A conjugated small molecule semiconductor material containing a condensed ring structure and its application

Abstract

The present invention discloses a conjugated small molecule semiconductor material containing a condensed ring structure and an application thereof. The conjugated small molecule semiconductor material containing a condensed ring structure has an acceptor-donor-acceptor structure; the structural formula of the conjugated small molecule semiconductor material containing a condensed ring structure is: The conjugated small molecule semiconductor material containing a condensed ring structure has the characteristics of repeated acceptor-donor-acceptor units and long absorption. A photodetector device using the conjugated small molecule semiconductor material as an active layer can effectively extend the response wavelength from visible light to a near-infrared region, thereby improving the sensitivity of the organic photodetector in the near-infrared band.

Description

Technical Field

[0001] The present invention relates to the field of organic semiconductor materials, and in particular to a conjugated small molecule semiconductor material containing a condensed ring structure and application thereof. Background Art

[0002] Photoelectric detectors are photoelectric devices that convert optical signals into electrical signals. In addition to converting optical signals into electrical signals, general photoelectric systems can also process electrical signals in different ways according to different needs, and store them for application in various fields. Infrared reconnaissance and air warning in the military field are inseparable from photoelectric detectors. In the civilian field, fire alarms, weather forecasts, forest fire prevention, etc. rely on the technical support of photoelectric detectors.

[0003] Organic photodetectors have attracted widespread attention due to their low cost and potential advantages in preparing large-area, flexible optoelectronic devices, especially in the fields of spectral detection and imaging.

[0004] Small molecule semiconductor materials containing condensed ring structures play an important role in realizing high-performance organic electronic devices (Angew. Chem. Int. Ed., 2017, 56, 2250-2259). Due to the planarity of their structures, molecules containing condensed rings have strong intermolecular forces and thus strong intermolecular charge transfer capabilities. Currently, heterocyclic molecules with condensed rings have become a research hotspot in the field of organic semiconductor materials.

[0005] However, the absorption peak of currently commonly used fused-ring small molecules, such as Y6 small molecules, is 821nm, and the absorption band edge is only 931nm, which limits their application in longer wavelength regions, such as in infrared night vision devices, optical communications, biological detection and other fields.

[0006] In summary, it is urgent to develop a new technical solution to solve the problems existing in the existing technology and meet the needs of practical applications. Summary of the invention

[0007] Based on this, the present invention provides a conjugated small molecule semiconductor material with a long absorption and a condensed ring structure having repeated acceptor-donor-acceptor units and its application. A photodetector device using an active layer containing the conjugated small molecule semiconductor material can effectively extend the response wavelength from visible light to the near-infrared region, thereby improving the sensitivity of the organic photodetector in the near-infrared band.

[0008] One object of the present invention is to provide a conjugated small molecule semiconductor material containing a condensed ring structure, wherein the conjugated small molecule semiconductor material containing a condensed ring structure has an acceptor-donor-acceptor structure;

[0009] The structural formula of the conjugated small molecule semiconductor material containing a condensed ring structure is:

[0010]

[0011] in,

[0012] R is selected from a C1-C36 straight or branched alkyl chain;

[0013] The BD unit is selected from a mono- or poly-aromatic ring structure, or a mono- or poly-aromatic heterocyclic structure;

[0014] The Ar unit is selected from a mono- or poly-aromatic ring structure, or a mono- or poly-aromatic heterocyclic structure.

[0015] It is worth noting that when the BD unit is an electron donor, and The donor unit is formed. is the receptor unit;

[0016] or

[0017] When the BD unit is an electron acceptor, is the donor unit, and constitute the receptor unit.

[0018] BD and Ar described in the present invention may be, but are not limited to, phenyl, biphenyl, indanyl, naphthyl, thienyl, furanyl, pyrrolyl, pyridyl, imidazolyl, acridinyl, azetidinyl, azinyl, benzimidazolyl, benzofuranyl, benzothiofuranyl, benzothiophenyl, benzoxazolyl, benzoxazolinyl, benzothiazolyl, benzotriazolyl, benzotetrazolyl, benzisoxazolyl, benzisothiazolyl, benzimidazolinyl, carbazolyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, 2-pyrrolidinone, 2H-pyrrolyl, quinazolinyl, quinolyl, 4H-quinolizinyl, quinoxalinyl, quinuclidine, tetrakis One or more of oxazolyl, tetrahydrofuranyl, tetrahydroisoquinolyl, tetrahydroquinolyl, 6H-1,2,5-thiadiazinyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, thianthrenyl, thiazolyl, thienyl, thiazolyl ...

