A fused ring compound, an ultranarrow-band-gap organic semiconductor material, and a preparation method and application thereof

Abstract

This invention provides a fused-ring compound, an ultra-narrow bandgap organic semiconductor material, its preparation method, and its applications, belonging to the technical field of organic functional semiconductor materials. This invention provides a fused-ring compound having the structure shown in Formula I or Formula II, which is a carbon-oxygen bridged ladder-shaped fused-ring compound with alkyl side chains substituted (R2 is -H) or a carbon-oxygen bridged ladder-shaped fused-ring compound with alkyl side chains substituted and functionalized (R2 is a substituent other than -H). That is, the solubilizing side chain on the carbon-oxygen bridge is alkyl, which can serve as an electron-rich fused-ring donor unit to construct an ultra-narrow bandgap organic semiconductor material with strong near-infrared II absorption properties. This invention provides a method for preparing the fused-ring compound having the structure shown in Formula I or Formula II. The method provided by this invention is simple to operate and has a high product yield.

Description

Technical Field

[0001] This invention relates to the field of organic functional semiconductor materials technology, specifically to a fused ring compound, an ultra-narrow bandgap organic semiconductor material, its preparation method, and its applications. Background Technology

[0002] Narrow-bandgap and ultra-narrow-bandgap organic semiconductor materials are an important class of optoelectronic materials, referring to materials with a bandgap of less than 1.6 eV and an absorption edge reaching the near-infrared (NIR) region. To achieve sufficient response to long-wavelength infrared light, only semiconductor materials with narrow optical bandgap can be used as photosensitive materials to generate excitons from low-energy photons. Near-infrared light accounts for 43% of the solar spectrum energy; therefore, narrow-bandgap photovoltaic materials can improve the utilization rate of the solar spectrum while reducing open-circuit voltage loss caused by charge transfer between donor and acceptor. Furthermore, near-infrared light has stronger penetrability in biological tissues; therefore, extending the spectral range of materials beyond the visible light spectrum can greatly enrich the applications of near-infrared light in fields such as medical health, flexible electronics, and energy and environment. Since 2015, Zhan Xiaowei et al. have reported excellent performance in constructing non-fullerene acceptor materials based on carbon-bridged trapezoidal fused ring acceptor units (Lin, Y.; Wang, J.; Zhang, ZG, et al. An Electron Acceptor Challenging Fullerenes for EfficientPolymer SolarCells[J]. Advanced Materials, 2015, 27: 1170-1174.). With technological advancements, the performance requirements for narrow bandgap organic semiconductor materials have increased. Compared to the visible and near-infrared I regions, organic semiconductor materials with strong absorption properties in the near-infrared II region (maximum absorption wavelength greater than 1000 nm) are currently very rare. Developing novel fused ring compounds as donor units to construct ultra-narrow bandgap organic semiconductor materials (i.e., maximum absorption wavelength greater than 1000 nm) is of great significance for improving the performance of organic optoelectronic materials and broadening their application range. Summary of the Invention

[0003] The purpose of this invention is to provide a fused ring compound, an ultra-narrow bandgap organic semiconductor material, a preparation method, and applications. The fused ring compound provided by this invention uses alkyl groups as solubilizing side chains and can be used as an electron-rich fused ring donor unit to construct an ultra-narrow bandgap organic semiconductor material with strong near-infrared II absorption properties with various aromatic acceptor units.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a fused-ring compound having the structure shown in Formula I or Formula II:

[0006]

[0007] In formulas I and II, R1 is an alkyl chain;

[0008] R2 can be -H, cyano, aldehyde, carboxyl, tin, halogen, alkyl, silyl, alkoxy, ester, alkynyl, alkenyl, or aryl.

[0009] Preferably, the alkyl group is C1 to C2. 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups.

[0010] Preferably, the tin group is -SnMe3 or -SnBu3;

[0011] The halogen group is -F, -Cl, -Br or -I;

[0012] The alkyl group is C1 to C2. 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups;

[0013] The silicon-based group is -Si(R)3, where R is a C1-C4 straight-chain alkyl group or a C3-C4 branched alkyl group.

[0014] The alkoxy group is -OR 1 R in the alkoxy group 1 C1~C 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups;

[0015] The ester group is -COOR 2 R in the ester group 2 It is a straight-chain alkyl group of C1 to C4 or a branched alkyl group of C3 to C4;

[0016] The alkynyl group is -C≡R 3 R in the alkynyl group 3 C1~C 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups;

[0017] The alkenyl group is

[0018] The aryl group is any one of the following groups:

[0019]

[0020] Preferably, the fused-ring compound is any one of the following compounds:

[0021]

[0022] This invention provides a method for preparing the fused-ring compound described above, comprising the following steps:

[0023] The starting compound, nucleophile, and first organic solvent are mixed and subjected to a nucleophilic addition reaction to obtain a tertiary alcohol compound;

[0024] The tertiary alcohol compound, the protic acid catalyst, and the second organic solvent were mixed and subjected to a ring-closure reaction to obtain the fused-ring compound with R2 being -H.

[0025] The fused-ring compound with R2 being -H, the functionalizing agent, and a third organic solvent were mixed and subjected to a substitution reaction to obtain the fused-ring compound with R2 being a substituent other than -H.

[0026] Wherein, the nucleophile is R1MgBr or R1Li, and the functionalizing agent is a reagent that provides R2 other than -H through a substitution reaction;

[0027] When preparing a fused-ring compound having the structure shown in Formula I, the starting compound is any one of the following compounds:

[0028]

[0029] When preparing a fused-ring compound having the structure shown in Formula II, the starting compound is any one of the following compounds:

[0030]

[0031] R3 in the raw material compound is C1 to C2. 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups.

[0032] This invention provides an ultra-narrow bandgap organic semiconductor material, which is prepared by coupling reaction of the fused ring compound and the electron-deficient acceptor compound described in the above technical solution.

[0033] Preferably, the aromatic acceptor unit comprises compound QC-Br, a benzothiadiazole derivative, a pyrrolopyrrole dione derivative, an isoindigo derivative, a boron fluoride dipyrrole derivative, or an indanone derivative; the compound QC-Br has the following structure:

[0034]

[0035] This invention provides a method for preparing the ultra-narrow bandgap organic semiconductor material described in the above technical solution, comprising the following steps:

[0036] The fused ring compound, the electron-deficient acceptor compound, and the fourth organic solvent are mixed and coupled to obtain the ultranarrow bandgap organic semiconductor material.

