Organic short-wave infrared detector acceptor material and preparation method thereof, and infrared photoelectric detector

Abstract

The invention belongs to the technical field of organic optoelectronic materials and devices, and particularly relates to an organic short-wave infrared detector acceptor material, a preparation method and an infrared photoelectric detector. The organic short-wave infrared detector acceptor material has a chemical structural formula shown in the specification. According to the organic short-wave infrared detector acceptor material provided by the invention, the near-infrared function of the acceptor material is realized by adding a conjugated system of the acceptor material, and compared with the conventional organic short-wave infrared material, the wavelength of the acceptor material can reach 1100nm at most, and organic near-infrared molecules can obtain detection with longer wavelength.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic materials and devices technology, specifically relating to organic short-wave infrared detector acceptor materials and their preparation methods, and infrared photodetectors. Background Technology

[0002] Short-wave infrared (SWIR) is an electromagnetic wave invisible to the human eye, with a wavelength range of 0.85 μm to 2.5 μm. The atmospheric transmission spectrum has at least three transmission windows in the infrared band (1.4 μm, 1.6 μm, and 1.9 μm), providing conditions for environmental monitoring, vehicle driving, and reconnaissance under different atmospheric conditions. Infrared photodetectors, as devices that directly convert infrared light signals into identifiable and processable electrical signals, have wide applications in image sensing, environmental monitoring, health monitoring, intelligent driving, optical communication, military aerospace, and intelligent detection of industrial and agricultural products. Composed of an infrared detection unit and a visible light emitting unit, they avoid expensive and complex epitaxial growth and flip-chip bonding processes. The emergence of infrared detection technology effectively fills the spectral gap between near-infrared night vision and infrared thermal imaging, and is of great significance for achieving full-spectrum detection of the atmospheric infrared window and acquiring comprehensive information in the infrared band.

[0003] Current research on conversion devices mainly focuses on optical output, while the electronic signals from the imager remain underutilized. For example, the structure of the organic short-wave near-infrared detector material CO1-4F is shown below:

[0004] .

[0005] The organic short-wave near-infrared detector material CO1-4F can only detect up to 1100 nm, which limits its application range. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides an organic shortwave infrared detector acceptor material and its preparation method, as well as an infrared photodetector.

[0007] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0008] The first objective of this invention is to provide an organic short-wave infrared detector acceptor material having the following chemical structural formula: ; The -EH group has the following chemical structural formula: .

[0009] R has the following chemical structural formula: or .

[0010] Wherein, R1 is hydrogen, halogen, phenyl or substituted phenyl, the substituent of substituted phenyl is halogen, and "*" is the linking site.

[0011] Furthermore, R1 is hydrogen, fluorine, chlorine, phenyl, or a substituted phenyl group, and the substituent of the substituted phenyl group is fluorine or chlorine.

[0012] Furthermore, R has the following chemical structural formula: .

[0013] Furthermore, the organic short-wave infrared detector acceptor material has the following chemical structural formula: .

[0014] A second objective of this invention is to provide a method for preparing the above-mentioned organic short-wave infrared detector acceptor material, comprising the following steps: Under a protective gas atmosphere, compounds a and b were used as raw materials to carry out aldol condensation or substitution reactions in a system of alkali or catalyst and reaction solvent to obtain organic short-wave infrared detector acceptor materials. When compound a is compound a1, compound b is compound b1, and the synthesis reaction formula is shown below: ; When compound a is compound a2, compound b is compound b2, and the synthesis reaction formula is shown below: .

[0015] Furthermore, when compound a is compound a1 and compound b is compound b1, the aldol condensation reaction is carried out at room temperature for 10-14 hours, and the molar ratio of compound 1 to compound 2 is 1-2:2-6.

[0016] Furthermore, when compound a is compound a2 and compound b is compound b2, the substitution reaction is carried out at 110℃ for 18h to 14h, and the molar ratio of compound 1 to compound 3 is 9 to 11: 19 to 25.

[0017] The third objective of this invention is to provide an infrared photodetector, which, along the thickness of the infrared photodetector, sequentially comprises, from bottom to bottom, a substrate layer, a hole transport layer, a functional layer, an electron transport layer, and an electrode layer, wherein the functional layer is a host material and a receptor material doped in the host material, and the receptor material is the aforementioned organic short-wave infrared detector receptor material.

[0018] Furthermore, the doping concentration of the acceptor material is 1wt% to 10wt%, and the host material is PTB7-Th.

[0019] Compared with the prior art, the present invention has the following advantages: The organic short-wave infrared detector acceptor material provided by this invention achieves a longer wavelength by increasing the conjugation degree of the organic material molecules and thus increasing their conjugation system. Compared to previous organic short-wave infrared materials with a maximum wavelength of 1100 nm, the acceptor material provided by this invention can reach a wavelength of 1400 nm by increasing the conjugation system of the acceptor material. This acceptor material has a narrow bandgap, which facilitates current injection, thereby achieving high external quantum efficiency. Attached Figure Description

[0020] Figure 1 This is a wavelength test diagram of the organic short-wave infrared detector acceptor material of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the organic shortwave infrared detector of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Currently, most organic short-wave near-infrared materials can only be detected up to 1100 nm. The structure of organic short-wave near-infrared materials is shown below:

[0024] .