[0019] Further, the BD unit is selected from the following structures:

[0020]

[0021] in,

[0022] R1 is selected from a C1-C36 linear or branched alkyl chain.

[0023] Further, the Ar unit is selected from the following structures:

[0024]

[0025] in,

[0026] X1 is selected from one or more of a hydrogen atom, a halogen atom, a cyano group, and a nitro group. Further, R is selected from the following structures:

[0027]

[0028] Furthermore, the BD unit is preferably of the following structure:

[0029]

[0030] Further, the Ar unit is preferably the following structure:

[0031]

[0032] Furthermore, the conjugated small molecule semiconductor material containing a condensed ring structure is selected from the following structures:

[0033]

[0034] Another object of the present invention is to provide a photoactive layer, comprising a donor polymer material and the above-mentioned conjugated small molecule semiconductor material containing a condensed ring structure.

[0035] Furthermore, the donor polymer material is PTB7-Th.

[0036] Furthermore, the donor polymer material and the conjugated small molecule semiconductor material containing a condensed ring structure are blended in a mass ratio of 1:(1-2).

[0037] Another object of the present invention is to provide a photodetector comprising the above-mentioned photoactive layer.

[0038] Another object of the present invention is to provide an application of the above-mentioned conjugated small molecule semiconductor material containing a condensed ring structure in improving the detection wavelength of a photodetector.

[0039] The present invention has the following beneficial effects:

[0040] The present invention discloses a conjugated small molecule semiconductor material with a condensed ring structure and an acceptor-donor-acceptor structure. Compared with the condensed ring small molecule Y6, the donor (D) unit in the small molecule of the present invention has a stronger electron donating ability, and improves the intermolecular stacking effect, so that the molecule has a stronger donor-acceptor (DA) effect and a tighter stacking. The test results show that the small molecule in the present invention has a more red-shifted absorption, the absorption peak is greater than 900nm, the absorption band edge is greater than 1000nm, and the maximum can reach nearly 1300nm, showing good application potential in near-infrared photoelectric detection. Using the conjugated small molecule semiconductor material of the present invention as the acceptor material of the photodetector can effectively extend the response wavelength from the visible light to the near-infrared region, and improve the sensitivity of the organic photodetector in the near-infrared band response. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic structural diagram of a photoelectric detection device is shown.

[0042] Figure 2 Absorption spectra of small molecule receptors are shown.

[0043] Figure 3 A diagram showing the energy level test results of a small molecule receptor is shown.

[0044] Figure 4 A performance test result diagram of a photoelectric detector is shown;

[0045] in,

[0046] Figure 4 (a) is the dark current density test result diagram;

[0047] Figure 4 (b) is the photocurrent density test result diagram;

[0048] Figure 4 (c) is the external quantum efficiency (EQE) test result diagram;

[0049] Figure 4 (d) is the feature detection rate diagram. DETAILED DESCRIPTION

[0050] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0051] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0052] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers expressing, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all instances by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0053] The structural formula of PTB7-Th in the application example of the present invention is

[0054]

[0055] Example 1

[0056] The synthesis of m-CNTIC-4F, the synthesis route is as follows:

[0057]

[0058] First, compound 1 was reacted with boron tribromide to obtain compound 2, which was then functionalized with bromohexane to obtain compound 3, which was then ring-closed to obtain compound 4, which was then brominated to obtain compound 5. Compound 6 was then formed by phosphorus oxychloride. Compound 7 was obtained by coupling, and finally reacted with cyanoindanone to obtain m-CNTIC-4F.

[0059] Specifically, the steps include:

[0060] S1. Synthesis of compound 2: Compound 1 (1000 mg, 1.852 mmol) was placed in a pre-dried 250 mL bottle and anhydrous DCM (40 mL) was added to prepare a solution. The solution was cooled to -78°C, and then a solution of boron tribromide (1 mol) dissolved in n-hexane (11.11 mL) was added dropwise under argon protection. The resulting mixture was kept at -78°C for 1.5 h, then returned to room temperature for overnight reaction, and then extracted with water and dichloromethane, and washed with water 3 times. The obtained organic layer was dried with magnesium sulfate and then concentrated under reduced pressure. The target product (900 mg) was obtained with a yield of about 90%.