[0037] This invention provides the application of the ultra-narrow bandgap organic semiconductor material described in the above technical solution in organic optoelectronic devices.

[0038] Preferably, the organic optoelectronic device includes an organic thin-film transistor, an organic photodetector, or an organic solar cell.

[0039] This invention provides a fused-ring compound having the structure shown in Formula I or Formula II, which is a carbon-oxygen bridged ladder-shaped fused-ring compound with alkyl side chains substituted (R2 is -H) or a carbon-oxygen bridged ladder-shaped fused-ring compound with alkyl side chains substituted and functionalized (R2 is a substituent other than -H). That is, the solubilizing side chain on the carbon-oxygen bridge is alkyl. Compared with using aromatic groups as solubilizing side chains, this avoids the problem of steric hindrance of aromatic groups disrupting the molecular arrangement or aggregation in the solid state, thus affecting the absorption spectrum and charge transport properties. The fused-ring compound provided by this invention possesses excellent light absorption and carrier transport characteristics and is readily soluble in common organic solvents (such as toluene, chloroform, chlorobenzene, or tetrahydrofuran). It can be used as an electron-rich fused-ring donor unit to construct ultra-narrow bandgap organic semiconductor materials with strong near-infrared II absorption properties, showing broad application prospects and high application value in organic optoelectronic devices.

[0040] This invention provides a method for preparing fused-ring compounds having the structure shown in Formula I or Formula II. The method provided by this invention is simple to operate and has a high product yield. Attached Figure Description

[0041] Figure 1 The 1H NMR spectrum of compound D1 obtained in Example 1;

[0042] Figure 2 The 1H NMR spectrum of compound E1 obtained in Example 2;

[0043] Figure 3 The 1H NMR spectrum of compound E2 obtained in Example 3;

[0044] Figure 4 The 1H NMR spectrum of compound E3 obtained in Example 4;

[0045] Figure 5 The 1H NMR spectrum of compound D2 obtained in Example 5;

[0046] Figure 6 The 1H NMR spectrum of compound E4 obtained in Example 6;

[0047] Figure 7The 1H NMR spectrum of compound 4TOC-2QC obtained in Example 7;

[0048] Figure 8 The image shows the UV-Vis absorption spectrum of compound 4TOC-2QC.

[0049] Figure 9 The cyclic voltammogram for compound 4TOC-2QC;

[0050] Figure 10 The 1H NMR spectrum of compound Q4TCO obtained in Example 9;

[0051] Figure 11 This is a schematic diagram of the organic thin-film transistor structure in Application Example 1;

[0052] Figure 12 This is a schematic diagram of the organic photodetector in Application Example 2. Detailed Implementation

[0053] This invention provides a fused-ring compound having the structure shown in Formula I or Formula II:

[0054]

[0055] In formulas I and II, R1 is an alkyl chain;

[0056] R2 can be -H, cyano (-CN), aldehyde (-CHO), carboxyl (-COOH), tin, halogen, alkyl, silyl, alkoxy, ester, alkynyl, alkenyl, or aryl.

[0057] In this invention, R1 is preferably C1 to C1. 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups, more preferably C3-C4 30 Straight-chain alkyl or C5-C 30 Branched alkyl groups, more preferably C8-C96 20 Straight-chain alkyl or C8-C 20 Branched alkyl groups.

[0058] In this invention, the tin-based group is preferably -SnMe3 or -SnBu3;

[0059] The halogen group is preferably -F, -Cl, -Br or -I;

[0060] The alkyl group is preferably C1-C6. 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups, more preferably C3-C4 30 Straight-chain alkyl or C5-C 30 Branched alkyl groups, more preferably C8-C96 20Straight-chain alkyl or C8-C 20 Branched alkyl groups;

[0061] The silicon-based group is -Si(R)3, and R in the silicon-based group is preferably a straight-chain alkyl group of C1 to C4 or a branched alkyl group of C3 to C4;

[0062] The alkoxy group is -OR 1 R in the alkoxy group 1 Preferably C1 to C 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups, more preferably C3-C4 30 Straight-chain alkyl or C5-C 30 Branched alkyl groups, more preferably C8-C96 20 Straight-chain alkyl or C8-C 20 Branched alkyl groups;

[0063] The ester group is -COOR 2 R in the ester group 2 Preferably, it is a straight-chain alkyl group of C1 to C4 or a branched alkyl group of C3 to C4;

[0064] The alkynyl group is -C≡R 3 R in the alkynyl group 3 Preferably C1 to C 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups, more preferably C3-C4 30 Straight-chain alkyl or C5-C 30 Branched alkyl groups, more preferably C8-C96 20 Straight-chain alkyl or C8-C 20 Branched alkyl groups;

[0065] The alkenyl group is preferably...

[0066] The aryl group is preferably any one of the following groups:

[0067]

[0068] In this invention, the fused ring compound is specifically any one of the following compounds:

[0069]

[0070] This invention provides a method for preparing the fused-ring compound described above, comprising the following steps:

[0071] The starting compound, nucleophile, and first organic solvent are mixed and subjected to a nucleophilic addition reaction to obtain a tertiary alcohol compound;

[0072] The tertiary alcohol compound, the protic acid catalyst, and the second organic solvent were mixed and subjected to a ring-closure reaction to obtain the fused-ring compound with R2 being -H.

[0073] The fused-ring compound with R2 being -H, the functionalizing agent, and a third organic solvent were mixed and subjected to a substitution reaction to obtain the fused-ring compound with R2 being a substituent other than -H.

[0074] Wherein, the nucleophile is R1MgBr or R1Li, and the functionalizing agent is a reagent that provides R2 other than -H through a substitution reaction;

[0075] When preparing a fused-ring compound having the structure shown in Formula I, the starting compound is any one of the following compounds:

[0076]

[0077] When preparing a fused-ring compound having the structure shown in Formula II, the starting compound is any one of the following compounds:

[0078]

[0079] R3 in the raw material compound is C1 to C2. 40 Straight-chain alkyl or C3-C 40 Branched alkyl groups.

