Heptacyclic fused heterocyclic organic compound, oligomer, mixture, and use

Abstract

The present application relates to a heptacyclic fused heterocyclic organic compound, an oligomer, a mixture, and a use. Specifically, the heptacyclic fused heterocyclic organic compound has a structure represented by general formula (I) or (I'), and the oligomer has a structure represented by general formula (III), wherein each variable is as defined in the description. The present application also provides a mixture comprising the heptacyclic fused heterocyclic organic compound represented by general formula (I) or (I') or the oligomer represented by general formula (III). In addition, the present application also relates to an organic photovoltaic device comprising the heptacyclic fused heterocyclic organic compound represented by general formula (I) or (I'), the oligomer represented by general formula (III), or the mixture.

Description

A heptane-fused heterocyclic organic compound, oligomer, mixture and its application

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 2025103791807, filed on March 28, 2025, entitled "A Heptane Fused Heterocyclic Organic Compound and Its Application", and Chinese Patent Application No. 2026101802267, filed on February 6, 2026, entitled "A Seven-Member Fused Heterocyclic Organic Compound and Its Application", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of organic semiconductor materials technology, specifically to a heptane fused heterocyclic organic compound, oligomer, mixture and its application, particularly a high-performance organic photovoltaic acceptor material and device suitable for indoor low-light environments. Background Technology

[0004] With global population growth and economic development, traditional fossil fuel reserves are dwindling, leading to increasingly severe energy shortages and environmental pollution. Solar energy, as an inexhaustible and renewable clean energy source, is a key way to alleviate the energy crisis. Solar cells have undergone three generations of development: the first generation, mainly crystalline silicon solar cells, is technologically mature and has the highest market share; the second generation is represented by thin-film photovoltaic cells such as copper indium selenide (CIGS), cadmium telluride (CdTe), and copper indium gallium selenide (CIGS); the third generation encompasses perovskite and organic photovoltaic (OPV) cells. Among them, organic photovoltaic devices use organic semiconductor materials as the core, employing solution-processable organic small molecules or polymers as the photoactive layer. Compared to traditional inorganic photovoltaic technologies, OPV not only has a wide range of raw material sources and low manufacturing costs, but also possesses unique advantages such as environmental friendliness, recyclability, light weight, flexibility, and the ability to be rolled up and printed on a large scale. Although its photoelectric conversion efficiency under standard outdoor lighting is slightly lower than that of silicon-based and perovskite cells, OPV shows great potential in specific application scenarios due to its tunable molecular energy levels, high molar extinction coefficient, and controllable spectral response range.

[0005] In recent years, with the rapid development of the Internet of Things (IoT) and smart home industries, the massive number of low-power electronic devices distributed indoors has created an urgent need for off-grid self-powered technology. Organic photovoltaic devices, due to their good biocompatibility and excellent photoelectric conversion performance under low light conditions, are considered an ideal choice for indoor energy harvesting. In the development of the non-fullerene acceptor material ITIC, the ITIC molecule reported by Zhan Xiaowei's research group in 2015 was a milestone. Its combination with the donor polymer PTB7-Th achieved an efficiency of 6.8%, ushering in the era of non-fullerenes. Subsequently, based on the optimization of the ITIC system (such as IT-4F) and the adjustment of device structure, its efficiency under standard sunlight exceeded 18%. Afterwards, research focus shifted further to the more efficient Y-series (such as Y6-O) and FCC system (such as FCC-Cl, FTCC-Br) non-fullerene acceptors, resulting in a relative decrease in in-depth exploration of the early ITIC framework.

[0006] However, existing high-efficiency non-fullerene acceptor materials are primarily designed for the solar spectrum, and their absorption spectra are significantly mismatched with the spectral distribution of indoor artificial light sources (such as LEDs and fluorescent lamps). Under low-light indoor conditions, due to limited incident light intensity and low photoexciton density, even tiny material defects or traps can easily lead to severe bimolecular recombination, directly limiting the improvement of the device's open-circuit voltage (Voc) and fill factor (FF). Currently, mainstream indoor photovoltaic materials are still concentrated in the aforementioned systems designed for strong outdoor light, and their efficiency improvement has encountered a bottleneck due to the inherent molecular structure. In addition, the development of new materials specifically designed for energy level and morphology control of indoor spectral characteristics is progressing slowly, causing the development of indoor photovoltaic technology to lag behind outdoor technology, making it difficult to meet the growing demand for low-light power generation from emerging industries.

[0007] Therefore, there is an urgent need to develop new, more efficient acceptor materials that are more suitable for the industrial application of indoor photovoltaics, so that they have better solution processability, absorption characteristics that are more matched to indoor spectra, and higher photoelectric conversion efficiency in low light. This is crucial for promoting the commercial application of organic photovoltaics indoors. Summary of the Invention

[0008] To address the technical challenges of existing non-fullerene acceptor materials, such as poor spectral matching under low indoor light conditions, severe exciton recombination leading to low photoelectric conversion efficiency, and limited processing in traditional halogen solvents, this invention provides a heptane-fused heterocyclic organic compound, oligomer, mixture, and its applications. Through synergistic molecular structure design, this invention significantly improves the material's solubility in non-halogen green solvents and optimizes its photoelectric response characteristics under indoor light sources, enabling the fabrication of efficient and green indoor organic photovoltaic devices.

[0009] To achieve the above objectives, this application adopts the following technical solution:

[0010] The first aspect of this application relates to a heptane-fused heterocyclic organic compound having a structure as shown in general formula (I):

[0011] in:

[0012] Each time M appears, it is independently selected from O or C(CN)2;

[0013] R 1 Each occurrence is independently selected from branched alkyl groups having 3-12 carbon atoms, or branched alkoxy groups having 3-12 carbon atoms;

[0014] R 2 Each occurrence is independently selected from straight-chain alkyl groups having 1-10 carbon atoms;

[0015] R 3 Each occurrence is independently selected from -H (hydrogen), -D (deuterium), methyl, -F, -Cl, -Br, -I, -CF3, or -CN;

[0016] Each time Y appears, it is independently selected from S or Se;

[0017] Each time m appears, it is independently selected from 0 or 1.

[0018] In an alternative embodiment, in formula (I), the R 1 Each occurrence is independently selected from branched alkyl groups having 3-12 carbon atoms; further, the R 1 Each occurrence is independently selected from isopropyl,

[0019] In a particular embodiment, in equation (I), the R 1 All selected from

[0020] In an alternative embodiment, in formula (I), the R 1 Each occurrence is independently selected from branched alkoxy groups having 8-12 carbon atoms; further, the R 1 Each time it appears, it is selected independently.

[0021] In a particular embodiment, in equation (I), the R 1 All selected from

[0022] In an alternative embodiment, in formula (I), Y is selected from S.

[0023] In an alternative embodiment, in formula (I), the Selected from

[0024] Furthermore, in equation (I), the R 2 Each occurrence is independently selected from a straight-chain alkyl group having 6-8 carbon atoms; furthermore, the R 2 Each occurrence is independently selected from -C6H 13 or -C8H 17 .

[0025] In one embodiment, in formula (I), the R 2 All selected from -C6H 13 .

[0026] In another embodiment, in formula (I), the R 2 All selected from -C8H 17 .

[0027] In one embodiment, in formula (I), the Selected from

[0028] In one embodiment, in equation (I), m = 0, the Selected from In another embodiment, in equation (I), m = 1, the Selected from In one specific embodiment, in formula (I), the Selected from any of the following groups:

[0029] Optionally, the heptane-fused heterocyclic organic compound of general formula (I) described in this application has the following structure, but is not limited thereto:

[0030] A second aspect of this application provides a heptacyclic fused heterocyclic organic compound having a structure as shown in general formula (I'):

[0031] in:

[0032] Each time Z appears, it is independently selected from O, S, or Se;

[0033] Each time X appears, it is independently selected from C or Si;

[0034] Each time R1 appears, it is selected independently. m0 is selected from 1, 2, or 3;

[0035] Each time R6 appears, it is independently selected from alkyl groups having 1-10 carbon atoms, whether substituted or unsubstituted by R*.

[0036] Each time R7 appears, it is independently selected from -H, alkyl groups having 1-10 carbon atoms that are substituted with R* or unsubstituted;

[0037] Each occurrence of R* is independently selected from R. a Substituted or unsubstituted aromatic groups having 6-20 carbon atoms, or those modified by R a One or a combination of at least two of the following heteroaromatic groups, substituted or unsubstituted, having 5-20 ring atoms;

[0038] R a Each occurrence is independently selected from -D, halogen, cyano, nitro, trifluoromethyl, alkyl having 1-10 carbon atoms, or alkoxy having 1-10 carbon atoms;

[0039] * indicates a connection point;

[0040] Each time R2 and R3 appear, they are independently selected from branched alkyl groups having 3-20 carbon atoms;

[0041] R4 and R5 are each independently selected from -H, -D, halogen, cyano, nitro, trifluoromethyl, alkyl with 1-10 carbon atoms, or alkoxy with 1-10 carbon atoms.

[0042] Group A is selected from electron-withdrawing units containing a cyano group.

[0043] In an alternative embodiment, in general formula (I'), each occurrence of R1 is independently selected from...

[0044] Furthermore, each occurrence of R6 is independently selected from straight-chain alkyl groups having 1-10 carbon atoms, whether substituted or unsubstituted by R*.

[0045] Furthermore, each occurrence of R7 is independently selected from straight-chain alkyl groups having 1-10 carbon atoms, substituted with R*, or unsubstituted.

[0046] In an alternative embodiment, each occurrence of R6 is independently selected from... The m1 is selected from 1, 2, 3, 4, 5, 6, 7, or 8; the R7, each time it appears, is independently selected from -H, or The m2 is selected from 1, 2, 3, 4, 5, 6, 7, or 8; the R 10 Each occurrence is independently selected from -H and controlled by R. a Substituted or unsubstituted aromatic groups having 6-10 carbon atoms, or those modified by R a A heteroaromatic group, substituted or unsubstituted, having 5-10 ring atoms.

[0047] Furthermore, the R 10Each occurrence is independently selected from -H and controlled by R. a Substituted or unsubstituted phenyl, R a Substituted or unsubstituted pyridinyl groups, R a Substituted or unsubstituted thiophene group, R a Substituted or unsubstituted furanyl groups, by R a Substituted or unsubstituted selenophenyl group, R a Substituted or unsubstituted naphthyl groups, R a Substituted or unsubstituted benzotriazole group, or R a Substituted or unsubstituted thiophene-thiophene group.

[0048] In a specific embodiment, the R a Each occurrence is independently selected from -D, -F, -Cl, -Br, -I, cyano, nitro, trifluoromethyl, methyl, ethyl, n-propyl, isopropyl, tert-butyl, or methoxy.

[0049] Optionally, each occurrence of R6 is independently selected from *-CH3, *-C2H5, *-C3H7, *-C4H9, and *-C5H. 11 、*-C6H 13 、*-C7H 15 、*-C8H 17 Or any of the following groups, but not limited to:

[0050] Furthermore, each occurrence of R7 is independently selected from -H, *-CH3, *-C2H5, *-C3H7, *-C4H9, *-C5H. 11 、*-C6H 13 、*-C7H 15 、*-C8H 17 Or any structure of the group (A'-1)-(A'-31).

[0051] In one alternative embodiment, when R7 is selected from -H, R6 is selected from an alkyl group having 1-10 carbon atoms substituted with R*; optionally, the R* is selected from an alkyl group substituted with R*. a Substituted or unsubstituted phenyl, R a Substituted or unsubstituted pyridinyl groups, R a Substituted or unsubstituted thiophene group, R a Substituted or unsubstituted furanyl groups, by R a Substituted or unsubstituted selenophenyl group, R a Substituted or unsubstituted naphthyl groups, R a Substituted or unsubstituted benzotriazole group, or R a Substituted or unsubstituted thiophene-thiophene group; R a The meaning is the same as described above.

[0052] Furthermore, in general formula (I'), each occurrence of R1 is independently selected from, but not limited to, any of the following groups:

[0053] In one embodiment, R2 and R3 in the general formula (I') are independently selected from... Among them, R8 and R9 are each selected independently from alkyl groups having 1-10 carbon atoms each time they appear.

[0054] Furthermore, each time R8 and R9 appear, they are independently selected from alkyl groups having 2-8 carbon atoms.

[0055] Optionally, each occurrence of R8 and R9 is independently selected from *-C2H5, *-C4H9, and *-C6H. 13 Or *-C8H 17 .

[0056] Furthermore, the aforementioned Each time it appears, it is selected independently.

[0057] In an alternative embodiment, in general formula (I'), each occurrence of R4 and R5 is independently selected from -H, -D, -F, -Cl, a straight-chain alkyl group having 1-6 carbon atoms, or a straight-chain alkoxy group having 1-6 carbon atoms.

[0058] In one embodiment, in general formula (I'), each of the R4 and R5 is independently selected from -H, -D, -F, -Cl, methyl, or methoxy.

[0059] In an optional embodiment, in general formula (I'), the group A is selected from... Wherein: Ar1, each occurrence, is independently selected from unsubstituted or R-type elements. # Replacing aromatic groups having 6-20 carbon atoms, or without substitution or by R # Substitutes heteroaromatic groups having 5-20 ring atoms; R # Each occurrence is independently selected from one or a combination of at least two of the following: -D, halogen, cyano, nitro, alkyl having 1-10 carbon atoms, alkoxy having 1-10 carbon atoms, aromatic group having 6-10 carbon atoms, and heteroaromatic group having 5-10 cyclic atoms.

[0060] Furthermore, each occurrence of Ar1 is independently selected from unsubstituted or R-substituted varieties. # The aromatic group having 6-10 carbon atoms is substituted, or it is unsubstituted or replaced by R. # It replaces heteroaromatic groups with 5-10 ring atoms.

[0061] Optionally, each occurrence of Ar1 is independently selected from the following groups:

[0062] Where: r1 is selected from 0, 1 or 2; r2 is selected from 0, 1, 2, 3 or 4; r3 is selected from 0, 1, 2, 3, 4, 5 or 6;

[0063] # indicates a fusion site, which is selected from C atoms.

