Organic short-wave infrared image sensor and preparation method thereof

Abstract

The invention provides an organic short-wave infrared image sensor. The organic short-wave infrared image sensor comprises a substrate and an organic photodiode arranged on an electrode layer of the substrate, the substrate comprises a TFT (thin film transistor) substrate or a CMOS (complementary metal oxide semiconductor) substrate; the organic photodiode comprises an upright device structure taking ITO or conductive metal as an anode, or an inverted device structure taking ITO or conductive metal as a cathode. According to the invention, high device performance is realized through an active layer material with low trap density, an interface layer material with high charge blocking capability and a high-quality film forming technology. According to the imaging array, the responsivity exceeding 0.3 AW <-1 >, the dark current lower than 10 <-9 > A <-2 > and the wide linear dynamic range exceeding 130 dB can be obtained, the blind pixel rate is smaller than 1%, and the effect of clear imaging under the weak light of 10 [mu] w cm <-2 > can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of short-wave infrared image sensing, and in particular to an organic short-wave infrared image sensor and a preparation method thereof. Background Art

[0002] Infrared imaging technology, which utilizes short-wavelength infrared light in the 1000-3000nm wavelength range, employs a reflective imaging method, enabling high resolution and widespread application in aerospace, military detection, machine vision, night vision, and medical monitoring. Currently, commercially available infrared image sensors are based on inorganic semiconductors, such as indium gallium arsenide (InGaAs) and mercury cadmium telluride (HgCdTe). However, the stringent crystal growth conditions and lattice matching requirements with the substrate material make InGaAs and HgCdTe-based image sensors very expensive to produce, limiting their application.

[0003] Organic photodetectors based on organic semiconductors offer the potential for use in image sensor development due to their large area, flexibility, low-cost solution processing, and ease of integration. For example, Panasonic has developed prototype CMOS image sensors and cameras based on visible-light organic photodetectors, while the University of Tokyo has used near-infrared organic photodetectors to fabricate image sensors for fingerprint recognition and health monitoring. However, organic photodetectors suffer from high noise current and low responsivity in the short-wave infrared region, resulting in poor detection performance and difficulty meeting the signal-to-noise ratio requirements of array devices. Furthermore, during system integration, film formation and compatibility issues lead to high blind pixel rates and dark current nonuniformity in array devices, compromising imaging performance. Therefore, the development of organic short-wave infrared image sensor arrays still faces significant challenges. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide an organic short-wave infrared image sensor. The organic short-wave infrared image sensor provided by the present invention can obtain wide-spectrum imaging of visible light, near-infrared light, and short-wave infrared light, and perform weak-light imaging, and has high device performance.

[0005] The present invention provides an organic short-wave infrared image sensor, comprising:

[0006] A substrate and an organic photodiode disposed on the substrate electrode layer;

[0007] The substrate includes a TFT substrate or a CMOS substrate;

[0008] Organic photodiodes include:

[0009] The positive device structure with ITO or conductive metal as the anode is sequentially deposited including the anode interface layer, photosensitive active layer, cathode interface layer and metal electrode;

[0010] or

[0011] Based on an inverted device structure with ITO or conductive metal as the cathode, a cathode interface layer, a photosensitive active layer, an anode interface layer and a metal electrode are deposited in sequence.

[0012] In some specific embodiments, the TFT substrate includes: a glass substrate, a gate electrode disposed on the glass substrate, a source / drain electrode, an insulating filling layer, and a transparent electrode layer connected to the source / drain electrode through the insulating filling layer; the CMOS substrate includes: a pixel array, a column circuit, an output buffer, a current reference, and row and column control.

[0013] In some specific embodiments, the material of the photoactive layer includes a donor material and an acceptor material; the mass ratio of the donor material to the acceptor material is 200:1 to 1:200;

[0014] The donor material is selected from the following structures:

[0015]

[0016] In some specific embodiments, the receptor material is selected from the following structures:

[0017]

[0018] Wherein, m, n, and f are natural numbers ranging from 1 to 50.

[0019]

[0020] Wherein, m is a positive integer ≥ 1; n is a natural number from 1 to 50. Preferred receptor materials are as follows:

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] In some specific embodiments, the anode interface layer includes CuSCN, Poly-TPD, PEDOT:PSS (4083), PEDOT:PSS (CH8000), and X-IFTPA for upright devices;

[0027] MoO for inverted devices x 、NiO x , VOx , transfer polymer donors P3HT, PM6, PBDB-T, PTB7-Th.

[0028] In some specific embodiments, the cathode interface layer includes: PFN-Br, PDINO, PDINN, PFN, Ca, LiF, n-PT7, n-PT8 or n-PT9 for upright devices;

[0029] For inverted devices: ZnO, SnO2 or NDI-A (PCy2).

[0030] In some embodiments, the metal electrode is selected from aluminum, silver, gold, silver nanowires, PEDOT:PSS (PH1000) or gallium-indium alloy.