[0025] The organic short-wave near-infrared detector material is CO1-4F, with a wavelength of 1100 nm. Therefore, in order to break through the 1100 nm detection range, the organic short-wave near-infrared detector material designed in this invention achieves detection at a greater distance by expanding the conjugated system of the material itself.

[0026] The first objective of this invention is to provide an organic short-wave infrared detector acceptor material having the following chemical structural formula: ; The -EH group has the following chemical structural formula: .

[0027] R has the following chemical structural formula: .

[0028] Wherein, R1 is hydrogen, halogen, phenyl or substituted phenyl, the substituent of substituted phenyl is halogen, and "*" is the linking site.

[0029] This invention achieves near-infrared functionality by increasing the conjugation system of the acceptor material. Compared to previous organic short-wave infrared materials, its wavelength can reach up to 1100 nm, and organic near-infrared molecules can achieve detection with longer wavelengths.

[0030] The following specific examples will provide further explanation.

[0031] Example 1 A method for preparing an organic shortwave infrared detector acceptor material includes the following steps: Compound a1 (500 mg, 0.45 mmol) was added to a 100 mL flask, followed by 20 mL of chloroform. The mixture was stirred under nitrogen protection, and then compound b1-1 (175 mg, 0.90 mmol) was added. After stirring for 5 min, 0.2 mL of pyridine was added, and the mixture was reacted under nitrogen and at room temperature for 12 hours. After the reaction was completed, the solvent was removed from the reaction system, and column chromatography was used to separate the dark green solid powder material 1, with a yield of 42%, which is the organic short-wave infrared detector acceptor material.

[0032] HRMS (APCI) m / z: [M + H] + calcd for C 86 H 83 N4O2S8 + , 1459.4276; found, 1459.4278.

[0033] Its synthetic route is as follows: .

[0034] EH has the following chemical structural formula: .

[0035] "*" indicates a connection point.

[0036] Example 2 A method for preparing an organic shortwave infrared detector acceptor material includes the following steps: Compound 1 (500 mg, 0.45 mmol) was added to a 100 mL flask, followed by 20 mL of chloroform. The mixture was stirred under nitrogen protection, then compound 4 (207 mg, 0.90 mmol) was added. After stirring for 5 min, 0.2 mL of pyridine was added, and the reaction was continued under nitrogen and at room temperature for 12 hours. After the reaction was complete, the solvent was removed from the reaction system, and column chromatography was used to separate the dark green solid powder material 3, with a yield of 46%, which is the organic short-wave infrared detector acceptor material.

[0037] HRMS (APCI) m / z: [M + H] + calcd for C 86 H 79 F4N4O2S8 + , 1531.3899; found, 1531.3894.

[0038] Its synthetic route is as follows: .

[0039] EH has the following chemical structural formula: .

[0040] "*" indicates a connection point.

[0041] Example 3 A method for preparing an organic shortwave infrared detector acceptor material includes the following steps: Compound a2 (500 mg, 0.36 mmol), compound b2-1 (377 mg, 0.76 mmol), and tetrakis(triphenylphosphine)palladium (23 mg, 0.02 mmol) were added to a 50 mL flask. Under nitrogen protection, 20 mL of toluene was added, and the reaction system was placed at 110 °C for 20 hours. After the reaction was complete, the temperature was lowered to room temperature, the solvent was removed, and column chromatography was performed to obtain a black solid powder material 9 with a yield of 51%, which is the organic short-wave infrared detector acceptor material.

[0042] HRMS (APCI) m / z: [M + H] + calcd for C 110 H 119 N4O4S 10 +,1879.6433; found,1879.6437.

[0043] Its synthetic route is as follows: .

[0044] EH has the following chemical structural formula: .

[0045] "*" indicates a connection point.

[0046] Example 4 A method for preparing an organic shortwave infrared detector acceptor material includes the following steps: Compound a2 (500 mg, 0.36 mmol), compound b2-3 (404 mg, 0.76 mmol), and tetrakis(triphenylphosphine)palladium (23 mg, 0.02 mmol) were added to a 50 mL flask. Under nitrogen protection, 20 mL of toluene was added, and the reaction system was placed at 110 °C for 20 hours. After the reaction was complete, the temperature was lowered to room temperature, the solvent was removed, and column chromatography was performed to obtain a black solid powder material 11 with a yield of 53%, which is the organic short-wave infrared detector acceptor material.

[0047] HRMS (APCI) m / z: [M + H] + calcd for C 94 H 81 F4N4O4S 10 + , 1725.3396; found, 1725.3394.

[0048] Its synthetic route is as follows: .

[0049] EH has the following chemical structural formula: .

[0050] "*" indicates a connection point.

[0051] The performance of the organic shortwave infrared detector acceptor materials prepared in Examples 1 to 4 was tested, and the results are shown in Table 1.