[0064] In a specific embodiment, the R # Each occurrence is independently selected from one or a combination of at least two of the following: -D, -F, -Cl, -Br, -I, -CF3, cyano, nitro, straight-chain alkyl with 1-6 carbon atoms, branched-chain alkyl with 3-6 carbon atoms, straight-chain alkoxy with 1-6 carbon atoms, branched-chain alkoxy with 3-6 carbon atoms, phenyl, and thiophene.

[0065] In a specific embodiment, the R # Each occurrence is independently selected from -D, -F, -Cl, -Br, -I, -CF3, cyano, nitro, or methyl.

[0066] In one specific embodiment, in general formula (I'), group A is independently selected from the following groups:

[0067] In one alternative embodiment, in general formula (I'), the group A is selected from the same group each time it appears.

[0068] In an alternative embodiment, the heptanomeric fused heterocyclic organic compound of general formula (I') has a structure as shown in general formulas (II-1), (II-2), (II-3), or (II-4):

[0069] In an alternative embodiment, in general formula (I'), Z is selected from S or Se.

[0070] In one specific embodiment, the heptaneously fused heterocyclic organic compound of general formula (I') described in this application is selected from, but not limited to, the following structures:

[0071] A third aspect of this application relates to an oligomer having a structure as shown in general formula (III):

[0072] in:

[0073] m3 is selected from integers greater than or equal to 2;

[0074] L is a linking group, selected from single bonds, double bonds, triple bonds, and bonds bonded by R. b Substituted or unsubstituted aromatic groups having 6-20 carbon atoms, or those modified by R b Substituted or unsubstituted heteroaromatic groups having 5-20 ring atoms;

[0075] R b Each occurrence is independently selected from one or a combination of at least two of the following: -D, halogen, cyano, nitro, alkyl group having 1-20 carbon atoms, alkoxy group having 1-20 carbon atoms, alkylthio group having 1-20 carbon atoms, ester group having 1-20 carbon atoms, aromatic group having 6-20 carbon atoms, and heteroaromatic group having 5-20 ring atoms; two adjacent R groups b They may form rings or not;

[0076] The definitions of X, Z, A, R1, R2, R3, R4, and R5 are as described in the definition of heptaneously fused heterocyclic organic compounds of general formula (I') in the second aspect.

[0077] In an alternative embodiment, in general formula (III), m3 is selected from 2, 3, 4, 5 or 6.

[0078] Furthermore, the oligomers of general formula (III) are selected from the structures shown in general formula (IV):

[0079] Furthermore, the oligomers of general formula (III) are selected from the structures shown in general formula (V):

[0080] in:

[0081] R 11 Each occurrence is independently selected from one or a combination of at least two of the following: -D, -F, -Cl, -CF3, cyano, nitro, straight-chain alkyl having 1-6 carbon atoms, branched alkyl having 3-6 carbon atoms, straight-chain alkoxy having 1-6 carbon atoms, branched alkoxy having 3-6 carbon atoms, phenyl, and thiophene.

[0082] Each time r4 appears, it is independently selected from 0, 1, 2, or 3;

[0083] The meaning of Ar1 is the same as described above.

[0084] In an alternative embodiment, the Selected from

[0085] In a specific embodiment, R in the general formula (V) 11Each occurrence is independently selected from -H, -F, or -Cl.

[0086] In a specific embodiment, L is selected from single bonds, Where: V is selected from O, S, or Se; r5 is selected from 1, 2, 3, 4, or 5; R 12 Each occurrence is independently selected from one or a combination of at least two of the following: -H, -D, halogen, cyano, nitro, alkyl group having 1-20 carbon atoms, alkoxy group having 1-20 carbon atoms, alkylthio group having 1-20 carbon atoms, ester group having 1-20 carbon atoms, aromatic group having 6-20 carbon atoms, and heteroaromatic group having 5-20 ring atoms; two adjacent R groups b They may form rings or not.

[0087] Furthermore, the R 12 Each time it appears, it is independently selected from -H, -D, -F, -Cl, -CF3, cyano, alkyl with 1-10 carbon atoms, alkoxy with 1-10 carbon atoms, alkylthio with 1-10 carbon atoms, or ester with 1-10 carbon atoms.

[0088] In one embodiment, Ar1 in the general formula (V) is selected from any structure of the group (C-1)-(C-4).

[0089] Furthermore, the aforementioned Selected from any structure of groups (D-1)-(D-25).

[0090] In an alternative embodiment, in formula (III), (IV) or (V), R1 is selected from any structure of groups (B'-1)-(B'-25).

[0091] In an optional embodiment, in formulas (III), (IV), or (V), R2 and R3 are each selected independently each time they appear.

[0092] In an optional embodiment, in general formulas (III), (IV) or (V), R4 and R5 are each independently selected from -H, -D, -F, -Cl, a straight-chain alkyl group having 1-6 carbon atoms, or a straight-chain alkoxy group having 1-6 carbon atoms.

[0093] In an alternative embodiment, Z in formulas (III), (IV) or (V) is selected from S or Se.

[0094] In an alternative embodiment, X in formulas (III), (IV) or (V) is selected from C.

[0095] In another alternative embodiment, X in formula (III), (IV) or (V) is selected from Si.

[0096] In one specific embodiment, the oligomer of general formula (III) is selected from, but is not limited to, the following structures:

[0097] A fourth aspect of this application relates to a mixture comprising:

[0098] Heptane-fused heterocyclic organic compounds of general formula (I) as described in the first aspect; or

[0099] Heptane-fused heterocyclic organic compounds of general formula (I') as described in the second aspect; or

[0100] Oligomers of general formula (III) as described in the third aspect.

[0101] Furthermore, the mixture further comprises a polymer donor material.

[0102] The polymer donor material can be selected from polythiophene material systems, such as P3AT, P3HT, P3OT, P3DDT, etc.; fluorene-containing polymer material systems, such as PF8BT, etc.; novel structural narrow bandgap polymer material systems, such as benzodithiophene (BDT), benzothiadiazoles (BT, BBT), quinoxalines (QU, PQ), pyrazines (TP, PQ) and electron-rich groups (such as thiophene derivatives), such as PM6, PM7, PBDB-T, D18, D18-Cl, PQM-Cl, PTQ10, PTQ11, PBQx-TCl, PBQx-TF, PB2, PCE10, etc., but is not limited to these.

[0103] The fifth aspect of this application relates to an organic photovoltaic device, the organic photovoltaic device comprising a cathode, an anode, and a photoactive layer located between the cathode and the anode, the photoactive layer material comprising:

[0104] Heptane-fused heterocyclic organic compounds of general formula (I) as described in the first aspect; or

[0105] Heptane-fused heterocyclic organic compounds of general formula (I') as described in the second aspect; or

[0106] oligomers of general formula (III) as described in the third aspect; or

[0107] The mixture as described in the fourth aspect.

[0108] Furthermore, the photoactive layer comprises a photoactive layer donor material and a photoactive layer acceptor material, wherein the photoactive layer acceptor material is:

[0109] Heptane-fused heterocyclic organic compounds of general formula (I) as described in the first aspect; or

[0110] Heptane-fused heterocyclic organic compounds of general formula (I') as described in the second aspect; or

[0111] Oligomers of general formula (III) as described in the third aspect.

[0112] Further, the donor material is selected from the polymer donor materials described above. Optionally, the polymer donor material is selected from one, two or more of PBDB-T, PM6, PM7, D18, D18-Cl, PBQx-TCl, PBQx-TF, PQM-Cl, PTQ10, and PTQ11, but is not limited thereto.

[0113] The method for preparing the photoactive layer material solution is as follows: the photoactive layer donor material and acceptor material are dissolved in an organic solvent at a certain mass ratio, and the mixture is stirred until fully dissolved to obtain the photoactive layer solution.

[0114] The above solution is used to prepare the photoactive layer by printing or coating methods. These printing or coating methods can include, but are not limited to, inkjet printing, gravure printing, inkjet printing, letterpress printing, screen printing, dip coating, spin coating, doctor blade coating, roller printing, torsional roller printing, offset printing, flexographic printing, rotary printing, spraying, brush coating, pad printing, and slot-loaded extrusion coating. Slot-loaded coating, spin coating, and inkjet printing are preferred.

[0115] The mass ratio of the photoactive layer donor material to the acceptor material in the organic solvent can be selected as 1:0.8 to 1:1.5; further, the mass ratio of the photoactive layer donor material to the acceptor material in the organic solvent can be selected as 1:1 to 1:1.5; the mass ratio of the photoactive layer donor material to the acceptor material in the organic solvent can be selected as 1:1 to 1:1.2.

[0116] The concentration of the photoactive layer donor material in the organic solvent is optionally 3 to 15 mg / mL; further, the concentration of the photoactive layer donor material in the organic solvent is optionally 4 to 10 mg / mL.

[0117] The organic solvent is selected from, but not limited to: tetrahydronaphthalene, 1,5-dimethyltetrahydrofuran, methyltetrahydrofuran, decahydronaphthalene, chlorobenzene, o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,4-dimethylnaphthalene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, acetophenone, diphenyl ether, 2-methylthiophene, 3-methylthiophene, monochloromethane, dichloromethane, chloroform, dichloroethylene, trichloroethylene, 1,1- One or a mixture of two or more of the following: trichlorotrifluoroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, carbon tetrachloride, tetrahydrofuran, anisole, 2,4-dimethylanisole, 1-methylnaphthalene, morpholine, 1,4-dioxane, N-methylpyrrolidone, acetone, cyclopentanone, cyclohexanone, methyl ethyl ketone, ethyl acetate, n-butyl acetate, carbon disulfide, carbon tetrachloride, N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, indane, methyl benzoate, ethyl benzoate, acetonitrile, and hexamethylphosphoramide.

[0118] Furthermore, the photoactive layer material solution may further include additives for adjusting viscosity, film-forming properties, and improving adhesion. The additives may be selected from, but are not limited to, 1,8-diiodooctane (DIO), diphenyl ether (DPE), anthracene, 1,4-diiodobenzene (DIB), 1,3-dibromo-5-chlorobenzene (DBCl), 3,5-dichlorobromobenzene (DCBB), 1-chloronaphthalene (1-CN), 1,3,5-tribromobenzene (TBB), etc., but are not limited to these.

[0119] At least one of the anode and cathode is transparent or translucent to allow light to enter. The materials used to prepare the electrodes can be selected from metals, such as vanadium (V), chromium (Cr), zinc (Zn), silver (Ag), aluminum (Al), platinum (Pt), tungsten (W), copper (Cu), molybdenum (Mo), gold (Au), nickel (Ni), palladium (Pd), or alloys of the above metals; conductive nanomaterials, such as metal nanowires, nanoparticle slurries, graphene, carbon nanotubes, etc.; metal oxides, such as zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), etc.; combinations of metals and oxides, such as ZnO:Al or SnO2:Sb, etc.; and conductive polymers, such as PEDOT:PSS, polypyrrole, and polyaniline, etc.; or composite structures with multilayer electrode materials, such as metal / ITO (or ITO / metal), as well as ITO / metal / ITO, AZO / metal / AZO, LiF / Al, LiO2 / Al, LiF / Fe, MoO3 / Al, Al:Li, Al:BaF2, and Al:BaF2:Ba, etc., but are not limited to these.

[0120] In one embodiment, the organic photovoltaic device comprises an anode, an anode buffer layer, a photoactive layer, a cathode buffer layer, and a cathode stacked sequentially. The photoactive layer comprises a heptane-fused heterocyclic organic compound of formula (I) as described in the first aspect, or a heptane-fused heterocyclic organic compound of formula (I') as described in the second aspect, or an oligomer of formula (III) as described in the third aspect, or a mixture as described in the fourth aspect.

[0121] In one specific embodiment, the anode material is selected from ITO, and the cathode material is selected from silver (Ag) or aluminum (Al).

[0122] In another specific embodiment, the cathode material is selected from ITO, and the anode material is selected from silver (Ag) or aluminum (Al).

[0123] Optionally, the cathode buffer layer material can be selected from low work function metal complexes, metal oxides, metal salts, etc., such as metal complexes of 8-hydroxyquinoline, complexes containing Alq3, metal complexes containing Liq, PEI-Zn, LiF, Ca, titanium oxide (TiO2). x It can be zinc oxide (ZnO), cesium carbonate (Cs2CO3), etc.; it can also be polymer materials, such as PFN-Br or PFN or PDINN or PDINO or PNDIT-F3N-Br or PNDIT-F3N, etc., but is not limited to these.

[0124] The anode buffer layer material is selected from PEDOT:PSS and molybdenum oxide (MoO). x ), vanadium oxide (V₂O₅), nickel oxide (NiO), tungsten oxide (WO₂) x Optional, x is selected from 2 or 3), small molecule self-assembled materials such as 2PACz, MeO-2PACz, etc., but not limited to these.

[0125] It should be noted that, in order to improve the performance of organic photovoltaic devices, the organic photovoltaic devices may further include other functional layers, including but not limited to charge blocking layers, charge transport layers, and passivation layers.

[0126] Furthermore, the organic photovoltaic device also includes a substrate. In one embodiment, the substrate is disposed on one side of the anode and on a different side from the photoactive layer. In another embodiment, the substrate is disposed on one side of the cathode and on a different side from the photoactive layer.

[0127] In one embodiment, a substrate with excellent transparency, surface smoothness, ease of handling, and water resistance can be used as the substrate. Specifically, a glass substrate, a thin-film glass substrate, or a transparent plastic substrate can be used. The plastic substrate may include, but is not limited to, single-layer or multi-layer films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), parylene, etc., and substrates commonly used in organic solar cells may also be used.

[0128] In an optional embodiment, the organic photovoltaic device described in this application is an indoor organic photovoltaic device.

[0129] The indoor organic photovoltaic devices can be applied to fields such as electronic paper displays, Internet of Things devices, smart homes, and consumer electronics.

[0130] The technical advantages of this application are:

[0131] 1. The heptaneously fused heterocyclic organic compound of general formula (I) provided in this application, by introducing R 1 And R 1 Selected from branched alkyl or alkoxy groups, this improves the molecular morphology and stacking, enhancing π-π stacking and charge transport properties in the thin film. Furthermore, it fine-tunes the molecular energy levels and improves solubility, resulting in a more uniform and stable thin film after blending with the donor material, and improving exciton dissociation and transport. As demonstrated in the device examples, when the heptane-fused heterocyclic organic compound described in this application is used as an acceptor material in indoor photovoltaic devices, its indoor photoelectric conversion efficiency exceeds 30%, meeting the product application requirements of indoor photovoltaic devices and significantly enhancing the application prospects of ITIC-configured acceptor materials in indoor photovoltaics.