[0080] This invention uses fused-ring lactone compounds or compounds containing both hydroxyl and ester groups as starting materials, and alkyl Grignard reagents (R1MgBr) or alkyllithium reagents (R1Li) as nucleophiles. A tertiary alcohol compound is obtained through nucleophilic addition, followed by a ring-closure reaction under a protic acid catalyst to yield a fused-ring compound with R2 being -H (a carbon-oxygen bridged ladder fused-ring compound with alkyl side chain substitution). This compound then undergoes a substitution reaction with a functionalizing agent to obtain a fused-ring compound with R2 substituents other than -H (i.e., a carbon-oxygen bridged ladder fused-ring compound with alkyl side chain substitution and functionalization modification). The reaction formulas involved are shown below (using p-toluenesulfonic acid as the protic acid catalyst as an example):

[0081]

[0082]

[0083] The method of the present invention will now be described in detail.

[0084] In this invention, unless otherwise specified, all raw materials used are commercially available products well known to those skilled in the art. In this invention, unless otherwise specified, all reactions are carried out in a protective gas atmosphere, preferably nitrogen, argon, or helium, more preferably argon.

[0085] This invention involves mixing a starting compound, a nucleophile, and a first organic solvent to perform a nucleophilic addition reaction to obtain a tertiary alcohol compound. In this invention, the molar ratio of the starting compound to the nucleophile is preferably 1:4–40, more preferably 1:4–24, and even more preferably 6–10. In this invention, the first organic solvent is preferably tetrahydrofuran, diethyl ether, dioxane, or n-hexane, more preferably diethyl ether; the first organic solvent is preferably an ultra-dry organic solvent; the molar ratio of the first organic solvent to the starting compound is preferably 10–100 mL:0.1–5 mmol, more preferably 30–50 mL:0.68–2.44 mmol, and even more preferably 30–50 mL:1.05–1.16 mmol. Preferably, the starting compound is dissolved in the first organic solvent, and then the nucleophile is added dropwise to the resulting solution to perform a nucleophilic addition reaction. This invention does not specifically limit the dropping rate of the nucleophile; a dropping rate well-known to those skilled in the art can be used, as long as it does not cause a change in the temperature of the reaction system during the dropping process. The nucleophile is preferably added at -80 to 25°C, more preferably at -78°C. The dropping is preferably carried out under stirring conditions. In this invention, the nucleophilic addition reaction preferably includes a first-stage reaction and a second-stage reaction sequentially. The temperature of the first-stage reaction is preferably -80 to 25°C, more preferably -78°C; the time of the first-stage reaction is preferably 0.5 to 4 hours, more preferably 1 hour; the temperature of the second-stage reaction is preferably 25 to 100°C, more preferably 40°C; the time of the second-stage reaction is preferably 1 to 48 hours, more preferably 12 hours; the nucleophilic addition reaction is preferably carried out under stirring conditions. After the nucleophilic addition reaction, this invention preferably adds a saturated ammonium chloride aqueous solution to the resulting system to quench the reaction, extracts with ethyl acetate, dries the resulting organic phase with anhydrous magnesium sulfate, filters, removes the solvent from the filtrate, and obtains a tertiary alcohol compound, which is directly added to the next reaction step.

[0086] After obtaining the tertiary alcohol compound, the present invention mixes the tertiary alcohol compound, the protic acid catalyst, and a second organic solvent to carry out a ring-closure reaction to obtain the fused-ring compound with R2 being -H. In the present invention, the protic acid catalyst is preferably sulfuric acid, tetrafluoroboric acid, hydrogen chloride, amberlyst15, or p-toluenesulfonic acid, more preferably p-toluenesulfonic acid; the molar ratio of the tertiary alcohol compound to the protic acid catalyst is preferably 1:0.1-4, more preferably 1:1-4, and even more preferably 1:2-3. In the present invention, the second organic solvent is preferably diethyl ether, tetrahydrofuran, dioxane, n-hexane, cyclohexane, or toluene, more preferably toluene; the second organic solvent is preferably an ultra-dry organic solvent; the molar ratio of the second organic solvent to the tertiary alcohol compound is preferably 10-100 mL:1 mmol, more preferably 30 mL:1 mmol. In this invention, the preferred temperature for the ring-closing reaction is 25–120°C, more preferably 100–110°C; the preferred time is 1–48 h, more preferably 8–12 h; the ring-closing reaction is preferably carried out under light-protected conditions. After the ring-closing reaction, this invention preferably adds a saturated sodium chloride aqueous solution and petroleum ether to the obtained product system for extraction, dries the obtained organic phase with anhydrous magnesium sulfate, filters, removes the solvent from the obtained filtrate, and separates the crude product using a neutral or basic alumina chromatographic column (preferably using n-pentane, n-hexane, or petroleum ether as the eluent) to obtain the fused-ring compound with R2 = -H.

[0087] After obtaining the fused-ring compound with R2 being -H, the present invention mixes the fused-ring compound with R2 being -H, a functionalizing reagent, and a third organic solvent to carry out a substitution reaction to obtain the fused-ring compound with R2 being a substituent other than -H. In the present invention, the functionalizing reagent is a reagent that provides R2 other than -H through a substitution reaction. Specifically, a suitable functionalizing reagent can be selected according to the type of R2, which will be described in detail below.

[0088] In this invention, when R2 is a cyano group, the functionalizing agent is preferably trimethylcyano (TMSCN) or KCN; when R2 is an aldehyde group, the functionalizing agent is preferably N,N-dimethylformamide (DMF); when R2 is a carboxyl group, the functionalizing agent is preferably dry ice; when R2 is a tin group, the functionalizing agent is preferably trimethyltin chloride (SnMe3Cl) or tributyltin chloride (SnBu3Cl); when R2 is a halogen group, the functionalizing agent is preferably N-halosuccinimide (the halogen group in the N-halosuccinimide is preferably Cl, Br, or I). The functionalizing agent can be Br2, I2, carbon tetrabromide, 1,2-dibromotetrachloroethane, N-fluorobis(benzenesulfonamide) (NFSI), XeF2, or N-fluoropyridinium salt; when R2 is alkyl, the functionalizing agent is preferably an alkyl halide or alkyl boron ester; when R2 is silicon-based, the functionalizing agent is preferably alkyl silicon chloride, more preferably trimethylsilicon chloride (TMSCl), tert-butyldiphenylsilicon chloride (TBDPSCl), tert-butyldimethylsilicon chloride (TBDMSCl), or triisopropylsilicon chloride (TIPSCl); when R2 is alkoxy, the functionalizing agent is preferably NaOR 1 When R2 is an ester group, R can be used. 2 OH acts as a functionalizing agent in the reaction with a carboxylic acid substrate, wherein the carboxylic acid substrate is preferably any one of the following compounds:

[0089]

[0090] When R2 is an alkyne group, the functionalizing agent is preferably HC≡R. 3 ,BrC≡R 3 IC≡R 3 Sn(Me)3C≡R 3 Sn(Bu)3C≡R 3 Or BpinC≡R 3 When R2 is alkenyl, the functionalizing agent is preferably alkenyl bromide, alkenyl iodide, alkenyl pinacol boryl ester, alkenyl trimethyltin, alkenyl tributyltin, or alkenyl N-p-toluenesulfonylhydrazone, with the following structural formula:

[0091]

[0092] When R2 is aryl, the functionalizing agent is preferably arylboronic acid, arylboronic ester, aryltrimethyltin, aryltributyltin, or aryl halide.