[0052] Table 1. Photophysical characterization data of organic shortwave infrared detector acceptor materials As shown in Table 1, the HOMO, LUMO, and Eg of acceptor materials 1, 3, 9, and 11 are listed in Table 1. All materials have achieved small energy level differences.

[0053] Figure 1 This is a wavelength measurement diagram of the organic short-wave infrared detector acceptor material of this invention. To extend the wavelength of the organic short-wave near-infrared material, it is necessary to reduce the energy difference (Eg) between the highest occupied orbital (HOMO) and the lowest unoccupied orbital (LUMO) of the molecule. Therefore, one effective method to reduce the Eg within the molecule is to increase the conjugation degree of the organic material molecule itself, thereby increasing its conjugated system to achieve a longer wavelength for the organic near-infrared material. For example... Figure 1 As shown, the external quantum efficiency (EQE) of the device based on material 1 increases significantly with increasing reverse bias voltage. This can be attributed to the narrow bandgap of the acceptor material, which makes it easy to inject current and thus obtain a high external quantum efficiency.

[0054] Acceptor material 1, acceptor material 3, acceptor material 9, and acceptor material 11 were used in organic short-wave infrared detectors, such as... Figure 2 As shown, along the thickness of the infrared photodetector, from bottom to top, it includes a substrate layer 1 (0.5 mm), a hole transport layer 2 (60 nm), a functional layer 3 (50 nm), an electron transport layer 4 (50 nm), and an electrode layer 5 (100 nm). The substrate layer 1 is a silicon substrate, the hole transport layer 2 is SiO2 / Al2O3, and the electron transport layer 4 is molybdenum oxide (MoO2). x Electrode layer 5 is Ag, and the functional layer is the host material and acceptor material 1, acceptor material 3, acceptor material 9 or acceptor material 11 doped in the host material. The doping concentration of the acceptor material is 3wt%, and the acceptor material is PTB7-Th.

[0055] The silicon substrate was placed in deionized water, ultrasonically cleaned, and then dried in a vacuum drying oven. Electrodes and functional layers were then sequentially solution-processed onto the treated silicon substrate according to the device structure to obtain the organic short-wave infrared detector. Performance tests were performed on the organic short-wave infrared detector (OPD device), and the results are shown in Table 2.

[0056] Table 2 Quantum efficiency of organic short-wave infrared detector acceptor materials As shown in Table 2, the maximum external quantum efficiency of acceptor materials 1, 2, 3, and 4 at 1.2 μm, 1.3 μm, and 1.4 μm all reached over 12%, which is not only longer than that of CO1-4F, but also improved.

[0057] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0058] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An organic short-wave infrared detector acceptor material, characterized in that, The organic shortwave infrared detector acceptor material has the following chemical structural formula: ； The -EH group has the following chemical structural formula: ； R has the following chemical structural formula: ； Wherein, R1 is hydrogen, halogen, phenyl or substituted phenyl, the substituent of substituted phenyl is halogen, and "*" is the linking site.

2. The organic short-wave infrared detector acceptor material according to claim 1, characterized in that, R1 is hydrogen, fluorine, chlorine, phenyl, or a substituted phenyl group, where the substituent of the substituted phenyl group is fluorine or chlorine.

3. The organic short-wave infrared detector acceptor material according to claim 1, characterized in that, The organic shortwave infrared detector acceptor material has the following chemical structural formula: 。 4. A method for preparing an organic shortwave infrared detector acceptor material according to any one of claims 1 to 3, characterized in that, Includes the following steps: Under a protective gas atmosphere, compounds a and b were used as raw materials to carry out aldol condensation or substitution reactions in a system of alkali or catalyst and reaction solvent to obtain organic short-wave infrared detector acceptor materials. When compound a is compound a1, compound b is compound b1, and the synthesis reaction formula is shown below: ； When compound a is compound a2, compound b is compound b2, and the synthesis reaction formula is shown below: 。 5. The method for preparing the organic shortwave infrared detector acceptor material according to claim 4, characterized in that, When compound a is compound a1 and compound b is compound b1, the aldol condensation reaction is carried out at room temperature for 10-14 hours, and the molar ratio of compound 1 to compound 2 is 1-2:2-6.

6. The method for preparing the organic short-wave infrared detector acceptor material according to claim 4, characterized in that, When compound a is compound a2 and compound b is compound b2, the substitution reaction is carried out at 110℃ for 18h to 14h, and the molar ratio of compound 1 to compound 3 is 9 to 11: 19 to 25.

7. An infrared photodetector, characterized in that, The thickness method of the infrared photodetector, from bottom to top, includes a substrate layer, a hole transport layer, a functional layer, an electron transport layer, and an electrode layer, wherein the functional layer is a host material and a receptor material doped in the host material, and the receptor material is the organic short-wave infrared detector receptor material according to any one of claims 1 to 3.

8. The infrared photodetector according to claim 7, characterized in that, The doping concentration of the acceptor material is 1wt% to 10wt%, and the acceptor material is PTB7-Th.

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