[0132] 2. This application also provides a heptane-fused heterocyclic organic compound of general formula (I'). By synergistically optimizing the selection of groups R1, R2, and R3, the compound exhibits excellent solubility in non-halogen solvents, making it suitable for large-area module fabrication. Simultaneously, this heptane-fused heterocyclic organic compound possesses suitable energy levels and absorption spectra. When used as an acceptor material in indoor organic photovoltaic modules, it demonstrates excellent indoor photoelectric conversion efficiency, with some compounds achieving photoelectric conversion efficiencies exceeding 32%. This significantly improves the indoor application level of organic photovoltaic technology and is of key significance for promoting the industrial application of organic photovoltaic modules.

[0133] 3. The oligomers formed by connecting the heptanomeric fused heterocyclic organic compounds of general formula (I') provided in this application break through the efficiency bottleneck of oligomer-type acceptor materials in green solvent systems, realize the characteristics of organic photovoltaic devices that can be processed with non-halogen solvents and have stability, and provide a reliable guarantee for the effective application of indoor organic photovoltaic devices.

[0134] 4. The synthetic routes for heptane fused heterocyclic compounds or oligomers provided in this application have high controllability and reproducibility, and low synthesis cost, making them suitable for industrial production needs. They play an important role in promoting the industrial application of organic photovoltaic devices in indoor low-light environments. Attached Figure Description

[0135] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0136] Figure 1 is a schematic diagram of the structure of the organic photovoltaic (OPV) device in the first part of the embodiments of this application.

[0137] Figure 2 is the 1H NMR spectrum of compound (A-1) in synthesis example A-1 in the first part of the embodiments of this application.

[0138] Figure 3 is the 1H NMR spectrum of compound (A-2) in synthesis example A-2 in Part 1 of this application.

[0139] Figure 4 is the 1H NMR spectrum of compound (A-3) in synthesis example A-3 in Part 1 of this application.

[0140] Figure 5 is the 1H NMR spectrum of compound (A-16) in synthesis example A-5 in Part 1 of this application.

[0141] Figure 6 is the 1H NMR spectrum of compound (B-1) in the second part of the embodiments of this application;

[0142] Figure 7 is the 1H NMR spectrum of compound (B-10) in the second part of the embodiments of this application;

[0143] Figure 8 is the 1H NMR spectrum of compound (B-19) in the second part of the embodiments of this application;

[0144] Figure 9 is the 1H NMR spectrum of compound (B-25) in the second part of the embodiments of this application;

[0145] Figure 10 is the 1H NMR spectrum of compound (B-37) in the second part of the embodiments of this application;

[0146] Figure 11 is the 1H NMR spectrum of compound (B-59) in the second part of the embodiments of this application;

[0147] Figure 12 is the 1H NMR spectrum of compound (B-87) in the second part of the embodiments of this application;

[0148] Figure 13 is an electrochemical curve of compounds (B-1) and (B-Ref1) in the second part of the embodiments of this application;

[0149] Figure 14 shows the morphology of the photoactive layer films prepared according to Examples B-1, B-2 and Comparative Example B-1 in the second part of the embodiments of this application under a microscope.

[0150] Figure 15 is a schematic diagram of the organic photovoltaic device module in the second part of the embodiment of this application, wherein: 10-substrate; 101-cathode (ITO); 102-cathode buffer layer; 103-photoactive layer; 104-anode buffer layer; 105-anode (Ag); 401-insulating channel (P1); 402-connecting channel (P2); 403-isolation channel (P3); 20-top cover plate; 30-sealant layer. Detailed Implementation

[0151] To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following provides a further detailed description of this application. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the described embodiments of this application without inventive effort are within the scope of protection of this application.

[0152] The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0153] In this application, organic photovoltaic devices, organic photovoltaic cells, organic solar cells, OPV, and OSC have the same meaning and can be used interchangeably.

[0154] In this application, the terms "photoactive layer" and "active layer" have the same meaning and can be used interchangeably.

[0155] In this application, when the same group contains multiple substituents with the same symbol, the substituents can be the same as or different from each other, for example... The six R's on the benzene ring can be the same or different from each other.

[0156] In this application, the phrase "when the..." Selected from When, it means Optional

[0157] In this application, "substitution" means that one or more hydrogen atoms in the substituent are replaced by the substituent.

[0158] In this application, "ring atom number" refers to the number of atoms in the ring itself of a structural compound (e.g., monocyclic compound, fused-ring compound, cross-linked compound, carbocyclic compound, heterocyclic compound) obtained by atomic bonding to form a ring. When the ring is substituted by a substituent, the atoms contained in the substituent are not included in the ring-forming atoms. The same applies to the "ring atom number" described below unless otherwise specified. In aromatic groups, the ring atom number is the same as the number of carbon atoms; in heteroaromatic groups, the ring atom number is the number of carbon atoms plus the number of heteroatoms; for example, the ring atom number of a benzene ring is 6, the ring atom number of a naphthalene ring is 10, the ring atom number of a quinoline ring is 10, the ring atom number of a thiophene group is 5, and the ring atom number of a thiophene is 8.

[0159] In this application, "aromatic group" refers to any optional functional group or substituent derived from an aromatic carbide ring. The aromatic group can be a monocyclic aryl (e.g., phenyl) or a polycyclic aryl; in other words, the aromatic group can be a monocyclic aromatic group or a fused-ring aromatic group. Optionally, the aromatic group is selected from aromatic groups having 6-20 carbon atoms; further, it is selected from aromatic groups having 6-10 carbon atoms; the aromatic group includes, but is not limited to: phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthryl, fluoranthyl, and their derivatives.

[0160] In this application, "heteroaromatic group" refers to a heteroaromatic ring or its derivative containing one, two, three, four, five, six or more heteroatoms, wherein the heteroatoms can be at least one of B, O, N, P, Si, Se and S. The heteroaromatic group can be a monocyclic heteroaryl or a polycyclic heteroaryl. The term "heteroaromatic group" as used herein also includes groups formed by fusion of one or more heteroaromatic groups with one or more aromatic rings, aliphatic rings or heterocycles. Optionally, the heteroaromatic group is selected from those having 5-20 ring atoms; further, it is selected from those having 5-10 ring atoms. Heteroaromatic groups include, but are not limited to: thiophene, furanyl, pyrrolyl, diazolyl, triazolyl, imidazole, pyridinyl, pyrimidinyl, triazinyl, acridineyl, pyrazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, benzothiophene, benzofuranyl, indolyl, pyrroloimidazolyl, pyrrolopyrryl, thienopyrryl, thienothiophene, furanolopyrryl, furanolofuranyl, thienofuranyl, benzoisoxazolyl, benzoisothiazolyl, benzoimidazolyl, o-diazonaphthyl, phenanthidyl, quinazolinone, dibenzothiophene, dibenzofuranyl, carbazole, phenazinyl and their derivatives.

[0161] In this application, alkyl groups include straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl groups, and combinations thereof. Straight-chain alkyl groups may have 1 to 20, 1 to 10, or 1 to 6 carbon atoms. Branched-chain alkyl groups may have 3 to 20, 3 to 12, 3 to 10, or 3 to 6 carbon atoms. Non-limiting examples of straight-chain alkyl groups include methyl (-CH3), ethyl (-C2H5), n-propyl (-C3H7), n-butyl (-C4H9), and n-pentyl (-C5H9). 11 ), n-hexyl (-C6H) 13 ), heptyl (-C7H) 15 ), n-octyl (-C8H) 17 ), non-nonyl (-C9H) 19 ), n-decyl (-C 10 H 21 Non-limiting examples of branched alkyl groups include: isopropyl, branched alkyl groups containing 4 carbon atoms, branched alkyl groups containing 5 carbon atoms, branched alkyl groups containing 6 carbon atoms, branched alkyl groups containing 7 carbon atoms, branched alkyl groups containing 8 carbon atoms, branched alkyl groups containing 9 carbon atoms, branched alkyl groups containing 10 carbon atoms, branched alkyl groups containing 11 carbon atoms, and branched alkyl groups containing 12 carbon atoms; the cycloalkyl group represents cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, etc.

[0162] The term "alkoxy" refers to a group with the structure "-O-alkyl", that is, an alkyl group as defined above that is attached to other groups via an oxygen atom. The straight-chain alkoxy means that the alkyl group in "-O-alkyl" is selected from straight-chain alkyl groups, wherein the number of carbon atoms in the straight-chain alkyl group can be 1 to 20, 1 to 10, or 1 to 6; the branched-chain alkoxy means that the alkyl group in "-O-alkyl" is selected from branched-chain alkyl groups, wherein the number of carbon atoms in the branched-chain alkyl group can be 3 to 20, 3 to 12, 3 to 10, or 3 to 6.

[0163] The "halogen" is selected from -F, -Cl, -Br, and -I.

[0164] In this application, when no linking site is specified in the group, it means that any linkable site in the group is selected as the linking site.

[0165] In this application, the phrase "independently selected" means that when one or more groups appear simultaneously and in multiple places in the compound, they are all independently selected and can be the same or different.

[0166] In describing the structural elements of this application, the terms "comprising" or "including" or similar terms used in this application mean that the device or material preceding the word covers the device or material listed after the word and its equivalents, but does not exclude other devices or materials.

[0167] In the description of this application, it should be understood that the terms "upper", "lower", "between layers", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when organic solar cell devices are in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0168] The phrase "mutually independent selection" in this application means that the groups may be selected from the same or different groups.

[0169] The terms “combinations thereof,” “any combination thereof,” “any combination thereof,” “combination,” etc., as used in this application, include all suitable combinations of any two, any three, or any three or more groups listed.

[0170] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0171] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0172] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0173] Example

[0174] The following embodiments are provided to facilitate a better understanding of the disclosure of this application, but are not intended to limit it in any way. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the materials and reagents used are prior art and can be obtained commercially.

[0175] Example Part 1: Synthesis of Heptane-fused Heterocyclic Organic Compounds of General Formula (I) and Their Application in Organic Photovoltaic Devices

[0176] Synthesis Example A-1: ​​Synthesis of Compound (A-1)

[0177] Synthesis of compound A-1-2:

[0178] Compound A-1-1 (10.10 g, 40 mmol) was added to a 250 mL three-necked flask; anhydrous THF (100 mL) was added to purge nitrogen three times, and the mixture was cooled to -78 °C. n-BuLi (2.5 M; 17.6 mL, 44 mmol) was slowly added dropwise under a -78 °C atmosphere. After reacting for 2 hours, tri-n-butyltin chloride (15.6 g, 48 mmol) was slowly added dropwise under a -78 °C atmosphere. After reacting for 15 minutes, the heat was removed, and the mixture was allowed to warm naturally to room temperature and stirred overnight at room temperature. The reaction was then quenched with a saturated potassium fluoride aqueous solution, and the aqueous phase was extracted three times with ethyl acetate. The combined organic phases were distilled under reduced pressure with anhydrous Na₂SO₄ to remove excess solvent, yielding 17.11 g of crude product.

[0179] Synthesis of compound A-1-3:

[0180] Diethyl 2,5-dibromoterephthalate (3.75 g, 9.8 mmol), compound A-1-2 (15.0 g, 27.7 mmol), and Tol (150 mL) were added to a 500 mL three-necked flask, and the mixture was purged with nitrogen three times. Pd(PPh3)2Cl2 (0.069 g, 0.098 mmol) was added to the reaction flask, and the mixture was purged with nitrogen three times. The mixture was refluxed at 110 °C for 1 hour. After the reaction mixture cooled to room temperature, it was poured into 200 mL of water, and extracted three times with ethyl acetate. The combined organic phases were dried over anhydrous Na2SO4 and concentrated. The crude product was purified by silica gel column chromatography with PE:DCM = 5:1 (v / v) to give approximately 4.10 g of compound A-1-3, in 57.8% yield. MS: 723.58.

[0181] Synthesis of compound A-1-4:

[0182] p-Hexylbromobenzene (13.34 g, 55.3 mmol) and anhydrous THF (80 mL) were added to a 250 mL three-necked flask, and the atmosphere was purged with nitrogen three times. n-BuLi (2.5 M; 22.12 mL, 55.3 mmol) was slowly added dropwise at -78 °C, and the reaction was allowed to proceed for 1 hour. Compound A-1-3 (2.0 g, 2.76 mmol) was dissolved in anhydrous THF (10 mL) and slowly added dropwise to the reaction mixture at -78 °C. The reaction mixture was allowed to return to room temperature and continue reacting for 30 minutes. The reaction solution was slowly poured into 150 mL of water to quench the reaction. The aqueous phase was extracted three times with ethyl acetate. The combined organic phases were dried over anhydrous MgSO4, and excess solvent was evaporated under reduced pressure. Silica gel column chromatography was performed using PE:DCM = 10:1 (volume ratio) as the eluent, yielding approximately 3.23 g of compound A-1-4. Yield 91.4%, MALDI-TOF-MS: 1280.41.

[0183] Synthesis of compound A-1-5:

[0184] Compound A-1-4 (3.2 g, 2.5 mmol) and glacial acetic acid (36 mL) were added to a three-necked flask. Concentrated sulfuric acid (3.6 mL) was slowly added dropwise to the reaction flask, and the reaction was carried out at room temperature for 2 hours. The reaction mixture was poured into 100 mL of water, and the aqueous phase was extracted three times with ethyl acetate. The organic phases were combined and washed three times with saturated sodium bicarbonate aqueous solution. The combined organic phases were dried over anhydrous MgSO4. Excess solvent was evaporated under reduced pressure, and silica gel column chromatography was performed with PE:DCM = 5:1 (v / v). The purified compound A-1-5 was approximately 2.11 g, with a yield of 67.8%. MALDI-TOF-MS: 1244.26.