[0093] In this invention, the molar ratio of the fused-ring compound with R2 being -H to the functionalizing agent is preferably 1:1 to 8, more preferably 1:2 to 4. In this invention, the third organic solvent is preferably dichloromethane, trichloromethane, tetrahydrofuran, toluene, diethyl ether, dioxane, N,N-dimethylformamide, or n-hexane, more preferably tetrahydrofuran; the third organic solvent is preferably an ultra-dry organic solvent; the ratio of the third organic solvent to the fused-ring compound with R2 being -H is preferably 10 to 100 mL: 0.1 to 2 mmol, more preferably 40 to 50 mL: 0.15 to 0.37 mmol. In this invention, when R2 is a cyano (-CN), aldehyde (-CHO), carboxyl (-COOH), tin, halogen, or silicon group, the substitution reaction is preferably carried out in the presence of a lithium reagent; the lithium reagent preferably includes an alkyl lithium reagent or an aryl lithium reagent, and the alkyl lithium reagent preferably includes n-butyllithium; the molar ratio of the lithium reagent to the fused ring compound in which R2 is -H is preferably 2 to 20:1, more preferably 2.5 to 4:1. When using a lithium reagent, the present invention preferably involves dissolving the fused-ring compound with R2 being -H in a third organic solvent, lyophilizing it with liquid nitrogen to remove oxygen, and then adding the lithium reagent dropwise to the resulting solution. After the addition is complete, the mixture is stirred at -80 to 0°C (preferably -78°C) for 0.5 to 3 hours (preferably 1 hour), then heated to -60 to 0°C (preferably -50°C) and stirred for another 0.5 to 3 hours (preferably 1.5 hours). During this process, H and Li in the fused-ring compound with R2 being -H undergo substitution exchange to obtain an organolithium compound intermediate. A functionalizing agent is then added to the resulting system to carry out a substitution reaction. When not using a lithium reagent, the present invention preferably involves dissolving the fused-ring compound with R2 being -H in a third organic solvent, and then adding a functionalizing agent to the resulting solution to carry out a substitution reaction. In the present invention, the temperature of the substitution reaction is preferably -80 to 120°C, more preferably 0 to 25°C; the time is preferably 5 minutes to 48 hours, more preferably 12 to 24 hours.Following the substitution reaction, the present invention preferably employs a suitable method to process the target compound (i.e., the fused-ring compound in which R2 is a substituent other than -H) according to its properties. Specifically, in embodiments of the present invention, when R2 is -SnMe3, the present invention preferably adds water to the product system obtained after the substitution reaction to quench the reaction, extracts with n-hexane, dries the resulting organic phase with anhydrous magnesium sulfate, filters, removes the solvent from the filtrate, and recrystallizes the crude product with diethyl ether to obtain the target compound. When R2 is -CHO, the present invention preferably adds water to the product system obtained after the substitution reaction to quench the reaction, extracts with ethyl acetate, dries the resulting organic phase with anhydrous magnesium sulfate, filters, and removes the solvent from the filtrate. After the reaction, the crude product is separated by silica gel column chromatography (preferably using dichloromethane as the eluent) to obtain the target compound; when R2 is -Br and the target compound has the structure shown in Formula I, the present invention preferably adds water to the product system obtained after the substitution reaction to quench the reaction, extracts with petroleum ether, dries the obtained organic phase with anhydrous magnesium sulfate, filters, removes the solvent from the obtained filtrate, and then separates the crude product by silica gel column chromatography (preferably using petroleum ether as the eluent) to obtain the target compound; when R2 is -Br and the target compound has the structure shown in Formula II, the present invention preferably separates the product system obtained after the substitution reaction by silica gel column chromatography under reduced pressure (preferably using petroleum ether as the eluent), removes the solvent from the obtained liquid by evaporation under reduced pressure, and obtains the target compound.

[0094] Due to limitations in past synthesis methods, solubilizing side chains were often bulky aromatic groups, inevitably leading to larger π-π stacking distances. In this invention, the regular alkyl groups used as solubilizing side chains enhance the crystallinity and molecular aggregation of the material, which is highly beneficial for optimizing the film morphology and improving mobility. Furthermore, further control over the length and steric hindrance of the solubilizing side chains allows for a trade-off between acceptor crystallinity and miscibility with the donor material. Therefore, the fused-ring compounds provided by this invention possess excellent light absorption and carrier transport properties, achieving high short-circuit current and energy conversion efficiency. The fused-ring compounds provided by this invention are strong electron donor units. Non-fullerene acceptor materials constructed based on these strong electron donor monomers can significantly improve molecular crystallinity, stacking, and mobility, achieving strong near-infrared light absorption and high electron mobility.

[0095] This invention provides an ultra-narrow bandgap organic semiconductor material, prepared by a coupling reaction between the fused-ring compound and the electron-deficient acceptor compound described in the above-mentioned technical solution. In this invention, the electron-deficient acceptor compound preferably includes compound QC-Br, benzothiadiazole (BT) derivatives, pyrrolopyrrole dione (DPP) derivatives, isoindigo (IID) derivatives, boron dipyrrole (BODIPY) derivatives, or indanone derivatives; compound QC-Br has the following structure:

[0096]

[0097] In this invention, the benzothiadiazole (BT) derivative preferably includes dicyanodibromobenzothiadiazole (DCNBT), the indanone derivative preferably includes 1,3-indanone, the pyrrolopyrrole dione (DPP) derivative preferably includes dibromothienyl-pyrrolopyrrole dione (DPP-2Br), the isoindigo (IID) derivative preferably includes dibromothienyl isoindigo (TII-2Br) or dibromothiazolium isoindigo (TzII-2Br), and the boron fluoride dipyrrole (BODIPY) derivative preferably includes dibromoaza-boron dipyrrole (Aza-BODIPY-2Br).

