhibits good electrochemical stability. In the calculated energy level redox potential measurements, the E LUMO level of V1264 was measured to be -3.81 eV, while E HOMO was measured to be -6.97 eV (Table 1). The E LUMO of the electron transport compound demonstrates a good alignment with the maximum of the conduction band of the perovskite absorber, while E HOMOThe energy level is high enough to block holes from the perovskite layer.

[0101] Table 3 Energy levels of electron-transporting SAM compounds [Table 3] [Example 10] Characterization of the ITO / NDI-SAM surface: Contact angle measurement, SEM images The electron-transporting molecule V1264 coated on ITO significantly increased the surface hydrophobicity of the ITO substrate to about 78.4°, while the bare ITO was about 28.5° (Figure 5). It should be noted that all samples were washed with their respective solvents to remove unbound SAM molecules from the ITO substrate. From this, it becomes clear that only the SAM attached to the ITO can affect the surface hydrophobicity that can be directly related to the SAM coverage on the ITO.

[20] The higher the hydrophobicity of the ITO / SAM substrate, the more it will affect the crystallization and morphology of the perovskite film. [21,22] The higher the hydrophobic surface of the ITO / NDI-SAM (the lower the wettability), the more the dragging force of the perovskite ink can be suppressed, and as a result, as shown in the top surface scanning electron microscopy (SEM) images of a and b in Figure 6, perovskite crystals with large particle sizes can be obtained. [21,22] Furthermore, the tert-butyl group of V1264 on the upper side can interact well with the perovskite layer, and as a result, the pinholes or voids formed at the ITO / V1264 / perovskite interface are reduced (see Figure 7).

[0102] Surface mapping of the contact potential difference (CPD) values of V1264 on ITO confirmed a uniform coverage of the SAM. This fairly homogeneous pattern is proportional to the narrow work function (WF) variations in a specific region (about 4.45 eV), indicating a good coverage of V1264 on ITO as a whole.

[0103] [Example 11] Photovoltaic cell manufacturing and performance measurement The performance of the electron transport self-assembled monolayer compound V1264 was tested in a hybrid perovskite solar cell (ITO / V1264 / hybrid perovskite / HTL / MoOx / Ag) using an ITO optical anode and an Ag cathode (Figure 8).

[0104] Device manufacturing: The patterned ITO / glass substrate was washed in an ultrasonic bath of acetone and isopropyl alcohol (IPA) for 15 minutes each, followed by treatment with UV-ozone for 15 minutes for surface cleaning and increasing oxygen concentration. Then, 0.5 - 1.0 mg / mL of V1264 was dissolved in chlorobenzene. The SAM solution was coated on ITO / glass by spin-coating at 5,000 r.p.m. for 30 seconds, followed by thermal annealing at 100 °C for 10 minutes. After cooling, the SAM film was washed with chlorobenzene and dynamically spin-coated at 5,000 r.p.m. for 30 seconds to remove unbound molecules. Subsequently, thermal annealing was performed at 80 °C for 5 minutes to evaporate the remaining solvent. A 1.55 eV bandgap perovskite solution (1.5 M) composed of a triple-A site cation mixture, of the formula Cs 0.03 (FA 0.90 MA 0.10 ) 0.97Based on PbI3, it was diluted with DMF:DMSO (4:1 v / v ratio) (S.-K. Jung, J.H. Heo, D.W. Lee, S.-C. Lee, S.-H. Lee, W. Yoon, H. Yun, S.H. Im, J.H. Kim, O.-P. Kwon, Advanced Functional Materials 2018, 28, 1800346). In this way, the perovskite solution was coated onto the SAM film by two-step spin coating at 2,000 r.p.m. for 40 seconds and 6,000 r.p.m. for 10 seconds to form a perovskite film. Solvent quenching using anisole (300 μl) as a standard procedure was applied during the last 10 seconds of the substrate rotation, followed by annealing at 100 °C for 40 minutes. After cooling, the HTL was coated onto the perovskite film at 4,000 r.p.m. for 35 seconds without additional annealing. The organic HTL was prepared by dissolving 72.3 mg of spiro-OMeTAD, 28.8 μl of tBP, and 17.5 μl of LiTFSI in 1 mL of chlorobenzene. Then, -6 under a vacuum of 10 x Torr, 5 nm of MoO 2 and 100 nm of Ag were thermally evaporated using a metal mask area of about 0.1 cm