[0185] Synthesis of compound A-1-6:

[0186] Prepare a dry 50 mL three-necked flask R1. After purging with nitrogen three times, add anhydrous DMF (5.2 mL) and POCl3 (1.3 mL) sequentially into R1. The reaction is exothermic. Allow it to cool to room temperature before use. Prepare another dry 50 mL three-necked flask reactor R2. Add compound A-1-5 (1.2 g, 0.92 mmol) and 1,2-dichloroethane (4 mL) to R2. Purge with nitrogen three times and cool to -10 °C using an ice-salt bath. Remove the reaction solution from R1 using a long needle and slowly add it dropwise to R2 under a -10 °C atmosphere, controlling the reaction temperature to not exceed -5 °C. After the reaction temperature stabilizes, allow it to return to room temperature, then raise the reaction temperature to 60 °C and react for 30 minutes. After cooling the reaction to room temperature, the reaction solution was slowly quenched by adding dropwise to 50 ml of water. The pH was then adjusted to 7 by adding saturated sodium bicarbonate solution. The aqueous phase was extracted three times with dichloromethane. The combined organic phases were dried, and excess solvent was removed by vacuum evaporation. The solution was then purified by silica gel column chromatography with PE:DCM at a 1:1 (volume ratio) eluent to obtain approximately 1.04 g of compound A-1-6, with a yield of 86.9%. MALDI-TOF-MS: 1300.08

[0187] Synthesis of compound (A-1):

[0188] Compound A-1-6 (390 mg, 0.3 mmol), 5,6-difluoro-3-(dicyanomethylene)indophenone (276 mg, 1.2 mmol), and anhydrous Tol (10 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.4 mL) was added dropwise, followed by the slow addition of acetic anhydride (0.8 mL). The reaction was allowed to proceed at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM = 1:1 (volume ratio) as the eluent. After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 400 mg of compound (A-1), with a yield of 77.3%. NMR data: 1 ¹H NMR (400MHz, Chloroform-d) δ 9.02 (s, 2H), 8.53 (dd, J = 9.9, 6.4Hz, 2H), 7.69–7.62 (m, 4H), 7.21 (d, J = 8.0Hz, 9H), 7.14 (d, J = 8.1Hz, 9H), 3.07 (s, 4H), 2.60–2.51 (m, 8H), 1.85 (s, 2H), 1.59 (p, J = 7.7Hz, 9H), 1.39–1.22 (m, 38H), 0.94–0.80 (m, 24H). The NMR spectrum is shown in Figure 2.

[0189] Synthesis Example A-2: Synthesis of Compound (A-2)

[0190] Compound A-1-6 (195 mg, 0.15 mmol), 5,6-dichloro-3-(dicyanomethylene)indophenone (158 mg, 0.6 mmol), and anhydrous Tol (10 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.2 mL) was added dropwise, followed by the slow addition of acetic anhydride (0.4 mL). The reaction was allowed to proceed at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM = 1:1 (volume ratio) as the eluent. After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 173 mg of compound (A-2), with a yield of 64.5%. NMR data: 1¹H NMR (400MHz, Chloroform-d) δ 9.04 (s, 1H), 8.76 (s, 1H), 7.93 (s, 1H), 7.65 (s, 1H), 7.21 (dd, J = 8.3, 1.9Hz, 4H), 7.14 (d, J = 8.1Hz, 4H), 3.15–2.98 (m, 2H), 2.63–2.48 (m, 4H), 1.85 (q, J = 6.3, 5.7Hz, 1H), 1.50–1.17 (m, 2³H), 0.94–0.77 (m, 1³H). The NMR spectrum is shown in Figure 3.

[0191] Synthesis Example A-3: Synthesis of Compound (A-3):

[0192] Compound A-1-6 (221 mg, 0.17 mmol), a mixture of 5(6)-chloro-3-(dicyanomethylene)indene-1-one (155 mg, 0.68 mmol), and anhydrous Tol (12 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.2 mL) was added dropwise, followed by the slow addition of acetic anhydride (0.4 mL). The reaction was carried out at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM = 1:1 (volume ratio) as the eluent. After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 196 mg of compound (A-3), with a yield of 67.1%. NMR data: 1 ¹H NMR (400MHz, Chloroform-d) δ 9.04 (s, 2H), 8.67–8.57 (m, 2H), 7.85–7.79 (m, 2H), 7.70–7.60 (m, 4H), 7.25–7.17 (m, 8H), 7.14 (d, J = 7.8Hz, 8H), 3.16–2.99 (m, 4H), 2.56 (t, J = 7.9Hz, 8H), 1.85 (q, J = 6.4Hz, 2H), 1.59 (t, J = 7.7Hz, 8H), 1.50–1.18 (m, 42H), 0.96–0.76 (m, 25H). The NMR spectrum is shown in Figure 4.

[0193] Synthesis Example A-4: Synthesis of Compound (A-10):

[0194] Synthesis of compound A-10-1:

[0195] 1-(4-bromophenyl)octane (14.82 g, 55.1 mmol) and anhydrous THF (80 mL) were added to a 250 mL three-necked flask, and the mixture was purged with nitrogen three times. n-BuLi (2.5 M, 22.04 mL, 55.1 mmol) was slowly added dropwise at -78 °C, and the reaction was allowed to proceed for 1 hour. Compound A-1-3 (2.0 g, 2.75 mmol) was dissolved in anhydrous THF (10 mL) and slowly added dropwise to the reaction mixture at -78 °C. The reaction mixture was allowed to return to room temperature and continue reacting for 30 minutes. The reaction solution was slowly poured into 150 mL of water to quench the reaction. The aqueous phase was extracted three times with ethyl acetate. The combined organic phases were dried over anhydrous MgSO4 and excess solvent was removed by vacuum evaporation. Silica gel column chromatography with a PE:DCM eluent ratio of 8:1 (v / v) yielded approximately 2.62 g of compound A-10-1, with a yield of 68.4%. MALDI-TOF-MS: 1392.45.

[0196] Synthesis of compound A-10-2:

[0197] Compound A-10-1 (2.20 g, 1.58 mmol) and glacial acetic acid (30 mL) were added to a three-necked flask. Concentrated sulfuric acid (3.0 mL) was slowly added dropwise to the reaction flask, and the reaction was carried out at room temperature for 1 hour. The reaction mixture was slowly poured into 100 mL of water, and the aqueous phase was extracted three times with ethyl acetate. The organic phases were combined and washed three times with saturated sodium bicarbonate aqueous solution. The combined organic phases were dried over anhydrous MgSO4 and the excess solvent was evaporated under reduced pressure. Silica gel column chromatography was performed with PE:DCM = 4:1 (v / v). The purified compound A-10-2 was approximately 1.67 g, with a yield of 77.9%. MALDI-TOF-MS: 1356.21. Synthesis of compound A-10-3:

[0198] Prepare a dry 50 mL three-necked flask R1. After purging with nitrogen three times, add anhydrous DMF (6.0 mL) and POCl3 (1.5 mL) sequentially into R1. The reaction is exothermic. Allow it to cool to room temperature before use. Prepare another dry 50 mL three-necked flask reactor R2. Add compound A-10-2 (1.50 g, 1.10 mmol) and 1,2-dichloroethane (5 mL) to R2. Purge with nitrogen three times and cool to -10 °C using an ice-salt bath. Remove the reaction solution from R1 using a long needle and slowly add it dropwise to R2 under a -10 °C atmosphere, controlling the reaction temperature to not exceed -5 °C. After the reaction temperature stabilizes, allow it to return to room temperature, then raise the reaction temperature to 60 °C and react for 30 minutes. After cooling the reaction to room temperature, the reaction solution was slowly quenched by adding dropwise to 50 ml of water. The pH was then adjusted to 7 by adding saturated sodium bicarbonate solution. The aqueous phase was extracted three times with dichloromethane. The combined organic phases were dried, and excess solvent was evaporated under reduced pressure. The solution was then purified by silica gel column chromatography with PE:DCM at a ratio of 2:1 (v / v) to obtain approximately 1.23 g of compound A-10-3, with a yield of 79.2%. MALDI-TOF-MS: 1411.76

[0199] Synthesis of compound (A-10):

[0200] Compound A-10-3 (706 mg, 0.5 mmol), 5,6-difluoro-3-(dicyanomethylene)indophenone (345 mg, 1.5 mmol), and anhydrous Tol (10 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.6 mL) was added dropwise, followed by the slow addition of acetic anhydride (1.2 mL). The reaction was carried out at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM = 1:1 (volume ratio) as the eluent. After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 585 mg of compound (A-10), with a yield of 63.7%. MALDI-TOF-MS: 1836.44.

[0201] Synthesis Example A-5: Synthesis of Compound (A-16):

[0202] Synthesis of compound A-16-1:

[0203] 13.62 g (80 mmol) of 3-methoxythiophene [3,2-B]thiophene, 140 mL of toluene, 1.52 g (8 mmol) of p-toluenesulfonic acid monohydrate, and 13 g (100 mmol) of 2-ethylhexanol were added to a 500 mL three-necked flask. The mixture was purged with nitrogen three times, heated to reflux, and reacted overnight. After the reaction was complete, 5% KOH aqueous solution was added to quench the reaction, the pH was adjusted to neutral, and the mixture was extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, and excess solvent was evaporated under reduced pressure. The mixture was then subjected to silica gel column chromatography with PE as the eluent. Approximately 18.72 g of compound A-16-1 was obtained, with a yield of 87.0% and an MS score of 268.97.

[0204] Synthesis of compound A-16-2:

[0205] Take a dry 500mL three-necked flask R1, add 2,2,6,6-tetramethylpiperidine (9.16g, 65mmol) and 150mL anhydrous THF, purge with nitrogen three times, and cool to -78℃. After the temperature stabilizes, slowly add n-BuLi (2.5M; 26.0mL; 65mmol) to the reactor, controlling the reaction temperature to not exceed -78℃; react for 30 minutes. Take another dry 500mL three-necked flask R2, add compound A-16-1 (13.42g, 50mmol) and 150mL anhydrous THF; cool to -78℃. After the temperature stabilizes, slowly add the reaction solution from R1 dropwise, controlling the temperature to not exceed -75℃. After reacting for 2 hours, add tri-n-butyltin chloride (22.75g; 70mmol) to the reactor; remove the heat preservation; allow the reaction to naturally warm to room temperature and react overnight. After the reaction was complete, a saturated potassium fluoride aqueous solution was added to the reaction solution, and the organic phase was extracted three times with ethyl acetate. The organic phases were combined and dried over anhydrous MgSO4. Excess solvent was removed by vacuum evaporation. The mixture was then passed through neutral alumina and eluent PE. Approximately 23.2 g of compound A-16-2 was obtained, with a yield of 83.2% and an MS value of 557.62.

[0206] Synthesis of compound A-16-3:

[0207] Compound A-16-2 (22.3 g; 40 mmol) was dissolved in 250 mL of anhydrous toluene and added to a 500 mL three-necked flask. Diethyl 2,5-dibromoterephthalate (5.06 g; 13.3 mmol) was added. The mixture was stirred, and nitrogen was purged three times. Then, palladium dichloride bis(triphenylphosphine) (1.41 g; 2 mmol) was added. Nitrogen was purged three times, and the mixture was heated to 90 °C. The reaction was allowed to proceed for 30 minutes. After the reaction was complete, the mixture was cooled to room temperature and quenched with water. The mixture was extracted three times with ethyl acetate, and the organic phases were combined and dried over anhydrous MgSO4. Excess solvent was removed by vacuum distillation, and the mixture was subjected to silica gel column chromatography with PE:DCM = 10:1 (v / v). Approximately 7.85 g of compound A-16-3 was obtained, yield 78.2%, MS: 755.24.

[0208] Synthesis of compound A-16-4:

[0209] p-Hexylbromobenzene (24.1 g, 100 mmol) and anhydrous THF (250 mL) were added to a 500 mL three-necked flask, and the mixture was purged with nitrogen three times. n-BuLi (2.5 M; 40 mL, 100 mmol) was slowly added dropwise at -78 °C, and the reaction was allowed to proceed for 1 hour. Compound A-16-3 (7.55 g, 10 mmol) was uniformly dispersed in anhydrous THF (25 mL) and slowly added dropwise to the reaction mixture at -78 °C. After the addition was complete, the mixture was allowed to return to room temperature, and the reaction was allowed to continue for 30 minutes. The reaction solution was slowly poured into 500 mL of water to quench the reaction. The aqueous phase was extracted three times with ethyl acetate. The combined organic phase was dried with anhydrous MgSO4 and the excess solvent was removed by vacuum evaporation. The mixture was then subjected to silica gel column chromatography with PE:DCM = 10:1 (volume ratio) as the eluent. Approximately 9.91 g of compound A-16-4 was obtained, with a yield of 75.5%. MALDI-TOF-MS: 1312.24.

[0210] Synthesis of compound A-16-5:

[0211] Compound A-16-4 (9.51 g, 7.25 mmol) was dissolved in 20 mL of acetic acid and added to a 50 mL three-necked flask. Nitrogen gas was purged three times, and 4 mL of concentrated sulfuric acid was added dropwise to the reactor. The reaction was stopped after 15 minutes. The reaction mixture was poured into 100 mL of water, and the aqueous phase was extracted three times with ethyl acetate. The combined organic phases were washed three times with saturated sodium bicarbonate solution. The combined organic phases were dried over anhydrous MgSO4, and excess solvent was evaporated under reduced pressure. Silica gel column chromatography was performed with PE:DCM = 5:1 (v / v). The purified compound A-16-5 was approximately 6.68 g, yield 72.2%, MALDI-TOF-MS: 1276.32.

[0212] Synthesis of compound A-16-6:

[0213] Prepare a dry 50 mL three-necked flask R1. After purging with nitrogen three times, add anhydrous DMF (15.6 mL) and POCl3 (4 mL) sequentially into R1. The reaction is exothermic. Allow it to cool to room temperature before use. Prepare another dry 250 mL three-necked flask reactor R2. Add compound A-16-5 (6.0 g, 4.70 mmol) and 1,2-dichloroethane (20 mL) to R2. Purge with nitrogen three times and cool to -10 °C using an ice-salt bath. Remove the reaction solution from R1 using a long needle and slowly add it dropwise to R2 under a -10 °C atmosphere, controlling the reaction temperature to not exceed -5 °C. After the reaction temperature stabilizes, allow it to return to room temperature, then raise the reaction temperature to 60 °C and react for 30 minutes. After cooling the reaction to room temperature, the reaction solution was slowly quenched by adding dropwise to 250 mL of water. The pH was then adjusted to 7 by adding saturated sodium bicarbonate solution. The aqueous phase was extracted three times with dichloromethane. The combined organic phases were dried and excess solvent was removed by vacuum evaporation. The solution was then purified by silica gel column chromatography with PE:DCM at a 1:1 (volume ratio) eluent to obtain approximately 5.28 g of compound A-16-6, with a yield of 84.3%. MALDI-TOF-MS: 1332.17.