[0098] In this invention, the ultra-narrow bandgap organic semiconductor material is preferably any one of the following compounds (wherein the A group is the corresponding group of the electron-deficient acceptor compound, and n is 2 to 50):

[0099]

[0100] In embodiments of the present invention, the ultranarrow bandgap organic semiconductor material is specifically any one of the following compounds (wherein the Mn of compound 4TOC-DCNBT is 14.5 kDa). ):

[0101]

[0102] This invention provides a method for preparing the ultra-narrow bandgap organic semiconductor material described in the above technical solution, comprising the following steps:

[0103] The fused ring compound, the electron-deficient acceptor compound, and the fourth organic solvent are mixed and coupled to obtain the ultranarrow bandgap organic semiconductor material.

[0104] In this invention, the molar ratio of the fused-ring compound to the electron-deficient acceptor compound is preferably 1:2 to 4, more preferably 1:2.1. In this invention, the fourth organic solvent preferably includes toluene, chlorobenzene, tetrahydrofuran, 1,4-dioxane, or N,N-dimethylformamide, more preferably toluene; the fourth organic solvent is preferably an ultra-dry organic solvent; the molar ratio of the fourth organic solvent to the fused-ring compound is preferably 10-100 mL:0.1-2 mmol, more preferably 50 mL:0.17 mmol. In this invention, the coupling reaction is preferably carried out in the presence of a catalyst, the catalyst preferably including Pd(PPh3)4; the molar ratio of the catalyst to the fused-ring compound is preferably 0.01-0.2:1, more preferably 0.1:1. In this invention, the fused-ring compound and the electron-deficient acceptor compound are preferably dissolved in the fourth organic solvent, lyophilized in liquid nitrogen to remove oxygen, and then the catalyst is added to carry out the coupling reaction. In this invention, the temperature of the coupling reaction is preferably 25–140°C, more preferably 110°C; the time is preferably 2–48 h, more preferably 3–24 h. After the coupling reaction, this invention preferably uses a suitable method to process the product system according to the properties of the ultra-narrow bandgap organic semiconductor material. In specific embodiments of this invention, when the ultra-narrow bandgap organic semiconductor material is a small molecule compound such as 4TOC-2QC, this invention preferably uses dichloromethane to extract the product system obtained after the coupling reaction, dries the obtained organic phase with anhydrous magnesium sulfate, filters, removes the solvent from the obtained filtrate, and separates the crude product by silica gel column chromatography (the eluent used is preferably petroleum ether: dichloromethane = 2:1 by volume) to obtain the ultra-narrow bandgap organic semiconductor material; when the ultra-narrow bandgap organic semiconductor material is a polymer such as 4TOC-DCNBT, this invention preferably precipitates the product system obtained after the coupling reaction in methanol, and then... The precipitate was purified by Soxhlet extraction with methanol, acetone, hexane, and chloroform in sequence. The resulting chloroform solution was concentrated and then poured into methanol for precipitation. The solid material was collected by filtration to obtain an ultranarrow bandgap organic semiconductor material. When the ultranarrow bandgap organic semiconductor material is a quinone compound such as Q4TCO, the present invention preferably cools the product system obtained after the coupling reaction to room temperature, adds deionized water to quench the reaction, and carries out an oxidation reaction in air under stirring for 25-35 min (preferably 30 min). Then, the obtained product liquid is extracted with dichloromethane, the organic phase is dried with anhydrous sodium sulfate, filtered, the obtained filtrate is evaporated to dryness, separated by silica gel column chromatography (the eluent used is preferably petroleum ether: dichloromethane = 1:2 by volume), and vacuum dried to obtain the ultranarrow bandgap organic semiconductor material.

[0105] This invention provides the application of the ultra-narrow bandgap organic semiconductor material described above in organic optoelectronic devices. In this invention, the organic optoelectronic device preferably includes an organic thin-film transistor, an organic photodetector, or an organic solar cell. In this invention, the organic thin-film transistor preferably includes a top-gate structure or a bottom-gate structure, more preferably a top-gate structure; the top-gate structure is further preferably a top-gate-bottom-contact structure. In an embodiment of this invention, the organic thin-film transistor sequentially includes a substrate, a source / drain electrode, an active layer, an insulating layer, and a gate. The upper surface of the substrate has a source and a drain electrode respectively disposed at both ends, and the source, drain, and the exposed substrate surface between them are provided with the active layer. The substrate is preferably a silicon wafer with a 300nm thick silicon dioxide layer deposited on its surface. The source / drain electrode is made of gold. The active layer is prepared from the ultra-narrow bandgap organic semiconductor material described in this invention. The insulating layer is preferably made of PMMA, and the gate electrode is preferably made of aluminum. In this invention, the organic photodetector preferably includes an upright structure or an inverted structure, more preferably an inverted structure. In embodiments of the present invention, the organic photodetector sequentially comprises a substrate, an anode, a hole transport layer, an active layer, an electron transport layer, and a cathode; the substrate and the anode are preferably ITO glass; the hole transport layer is preferably made of zinc oxide; the active layer is preferably prepared from PTB7-Th and the ultra-narrow bandgap organic semiconductor material of the present invention; the electron transport layer is preferably made of molybdenum trioxide; and the cathode is preferably made of silver. In the present invention, the organic solar cell preferably comprises an upright structure or an inverted structure.

[0106] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0107] Preparation Example 1

[0108] The reaction formula for preparing compound C1 is shown below:

[0109]

[0110] In an argon atmosphere, compound A1 (946 mg, 2.44 mmol) was dissolved in 50 mL of ultradry diethyl ether, and C8H was added dropwise under stirring at -78 °C. 17MgBr diethyl ether solution (7.6 mL, 2 mol / L) was added dropwise and stirred at -78℃ for 1 h. The temperature was then raised to 40℃ and stirred for 12 h. The reaction was then quenched by adding saturated ammonium chloride aqueous solution to the resulting system. The system was extracted with ethyl acetate, dried over anhydrous magnesium sulfate, filtered, and the solvent in the filtrate was removed to obtain compound C1, which was directly added to the next reaction.

[0111] Preparation Example 2

[0112] The reaction formula for preparing compound C1 is shown below:

[0113]

[0114] In an argon atmosphere, compound B1 (310 mg, 0.68 mmol) was dissolved in 30 mL of ultradry diethyl ether, and C8H was added dropwise under stirring at -78 °C. 17 MgBr diethyl ether solution (3.4 mL, 2 mol / L) was added dropwise and stirred at -78℃ for 1 h. The temperature was then raised to 40℃ and stirred for 12 h. After that, saturated ammonium chloride aqueous solution was added to the resulting system to quench the reaction. Ethyl acetate was used for extraction. The resulting organic phase was dried with anhydrous magnesium sulfate, filtered, and the solvent in the filtrate was removed to obtain compound C1, which was directly added to the next reaction.