[0061] S2. Synthesis of compound 3: Compound 2 (900 mg, 3.72 mmol), potassium carbonate solid (1.5 g, 10.87 mmol) and bromohexane (1.6 g, 9.7 mmol) were added to a pre-dried 250 mL bottle, and DMF (50 mL) was added to react at 75°C overnight, extracted with water and dichloromethane, and washed with water 3 times. The organic layer was dried over magnesium sulfate and further purified by column chromatography using dichloromethane / petroleum ether (v / v, 1:4) as the eluent. Finally, the product was concentrated under reduced pressure to obtain the product (810 mg) with a yield of 60%. 1H NMR(400MHz,Chloroform-d)δ7.52(dd,J=2.6,1.6Hz,2H),7.46(dt,J=7.6,1.3Hz,2H),7.38( t,J=7.9Hz,2H),7.19(ddd,J=8.2,2.7,1.1Hz,2H),4.01(t,J=6.5Hz,4H),1.85–1.74(m,4H).

[0062] S3. Synthesis of compound 4: Compound 3 (810 mg, 1.97 mmol), triethylamine (0.4 mL) and 3,4-diaminothiophene (250 mg, 1.97 mmol) were placed in a pre-dried 250 mL bottle, ethanol (80 mL) was added, and the mixture was stirred at room temperature for 48 h. The mixture was extracted with water, the organic phase was extracted with dichloromethane, and the mixture was washed three times with water. The organic layer was dried over magnesium sulfate and further purified by column chromatography using dichloromethane / petroleum ether (v / v, 1:2) as the eluent. The mixture was concentrated under reduced pressure to obtain the product (400 mg) with a yield of 50%. 1H NMR(400MHz,Chloroform-d)δ8.05(s,2H),7.22–7.17(m,2H),6.99(dd,J=7.2,1.5Hz,4H),6 .91–6.86(m,2H),3.82(t,J=6.6Hz,4H),1.73–1.66(m,4H),1.59(s,6H),0.94–0.89(m,6H).

[0063] S4. Synthesis of compound 5: Compound 4 (400 mg, 0.82 mmol) was added to a pre-dried 250 mL bottle, and DMF (30 mL) was added, and N-bromosuccinimide (145.2 mg, 0.82 mmol) was slowly added dropwise at 0°C, and the mixture was returned to room temperature for overnight reaction after 1.5 h, and then extracted with water, and the organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic layer was dried with magnesium sulfate. Dichloromethane / petroleum ether (v / v, 1:4) was used as an eluent for column chromatography for further purification, and finally concentrated under reduced pressure to obtain the product (330 mg) with a yield of 71%. 1H NMR(500MHz,Chloroform-d)δ8.07(s,1H),7.22(td,J=7.9,4.3Hz,2H),7.09–7.03(m,2H),7.02–6.97(m,2H), 6.91(ddd,J=8.4,2.5,1.2Hz,2H),3.84(td,J=6.6,1.4Hz,4H),1.75–1.69(m,4H),0.93(td,J=7.0,1.5Hz,6H).

[0064] S5. Synthesis of compound 6: Compound 5 (300 mg, 0.52 mmol) was added to a pre-dried 250 mL bottle, and then anhydrous dichloroethane (30 mL) was added, and the solution temperature was lowered to 0 ° C. Phosphorus oxychloride (0.1 mL, 1.05 mmol) and DMF (0.15 mL, 2.1 mmol) were added under argon protection, and the reaction was carried out at this temperature for 30 min, and then the temperature was returned to room temperature, and the reaction was heated to 60 ° C after 2 h, and the reaction was allowed to proceed overnight. The organic phase was extracted with water, and the organic phase was extracted with dichloromethane, washed with water three times, and the obtained organic layer was dried with magnesium sulfate, and dichloromethane / petroleum ether (v / v, 1:2) was used as an eluent for column chromatography for further purification, and finally concentrated under reduced pressure to obtain the product (240 mg). 1HNMR (400MHz, Chloroform-d) δ10.69 (s, 1H), 7.23 (td, J=7.9, 3.1Hz, 2H), 7.07 (dt, J=5.2, 2.0Hz, 2H), 7.03 (ddt, J=7. 7,6.5,1.2Hz,2H),6.94(tdd,J=8.2,2.6,1.0Hz,2H),3.84(td,J=6.6,3.3Hz,4H),1.75–1.69(m,4H),0.95–0.89(m,6H).

[0065] S6. Synthesis of compound 7: Compound 6 (240 mg, 0.4 mmol), 2,6-bis(trimethyltin)-4,4-bis(2-ethylhexyl)-dithienocyclopentadiene (157.95 mg, 0.16 mmol) and tetrakistriphenylphosphine palladium (14.85 mg, 0.012 mmol) were added to a pre-dried 250 mL bottle. Anhydrous toluene (30 mL) was added, and the mixture was reacted overnight at 110° C., extracted with water, and the organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic layer was dried with magnesium sulfate, and further purified by column chromatography using dichloromethane / petroleum ether (v / v, 1:1) as an eluent, and finally concentrated under reduced pressure to obtain the product (200 mg). 1H NMR(500MHz,Chloroform-d)δ10.67(d,J=0.8Hz,2H),7.82(s,2H),7.32(t,J=7.9Hz,2H),7.26–7.21(m,4H),7.12(dt,J=2.6, 1.3Hz,2H),7.07(ddt,J=5.5,2.8,1.4Hz,4H),6.97(td,J=8.1,2.6Hz,4H),3.85(dt,J=19.3,6.6Hz,8H),0.72–0.60(m,12H).