[0214] Synthesis of compound (A-16):

[0215] Compound A-16-6 (666 mg, 0.50 mmol), 5,6-difluoro-3-(dicyanomethylene)indophenone (345 mg, 1.5 mmol), and anhydrous Tol (10 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.6 mL) was added dropwise, followed by the slow addition of acetic anhydride (1.2 mL). The reaction was carried out at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM = 1:1 (volume ratio) as the eluent. After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 515 mg of compound (A-16), with a yield of 58.7%. NMR data: 1H NMR (400MHz, Chloroform-d) δ 9.18 (s, 2H), 8.49 (dd, J = 10.1, 6.4Hz, 2H), 7.61 (d, J = 8.5Hz, 4H), 7.19 (d, J = 8.1Hz, 8H), 7.14 (d, J = 8.0Hz, 8H), 4.61–4.48 (m, 5H), 2.57 (t, J = 7.9Hz, 10H), 1.99 (d, J = 7.3Hz, 4H), 1.54 (d, J = 41.3Hz, 40H), 1.40–1.16 (m, 65H), 1.04–0.77 (m, 36H). The NMR spectrum is shown in Figure 5.

[0216] Synthesis Example A-6: Synthesis of Compound (A-17)

[0217] Compound A-16-6 (533 mg, 0.4 mmol), 5,6-dichloro-3-(dicyanomethylene)indophenone (316 mg, 1.2 mmol), and anhydrous Tol (10 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.6 mL) was added dropwise, followed by the slow addition of acetic anhydride (1.2 mL). The reaction was allowed to proceed at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM at a ratio of 1:1 (volume). After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 374 mg of compound (A-17), with a yield of 51.3%. MALDI-TOF-MS: 1822.31.

[0218] Synthesis Example A-7: Synthesis of Compound (A-21):

[0219] Compound A-16-6 (533 mg, 0.4 mmol), a mixture of 5(6)-methyl-3-(dicyanomethylene)indene-1-one (250 mg, 1.2 mmol), and anhydrous Tol (10 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.6 mL) was added dropwise, followed by the slow addition of acetic anhydride (1.2 mL). The reaction was allowed to proceed at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM = 1:1 (volume ratio) as the eluent. After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 517 mg of compound (A-21), with a yield of 75.5%. MALDI-TOF-MS: 1712.31.

[0220] Synthesis Example A-8: Synthesis of Compound (A-28):

[0221] Compound A-10-3 (500 mg, 0.354 mmol), 2-(6,7-difluoro-3-oxo-2,3-dihydro-1H-cyclopenta[B]naphth-1-yl)malononitrile (298 mg, 1.06 mmol), and anhydrous Tol (10 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.3 mL) was added dropwise, followed by the slow addition of acetic anhydride (0.6 mL). The reaction was carried out at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM = 1:1 (volume ratio) as the eluent. After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 501 mg of compound (A-28), with a yield of 73.1%. MALDI-TOF-MS: 1936.58.

[0222] Synthesis Example A-9: Synthesis of Compound (A-31):

[0223] Compound A-16-6 (800 mg, 0.6 mmol), 2-(6,7-difluoro-3-oxo-2,3-dihydro-1H-cyclopenta[B]naphth-1-yl)malonidon (504 mg, 1.8 mmol), and anhydrous Tol (10 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.6 mL) was added dropwise, followed by the slow addition of acetic anhydride (1.2 mL). The reaction was allowed to proceed at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM = 1:1 (volume ratio) as the eluent. After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 793 mg of compound (A-31), with a yield of 71.2%. MALDI-TOF-MS: 1856.45.

[0224] Synthesis Example A-10: Synthesis of compound (A-32):

[0225] Compound A-16-6 (413 mg, 0.31 mmol), 2-(6,7-dichloro-3-oxo-2,3-dihydro-1H-cyclopentadiene[B]naphthalene-1-ylidene)malonitrile (291 mg, 0.93 mmol), and anhydrous Tol (10 mL) were added to a 50 mL three-necked flask. After purging with nitrogen three times, boron trifluoride diethyl ether (0.4 mL) was added dropwise, followed by the slow addition of acetic anhydride (0.8 mL). The reaction was allowed to proceed at room temperature for 1 hour. The reaction solution was concentrated to approximately 2 mL and added dropwise to 100 mL of methanol, precipitating a solid. The solid was filtered to obtain the crude product. The crude product was subjected to silica gel column chromatography with PE:DCM = 1:1 (volume ratio) as the eluent. After concentration, the crude product was added dropwise to 150 mL of methanol, precipitating a solid. The solid was filtered and dried to obtain approximately 458 mg of compound (A-32), with a yield of 76.9%. MALDI-TOF-MS: 1922.28.

[0226] Organic photovoltaic (OPV) device examples

[0227] Referring to Figure 1, an organic photovoltaic cell comprises a substrate, an anode, an anode buffer layer, a photoactive layer, a cathode buffer layer, and a cathode layer stacked sequentially. The materials of the anode, anode buffer layer, photoactive layer, cathode buffer layer, and cathode layer are, in sequence: Indium Tin Oxide (ITO) / PEDOT:PSS / Photoactive Layer Material / PDINN / Ag.

[0228] The fabrication steps of device example A-1 are as follows:

[0229] 1) ITO substrate cleaning:

[0230] Clean the ITO conductive glass with detergent, rinse it thoroughly, and then ultrasonically clean it for 15 minutes with deionized water, acetone, and isopropanol. After that, dry it with nitrogen and treat it in a plasma cleaner for 5 minutes to further clean the surface and improve wettability.

[0231] 2) Preparation of the anode buffer layer

[0232] PEDOT:PSS (Clevios) in the air TM PVP Al 4083 was uniformly spin-coated onto ITO at a spin speed of 3000 rpm for 30 s, and then dried at 150 °C for 15 min to obtain an anode buffer layer.

[0233] 3) Preparation of photoactive layer

[0234] In a glove box (inert gas atmosphere), the photoactive layer material solution is uniformly spin-coated onto the anode buffer layer at a speed of 1800-4000 rpm to obtain an active material layer with a total thickness of about 100 nm; wherein the donor material in the photoactive layer material solution is selected from polymer PTQ10; the acceptor material is selected from compound (1); polymer PTQ10: compound (A-1) is added to chloroform solution at a mass ratio of 1:1, with a total concentration of 16 mg / mL.

[0235] 4) Preparation of cathode buffer layer

[0236] The cathode buffer layer material PDINN solution (PDINN dissolved in methanol to prepare a solution with a concentration of 1 mg / mL) was uniformly spin-coated onto the photoactive layer at a spin speed of 3000 rpm for 30 s to obtain the cathode buffer layer.

[0237] 5) Cathode layer preparation

[0238] In high vacuum (1×10) -6 Ag is deposited onto the cathode buffer layer in millibars to form a cathode layer with a thickness of approximately 100 nm.

[0239] 6) Packaging

[0240] The device is encapsulated in a nitrogen glove box using UV-cured resin.

[0241] Device Example A-2

[0242] The preparation method of device embodiment A-2 is the same as that of device embodiment A-1, except that the photoactive layer acceptor material is different. Specifically, the acceptor material compound (A-1) is replaced with compound (A-2).

[0243] Device Example A-3

[0244] The preparation method of device example A-3 is the same as that of device example A-1, except that the photoactive layer acceptor material is different. Specifically, the acceptor material compound (A-1) is replaced with compound (A-3).

[0245] Device Example A-4

[0246] The preparation method of device example A-4 is the same as that of device example A-1, except that the photoactive layer acceptor material is different. Specifically, the acceptor material compound (A-1) is replaced with compound (A-16).

[0247] Device Example A-5

[0248] The preparation method of device example A-5 is the same as that of device example A-1, except that the photoactive layer acceptor material is different. Specifically, the acceptor material compound (A-1) is replaced with compound (A-17).

[0249] Device Example A-6

[0250] The preparation method of device example A-6 is the same as that of device example A-1, except that the photoactive layer acceptor material is different. Specifically, the acceptor material compound (A-1) is replaced with compound (A-31).

[0251] Comparative Example A-1

[0252] The preparation method of the device comparative example A-1 is the same as that of the device example A-1, the difference being the selection of the photoactive layer acceptor material. Specifically, the acceptor material compound (A-1) is replaced with compound (A-Ref-1).

[0253] Comparative Example A-2

[0254] The preparation method of the device comparative example A-2 is the same as that of the device example A-1, the difference being the selection of the photoactive layer acceptor material. Specifically, the acceptor material compound (A-1) is replaced with compound (A-Ref-2).

[0255] Comparative Examples of Devices A-3

[0256] The preparation method of the device comparative example A-3 is the same as that of the device example A-1, the difference being the selection of the photoactive layer acceptor material. Specifically, the acceptor material compound (A-1) is replaced with compound (A-Ref-3).

[0257] The structural formulas of compounds (A-Ref-1), (A-Ref-2), and (A-Ref-3) are as follows:

[0258] The prepared organic photovoltaic cells were tested under indoor light. The cell current-voltage curves were tested under a 3000K LED light source (1000 lux) simulator, and the photoelectric conversion efficiency was calculated, as shown in Table 1.

[0259] Table 1

[0260] According to the data in Table 1, the indoor photovoltaic device of Example A-1-6, prepared using the heptaneously fused heterocyclic organic compound of general formula (I) as the acceptor material, exhibits significantly better performance than the device of Comparative Example A-1-3. This is because the present application adjusts its molecular structure by introducing R into general formula (I).1 And R 1 Selected from branched alkyl or alkoxy groups, this improves the molecular morphology and stacking, enhancing π-π stacking and charge transport properties in the film. Furthermore, it fine-tunes the molecular energy levels and improves solubility, resulting in more uniform and stable films after blending with donor materials, and enhancing exciton dissociation and transport.

[0261] The data in Table 1 shows that when R 1 When selected from branched alkoxy groups, the devices all exhibited excellent photoelectric efficiency (exceeding 29%), because: compared to R... 1 Selected from branched alkyl groups, R 1 When compounds are selected from branched alkoxy groups, the band gap widens, leading to an increase in the LUMO energy level, which in turn increases the open-circuit voltage (Voc) of the device.

[0262] As can be seen from the device examples, when the heptathione fused heterocyclic organic compound described in this application is used as an acceptor material in indoor photovoltaic devices, its indoor photoelectric conversion efficiency is greatly improved, exceeding 30%, which meets the product application requirements of indoor photovoltaic devices and will be applied in the commercialization of indoor organic photovoltaics.

[0263] Example Part 2: Synthesis of heptane-fused heterocyclic organic compounds of general formula (I') and oligomers of general formula (III), and their application in organic photovoltaic devices.

[0264] Synthesis Example B-1: Synthesis of Compound (B-1)

[0265] Synthesis of compound B-1-3:

[0266] Accurately weigh compound B-1-1 (15.1 g, 60.0 mmol) and dissolve it in tetrahydrofuran (THF, 300 mL). Purge with nitrogen three times, cool the solution to -78 °C, and hold at this temperature for 30 minutes. Then, add n-butyllithium (2.5 M, 26.4 mL, 66.0 mmol) dropwise. After half an hour, add ZnCl2 (1.0 M, 60.0 mL, 60.0 mmol) dropwise. Slowly restore the solution to room temperature, and then add compound B-1-2 (7.60 g, 20.0 mmol), Pd(dppf)Cl2 (100 mg, 0.14 mmol), and CuI (100 mg, 0.53 mmol) in sequence. Stir for 3 hours. After the reaction was completed, the reaction solution was poured into 500 mL of water and extracted three times with ethyl acetate. The organic phases were combined, dried with anhydrous sodium sulfate, concentrated under vacuum, and purified by column chromatography (petroleum ether: dichloromethane = 2:1, v / v) to give about 13.67 g of compound B-1-3, yield: 94.6%, MS: 723.58.

[0267] Synthesis of compound B-1-4:

[0268] Compound B-1-3 (10.85 g, 15.0 mmol) was accurately weighed and added to a 500 mL three-necked flask. It was dissolved in 1,4-dioxane (180 mL), and sodium hydroxide (25%, 48 mL, 300 mmol) and tetraethylammonium hydroxide (25%, 10 mL) were added. The reaction was carried out at 110 °C for 5 h. After the reaction was complete, the mixture was cooled to room temperature and poured into 500 mL of water. The pH was adjusted to 1–2 with concentrated hydrochloric acid, and the mixture was extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, concentrated under vacuum, and the residue was slurried with petroleum ether and filtered to give approximately 9.62 g of compound B-1-4 (yield: 96.2%, MS: 666.74).

[0269] Synthesis of compound B-1-5:

[0270] Accurately weigh 6.67 g (10.0 mmol) of compound B-1-4 into a 250 mL three-necked flask, dissolve in dichloromethane (180 mL), add two drops of N,N-dimethylformamide (DMF) at room temperature, and then slowly add oxaloyl chloride (8.5 mL, 100 mmol) while stirring. After 3 hours, remove the solvent and excess oxaloyl chloride under reduced pressure, dissolve again in dichloromethane, add SnCl4 at room temperature, and stir for 3 hours. Cool to room temperature, pour the reaction solution into 500 mL of ethanol, precipitate a solid, filter, and wash the residual solid several times with dichloromethane. The final yield is approximately 4.41 g of compound B-1-5, yield: 69.9%, MS: 631.02.

[0271] Synthesis of compound B-1-6:

[0272] Accurately weigh compound B-1-5 (3.15 g, 5.00 mmol), 4-dimethylaminopyridine (30 g), o-xylene (15 mL), hydrazine hydrate (10 mL), and diethylene glycol (15 mL) into a 250 mL three-necked flask. Purge with nitrogen three times and stir at 150 °C for 6 hours. Cool to room temperature, pour the reaction mixture into 500 mL of water, and extract three times with ethyl acetate. Combine the organic phases, dry with anhydrous sodium sulfate, concentrate under vacuum, and slurry the residue with petroleum ether. Filter to give approximately 1.26 g of compound B-1-6, yield: 41.8%, MS: 602.35.