[0115] Preparation Example 3

[0116] The reaction formula for preparing compound C2 is shown below:

[0117]

[0118] In an argon atmosphere, compound A2 (450 mg, 1.16 mmol) was dissolved in 50 mL of ultradry diethyl ether, and C8H was added dropwise under stirring at -78 °C. 17 Add 5.8 mL of MgBr diethyl ether solution (2 mol / L) and stir at -78 °C for 0.5 h after the addition is complete. Then, raise the temperature to 25 °C and stir for 12 h. After that, add saturated ammonium chloride aqueous solution to the obtained system to quench the reaction, extract with ethyl acetate, dry the obtained organic phase with anhydrous magnesium sulfate, filter, remove the solvent from the obtained filtrate, and obtain compound C2, which is directly added to the next reaction.

[0119] Preparation Example 4

[0120] The reaction formula for preparing compound C2 is shown below:

[0121]

[0122] In an argon atmosphere, compound B2 (505 mg, 1.05 mmol) was dissolved in 30 mL of ultradry diethyl ether, and C8H was added dropwise under stirring at -78 °C. 17 Add 5.3 mL of MgBr diethyl ether solution (2 mol / L) and stir at -78 °C for 0.5 h after the addition is complete. Then, raise the temperature to 25 °C and stir for 12 h. After that, add saturated ammonium chloride aqueous solution to the obtained system to quench the reaction, extract with ethyl acetate, dry the obtained organic phase with anhydrous magnesium sulfate, filter, remove the solvent from the obtained filtrate, and obtain compound C2, which is directly added to the next reaction.

[0123] Example 1

[0124] The reaction formula for preparing compound D1 is shown below:

[0125]

[0126] In an argon atmosphere, compound C1 (844 mg, 1 mmol) was dissolved in 30 mL of ultra-dry toluene, and p-toluenesulfonic acid (344 mg, 2 mmol) was added. The mixture was reacted at 110 °C in the dark for 12 h. After the reaction was completed, the product system was extracted with saturated sodium chloride aqueous solution and petroleum ether. The resulting organic phase was dried with anhydrous magnesium sulfate, filtered, and the solvent in the filtrate was removed. The crude product was separated by a neutral alumina column (petroleum ether was used as the eluent) to give compound D1 as a yellow solid (yield of 1.18 g, yield 60%).

[0127] 1 1H NMR (500MHz, Chloroform-d) δ 7.04 (d, J = 5.0Hz, 2H), 6.72 (d, J = 5.0Hz, 2H), 1.91 (m, 8H), 1.40 (m, 8H), 1.22 (m, 40H), 0.86 (t, 12H) MALDI-TOF (m / z): Calculated value 808.44, measured value 808.284; 1H NMR spectrum of compound D1 is as follows Figure 1 As shown.

[0128] Example 2

[0129] The reaction formula for preparing compound E1 is shown below:

[0130]

[0131] In an argon atmosphere, compound D1 (300 mg, 0.37 mmol) was dissolved in 50 mL of ultra-dry tetrahydrofuran, lyophilized in liquid nitrogen to remove oxygen, and then 0.6 mL of n-butyllithium tetrahydrofuran solution (2 mol / L) was added dropwise under stirring at -78 °C. After the addition was complete, the mixture was stirred at -78 °C for 1 h, then heated to -50 °C and stirred for another 1.5 h. Trimethyltin chloride (300 mg, 1.5 mmol) was then added to the resulting system, and the mixture was heated to room temperature and stirred for 12 h. The reaction was then quenched with water, extracted with n-hexane, and the resulting organic phase was dried over anhydrous magnesium sulfate. After filtration to remove the solvent from the filtrate, the crude product was recrystallized from diethyl ether to give compound E1 as yellow crystals (yield 336 mg, 80% yield).

[0132] 1 1H NMR (400MHz, THF-d8) δ 6.81 (s, 2H), 1.86 (m, J = 5.3Hz, 8H), 1.18 (m, J = 5.0Hz, 8H), 1.14 (m, 40H), 0.75 (t, 12H), 0.27 (s, 18H); The 1H NMR spectrum of compound E1 is as follows: Figure 2 As shown.

[0133] Example 3

[0134] The reaction formula for preparing compound E2 is shown below:

[0135]

[0136] In an argon atmosphere, compound D1 (300 mg, 0.37 mmol) was dissolved in 50 mL of ultra-dry tetrahydrofuran, lyophilized in liquid nitrogen to remove oxygen, and then 0.6 mL of n-butyllithium tetrahydrofuran solution (2 mol / L) was added dropwise under stirring at -78 °C. After the addition was complete, the mixture was stirred at -78 °C for 1 h, and then heated to -50 °C and stirred for another 1.5 h. N,N-dimethylformamide (DMF, 0.12 mL) was then added to the resulting system, and the mixture was heated to room temperature and stirred for 12 h. The reaction was then quenched with water, and the mixture was extracted with ethyl acetate (EA). The resulting organic phase was dried over anhydrous magnesium sulfate, filtered, and the solvent in the filtrate was removed. The crude product was separated by silica gel column chromatography (using dichloromethane as the eluent) to give compound E2 as an orange-red solid (yield 247 mg, 77%).

[0137] 11H NMR (400MHz, Methylene Chloride-d2) δ 9.72 (s, 2H), 7.30 (s, 2H), 1.88 (m, 8H), 1.31 (m, 8H), 1.14 (m, 40H), 0.76 (t, 12H). The 1H NMR spectrum of compound E2 is as follows: Figure 3 As shown.

[0138] Example 4

[0139] The reaction formula for preparing compound E3 is shown below:

[0140]

[0141] In an argon atmosphere, compound D1 (300 mg, 0.37 mmol) was dissolved in 50 mL of ultra-dry tetrahydrofuran, lyophilized in liquid nitrogen to remove oxygen, and then 0.6 mL of n-butyllithium tetrahydrofuran solution (2 mol / L) was added dropwise under stirring at -78 °C. After the addition was complete, the mixture was stirred at -78 °C for 1 h, and then heated to -50 °C and stirred for another 1.5 h. CBr4 (490 mg, 0.37 mmol) was then added to the resulting system, and the mixture was heated to room temperature and stirred for 12 h. The reaction was then quenched with water, and the mixture was extracted with petroleum ether. The resulting organic phase was dried over anhydrous magnesium sulfate, filtered, and the solvent in the filtrate was removed. The crude product was separated by silica gel column chromatography (petroleum ether was used as the eluent) to give compound E3 as a yellow solid (yield of 290 mg, 81%).