[0066] Synthesis of S7.m-CNTIC-4F: Compound 7 (200 mg, 0.17 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (118.98 mg, 0.51 mmol) were added to a pre-dried 250 mL bottle, and then anhydrous chloroform (20 mL) was added. Pyridine (0.6 mL) was added under argon protection, and the reaction was carried out at 70 ° C overnight. Extract with water, extract the organic phase with dichloromethane, wash with water three times, and dry the obtained organic layer with magnesium sulfate. Dichloromethane / petroleum ether (v / v, 2:1) was used as the eluent for column chromatography for further purification, and finally concentrated under reduced pressure to obtain the product (180 mg). 1H NMR(500MHz,Chloroform-d)δ10.14(d,J=1.4Hz,2H),8.55(dd,J=9.9,6.4Hz,2H),8.12(s,2H),7.70(t,J=7.4Hz,2H),7.39(dt,J=14.4,7.8Hz, 6H),7.23(d,J=3.8Hz,4H),7.13(q,J=1.9Hz,2H),7.07–7.04(m,2H),7.00(dt,J=5.9,2.6Hz,2H),3.97(t,J=6.6Hz,4H),3.88(t,J=6.7Hz,4H).

[0067] Example 2

[0068] The synthesis route of ICS-EH-4F is as follows:

[0069]

[0070] Specifically, the steps include:

[0071] S1. Synthesis of compound 10: Compound 9 (167.7 mg, 0.5 mmol), 2,6-bis(trimethyltin)-4,4-bis(2-ethylhexyl)-dithienocyclopentadiene (145.7 mg, 0.2 mmol) and tetrakis(triphenylphosphine)palladium (15.8 mg, 0.015 mmol) were added to a pre-dried 100 mL round-bottom flask, and then anhydrous toluene (30 mL) was added, and the mixture was reacted at 110°C overnight. The reaction was quenched with water. The organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic phase was dried over anhydrous magnesium sulfate. After removing the solvent by a rotary evaporator, it was separated and purified by silica gel column chromatography (petroleum ether / dichloromethane, v / v, 1 / 2) to obtain a red oily liquid with a metallic luster.

[0072] Synthesis of S2.ICS-EH-4F: Compound 10 (100 mg, 0.11 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (126.59 mg, 0.55 mmol) were added to a pre-dried 50 mL round-bottom flask under argon protection, and anhydrous chloroform (20 mL) was added to dissolve the reaction substrate. Pyridine (0.6 mL) was added and the reaction was allowed to proceed overnight at 70 ° C. The reaction was quenched with water. The organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic phase was dried over anhydrous magnesium sulfate. After removing the solvent by rotary evaporator, silica gel column chromatography was used for separation and purification (petroleum ether / dichloromethane, v / v, 1 / 2) to obtain a green solid (60 mg). 1HNMR(400MHz,Chloroform-d)δ8.73(s,2H),8.55(dd,J=9.9,6.5Hz,2H),7.80–7.66(m,6H),3.00(dt,J=6.2,1.7Hz,4H),2.01(p,J=9.1Hz,4H), 1.64(dt,J=12.3,6.2Hz,3H),1.47(dp,J=20.9,7.1,6.5Hz,8H),1.30(s ,12H),1.09–0.86(m,31H),0.72(t,J=6.2Hz,9H),0.66(t,J=6.8Hz,6H).

[0073] Example 3

[0074] The synthesis of CPTNC-4F, the synthesis route is as follows:

[0075]

[0076] Specifically, the steps include:

[0077] S1. Synthesis of compound 13: Compound 12 (240.27 mg, 0.5 mmol), 2,6-bis(trimethyltin)-4,4-bis(2-ethylhexyl)-dithienocyclopentadiene (145.7 mg, 0.2 mmol) and tetrakis(triphenylphosphine)palladium (15.8 mg, 0.015 mmol) were added to a pre-dried 100 mL round-bottom flask, and anhydrous toluene (30 mL) was added, and the mixture was reacted at 110°C overnight. The reaction was quenched with water. The organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic phase was dried over anhydrous magnesium sulfate. After removing the solvent by a rotary evaporator, it was separated and purified by silica gel column chromatography (petroleum ether / dichloromethane, v / v, 1 / 2) to obtain a red oily liquid with a metallic luster.