[0273] Synthesis of compound B-1-7:

[0274] Accurately weigh compound B-1-6 (1.20 g, 2.00 mmol) and isooctane bromo (3.86 g, 20.0 mmol) into a 250 mL three-necked flask. Add dimethyl sulfoxide (DMSO, 50 mL) and THF (50 mL). Dissolve potassium tert-butoxide (2.24 g, 20 mmol) in DMSO (50 mL) and slowly add it dropwise to the reaction system. Stir at room temperature for 2 hours. Pour the reaction solution into 500 mL of water and extract three times with ethyl acetate. Combine the organic phases, dry with anhydrous sodium sulfate, concentrate under vacuum, and purify by column chromatography (petroleum ether:dichloromethane = 2:1, v / v) to give approximately 1.70 g of compound B-1-7, yield: 80.7%, MALDI-TOF-MS: 1051.88.

[0275] Synthesis of compound B-1-8:

[0276] Accurately weigh 1.58 g (1.50 mmol) of compound B-1-7 into a 100 mL three-necked flask, dissolve it in 30 mL of 1,2-dichloroethane, and then add 2 mL of DMF and 3 mL of POCl3 sequentially. Stir at 80 °C for 2 hours. After the reaction is complete, cool to room temperature, pour the reaction solution into 500 mL of potassium carbonate aqueous solution (15 mg / mL), add 5 mL of triethylamine and stir moderately, then extract three times with ethyl acetate. Combine the organic phases, dry with anhydrous sodium sulfate, concentrate under vacuum, and purify by column chromatography (petroleum ether:dichloromethane = 1:2, v / v) to give approximately 1.39 g of compound B-1-8, yield: 83.7%, MALDI-TOF-MS: 1107.64.

[0277] Synthesis of compound (B-1):

[0278] Accurately weigh compound B-1-8 (1.11 g, 1.00 mmol) and compound B-1-9 (0.81 g, 3.50 mmol) into a 100 mL three-necked flask, followed by the addition of THF (30 mL) and pyridine (5 mL). Purge with nitrogen three times and stir at 50 °C for 6 hours. Cool to room temperature, pour the reaction mixture into 500 mL of methanol, precipitating a solid. Filter the solid, and purify the remaining solid by column chromatography (petroleum ether:dichloromethane = 1:2, v / v) to obtain approximately 1.19 g of compound (B-1), yield: 77.7%. The 1H NMR spectrum is shown in Figure 6.

[0279] Synthesis Example B-2: Synthesis of Compound (B-5)

[0280] Synthesis of compound B-2-3:

[0281] Accurately weigh compound B-2-1 (9.94 g, 30.0 mmol) and dissolve it in THF (300 mL). Purge with nitrogen three times and cool the solution to -78 °C, holding it at this temperature for 30 minutes. Then, add lithium diisopropylamino (1.0 M, 33 mL, 33.0 mmol) dropwise. After half an hour, add ZnCl2 (1.0 M, 30.0 mL, 30.0 mmol) dropwise. Transfer the solution to room temperature, then add compound B-2-2 (4.88 g, 10.0 mmol), Pd(dppf)Cl2 (100 mg, 0.14 mmol), and CuI (100 mg, 0.53 mmol) sequentially. Stir for 3 hours. After the reaction was completed, the reaction solution was poured into 500 mL of water and extracted three times with ethyl acetate. The organic phases were combined, dried over anhydrous sodium sulfate, concentrated under vacuum, and purified by column chromatography (petroleum ether: dichloromethane = 2:1, volume ratio) to give about 5.13 g of compound B-2-3, yield: 57.4%, MS: 894.22.

[0282] Synthesis of compound B-2-4:

[0283] Accurately weigh compound B-2-3 (4.47 g, 5.00 mmol) and dissolve it in THF (200 mL). Purge with nitrogen three times, cool the solution to -78 °C, and maintain this temperature for 30 minutes. Then, add n-butyllithium (2.5 M, 8.8 mL, 22.0 mmol) dropwise. After half an hour, add diisooctyldichlorosilane (3.56 g, 11.0 mmol), transfer to room temperature, and stir for 1 hour. After the reaction is complete, pour the reaction solution into 500 mL of water, extract three times with ethyl acetate, combine the organic phases, dry with anhydrous sodium sulfate, concentrate under vacuum, and purify by column chromatography (petroleum ether:dichloromethane = 2:1, v / v) to give approximately 2.44 g of compound B-2-4, yield: 45.1%, MALDI-TOF-MS: 1082.86.

[0284] Synthesis of compound B-2-5:

[0285] Compound B-2-4 (1.62 g, 1.50 mmol) was accurately weighed and added to a 100 mL three-necked flask. The subsequent synthesis steps were the same as those for compound B-1-8. The final yield of compound B-2-5 was approximately 1.34 g, yield: 78.4%, MALDI-TOF-MS: 1139.59.

[0286] Synthesis of compound (B-5):

[0287] Accurately weigh compound B-2-5 (1.14 g, 1.00 mmol) and compound B-1-9 (0.81 g, 3.50 mmol) and add them to a 100 mL three-necked flask. The subsequent synthesis steps are the same as those for compound (B-1). Finally, about 1.16 g of compound (B-5) was obtained, with a yield of 74.2% and a MALDI-TOF-MS value of 1564.17.

[0288] Synthesis Example B-3: Synthesis of Compound (B-10)

[0289] Synthesis of compound B-3-2:

[0290] Accurately weigh compound B-3-1 (12.5 g, 30.0 mmol), 6-ethylhexyl-(thieno[3,2-b]thieno-2-yl)tributyltin (40.6 g, 75 mmol), tris(dimethylacetone)dipalladium (100 mg), and tris(o-tolyl)phosphine (130 mg) into a 500 mL three-necked flask, dissolve in toluene (200 mL), and then heat to 110 °C and react for 12 h. After the reaction is complete, cool to room temperature, concentrate the reaction solution under vacuum, and purify by column chromatography (petroleum ether:dichloromethane = 2:1, v / v) to give approximately 21.36 g of compound B-3-2, yield: 93.8%, MS: 759.12.

[0291] Synthesis of compound B-3-3:

[0292] The synthesis procedure was the same as that of compound B-1-4, except that compound B-1-3 was replaced with an equimolar amount of compound B-3-2, resulting in approximately 10.05 g of compound B-3-3. Yield: 95.4%, MS: 702.54.

[0293] Synthesis of compound B-3-4:

[0294] The synthesis procedure was the same as that of compound B-1-5, except that compound B-1-4 was replaced with an equimolar amount of compound B-3-3, resulting in approximately 3.57 g of compound B-3-4. Yield: 53.5%, MS: 666.80.

[0295] Synthesis of compound B-3-5:

[0296] The synthesis procedure was the same as that for compound B-1-6, except that compound B-1-5 was replaced with an equimolar amount of compound B-3-4, resulting in approximately 1.34 g of compound B-3-5. Yield: 42.0%, MS: 638.79.

[0297] Synthesis of compound B-3-6:

[0298] The synthesis procedure was the same as that of compound B-1-7, except that compound B-1-6 was replaced with an equimolar amount of compound B-3-5. The final yield of compound B-3-6 was approximately 1.73 g, with a yield of 79.5% and a MALDI-TOF-MS value of 1087.42.

[0299] Synthesis of compound B-3-7:

[0300] The synthesis procedure was the same as that of compound B-1-8, except that compound B-1-7 was replaced with an equimolar amount of compound B-3-6, resulting in approximately 1.41 g of compound B-3-7, yield: 82.2%, MALDI-TOF-MS: 1143.87.

[0301] Synthesis of compound (B-10):

[0302] The synthesis procedure was the same as that for compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-3-7, ultimately yielding approximately 1.25 g of compound (B-10), with a yield of 79.7%. The 1H NMR spectrum is shown in Figure 7.

[0303] Synthesis Example B-4: Synthesis of Compound (B-19)

[0304] Synthesis of compound B-4-2:

[0305] The synthesis procedure was the same as that of compound B-1-3, except that compound B-1-1 was replaced with an equimolar amount of compound B-4-1, resulting in approximately 15.18 g of compound B-4-2. Yield: 90.9%, MS: 835.32.

[0306] Synthesis of compound B-4-3:

[0307] The synthesis procedure was the same as that of compound B-1-4, except that compound B-1-3 was replaced with an equimolar amount of compound B-4-2. The final yield of compound B-4-3 was approximately 11.01 g, yield: 94.2%, MS: 779.28.

[0308] Synthesis of compound B-4-4:

[0309] The synthesis procedure was the same as that of compound B-1-5, except that compound B-1-4 was replaced with an equimolar amount of compound B-4-3, resulting in approximately 5.26 g of compound B-4-4. Yield: 70.8%, MS: 742.93.

[0310] Synthesis of compound B-4-5:

[0311] The synthesis procedure was the same as that of compound B-1-6, except that compound B-1-5 was replaced with an equimolar amount of compound B-4-4, resulting in approximately 1.47 g of compound B-4-5, yield: 41.1%, MS: 715.14.

[0312] Synthesis of compound B-4-6:

[0313] The synthesis procedure was the same as that of compound B-1-7, except that compound B-1-6 was replaced with an equimolar amount of compound B-4-5, and bromoisooctane was replaced with an equimolar amount of 5-(bromomethyl)undecane. The final yield was approximately 2.30 g of compound B-4-6, with a yield of 82.7% and a MALDI-TOF-MS score of 1388.67.

[0314] Synthesis of compound B-4-7:

[0315] The synthesis procedure was the same as that of compound B-1-8, except that compound B-1-7 was replaced with an equimolar amount of compound B-4-6, resulting in approximately 1.68 g of compound B-4-7, yield: 77.5%, MALDI-TOF-MS: 1444.31.

[0316] Synthesis of compound (B-19):

[0317] The synthesis procedure was the same as that for compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-4-7, ultimately yielding approximately 1.39 g of compound (B-19), with a yield of 74.4%. The 1H NMR spectrum is shown in Figure 8.

[0318] Synthesis Example B-5: Synthesis of Compound (B-23)

[0319] Synthesis of compound B-5-2:

[0320] The synthesis procedure was the same as that of compound B-1-3, except that compound B-1-1 was replaced with an equimolar amount of compound B-5-1, resulting in approximately 14.85 g of compound B-5-2. Yield: 90.8%, MS: 817.46.

[0321] Synthesis of compound B-5-3:

[0322] The synthesis procedure was the same as that of compound B-1-4, except that compound B-1-3 was replaced with an equimolar amount of compound B-5-2, and the final yield of compound B-5-3 was approximately 10.17 g, yield: 89.0%, MS: 761.43.

[0323] Synthesis of compound B-5-4:

[0324] The synthesis procedure was the same as that of compound B-1-5, except that compound B-1-4 was replaced with an equimolar amount of compound B-5-3, resulting in approximately 5.05 g of compound B-5-4. Yield: 69.6%, MS: 725.29.

[0325] Synthesis of compound B-5-5:

[0326] The synthesis procedure was the same as that for compound B-1-6, except that compound B-1-5 was replaced with an equimolar amount of compound B-5-4, resulting in approximately 1.42 g of compound B-5-5, yield: 40.7%, MS: 697.65.

[0327] Synthesis of compound B-5-6:

[0328] The synthesis procedure was the same as that of compound B-1-7, except that compound B-1-6 was replaced with an equimolar amount of compound B-5-5. The final yield was approximately 1.79 g of compound B-5-6, with a yield of 78.1% and a MALDI-TOF-MS value of 1145.93.

[0329] Synthesis of compound B-5-7:

[0330] The synthesis procedure was the same as that of compound B-1-8, except that compound B-1-7 was replaced with an equimolar amount of compound B-5-6. The final yield was approximately 1.44 g of compound B-5-7, with a yield of 79.9% and a MALDI-TOF-MS result of 1202.17.

[0331] Synthesis of compound (B-23):

[0332] The synthesis procedure was the same as that of compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-5-7, and compound B-1-9 was replaced with an equimolar amount of compound B-5-8. The final product was approximately 1.29 g of compound (B-23), with a yield of 76.3% and a MALDI-TOF-MS value of 1691.66.

[0333] Synthesis Example B-6: Synthesis of Compound (B-25)

[0334] Synthesis of compound B-6-1:

[0335] The synthesis steps were the same as those for compound B-1-7, except that bromoisooctane was replaced with an equimolar amount of 1-((5-bromomethyl)heptyl)benzene, finally yielding approximately 2.07 g of compound B-6-1, yield: 76.4%, MALDI-TOF-MS: 1355.42.

[0336] Synthesis of compound B-6-2:

[0337] The synthesis procedure was the same as that of compound B-1-8, except that compound B-1-7 was replaced with an equimolar amount of compound B-6-1, resulting in approximately 1.69 g of compound B-6-2, yield: 79.8%, MALDI-TOF-MS: 1412.13.

[0338] Synthesis of compound (B-25):

[0339] The synthesis procedure was the same as that for compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-6-2, resulting in approximately 1.36 g of compound (B-25), with a yield of 74.1%. The 1H NMR spectrum is shown in Figure 9.

[0340] Synthesis Example B-7: Synthesis of Compound (B-33)

[0341] Synthesis of compound B-7-2:

[0342] The synthesis procedure was the same as that for compound B-3-2, except that compound B-3-1 was replaced with an equimolar amount of compound B-7-1. The final yield of compound B-7-2 was approximately 20.22 g, yield: 89.7%, MS: 751.04.

[0343] Synthesis of compound B-7-3:

[0344] The synthesis procedure was the same as that of compound B-1-4, except that compound B-1-3 was replaced with an equimolar amount of compound B-7-2, resulting in approximately 9.68 g of compound B-7-3, yield: 92.9%, MS: 694.65.

[0345] Synthesis of compound B-7-4:

[0346] The synthesis procedure was the same as that of compound B-1-5, except that compound B-1-4 was replaced with an equimolar amount of compound B-7-3, resulting in approximately 3.31 g of compound B-7-4. Yield: 50.2%, MS: 658.92.

[0347] Synthesis of compound B-7-5:

[0348] The synthesis procedure was the same as that of compound B-1-6, except that compound B-1-5 was replaced with an equimolar amount of compound B-7-4, resulting in approximately 1.32 g of compound B-7-5, yield: 41.8%, MS: 630.45.