[0031] In some specific embodiments, the pixel specification of the organic short-wave infrared image sensor ranges from 64 to 2048×64 to 2048, and the pixel size ranges from 1 μm to 500 μm.

[0032] The present invention provides a method for preparing an organic shortwave infrared image sensor according to any one of the above technical solutions, comprising:

[0033] A) Cleaning a TFT substrate or a CMOS substrate;

[0034] B) depositing an anode interface layer, a photosensitive active layer, a cathode interface layer, and a metal electrode in sequence on the cleaned TFT substrate or CMOS substrate, and encapsulating the substrate;

[0035] or

[0036] A cathode interface layer, a photosensitive active layer, an anode interface layer and a metal electrode are sequentially deposited on the cleaned TFT substrate or CMOS substrate, and then packaged.

[0037] In some specific embodiments, the thickness of the anode interface layer is 2 to 100 nm; the thickness of the photoactive layer is 50 to 1000 nm; the thickness of the cathode interface layer is 2 to 100 nm; and the thickness of the metal electrode is 10 to 300 nm.

[0038] Compared with the prior art, the present invention provides an organic short-wave infrared image sensor, comprising: a substrate and an organic photodiode arranged on the substrate electrode layer; the substrate comprises a TFT substrate or a CMOS substrate; the organic photodiode comprises: an upright device structure with ITO or a conductive metal as the anode, sequentially deposited with an anode interface layer, a photosensitive active layer, a cathode interface layer and a metal electrode; or an inverted device structure based on ITO or a conductive metal as the cathode, sequentially deposited with a cathode interface layer, a photosensitive active layer, an anode interface layer and a metal electrode. The present invention achieves high device performance through active layer materials with low trap density, interface layer materials with high charge blocking ability, and high-quality film-forming technology. Based on the imaging array developed by the present invention, more than 0.3AW -1 The responsiveness is less than 10 –9 A cm -2 The dark current is small, and the wide linear dynamic range is more than 130dB, the blind pixel rate is less than 1%, and it can achieve 10μW cm -2 Clear imaging effect in low light. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The short-wave infrared array device structure of embodiment 1 of the present invention;

[0040] Figure 2 The device structure of the photodiode part of Example 1 of the present invention;

[0041] Figure 3 This is a cross-sectional scanning electron microscope image of the short-wave infrared array pixel region of Example 1 of the present invention;

[0042] Figure 4 The absorption spectrum of the electron acceptor material of the active layer of Example 2 of the present invention;

[0043] Figure 5 This is a cyclic voltammetry test curve of the active layer electron acceptor material of Example 2 of the present invention;

[0044] Figure 6 This is the dark state JV curve of Example 3 of the present invention;

[0045] Figure 7 3 is a curve of the dark state noise frequency spectrum of Example 3 of the present invention;

[0046] Figure 8 This is the responsivity-wavelength curve of Example 3 of the present invention;

[0047] Figure 9 This is the linear dynamic range curve of Example 4 of the present invention;

[0048] Figure 10 This is the response time test curve of Example 5 of the present invention;

[0049] Figure 11 This is the cutoff frequency test curve of Example 5 of the present invention;

[0050] Figure 12 This is a picture showing the short-wave infrared imaging results of Example 7 of the present invention;

[0051] Figure 13 This is the responsivity curve of the organic photodetector prepared by BTQ-1 in Comparative Example 1 of the present invention;

[0052] Figure 14 This is a picture showing the imaging of the main building stamp of the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences using a short-wave infrared imaging array prepared with BTQ-1 in Comparative Example 1 of the present invention;

[0053] Figure 15 Schematic diagram of a single-pixel imaging device in Comparative Example 2 of the present invention;

[0054] Figure 16 The results of single-pixel imaging in Comparative Example 2 of the present invention are shown. DETAILED DESCRIPTION

[0055] The present invention provides an organic shortwave infrared image sensor and a method for preparing the same. Those skilled in the art can draw upon the disclosure herein and appropriately modify the process parameters to achieve the desired result. It is particularly important to note that all similar substitutions and modifications will be readily apparent to those skilled in the art and fall within the scope of protection of the present invention. The methods and applications of the present invention have been described using preferred embodiments. It is readily apparent that those skilled in the art can modify, alter, and combine the methods and applications herein to implement and apply the technology of the present invention without departing from the content, spirit, and scope of the present invention.

[0056] It should be understood that the expression "one or more of" includes individually each of the items recited after the expression and various combinations of two or more of the recited items, unless otherwise apparent from the context and usage. The expression "and / or" in conjunction with three or more recited items should be understood to have the same meaning, unless otherwise apparent from the context.

[0057] The terms "comprising", "having" or "containing", including their grammatical synonyms, should generally be understood as open and non-restrictive, e.g., not excluding other unrecited elements or steps, unless otherwise specifically stated or understood from the context.

[0058] In this application, the term "and / or" describes the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0059] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items.