[0105] An n-i-p type PSC with pure SnO2 was used for comparison. SnO2 was prepared as follows: The patterned ITO / glass substrate was washed in an ultrasonic bath in acetone and isopropyl alcohol (IPA) for 15 minutes each, followed by treatment with UV-ozone for 15 minutes for surface cleaning and increasing the oxygen concentration. Then, 15% SnO2 in H2O (Alfa Aesar) was diluted with SnO2:DI water (1:4 v / v ratio) and stirred overnight at room temperature. Thus, the film deposition rate was 4,000 r.p.m. for 35 seconds and annealed at 150 °C for 25 minutes.

[0106] Characterization of the Device: The fabricated perovskite solar cells were evaluated by the photocurrent density-voltage (J-V) characteristics. The performance of the J-V characteristic device was measured in a steady-state N2 purge glove box under an Abet Technologies Sun 3000 solar simulator equipped with a Keithley 2400 source unit. The light source was calibrated to AM 1.5G (100 mW cm 2 ) using a monosilicon standard cell (Newport). Forward and reverse scans were performed with light illumination treatment 30 seconds before each measurement and applied to all devices at a scan rate of 100 mV s -1 . The external quantum efficiency (EQE) spectrum was managed on an optical breadboard equipped with a 400 W xenon lamp through a monochromator and filter inside an N2 glove box and calibrated to a 603621 silicon and germanium reference detector. Capacitance-voltage measurements were performed to obtain the capacitance at a sweep frequency from 1 MHz to 1 Hz (10 mV AC voltage). The voltage varied from 0 to 1.2 V and the frequency was constant at 1 kHz. The ETM self-assembled monolayer compound V1264 showed a maximum PCE of 21.5% (V OC 1.13 V, J SC 24.7 mA cm -2 , FF 77%) in the reverse scan, presenting higher device performance with negligible hysteresis (Figure 9). The external quantum efficiency (EQE) of the V1264-based device showed slightly higher J SC overall than that of the SnO2-based device because the absorption at the EQE edge was high due to the lower optical reflection loss of the ITO / V1264 film. The statistical distribution of the electron-selective SAM from 25 devices is shown in (Figure 11), which indicates the reproducibility of the V1264-based device with a narrower PCE distribution. This result represents the higher performance of the reported electron-selective SAM and ETL-free based on n-i-p type PSC (Figure 12).

[0107] [Example 12] Long-Term Stability Test of the Photovoltaic Cell First, devices based on SnO2-ETL and SAM molecule V1264 were stored in an N2-glove box at room temperature for 1000 hours, and the devices were measured at any time (Figure 13a). The SnO2-based n-i-p type device could only retain about 58% of the initial PCE after 1000 hours of storage, while the V1264-based device showed a longer lifespan with a retention of about 84%.

[0108] Next, the thermal stability of the photovoltaic device was also evaluated under dark conditions at 65 °C for more than 1000 hours under an N2-glove box on a hot plate, and the devices based on SAM molecule V1264 and SnO2 were compared in Figure 13b. It was clearly shown that the device based on SAM molecule V1264 retained about 72% of the initial PCE, demonstrating better thermal stability, compared to only 38% PCE retention by the SnO2-based device under the same conditions.

[0109] Note that the degradation of the n-i-p type device can also occur due to the doped spiro-OMeTAD HTL at high temperatures. [7,12] Therefore, the device based on SAM molecule V1264 was also evaluated using a relatively thermally stable HTL using poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and showed a retention rate of over 90% under the same conditions.