[0078] Synthesis of S2.CPTNC-4F: Compound 13 (100 mg, 0.08 mmol) and 2-(6,7-difluoro-3-oxo-2,3-dihydro-1H`cyclopenta[b]naphthalene-1-yl)malononitrile (114.89 mg, 0.41 mmol) were added to a pre-dried 50 mL round-bottom flask under argon protection, and anhydrous chloroform (20 mL) was added to dissolve the reaction substrate. Pyridine (0.6 mL) was added and the reaction was allowed to proceed overnight at 70 ° C. The reaction was quenched with water. The organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic phase was dried over anhydrous magnesium sulfate. After removing the solvent by rotary evaporator, silica gel column chromatography was used for separation and purification (petroleum ether / dichloromethane, v / v, 1 / 2) to obtain a green solid (58 mg). 1H NMR(400MHz,Chloroform-d)δ9.06(d,J=35.6Hz,4H),8.20(s,2H),7.76(dt,J=18.2,9.2Hz,4H),7.64(t,J=2.5Hz,2H),4.20 (d,J=34.9Hz,8H),2.08–1.94(m,4H),1.57–1.19(m,65H),1.10–0.86(m,31H),0.76(t,J=6.6Hz,9H),0.67(t,J=7.2Hz,6H).

[0079] Example 4

[0080] The synthesis of p-CNTIC-4F, the synthesis route is as follows:

[0081]

[0082] Specifically, the steps include:

[0083] S1. Synthesis of compound 16: Compound 15 (290 mg, 0.48 mmol), 2,6-bis(trimethyltin)-4,4-bis(2-ethylhexyl)-dithienocyclopentadiene (141.7 mg, 0.2 mmol) and tetrakis(triphenylphosphine)palladium (15.8 mg, 0.015 mmol) were added to a pre-dried 100 mL round-bottom flask, and anhydrous toluene (30 mL) was added, and the mixture was reacted at 110 ° C overnight. The reaction was quenched with water. The organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic phase was dried over anhydrous magnesium sulfate. After removing the solvent by a rotary evaporator, it was separated and purified by silica gel column chromatography (petroleum ether / dichloromethane, v / v, 1 / 1) to obtain a green solid.

[0084] Synthesis of S2.P-CNTIC-4F: Compound 16 (166 mg, 0.115 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (80 mg, 0.35 mmol) were added to a pre-dried 50 mL round-bottom flask under argon protection, and anhydrous chloroform (20 mL) was added to dissolve the reaction substrate. Pyridine (0.6 mL) was added and the reaction was allowed to proceed overnight at 70 ° C. The reaction was quenched with water. The organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic phase was dried over anhydrous magnesium sulfate. After removing the solvent by rotary evaporator, it was separated and purified by silica gel column chromatography (petroleum ether / dichloromethane, v / v, 3 / 2) to obtain a brown solid (158 mg). 1HNMR(400MHz,Chloroform-d)δ10.02(s,2H),8.51–8.43(m,2H),8.05(s,2H),7.71(dd,J=28.4,8.3Hz,9H),7.56(d,J=6.4Hz ,2H),6.98(s,5H),6.80(d,J=7.2Hz,4H),4.09(s,4H),4.00(s,4H),2.07(s,5H),1.85(dp,J=28.6,6.6Hz,11H),0.74(s,15H).

[0085] Example 5

[0086] The synthesis route of CNTIC-2Br is as follows:

[0087]

[0088] Specifically, the steps include:

[0089] S1. Synthesis of compound 16: Compound 16 was prepared according to the method in Example 4.

[0090] Synthesis of S2.CNTIC-2Br: Compound 16 (340 mg, 0.23 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (160 mg, 0.7 mmol) were added to a pre-dried 50 mL round-bottom flask under argon protection, and anhydrous chloroform (20 mL) was added to dissolve the reaction substrate. Pyridine (0.6 mL) was added and the reaction was allowed to proceed overnight at 70 ° C. The reaction was quenched with water. The organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic phase was dried over anhydrous magnesium sulfate. After removing the solvent by rotary evaporator, it was separated and purified by silica gel column chromatography (petroleum ether / dichloromethane, v / v, 3 / 2) to obtain a brown solid (160 mg). 1HNMR(400MHz,Chloroform-d)δ10.08(s,2H),8.62(d,J=110.5Hz,2H),8.07(s,2H),7.77(d,J=5.9Hz,6 H),7.69(d,J=8.0Hz,6H),7.28(s,2H),7.00(d,J=8.2Hz,4H),6.83(d,J=8.3Hz,4H),4.14–3.98(m,8H).