[0349] Synthesis of compound B-7-6:

[0350] The synthesis procedure was the same as that of compound B-1-7, except that compound B-1-6 was replaced with an equimolar amount of compound B-7-5, and bromoisooctane was replaced with an equimolar amount of 1-((5-bromomethyl)heptyl)benzene. The final yield was approximately 2.21 g of compound B-7-6, with a yield of 79.8% and a MALDI-TOF-MS value of 1383.89.

[0351] Synthesis of compound B-7-7:

[0352] The synthesis procedure was the same as that of compound B-1-8, except that compound B-1-7 was replaced with an equimolar amount of compound B-7-6, resulting in approximately 1.63 g of compound B-7-7, yield: 75.4%, MALDI-TOF-MS: 1440.73.

[0353] Synthesis of compound (B-33):

[0354] The synthesis procedure was the same as that of compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-7-7, and compound B-1-9 was replaced with an equimolar amount of compound B-5-8. The final product was approximately 1.48 g of compound (B-33), with a yield of 76.7% and a MALDI-TOF-MS value of 1930.57.

[0355] Synthesis Example B-8: Synthesis of Compound (B-37)

[0356] Synthesis of compound B-8-1:

[0357] The synthesis procedure was the same as that of compound B-1-7, except that bromoisooctane was replaced with an equimolar amount of 6-bromohexane. The final yield of compound B-8-1 was approximately 1.97 g, with a yield of 79.2% and a MALDI-TOF-MS value of 1244.22.

[0358] Synthesis of compound B-8-2:

[0359] The synthesis procedure was the same as that of compound B-1-8, except that compound B-1-7 was replaced with an equimolar amount of compound B-8-1, resulting in approximately 1.64 g of compound B-8-2, yield: 84.1%, MALDI-TOF-MS: 1299.58.

[0360] Synthesis of compound (B-37):

[0361] The synthesis procedure was the same as that for compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-8-2, ultimately yielding approximately 1.32 g of compound (B-37), with a yield of 76.6%. The 1H NMR spectrum is shown in Figure 10.

[0362] Synthesis Example B-9: Synthesis of Compound (B-44)

[0363] The synthesis procedure was the same as that of compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-4-7, and compound B-1-9 was replaced with an equimolar amount of compound B-9-1. The final product was approximately 1.33 g of compound (B-44), with a yield of 67.5% and a MALDI-TOF-MS value of 1969.05.

[0364] Synthesis Example B-10: Synthesis of Compound (B-49)

[0365] The synthesis procedure was the same as that of compound (B-1), except that compound B-1-9 was replaced with an equimolar amount of compound B-10-1, and the final product (B-49) was about 1.15 g, with a yield of 74.6% and a MALDI-TOF-MS value of 1540.67.

[0366] Synthesis Example B-11: Synthesis of Compound (B-59)

[0367] The synthesis procedure was the same as that for compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-8-2, and compound B-1-9 was replaced with an equimolar amount of compound B-10-1. The final product was approximately 1.39 g of compound (B-59), with a yield of 80.2%. The 1H NMR spectrum is shown in Figure 11.

[0368] Synthesis Example B-12: Synthesis of Compound (B-63)

[0369] Synthesis of compound B-12-1:

[0370] The synthesis steps were the same as those for compound B-1-7, except that bromoisooctane was replaced with an equimolar amount of 1-((5-bromomethyl)heptyl)fluorobenzene, finally yielding approximately 2.25 g of compound B-12-1, yield: 78.8%, MALDI-TOF-MS: 1428.18.

[0371] Synthesis of compound B-12-2:

[0372] The synthesis procedure was the same as that of compound B-1-8, except that compound B-1-7 was replaced with an equimolar amount of compound B-12-1, resulting in approximately 1.68 g of compound B-12-2. Yield: 75.5%, MALDI-TOF-MS: 1484.34.

[0373] Synthesis of compound (B-63):

[0374] The synthesis procedure was the same as that of compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-12-2, and the final product (B-63) was approximately 1.43 g, yield: 74.9%, MALDI-TOF-MS: 1907.91.

[0375] Synthesis Example B-13: Synthesis of Compound (B-68)

[0376] Synthesis of compound B-13-1:

[0377] The synthesis steps were the same as those for compound B-1-7, except that bromoisooctane was replaced with an equimolar amount of 1-((5-bromomethyl)heptyl)thiophene, finally yielding approximately 2.18 g of compound B-13-1, yield: 79.0%, MALDI-TOF-MS: 1380.36.

[0378] Synthesis of compound B-13-2:

[0379] The synthesis procedure was the same as that of compound B-1-8, except that compound B-1-7 was replaced with an equimolar amount of compound B-13-1, resulting in approximately 1.73 g of compound B-13-2. Yield: 80.3%, MALDI-TOF-MS: 1435.82.

[0380] Synthesis of compound (B-68):

[0381] The synthesis procedure was the same as that of compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-13-2, and the final product (B-68) was approximately 1.46 g, yield: 78.5%, MALDI-TOF-MS: 1860.23.

[0382] Synthesis Example B-14: Synthesis of Compound (B-87)

[0383] Synthesis of compound B-14-2:

[0384] The synthesis procedure was the same as that of compound B-1-7, except that isooctane bromo was replaced with an equimolar amount of compound B-14-1, resulting in approximately 2.35 g of compound B-14-2. Yield: 81.3%, MALDI-TOF-MS: 1444.78.

[0385] Synthesis of compound B-14-3:

[0386] The synthesis procedure was the same as that of compound B-1-8, except that compound B-1-7 was replaced with an equimolar amount of compound B-14-2, resulting in approximately 1.75 g of compound B-14-3. Yield: 77.9%, MALDI-TOF-MS: 1500.49.

[0387] Synthesis of compound (B-87):

[0388] The synthesis procedure was the same as that for compound (B-1), except that compound B-1-8 was replaced with an equimolar amount of compound B-14-3, resulting in approximately 1.53 g of compound (B-87), with a yield of 79.5%. The 1H NMR spectrum is shown in Figure 12.

[0389] Synthesis Example B-15: Synthesis of Compound (B-92)

[0390] Synthesis of compound B-15-1:

[0391] Accurately weigh compound B-4-7 (2.89 g, 2.00 mmol) and compound B-1-9 (0.55 g, 2.40 mmol) into a 100 mL three-necked flask, followed by tetrahydrofuran (45 mL) and pyridine (8 mL). Purge with nitrogen three times and stir at 50 °C for 2 hours. Cool to room temperature, pour the reaction mixture into 500 mL of methanol, and precipitate a solid, which is then filtered. Remove the solvent from the collected filtrate under reduced pressure, and then purify by column chromatography (petroleum ether:dichloromethane = 1:2, v / v) to give approximately 1.17 g of compound B-15-1, yield: 35.4%, MALDI-TOF-MS: 1656.20.

[0392] Synthesis of compound B-15-3:

[0393] Accurately weigh compound B-15-1 (500 mg, 0.30 mmol) and compound B-15-2 (0.175 g, 0.60 mmol), add them to a 100 mL three-necked flask, then add tetrahydrofuran (30 mL) and pyridine (5 mL). Purge with nitrogen three times, and stir at 50 °C for 6 hours. Cool to room temperature, pour the reaction solution into 500 mL of methanol, precipitate the solid, filter, and purify the remaining solid by column chromatography (petroleum ether: dichloromethane = 1:2, v / v) to give approximately 495 mg of compound B-15-3, yield: 85.5%, MALDI-TOF-MS: 1930.36.

[0394] Synthesis of compound (B-92):

[0395] Accurately weigh compound B-15-3 (0.483 g, 0.25 mmol), trans-1,2-bis(tributyltin)ethylene (0.061 g, 0.10 mmol), and tetra(triphenylphosphine)palladium (20 mg) into a 25 mL three-necked flask. Dissolve the precipitate in toluene (50 mL) and then heat to 110 °C for 3 h. After the reaction is complete, cool to room temperature and pour the reaction solution into 500 mL of methanol. The solid precipitates, is filtered, and the remaining solid is purified by column chromatography (petroleum ether:dichloromethane = 1:2, v / v) to give approximately 278 mg of compound (B-92), yield: 74.6%, MALDI-TOF-MS: 3725.11.

[0396] Synthesis Example B-16: Synthesis of Compound (B-95)

[0397] Synthesis of compound B-16-2:

[0398] The synthesis procedure was the same as that of compound B-15-3, except that compound B-15-2 was replaced with an equimolar amount of compound B-16-1, and the final yield was approximately 498 mg of compound B-16-2, with a yield of 86.8% and a MALDI-TOF-MS result of 1911.80.

[0399] Synthesis of compound (B-95):

[0400] The synthesis procedure was the same as that of compound (B-92), except that compound B-15-3 was replaced with an equimolar amount of compound B-16-2, and trans-1,2-bis(tributyltin)ethylene was replaced with an equimolar amount of 2,5-bis(tributyltin)thiophene. The final product was approximately 271 mg of compound (B-95), yield: 72.3%, MALDI-TOF-MS: 3745.59.

[0401] Synthesis Example B-17: Synthesis of Compound (B-97)

[0402] The synthesis procedure was the same as that of compound (B-92), except that trans-1,2-bis(tributyltin)ethylene was replaced with an equimolar amount of 2,5-bis(tributyltin)thiophene, and the final product (B-97) was approximately 303 mg, yield: 80.1%, MALDI-TOF-MS: 3781.78.

[0403] Examples of Photoactive Layer Thin Film Preparation and Characterization

[0404] Example B-1 of Photoactive Layer Thin Film Preparation

[0405] A conductive glass containing ITO is provided, and a photoactive layer solution is uniformly spin-coated onto the ITO layer at a rotation speed of 1800-4000 rpm to obtain a photoactive layer film with a total thickness of approximately 110 nm.

[0406] The photoactive layer solution was prepared by dissolving the active layer donor material polymer PM7 and the active layer acceptor material compound (B-1) in the organic solvent o-xylene at a mass ratio of 1:1.2, with a total concentration of 16.5 mg / mL.

[0407] The preparation method of photoactive layer thin film preparation example B-2 is the same as that of photoactive layer thin film preparation example B-1, except that the active layer acceptor material compound (B-1) is replaced with compound (B-87).

[0408] Comparative Example B-1 for the Preparation of Photoactive Layer Thin Films

[0409] The preparation method is the same as in Example B-1 of the preparation of photoactive layer thin film, except that the active layer acceptor material compound (B-1) is replaced with compound (B-Ref1).

[0410] Figure 14 shows the morphology of the photoactive layer films prepared in Examples B-1, B-2 and Comparative Example B-1 under a step sampler microscope. As can be seen from Figure 14, the photoactive layer films prepared in Examples B-1 and B-2 have very clean film surfaces, while the photoactive layer film prepared in Comparative Example B-1 has small particles on its film surface.

[0411] OPV device module fabrication (effective module area is 2.025 cm²) 2 (Number of sub-cells is 5) and characterization

[0412] The module structure is shown in Figure 15, including a substrate 10, a cathode 101, a cathode buffer layer 102, a photoactive layer 103, an anode buffer layer 104, and an anode 105 stacked sequentially; the materials are, in order: indium tin oxide (ITO) / PEI-Zn / photoactive layer material / MoO3 / Ag.

[0413] Device Example B-1

[0414] a. Provide conductive glass containing ITO, and etch insulating channels 401 on the ITO using a green picosecond laser. The insulating channels 401 extend through the ITO layer to the glass substrate. Then, clean the ITO conductive glass with insulating channels using detergent. After rinsing, ultrasonically clean it with deionized water, acetone, and isopropanol for 15 minutes. Then, dry it with nitrogen and treat it in a plasma cleaner for 5 minutes to further clean the surface and improve wettability.

[0415] b. Preparation of cathode buffer layer: The PEI-Zn precursor solution was uniformly spin-coated onto ITO in air and dried on a hot stage at 150°C for 10 min to obtain a cathode buffer layer with a thickness of about 30 nm.

[0416] c. Preparation of photoactive layer: The photoactive layer solution is uniformly spin-coated onto the cathode buffer layer in air to obtain an active material layer with a total thickness of approximately 110 nm.

[0417] The photoactive layer solution was prepared by dissolving the active layer donor material polymer PM7 and the active layer acceptor material compound (B-1) in the organic solvent o-xylene at a mass ratio of 1:1.2, with a total concentration of 16.5 mg / mL.

[0418] d. Preparation of the anode buffer layer: under high vacuum (1×10⁻⁶) -6 MoO3 is vapor-deposited onto the photoactive layer in millibar (mbar) to form an anode buffer layer with a thickness of approximately 10 nm.

[0419] e. Etching the connection channel 402: The connection channel 402 is etched on the anode buffer layer using a green picosecond laser. The connection channel 402 penetrates the anode buffer layer, the photoactive layer, and the cathode buffer layer to the ITO layer.

[0420] f. Anode layer preparation: under high vacuum (1×10⁻⁶) -6 Ag is deposited onto the anode buffer layer in millibars to form an anode layer with a thickness of approximately 100 nm.

[0421] g. Etching isolation channel 403: Isolation channel 403 is etched on the anode layer using a green picosecond laser, wherein the isolation channel 403 at least penetrates the anode layer.

[0422] h. Encapsulation: The device is encapsulated in a nitrogen glove box with ultraviolet-cured resin, and the top cover 20 is selected from glass.

[0423] Device Examples B-2 to B-14

[0424] The preparation methods of device examples B-2 to B-14 are the same as those of device example B-1, except that the active layer acceptor material is selected differently. Specifically, the acceptor material compound (B-1) is replaced with compounds (B-5), (B-10), (B-19), (B-23), (B-25), (B-33), (B-37), (B-44), (B-49), (B-59), (B-63), (B-68), and (B-87), as shown in Table 2.

[0425] Comparative Example B-1

[0426] The preparation method of the device comparative example B-1 is the same as that of the device example B-1, the difference being the selection of the active layer receptor material. Specifically, the receptor material compound (B-1) is replaced with compound (B-Ref1).

[0427] The organic photovoltaic device was tested under indoor light. The battery current-voltage curve was tested under a 3000K LED light source (1000 lux) simulator, and the photoelectric conversion efficiency was calculated, as shown in Table 2.