[0110] [Example 13] Table 4. Solubility of Various Compounds [Table 4] [Example 14] Further aspects of the present disclosure are illustrated by the following numbered sections:

[0111] Section 1. A compound of formula (I), (IV) or (V): [Chemical formula] wherein In the formula X is -L1-A1, H, NH2, C1-C 10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C4-C10 aryl, C4-C20 alkylaryl, C4-C20 alkenylaryl, and C4-C20 alkynylaryl, each of which is optionally substituted with C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C1-C10 heteroalkyl, C4-C10 aryl, C2-C10 heteroalkenyl, C2-C10 heteroalkynyl, C4-C10 heteroaryl, or one or more heteroatoms selected from N, S, and O; R1, R2, R3, and R4 are independently selected from H, CN, Cl, Br, F, CF3, NO2, C1-C20-alkyl, C2-20-perfluoroalkyl, C5-20-aryl, and C5-20-heteroaryl; A, A1, and A2 are phosphonic acid, monoalkyl ether of phosphonic acid, phosphoric acid, monoalkyl ether of phosphoric acid:

Chemical formula

Chemical formula

Chemical formula

[0112] Section 2. The compound according to Section 1, wherein the compound is of formula (I).

[0113] When each of R1, R2, R3, and R4 is H and each of A and A1 is a phosphonic acid, L and L1 are independently selected from C3-C9-alkylene, C4-C20 arylene, C4-C20 heteroarylene, C4-C20 alkylarylene, C4-C20 heteroalkylarylene, C4-C20 heteroalkenearylene, where the heteroatom is from O, N, S, Se, Si, or the structure:

Chemical formula

[0114] The compound according to any one of the preceding sections, where A, A1, and A2 are phosphonic acids.

[0115] The compound according to any one of the preceding sections, where L and L1 are the same.

[0116] The compound according to any one of the preceding sections, where X is -L1-A1.

[0117] The compound according to any one of Sections 1 to 4, where X is selected from H, NH2, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C4-C10 aryl, C4-C20 alkylaryl, C4-C20 alkenylaryl, and C4-C20 alkynylaryl, each of which is optionally substituted with one or more heteroatoms selected from C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C1-C10 heteroalkyl, C4-C10 aryl, C2-C10 heteroalkenyl, C2-C10 heteroalkynyl, C4-C10 heteroaryl, or N, S, and O.

[0118] The compound according to Section 7, where X is selected from C4-C20 alkylaryl optionally substituted with C1-C10 alkyl.

[0119] Section 9. A composition comprising one or more compounds described in any one of the preceding sections.

[0120] Section 10. The composition according to Section 9, further comprising a filler molecule (FM), wherein the FM is at least one type of molecule composed of an anchor group, an alkyl chain of N carbon atoms (N ranges from 1 to 18), and at least one functional group selected from the group consisting of a methyl functional group, a halogen functional group, an amino functional group, a bromide functional group, an ammonium functional group, and a sulfur functional group.

[0121] Section 11. An optoelectronic device and / or a photoelectrochemical device comprising an electron transport layer containing the compound described in any one of Sections 1 to 8 or the composition described in Section 9 or Section 10.

[0122] Section 12. The optoelectronic device and / or the photoelectrochemical device according to Section 11, wherein the device is selected from a photovoltaic device, an organic photovoltaic device, a solid photovoltaic device, an organic solar cell, a solid solar cell, a perovskite solar cell, a tandem solar cell, a light-emitting electrochemical cell, and an OLED.

[0123] Section 13. The optoelectronic device and / or the photoelectrochemical device according to Section 12, wherein the device is a photovoltaic device.

[0124] Section 14. A photovoltaic device according to Section 13, comprising a conductive support layer, a sensitizer layer, a hole transport layer, and a counter electrode covered with an electron transport layer, wherein the electron transport layer contains the compound described in any one of Sections 1 to 8 or the composition described in Section 9 or Section 10.

[0125] Section 15. The photovoltaic device according to Section 14, wherein the electron transport layer consists of the compound described in any one of Sections 1 to 8 or the composition described in Section 9 or Section 10.

[0126] Section 16. The device is a tandem solar cell, and preferably, the tandem solar cell includes at least one perovskite solar cell, and is the photovoltaic device according to any one of Sections 12 to 15.

[0127] Section 17. The photovoltaic device according to any one of Sections 14 to 16, wherein the sensitizer layer contains an organic-inorganic perovskite.