[0142] 1 1H NMR (400MHz, Methylene Chloride-d2) δ 6.74 (s, 2H), 1.88 (m, 8H), 1.40–1.01 (m, 48H), 0.85 (t, 12H). The 1H NMR spectrum of compound E3 is as follows: Figure 4 As shown.

[0143] Example 5

[0144] The reaction formula for preparing compound D2 is shown below:

[0145]

[0146] In an argon atmosphere, compound C2 (845 mg, 1 mmol) was dissolved in 30 mL of ultra-dry toluene, and p-toluenesulfonic acid (344 mg, 2 mmol) was added. The mixture was reacted at 110 °C in the dark for 0.5 h. After the reaction was completed, the product system was extracted with saturated sodium chloride aqueous solution and petroleum ether. The resulting organic phase was dried with anhydrous magnesium sulfate, filtered, and the solvent in the filtrate was removed. The crude product was separated by a neutral alumina column (petroleum ether was used as the eluent) to give compound D2 as a yellow solid (yield of 565 mg, yield of 69%).

[0147] 1 1H NMR (400MHz, Benzene-d6) δ 6.57 (d, J = 5.2Hz, 2H), 6.44 (d, J = 5.2Hz, 2H), 2.15 (m, 8H), 1.73–1.53 (m, 8H), 1.16 (m, 40H), 0.87 (t, J = 7.0Hz, 12H). The 1H NMR spectrum of compound D2 is as follows: Figure 5 As shown.

[0148] Example 6

[0149] The reaction formula for preparing compound E4 is shown below:

[0150]

[0151] In an argon atmosphere, compound D2 (122 mg, 0.15 mmol) was dissolved in 40 mL of n-hexane, and N-bromosuccinimide (NBS, 53.4 mg, 0.3 mmol) was added at 0 °C. The reaction was carried out at 0 °C for 5 min. After the reaction was completed, the resulting product system was separated by vacuum silica gel column chromatography (petroleum ether was used as the eluent), and the solvent in the resulting liquid was removed by vacuum evaporation to obtain compound E4 as a yellow solid (yield of 140 mg, yield of 96%).

[0152] 1 1H NMR (400MHz, Benzene-d6) δ 6.57 (s, 2H), 2.18–2.00 (m, 8H), 1.69–1.57 (m, 8H), 1.17 (m, 40H), 0.87 (t, 12H). The 1H NMR spectrum of compound E4 is as follows: Figure 6 As shown.

[0153] Example 7

[0154] The reaction formula for preparing compound 4TOC-2QC is shown below:

[0155]

[0156] In an argon atmosphere, compound E1 (193 mg, 0.17 mmol) and compound QC-Br (98 mg, 0.36 mmol) were added to a 50 mL Shrek flask, dissolved in 10 mL of ultra-dry toluene, then lyophilized in liquid nitrogen to remove oxygen. Pd(PPh3)4 (19.6 mg, 0.017 mmol) was added, and the mixture was refluxed at 110 °C for 3 h. The mixture was extracted with dichloromethane, and the resulting organic phase was dried over anhydrous magnesium sulfate, filtered, and the solvent in the filtrate was removed. The crude product was separated by silica gel column chromatography (the eluent used was petroleum ether:dichloromethane = 2:1 by volume) to give compound 4TOC-2QC as a brown solid (yield 126 mg, 61%).

[0157] 1 1H NMR (400MHz, Chloroform-d) δ 8.87–8.77 (m, 2H), 8.39–8.30 (m, 2H), 7.96 (s, 2H), 7.87–7.71 (m, 4H), 7.53 (s, 2H), 2.00 (s, 8H), 1.17 (m, 40H), 0.84 (s, 12H). The 1H NMR spectrum of compound 4TOC-2QC is as follows: Figure 7 As shown.

[0158] Figure 8 The UV-Vis absorption spectrum of compound 4TOC-2QC is shown. The results show that, according to the formula Eg(eV)=1240 / λ(onset), the optical band gap of compound 4TOC-2QC is 0.78eV.

[0159] Cyclic voltammetry (CV) was used to determine the energy levels of compound 4TOC-2QC. The three-electrode system used was as follows: glassy carbon electrode as the working electrode, platinum wire electrode as the counter electrode, and saturated calomel electrode as the reference electrode; tetrabutylammonium hexafluorophosphate (Bu4NPF6, 0.1 mol / L) was used as the supporting electrolyte, and the scan rate was 100 Mv / s. Specifically, compound 4TOC-2QC was prepared into a 10% concentration using ultra-dry dichloromethane. -3 The compound was tested with a mol / L solution of 4TOC-2QC and finally standardized with ferrocene. Figure 9 The cyclic voltammogram of compound 4TOC-2QC is shown. Based on the redox potential, the LUMO level of compound 4TOC-2QC is -4.20 eV and the HOMO level is -5.13 eV. This indicates that compound 4TOC-2QC has suitable molecular energy levels, which are conducive to balanced carrier transport and suppress charge accumulation and recombination.

[0160] Table 1 compares compound 4TOC-2QC with compound CO in the prior art (Mater. Chem. Front., 2018, 2, 700-703). i Comparison of energy level band gaps for 6DFIC (an aryl side-chain fused ring compound), wherein the compound CO i The structural formula of 6DFIC is shown below:

[0161]

[0162] Table 1. Compound 4TOC-2QC and Compound CO i Comparison results of energy level band gaps in 6DFIC

[0163]

[0164] As shown in Table 1, compared with the previously reported narrowest bandgap compound CO... i Compared with 6DFIC, the optical bandgap of compound 4TOC-2QC in this invention is significantly reduced.

[0165] Example 8

[0166] The polymer 4TOC-DCNBT was prepared according to the following reaction formula:

[0167]

[0168] In an argon atmosphere, compound E1 (56.7 mg, 0.050 mmol) and dicyandibromobenzothiadiazole (17.2 mg, 0.050 mmol) were added to a 10 mL Shrek flask, dissolved in 1 mL of ultra-dry toluene, then lyophilized in liquid nitrogen to remove oxygen. Pd(PPh3)4 (5.8 mg, 0.0050 mmol) was added, and the mixture was refluxed at 110 °C for 12 h. After the reaction, the resulting product system was precipitated in methanol, and the precipitate was purified by Soxhlet extraction with methanol, acetone, hexane, and chloroform. The chloroform solution was concentrated and then precipitated in methanol. The solid material was collected by filtration to obtain polymer 4TOC-DCNBT (80%). Gel permeation chromatography (GPC): Mn = 14.5 kDa. λ(onset) = 1100nm.