[0428] Table 2

[0429] As shown in Table 2, the heptanolyptic fused-heterocyclic organic compound of general formula (I') described in this application exhibits significantly improved performance compared to compound (B-Ref1) when applied to OPV modules prepared using green solvents. The photoelectric conversion efficiency of these modules exceeds 32%, representing a technological breakthrough in the photoelectric conversion efficiency of organic photovoltaics under indoor lighting conditions and solving the problem of existing high-efficiency acceptor materials being unable to simultaneously achieve solubility and efficiency in green solvents. This is because R1 in general formula (I') is selected from… Compared to traditional aromatic side chains, On the one hand, it can optimize the solubility of molecules; on the other hand, it enhances molecular packing, improves charge transport, and suppresses the probability of bimolecular recombination in the dark state. Furthermore, this application, through synergistic optimization of the selection of groups R1, R2, and R3, enables the compound to have excellent solubility in non-halogen solvents while also possessing high indoor photoelectric conversion efficiency, making it suitable for the mass production of large-area modules and of great significance for the industrial application of organic photovoltaic modules.

[0430] The electrochemical curves shown in Figure 13 (with ferrocene as the potential reference) indicate that the HOMO and LUMO energy levels of compound (B-1) are -5.83 eV and -3.93 eV, respectively, while those of compound (B-Ref1) are -5.83 eV and -4.01 eV, respectively. Compared with compound (B-Ref1), compound (B-1) provided in this application effectively reduces the LUMO energy level and broadens the band gap, making the spectrum of the compound more compatible with the indoor spectrum. This indicates that the heptanomeric fused heterocyclic organic compound provided in this application has excellent performance when applied to indoor organic photovoltaic devices.

[0431] Example of organic photovoltaic (OPV) device fabrication (effective area 0.06 cm²) 2 )

[0432] Device Example B-15

[0433] The organic photovoltaic device comprises a substrate 10, a cathode 101, a cathode buffer layer 102, a photoactive layer 103, an anode buffer layer 104, and an anode 105 stacked sequentially; the materials are, in order: indium tin oxide (ITO) / PEI-Zn / photoactive layer material / MoO3 / Ag.

[0434] Its preparation method includes the following steps:

[0435] 1) ITO substrate cleaning

[0436] Clean the ITO conductive glass with detergent, rinse it thoroughly, and then ultrasonically clean it for 15 minutes with deionized water, acetone, and isopropanol. After that, dry it with nitrogen and treat it in a plasma cleaner for 5 minutes to further clean the surface and improve wettability.

[0437] 2) Preparation of cathode buffer layer

[0438] The PEI-Zn precursor solution was uniformly spin-coated onto ITO in air and dried on a hot stage at 150°C for 10 min to obtain a cathode buffer layer with a thickness of about 30 nm.

[0439] 3) Preparation of photoactive layer

[0440] In a glove box (inert gas atmosphere), the photoactive layer material solution was uniformly spin-coated onto the cathode buffer layer at a speed of 1800-3000 rpm to obtain a photoactive layer with a total thickness of approximately 110 nm.

[0441] The photoactive layer solution was prepared by dissolving the active layer donor material polymer PM6 and the active layer acceptor material compound (B-92) in the organic solvent o-xylene at a mass ratio of 1:1.2, with a total concentration of 15.4 mg / mL.

[0442] 4) Preparation of the anode buffer layer

[0443] In high vacuum (1×10 -6 MoO3 is vapor-deposited onto the photoactive layer in millibar (mbar) to form an anode buffer layer with a thickness of approximately 10 nm.

[0444] 5) Cathode layer preparation

[0445] In high vacuum (1×10) -6 Ag is deposited onto the cathode buffer layer in millibars to form a cathode layer with a thickness of approximately 100 nm.

[0446] 6) Packaging

[0447] The device is encapsulated in a nitrogen glove box using UV-cured resin.

[0448] Device Examples B-16 to B-17

[0449] The preparation methods of device examples B-16 to B-17 are the same as those of device example B-15. The difference lies in the selection of the acceptor material in the photoactive layer. Specifically, the acceptor material compound (B-92) is replaced with compound (B-95) and compound (B-97), respectively. See Table 3 for details.

[0450] The prepared organic photovoltaic cell device was tested under indoor light. The cell current-voltage curve was tested under a 3000K LED light source (1000 lux) simulator, and the photoelectric conversion efficiency was calculated, as shown in Table 3.

[0451] Table 3

[0452] As shown in Table 3, when the oligomers provided in this application are applied to OPV devices prepared with green solvents, they achieve a photoelectric conversion efficiency of over 27.5% and an efficiency retention rate of over 97%, demonstrating excellent stability of photoelectric conversion efficiency.

[0453] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A heptane-fused heterocyclic organic compound, characterized in that: It has a structure as shown in general formula (I): in: Each time M appears, it is independently selected from O or C(CN)2; R 1 Each occurrence is independently selected from branched alkyl groups having 3-12 carbon atoms, or branched alkoxy groups having 3-12 carbon atoms; R 2 Each occurrence is independently selected from straight-chain alkyl groups having 1-10 carbon atoms; R 3 Each occurrence is independently selected from -H (hydrogen), -D (deuterium), methyl, -F, -Cl, -Br, -I, -CF3, or -CN; Each time Y appears, it is independently selected from S or Se; Each time m appears, it is independently selected from 0 or 1.

2. The heptacyclic fused heterocyclic organic compound according to claim 1, characterized in that: The R 1 Each occurrence is independently selected from branched alkyl groups having 3-12 carbon atoms; optionally, the R 1 Each occurrence is independently selected from isopropyl, 3. The heptacyclic fused heterocyclic organic compound according to claim 1, characterized in that: The R 1 Each occurrence is independently selected from branched alkoxy groups having 8-12 carbon atoms; optionally, the R 1 Each time it appears, it is selected independently.

4. The heptacyclic fused heterocyclic organic compound according to claim 1, characterized in that: The Selected from Optionally, the R 2 Each occurrence is independently selected from straight-chain alkyl groups having 6-8 carbon atoms.

5. The heptacyclic fused heterocyclic organic compound according to any one of claims 1-4, characterized in that: The Selected from Where: * indicates a connection site.

6. The heptacyclic fused heterocyclic organic compound according to claim 1, characterized in that: The Selected from any of the following groups:

7. A heptane-fused heterocyclic organic compound, characterized in that, The heptacyclic fused heterocyclic organic compound has a structure as shown in general formula (I'): in: Each time Z appears, it is independently selected from O, S, or Se; Each time X appears, it is independently selected from C or Si; Each time R1 appears, it is selected independently. m0 is selected from 1, 2, or 3; Each time R6 appears, it is independently selected from alkyl groups having 1-10 carbon atoms, whether substituted or unsubstituted by R*. Each time R7 appears, it is independently selected from -H, alkyl groups having 1-10 carbon atoms that are substituted with R* or unsubstituted; Each time R* appears, it is independently selected from R. a Substituted or unsubstituted aromatic groups having 6-20 carbon atoms, or those modified by R a One or a combination of at least two of the following heteroaromatic groups, substituted or unsubstituted, having 5-20 ring atoms; R a Each occurrence is independently selected from -D, halogen, cyano, nitro, trifluoromethyl, alkyl having 1-10 carbon atoms, or alkoxy having 1-10 carbon atoms; * indicates a connection point; Each time R2 and R3 appear, they are independently selected from branched alkyl groups having 3-20 carbon atoms; R4 and R5 are each independently selected from -H, -D, halogen, cyano, nitro, trifluoromethyl, alkyl with 1-10 carbon atoms, or alkoxy with 1-10 carbon atoms. Group A is selected from electron-withdrawing units containing a cyano group.

8. The heptacyclic fused heterocyclic organic compound according to claim 7, characterized in that, Each occurrence of R1 is independently selected from... Optionally, each occurrence of R6 is independently selected from... The m1 is selected from 1, 2, 3, 4, 5, 6, 7, or 8; the R7, each time it appears, is independently selected from -H, or The m2 is selected from 1, 2, 3, 4, 5, 6, 7, or 8; the R 10 Each occurrence is independently selected from -H and controlled by R. a Substituted or unsubstituted aromatic groups having 6-10 carbon atoms, or those modified by R a A heteroaromatic group, substituted or unsubstituted, having 5-10 ring atoms.

9. The heptacyclic fused heterocyclic organic compound according to claim 7, characterized in that, In the general formula (I'), R2 and R3 are independently selected from... Among them, R8 and R9 are each selected independently from alkyl groups having 1-10 carbon atoms each time they appear.

10. The heptacyclic fused heterocyclic organic compound according to claim 7, characterized in that, The group A is selected from Wherein: Ar1, each occurrence, is independently selected from unsubstituted or R-type elements. # Replacing aromatic groups having 6-20 carbon atoms, or without substitution or by R # Substituted heteroaromatic groups having 5-20 ring atoms; R # Each occurrence is independently selected from one or a combination of at least two of the following: -D, halogen, cyano, nitro, alkyl having 1-10 carbon atoms, alkoxy having 1-10 carbon atoms, aromatic group having 6-10 carbon atoms, and heteroaromatic group having 5-10 cyclic atoms. Optionally, each occurrence of Ar1 is independently selected from the following groups: Where: r1 is selected from 0, 1 or 2; r2 is selected from 0, 1, 2, 3 or 4; r3 is selected from 0, 1, 2, 3, 4, 5 or 6; # indicates a fusion site, which is selected from C atoms.

11. The heptaneously fused heterocyclic organic compound according to any one of claims 7-10, characterized in that, The heptacyclic fused heterocyclic organic compounds have structures as shown in general formulas (II-1), (II-2), (II-3), or (II-4):

12. An oligomer, characterized in that, The oligomer has a structure as shown in general formula (III): in: m3 is selected from integers greater than or equal to 2; L is a linking group, selected from single bonds, double bonds, triple bonds, and bonds bonded by R. b Substituted or unsubstituted aromatic groups having 6-20 carbon atoms, or those modified by R b Substituted or unsubstituted heteroaromatic groups having 5-20 ring atoms; R b Each occurrence is independently selected from one or a combination of at least two of the following: -D, halogen, cyano, nitro, alkyl group having 1-20 carbon atoms, alkoxy group having 1-20 carbon atoms, alkylthio group having 1-20 carbon atoms, ester group having 1-20 carbon atoms, aromatic group having 6-20 carbon atoms, and heteroaromatic group having 5-20 ring atoms; two adjacent R groups b They may form rings or not; Each time Z appears, it is independently selected from O, S, or Se; Each time X appears, it is independently selected from C or Si; Each time R1 appears, it is selected independently. m0 is selected from 1, 2, or 3; Each time R6 appears, it is independently selected from alkyl groups having 1-10 carbon atoms, whether substituted or unsubstituted by R*. Each time R7 appears, it is independently selected from -H, alkyl groups having 1-10 carbon atoms that are substituted with R* or unsubstituted; Each time R* appears, it is independently selected from R. a Substituted or unsubstituted aromatic groups having 6-20 carbon atoms, or those modified by R a One or a combination of at least two of the following heteroaromatic groups, substituted or unsubstituted, having 5-20 ring atoms; R a Each occurrence is independently selected from -D, halogen, cyano, nitro, trifluoromethyl, alkyl having 1-10 carbon atoms, or alkoxy having 1-10 carbon atoms; * indicates a connection point; Each time R2 and R3 appear, they are independently selected from branched alkyl groups having 3-20 carbon atoms; R4 and R5 are each independently selected from -H, -D, halogen, cyano, nitro, trifluoromethyl, alkyl with 1-10 carbon atoms, or alkoxy with 1-10 carbon atoms. Group A is selected from electron-withdrawing units containing a cyano group.

13. The oligomer according to claim 12, characterized in that, The oligomers are selected from the structures represented by general formula (IV): Optionally, the oligomer is selected from the structure represented by general formula (V): in: R 11 Each occurrence is independently selected from one or a combination of at least two of the following: -D, -F, -Cl, -CF3, cyano, nitro, straight-chain alkyl having 1-6 carbon atoms, branched alkyl having 3-6 carbon atoms, straight-chain alkoxy having 1-6 carbon atoms, branched alkoxy having 3-6 carbon atoms, phenyl, and thiophene. Each time r4 appears, it is independently selected from 0, 1, 2, or 3; Each occurrence of Ar1 is independently selected from either unsubstituted or R. # Replacing aromatic groups having 6-20 carbon atoms, or without substitution or by R # Substituted heteroaromatic groups having 5-20 ring atoms; R # Each occurrence is independently selected from one or a combination of at least two of the following: -D, halogen, cyano, nitro, alkyl having 1-10 carbon atoms, alkoxy having 1-10 carbon atoms, aromatic group having 6-10 carbon atoms, and heteroaromatic group having 5-10 cyclic atoms.

14. The oligomer according to claim 13, characterized in that, The L is selected from single bond, Where: V is selected from O, S, or Se; r5 is selected from 1, 2, 3, 4, or 5; R 12 Each occurrence is independently selected from one or a combination of at least two of the following: -H, -D, halogen, cyano, nitro, alkyl group having 1-20 carbon atoms, alkoxy group having 1-20 carbon atoms, alkylthio group having 1-20 carbon atoms, ester group having 1-20 carbon atoms, aromatic group having 6-20 carbon atoms, and heteroaromatic group having 5-20 ring atoms; two adjacent R groups b They may form rings or not.

15. A mixture, characterized in that, The mixture comprises: A heptane-fused heterocyclic organic compound of general formula (I) as described in any one of claims 1-6; or The heptane-fused heterocyclic organic compound of general formula (I') as described in any one of claims 7-11; or Oligomers of general formula (III) as described in any one of claims 12-14.

16. An organic photovoltaic device, characterized in that, The organic photovoltaic device includes a cathode, an anode, and a photoactive layer located between the cathode and the anode, wherein the material of the photoactive layer includes: A heptane-fused heterocyclic organic compound of general formula (I) as described in any one of claims 1-6; or A heptane-fused heterocyclic organic compound of general formula (I') as described in any one of claims 7-11; or The oligomer as described in any one of claims 12-14; or The mixture as described in claim 15.

17. The organic photovoltaic device according to claim 16, characterized in that, The photoactive layer comprises a donor material and an acceptor material, wherein the acceptor material is: A heptane-fused heterocyclic organic compound of general formula (I) as described in any one of claims 1-6; or A heptane-fused heterocyclic organic compound of general formula (I') as described in any one of claims 7-11; or The oligomer as described in any one of claims 12-14.

18. The organic photovoltaic device according to claim 16, characterized in that: The organic photovoltaic device is an indoor organic photovoltaic device.

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