[0128] Section 18. The organic-inorganic perovskite is of formula (II): AMX3 (II) and includes a perovskite structure of wherein A is an alkali metal ion, preferably Li + , Na + , K + , Rb + , Cs + ; an ammonium ion or an amidinium ion, wherein one or more hydrogens are substituted by an alkyl group or an acyl group; M is a divalent metal cation selected from the group consisting of Cu 2+ , Ni 2+ , Co 2+ , Fe 2+ , Mn 2+ , Cr 2+ , Pd 2+ , Cd 2+ , Ge 2+ , Sn 2+ , Pb 2+ , Eu 2+ , or Yb 2+ ; X is a monovalent anion independently selected from the group consisting of Cl - , Br - , I - , NCS - , CN - , and NCO - is the photovoltaic device according to Section 17. Section 19. The organic-inorganic perovskite is of formula (III): A 1 1-y A 2 yPbX 1 3-z X 2 z(III) is a mixed perovskite structure by wherein: A 1 and A 2 are organic monovalent cations independently selected from Li+, Na+, K+, Rb+, Cs+, ammonium, or amidinium ions; wherein one or more hydrogens of the ammonium ion or amidinium ion are substituted by an alkyl group or an acyl group or a halogen; X 1 and X 2 are the same or different monovalent anions selected from Cl-, Br-, I-, NCS-, CN- and NCO-; y ranges between 0.1 and 0.9; z ranges between 0.2 and 2, a photovoltaic device described in Section 18.

[0129] Section 20. A photovoltaic device according to any one of Sections 14 to 19, wherein the conductive support layer comprises a conductive material selected from indium-doped tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), metal and / or other conductors.

[0130] The research activities of this project received financial support from the Horizon Europe Research and Innovation Action program under the grant contract number 101082176 of the VALHALLA project. References

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Claims

1. A compound of formula (I), (IV) or (V) 【Chemical 1】 wherein in the formula X is -L １ -A １ , H, NH ２ , C １ ~C １０ selected from C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C4-C10 aryl, C4-C20 alkylaryl, C4-C20 alkenylaryl, and C4-C20 alkynylaryl, each of which is optionally substituted with one or more heteroatoms selected from C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C1-C10 heteroalkyl, C4-C10 aryl, C2-C10 heteroalkenyl, C2-C10 heteroalkynyl, C4-C10 heteroaryl, or N, S, and O; R １ 、 R ２ 、 R ３ 、 R ４ are independently selected from H, CN, Cl, Br, F, CF ３ , NO ２ , C1-C20-alkyl, C2-20-perfluoroalkyl, C5-20-aryl, C5-20-heteroaryl; A, A １ , A ２ A is a phosphonic acid, a monoalkyl ether of phosphonic acid, a phosphoric acid, or a monoalkyl ether of phosphoric acid: 【Chemical 2】 or structure 【Chemical 3】 is independently selected from R ７ is a C1-C9 alkyl group; L, L １ is independently selected from C1-C9-alkylene, C4-C20 arylene, C4-C20 heteroarylene, C4-C20 alkylarylene, C4-C20 alkenearylene, C4-C20 heteroalkylarylene, C4-C20 heteroalkenearylene, where the heteroatom is from O, N, S, Se, Si, or the structure: 【Chemical 4】 selected from, a compound.

2. The compound according to claim 1, wherein the compound is of formula (I).

3. R １ , R ２ , R ３ , R ４ each of which is H, and when each of A, A １ is phosphonic acid, L, L １ is independently selected from C3-C9-alkylene, C4-C20 arylene, C4-C20 heteroarylene, C4-C20 alkylarylene, C4-C20 heteroalkylarylene, C4-C20 heteroalkenarylene, where the heteroatom is from O, N, S, Se, Si, or the structure: [Chemical Formula 5] The compound according to claim 1 or 2, selected from

4. A, A １ and A ２ The compound according to claim 1 or 2, wherein A, A, and A are phosphonic acids. It should be noted that there may be some inaccuracies in the original text as the description seems a bit unclear. The translation is adjusted based on the overall context as best as possible.