[0091] Example 6

[0092] The synthesis route of CTTIC-4F is as follows:

[0093]

[0094] Specifically, the steps include:

[0095] S1. Synthesis of compound 19: Compound 18 (200 mg, 0.496 mmol), 2,6-bis(trimethyltin)-4,4-bis(2-ethylhexyl)-dithienocyclopentadiene (144 mg, 0.2 mmol) and tetrakis(triphenylphosphine)palladium (15.8 mg, 0.015 mmol) were added to a pre-dried 100 mL round-bottom flask, and anhydrous toluene (30 mL) was added, and the mixture was reacted at 110 ° C overnight. The reaction was quenched with water. The organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic phase was dried over anhydrous magnesium sulfate. After removing the solvent by a rotary evaporator, it was separated and purified by silica gel column chromatography (petroleum ether / dichloromethane, v / v, 2 / 1) to obtain a purple solid.

[0096] Synthesis of S2.CTTIC-4F: Compound 19 (200 mg, 0.19 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (110 mg, 0.48 mmol) were added to a pre-dried 50 mL round-bottom flask under argon protection, and anhydrous chloroform (20 mL) was added to dissolve the reaction substrate. Pyridine (0.6 mL) was added and the reaction was allowed to proceed overnight at 70 ° C. The reaction was quenched with water. The organic phase was extracted with dichloromethane, washed three times with water, and the obtained organic phase was dried over anhydrous magnesium sulfate. After removing the solvent by rotary evaporator, silica gel column chromatography was used for separation and purification (petroleum ether / dichloromethane, v / v, 1 / 1) to obtain a green solid (160 mg). 1HNMR(400MHz,Chloroform-d)δ8.88(s,2H),8.50(s,2H),8.08(s,2H),7.74(d,J=3.0Hz,2H),7.65(t,J=7.4Hz,2H),4.32(d,J=5.9Hz,4H),2.12(s,4H ),1.80(s,2H),1.54–1.21(m,24H),1.19–0.83(m,20H),0.74(d,J=6.8Hz,12H).HRMS(m / z):calcd.forC81H78F4N4O6S6,1471.4215; found:1471.4165.

[0097] Application Example 1

[0098] Photodetection device containing CTTIC-4F receptor small molecule.

[0099] A photodetector device with an ITO / PEDOT:PSS / active layer / ZnO nanoparticles (NCs) / Al structure was prepared. Among them, ITO was the anode, PEDOT:PSS was the anode interface layer, ZnO NCs and Al were the cathode interface layer and cathode, respectively. The active layer was prepared by PTB7-Th donor polymer and CTTIC-4F receptor.

[0100] The preparation method comprises the following steps:

[0101] S1. The ITO substrate was ultrasonically cleaned with detergent, deionized water, acetone, and isopropanol, then dried in an oven and cleaned in a UV ozone machine for 15 minutes. The PEDOT:PSS [poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)] aqueous solution was filtered through a 0.22 μm filter membrane, and then spin-coated on the ITO electrode at 3000 rpm for 30 seconds, and then annealed at 150°C for 10 minutes. The thickness of the PEDOT:PSS layer was about 25 nm. Subsequently, the ITO / PEDOT:PSS substrate was transferred to a glove box filled with nitrogen. The receptor material CTTIC-4F prepared in Example 6 was mixed with PTB7-Th (1.5:1, w / w) and dissolved in chloroform to obtain a mixed solution.

[0102] S2. The mixed solution was spin-coated on the PEDOT:PSS layer to obtain an active layer with a thickness of about 90 nm, and then the active layer was thermally annealed at 100°C for 10 min to optimize the morphology of the active layer. ZnO NCs dispersed in an ethanol solution were spin-coated on the active layer to prepare a cathode interface layer. Finally, the substrate was transferred to a vacuum coating device and heated to 2×10 -6 The Al electrode was deposited at 100 mbar and the thickness of the Al electrode was about 120 nm. The effective area of ​​the device was 0.16 cm 2 .

[0103] Figure 1 A schematic structural diagram of a photoelectric detection device is shown.

[0104] Application Example 2

[0105] The active layer contains PTB7-Th and ICS-EH-4F receptor small molecules.

[0106] The difference between this application example and application example 1 is that ICS-EH-4F is used to replace CTTIC-4F, and other materials and preparation methods are the same as those in application example 1.

[0107] Application Example 3

[0108] The active layer contains PTB7-Th and CPTNC-4F receptor small molecules.