[0169] Example 9

[0170] The reaction formula for preparing compound Q4TCO is shown below:

[0171]

[0172] In an argon atmosphere, compound E4 (97 mg, 0.1 mmol), 1,3-indanedione (2.1 mmol), Pd(PPh3)4 (11.6 mg, 0.01 mmol), sodium hydride (4.3 mmol), and 10 mL of 1,4-dioxane were added to a Shrek flask and reacted at 70 °C in the dark for 12 h. After the reaction was completed, the mixture was cooled to room temperature, and the reaction was quenched with deionized water. Oxidation was then carried out in air with stirring for 30 min. After the oxidation was complete, the resulting product was extracted with dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and the filtrate was evaporated to dryness. Separation was performed by silica gel column chromatography (eluent: petroleum ether:dichloromethane = 1:2 by volume). Vacuum drying yielded a metallic solid, which was compound Q4TCO, with a yield of 63%. λ(onset) = 1010 nm.

[0173] 1 1H NMR (400MHz, Chloroform-d) δ 7.86–7.83 (m, 4H), 7.71–7.64 (m, 6H), 2.06 (M, 8H), 1.26 (m, 40H), 0.84 (s, 12H). The 1H NMR spectrum of compound 4TOC-2QC is as follows: Figure 10 As shown.

[0174] Application Example 1

[0175] Organic thin-film transistors (OTFTs) were fabricated using compound 4TOC-2QC from this invention as a semiconductor material, as shown in the schematic diagram below. Figure 11 As shown, the specific steps are as follows:

[0176] A silicon wafer with a 300 nm thick silicon dioxide layer on its surface was used as a substrate. A 35 nm thick gold (Au) layer was prepared on the substrate using vacuum evaporation as the source / drain electrode. Compound 4TOC-2QC was dissolved in chlorobenzene to obtain a 4 mg / mL solution of compound 4TOC-2QC. In an argon-atmosphere glove box, the 4TOC-2QC solution was spin-coated onto the substrate with the source / drain electrode using a spin coater at a speed of 1000 rpm for 90 s. After spin coating, the substrate was heat-annealed at 150 °C for 10 min and then cooled to room temperature to obtain the active layer. A 600 nm thick PMMA layer was prepared on the surface of the active layer using spin coating as an insulating layer. Then, a 90 nm thick aluminum (Al) layer was prepared on the surface of the insulating layer using vacuum evaporation as the gate electrode to obtain an OTFT device.

[0177] Following the above method, compound CO iOTFT devices were fabricated using 6DFIC as the semiconductor material, and their carrier mobilities were compared with those of OTFT devices fabricated using 4TOC-2QC as the semiconductor material, as shown in Table 2. Table 2 shows that, due to the introduction of the sterically hindered alkyl side chain, the intermolecular interactions are enhanced. Therefore, the carrier mobility of the OTFT device fabricated using compound 4TOC-2QC as the semiconductor material in this invention is superior to that using compound CO. i Carrier mobility of OTFT devices fabricated using 6DFIC as a semiconductor material.

[0178] Table 2 Performance Measurement Results of OTFT Devices

[0179]

[0180] Application Example 2

[0181] Organic photodetectors with an inverted structure were prepared using the compound 4TOC-2QC from this invention. The structure is represented as ITO / ZnO / active layer(PTB7-Th:4TOC-QC) / MoO3 / Ag, and the schematic diagram is shown below. Figure 12 As shown, the preparation process is as follows:

[0182] Using ITO glass as a substrate, the substrate was sequentially ultrasonically cleaned with isopropanol, deionized water, acetone, deionized water, semiconductor cleaning solution, deionized water, and isopropanol, followed by UVO cleaning for 30 minutes. A zinc oxide precursor was prepared in advance by mixing 1g of zinc acetate, 10mL of ethylene glycol monomethyl ether, and 280μL of ethanolamine, adding the mixture to a magnetic rotor, and stirring at 60°C for 12 hours. The substrate was then placed on a spin coater, and the zinc oxide precursor was spin-coated onto the substrate. The substrate was then heated at 200°C for 60 minutes to form a dense zinc oxide film.

[0183] 0.2% (v / v) of 1-chloronaphthalene was added to CHCl3 to obtain a mixed solution. PTB7-Th and 4TOC-QC were dissolved in the mixed solution at a mass ratio of 1:1.2 to obtain a PTB7-Th:4TOC-QC solution with a total concentration of 15 mg / mL. The PTB7-Th:4TOC-QC solution was spin-coated onto the surface of the zinc oxide film at a spin speed of 1600 rpm for 30 s. After spin-coating, the film was annealed at 110 °C for 5 min to obtain the active layer.

[0184] Vacuum evaporation method (vacuum degree 10) was used. -5Pa) sequentially prepares a MoO3 layer with a thickness of 5 nm and an Ag electrode with a thickness of 80 nm on the surface of the active layer to obtain an organic photodetector.

[0185] Table 3 shows the performance parameters of the organic photodetector, where λ * Where D* is the wavelength corresponding to the maximum D* in the near-infrared region, Bias is the bias voltage applied to the device, and D* is the specific detectivity. The results show that the organic photodetector prepared using compound 4TOC-2QC of this invention as the active layer has excellent detection performance in the near-infrared II region (wavelength greater than 1000 nm).

[0186] Table 3 Performance parameters of organic photodetectors

[0187]

[0188] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. Application of ultra-narrow bandgap organic semiconductor materials in organic optoelectronic devices, wherein the organic optoelectronic device is an organic photodetector, and the organic photodetector sequentially comprises a substrate, an anode, a hole transport layer, an active layer, an electron transport layer, and a cathode; the substrate and the anode are ITO glass; the hole transport layer is made of zinc oxide; the active layer is prepared by combining PTB7-Th with the ultra-narrow bandgap organic semiconductor material; the electron transport layer is made of molybdenum trioxide; and the cathode is made of silver. The ultra-narrow bandgap organic semiconductor material is compound 4TOC-2QC, with the following structural formula: 。

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