5. L and L １ The compound according to claim 1 or 2, wherein L and L are the same.

6. X is -L １ -A １ The compound according to claim 1 or 2, wherein

7. X is H, NH ２ , C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C4-C10 aryl, C4-C20 alkylaryl, C4-C20 alkenylaryl, and C4-C20 alkynylaryl, each of which is optionally substituted with one or more heteroatoms selected from C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, C1-C10 heteroalkyl, C4-C10 aryl, C2-C10 heteroalkenyl, C2-C10 heteroalkynyl, C4-C10 heteroaryl, or N, S and O, the compound according to claim 1 or 2.

8. The compound according to claim 7, wherein X is selected from C4-C20 alkylaryl optionally substituted with C1-C10 alkyl.

9. A composition comprising one or more compounds according to claim 1.

10. Further comprising a filler molecule (FM), wherein FM is at least one molecule consisting of an anchor group, an alkyl chain of N carbon atoms (N ranges from 1 to 18), and at least one functional group selected from the group consisting of a methyl functional group, a halogen functional group, an amino functional group, a bromide functional group, an ammonium functional group and a sulfur functional group, the composition according to claim 9.

11. An optoelectronic device and / or a photoelectrochemical device comprising an electron transport layer comprising the compound according to claim 1 or the composition according to claim 9.

12. The optoelectronic device and / or the photoelectrochemical device according to claim 11, wherein the optoelectronic device and / or the photoelectrochemical device is selected from a photovoltaic device, an organic photovoltaic device, a solid-state photovoltaic device, an organic solar cell, a solid-state solar cell, a perovskite solar cell, a tandem solar cell, a light-emitting electrochemical cell, and an OLED.

13. The optoelectronic device and / or the photoelectrochemical device according to claim 12, wherein the optoelectronic device and / or the photoelectrochemical device is a photovoltaic device.

14. A photovoltaic device according to claim 13, comprising a conductive support layer, a sensitizer layer, a hole transport layer and a counter electrode covered with an electron transport layer, wherein the electron transport layer comprises the compound according to claim 1 or the composition according to claim 9.

15. The photovoltaic device according to claim 14, wherein the electron transport layer consists of the compound according to claim 1 or the composition according to claim 9.

16. The optoelectronic device and / or the photoelectrochemical device according to claim 12, wherein the optoelectronic device and / or the photoelectrochemical device is a tandem solar cell, preferably, the tandem solar cell comprises at least one perovskite solar cell.

17. The photovoltaic device according to claim 14, wherein the sensitizer layer contains an organic-inorganic perovskite.

18. The organic-inorganic perovskite has a perovskite structure of formula (II): AMX ３ (II) and includes wherein A is an alkali metal ion, preferably Li ＋ , Na ＋ , K ＋ , Rb ＋ , Cs ＋ ; an ammonium ion or an amidinium ion, wherein one or more hydrogens are substituted by an alkyl group or an acyl group; M is Cu ２＋ , Ni ２＋ , Co ２＋ , Fe ２＋ , Mn ２＋ , Cr ２＋ , Pd ２＋ , Cd ２＋ , Ge ２＋ , Sn ２＋ , Pb ２＋ , Eu ２＋ , or Yb ２＋ and is a divalent metal cation selected from the group consisting of; X is Cl － , Br － , I － , NCS － , CN － , and NCO － The photovoltaic device according to claim 17, which is a monovalent anion independently selected from the group consisting of

19. The organic-inorganic perovskite has a mixed perovskite structure according to formula (III): A １ １－ｙ A ２ ｙ PbX １ ３－ｚ X ２ z (III) and wherein: A １ and A ２ is an organic monovalent cation independently selected from Li+, Na+, K+, Rb+, Cs+, ammonium, or amidinium ions, where one or more hydrogens of said ammonium or amidinium ions are substituted by an alkyl group or an acyl group or a halogen; X １ and X ２ are the same or different monovalent anions selected from Cl−, Br−, I−, NCS−, CN− and NCO−; y ranges between 0.1 and 0.9; z ranges between 0.2 and 2. The photovoltaic device according to claim 18.

20. The photovoltaic device according to claim 14, wherein the conductive support layer contains a conductive material selected from indium-doped tin oxide (ITO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), a metal, and / or other conductors.

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