[0109] The difference between this application example and application example 1 is that CPTNC-4F is used to replace CTTIC-4F, and other materials and preparation methods are the same as those in application example 1.

[0110] Application Example 4

[0111] Photodetection device with active layer containing PTB7-Th and CNTIC-2Br acceptor small molecules.

[0112] The difference between this application example and application example 1 is that CNTIC-2Br is used to replace CTTIC-4F, and other materials and preparation methods are the same as those in application example 1.

[0113] Application Example 5

[0114] Photodetection device with active layer containing PTB7-Th and m-CNTIC-4F acceptor small molecules.

[0115] The difference between this application example and application example 1 is that m-CNTIC-4F is used to replace CTTIC-4F, and other materials and preparation methods are the same as those in application example 1.

[0116] Application Example 6

[0117] Photodetection device with active layer containing PTB7-Th and p-CNTIC-4F receptor small molecules.

[0118] The difference between this application example and application example 1 is that p-CNTIC-4F is used to replace CTTIC-4F, and other materials and preparation methods are the same as those in application example 1.

[0119] Comparative Example 1

[0120] The receptor small molecule Y6 was synthesized according to the method reported in the literature (Joule, 2019, 3, 1140-1151.), and its structure is as follows:

[0121]

[0122] Comparative application example 1

[0123] The active layer contains PTB7-Th and Y6 receptor small molecules.

[0124] The difference between this comparative application example and application example 1 is that Y6 is used to replace CTTIC-4F, and other materials and preparation methods are the same as those in application example 1.

[0125] Test Example 1

[0126] Performance tests were performed on the small molecule receptors prepared in the examples and comparative examples and the photoelectric detection devices prepared in the application examples and comparative application examples.

[0127] Test method:

[0128] The photodetector was tested for current density-voltage (JV). -2) The JV curve of the device under light was measured by a computer-controlled Keithley 2400 source measurement unit. The JV characteristic curve of the device in the dark state was measured by a computer-controlled Keithley 2365 source measurement unit in a dark box. The single-color external quantum efficiency was measured at room temperature using a DSR100UV-B spectrometer and an SR830 lock-in amplifier. A bromine tungsten lamp was used as the light source in this test.

[0129] In the field, there are several parameters that can be used to evaluate the quality and effectiveness of experimental photodetectors. One of these parameters is the noise equivalent power (NEP), which is calculated as:

[0130] NEP=(AΔf) 1 / 2 / D*

[0131] Where A is the effective area of ​​the detector, in cm 2 ; Δf is the electrical bandwidth, in Hz; D* is the characteristic detection rate, in Jones. When only the impact of shot noise is considered, the formula can be used:

[0132] D*=EQE×(λ / 1240) / (2qJ d ) 1 / 2

[0133] Calculate the D* value, where q is the absolute charge 1.60×10 -19 C; J d is the dark current density of the device, in A / cm 2 ; λ is the wavelength.

[0134] Test results such as Figure 2 , Figure 3 , Figure 4 And as shown in Table 1.

[0135] Figure 2 Absorption spectra of small molecule receptors are shown.

[0136] Figure 3 A diagram showing the energy level test results of a small molecule receptor is shown.

[0137] Figure 4 A performance test result diagram of a photoelectric detector is shown;

[0138] in,

[0139] Figure 4 (a) is a dark current density-voltage test result diagram;

[0140] Figure 4 (b) Light intensity 100mW / cm 2Photocurrent density-voltage test result diagram under different conditions;

[0141] Figure 4 (c) is the external quantum efficiency (EQE) test result under bias voltage -0.2V;

[0142] Figure 4 (d) is the characteristic detection rate diagram under bias voltage of -0.2V.

[0143] Table 1 shows the performance test results of different photodetectors.

[0144] Table 1 Performance test results of photodetector

[0145]

[0146]

[0147] according to Figure 2 It can be seen that the absorption peak of the small molecule Y6 in Comparative Example 1 is at 821nm, and the small molecules of Examples 1-6 all have a more red-shifted absorption than Y6. The absorption peak of the CTTIC-4F small molecule of the embodiment of the present invention is 966nm, the absorption peak of ICS-4F is 922nm, the absorption peak of CPTNC-4F is 904nm, and the absorption peaks of the remaining small molecules are all greater than 1000nm, among which the absorption peak of CNTIC-2Br is 1079nm, the absorption peak of m-CNTIC is 1111nm, and the absorption peak of p-CNTIC-4F is 1080nm. The present invention designs the molecule, adds a conjugated structure, enhances its planarity, thereby enhancing the intermolecular charge transfer ability, and then gradually red-shifts the absorption peak of the small molecule receptor.

[0148] Figure 3 It is the energy level test result of small molecules in Examples 1-6 and Comparative Example 1, and its highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) are shown in the figure. The LUMO energy levels of the small molecules in Examples 1-6 are -4.17eV, -3.54eV, -3.89eV, -4.13eV, -4.09eV and -4.11eV, respectively. The LUMO energy level of the small molecule Y6 in Comparative Example 1 is -4.10eV. The CTTIC-4F, CNTIC-2Br and p-CNTIC-4F small molecules of the present invention have lower LUMO energy levels than Y6.

[0149] The current-voltage characteristics of the photodetectors prepared in Application Examples 1-6 and Comparative Application Example 1 are as follows: Figure 4 shown. Figure 4 (a) and Figure 4(b) The dark current density and photocurrent density test results of the photodetectors based on these receptor molecules are given respectively. Under a bias voltage of -0.2 V, the device of comparative application example 1 has a 1.52 x 10 -8 A / cm 2 The dark current of CTTIC-4F, CNTIC-2Br, m-CNTIC-4F and p-CNTIC-4F are higher, which are 1.01×10 -6 A / cm 2 , 2.69ⅹ10 -7 A / cm 2 7.84ⅹ10 -7 A / cm 2 and 4.69 x 10 -7 A / cm 2 The devices using ICS-4F and CPTNC-4F have 7.89ⅹ10 -9 A / cm 2 and 7.23 x 10 -9 A / cm 2 The dark current is 0.0210A / cm 2 and 0.0164A / cm 2 The photocurrent is lower than the dark current of Comparative Application Example 1 and the rectification ratio is higher.

[0150] Figure 4 (c) shows the test results of the external quantum efficiency of the photodetector. Compared with the Y6 device in Application Example 1, which has no light response after 960nm, Application Examples 1-6 all have a wider response range than it. Compared with silicon detectors, the photodetector using m-CNTIC-4F has a wider response range, greater than 1200nm.

[0151] Figure 4 (d) shows the characteristic detectivity of the organic photodetector, where the dark current of each device at -0.2 V is shown in Table 1. It can be seen that the detectivity of the devices based on the small molecules of Examples 1-6 is better than that of the photodetector containing Y6 after 950 nm. The detection range of the device containing m-CNTIC-4F can reach 1300 nm, and the detectivity exceeds 10 12 The detection rate of the device in the comparative application example 1 starts to decrease after 900nm. At 950nm, the detection rate (under the bias voltage -0.2V) is 4.30×10 12 Jones. The ICS-4F and CPTNC-4F devices have longer detection ranges, reaching 1070nm and 1020nm respectively; the detectivity at 950nm (under bias voltage -0.2V) is 6.07×10 13 Jones and 4.18×1013 Jones. The detectivities of devices containing CTTIC-4F, CNTIC-2Br, m-CNTIC-4F, and p-CNTIC-4F at 950nm (under bias voltage -0.2V) are 2.99×10 12 Jones, 4.04×10 12 Jones, 8.89×10 12 Jones and 1.05×10 12 Jones, its detection range is also longer, reaching 1200nm, 1220nm, 1300nm and 1200nm.

[0152] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0153] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A conjugated small molecule semiconductor material containing a condensed ring structure, characterized in that: The conjugated small molecule semiconductor material containing a condensed ring structure has the following structural formula: ； in, R is selected from a C1-C36 straight or branched alkyl chain; The Ar unit is selected from the following structures: ； in, X1 is selected from one or more of hydrogen atoms and halogen atoms; The BD unit is selected from the following structures: ； in, R1 is selected from a C1-C36 linear or branched alkyl chain.

2. The conjugated small molecule semiconductor material containing a condensed ring structure according to claim 1, characterized in that: The Ar unit is selected from the following structures: 。 3. The conjugated small molecule semiconductor material containing a condensed ring structure according to claim 1, characterized in that: The R is selected from the following structures: 。 4. The conjugated small molecule semiconductor material containing a condensed ring structure according to claim 1, characterized in that: The conjugated small molecule semiconductor material containing a condensed ring structure is selected from the following structures: 。 5. A photoactive layer, characterized in that: The invention comprises a donor-type polymer material and a conjugated small molecule semiconductor material containing a condensed ring structure as claimed in any one of claims 1 to 4.

6. The photoactive layer according to claim 5, characterized in that: The donor polymer material is PTB7-Th, which has the following structure: 。 7. The photoactive layer according to claim 6, characterized in that: The donor polymer material and the conjugated small molecule semiconductor material containing a condensed ring structure are blended in a mass ratio of 1:(1-2).

Images