[0060] The present invention specifically relates to a solution-processed organic shortwave infrared (SWIR, 1000-3000 nm) image sensor array and its fabrication method. The present invention provides a high-resolution organic shortwave infrared image sensor array, in which the photosensitive layer utilizes an organic photodiode-type device structure. By integrating it with a field-effect transistor array substrate and employing a readout circuit system, the array device enables low-light imaging in the shortwave infrared region.

[0061] The present invention provides an organic short-wave infrared image sensor, comprising:

[0062] A substrate and an organic photodiode disposed on the substrate electrode layer;

[0063] The substrate includes a TFT substrate or a CMOS substrate;

[0064] Organic photodiodes include:

[0065] The positive device structure with ITO or conductive metal as the anode is sequentially deposited including the anode interface layer, photosensitive active layer, cathode interface layer and metal electrode;

[0066] or

[0067] Based on an inverted device structure with ITO or conductive metal as the cathode, a cathode interface layer, a photosensitive active layer, an anode interface layer and a metal electrode are deposited in sequence.

[0068] The organic short-wave infrared image sensor provided by the present invention includes a substrate, wherein the pixel area of ​​the substrate is less than 4 square centimeters and the thickness is about 1 micron. The substrate of the present invention includes a TFT substrate or a CMOS substrate.

[0069] In some specific embodiments, the TFT substrate includes: a glass substrate, a gate electrode disposed on the glass substrate, source / drain electrodes, an insulating filler layer, and a transparent electrode layer connected to the source / drain electrodes via the insulating filler layer. The CMOS substrate includes: a pixel array, column circuits, an output buffer, a current reference, and row and column control.

[0070] The present invention does not limit the TFT substrate or the CMOS substrate, and any commercially available substrate known to those skilled in the art may be used.

[0071] The organic short-wave infrared image sensor provided by the present invention comprises an organic photodiode arranged on the substrate electrode layer.

[0072] In the organic photodiode of the present invention:

[0073] The positive device structure with ITO or conductive metal as the anode is sequentially deposited, including the anode interface layer, the photosensitive active layer, the cathode interface layer and the metal electrode;

[0074] Among them, the anode interface layer is a p-type anode interface layer with hole transport capability; in some specific embodiments, the anode interface layer includes CuSCN, Poly-TPD, PEDOT:PSS (4083), PEDOT:PSS (CH8000), and X-IFTPA for upright devices; the present invention does not limit the source thereof, and commercially available ones known to those skilled in the art can be used.

[0075] The thickness of the anode interface layer is 2 to 100 nm; specifically, it can be any thickness within the range of 2 to 100 nm, specifically 2 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, or 100 nm.

[0076] The cathode interface layer is an n-type cathode interface layer which has the ability to modify the electrode work function and can transmit electrons.

[0077] In some specific embodiments, the cathode interface layer includes: PFN-Br, PDINO, PDINN, PFN, Ca, LiF, n-PT7, n-PT8 or n-PT9 for upright devices; the present invention does not limit the source thereof, and commercially available ones known to those skilled in the art can be used.

[0078] The thickness of the cathode interface layer is 2 to 100 nm; specifically, it can be: 2 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm.

[0079] In some specific embodiments, the metal electrode includes an evaporation-type metal electrode such as aluminum, silver, or gold, a transfer-type silver nanowire, PEDOT:PSS (PH1000), a spray-type liquid metal electrode such as gallium-indium alloy, and the like.

[0080] The thickness of the metal electrode ranges from 10 to 300 nm. Specifically, the thickness can be any thickness within the range of 10 to 300 nm: 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, or 300 nm.

[0081] In some specific embodiments, the material of the photoactive layer includes a donor material and an acceptor material;

[0082] The donor material is selected from the following structures:

[0083]

[0084] In some embodiments, the receptor material is selected from the following structures

[0085]

[0086] Wherein, m, n, and f are natural numbers ranging from 1 to 50.

[0087]

[0088] Wherein, m is a positive integer ≥ 1; n is a natural number from 1 to 50. Preferred receptor materials are as follows:

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] The mass ratio of the donor material to the acceptor material is 200:1 to 1:200; preferably 100:1 to 1:100; more preferably 50:1 to 1:50; particularly preferably 1:30;

[0095] Based on an inverted device structure with ITO or conductive metal as the cathode, a cathode interface layer, a photosensitive active layer, an anode interface layer and a metal electrode are deposited in sequence.

[0096] The thickness and composition of the above-mentioned specific layers have been clearly described above and will not be repeated here.

[0097] The difference is: the anode interface layer is used for the MoO2 in the inverted device x 、NiO x , VO x , transfer polymer donors P3HT, PM6, PBDB-T, PTB7-Th.

[0098] Cathode interface layer for inverted devices: ZnO, SnO2 or NDI-A (PCy2).

[0099] The present invention does not limit the sources of the above materials, and any commercially available materials may be used.

[0100] In some specific embodiments, the pixel specification of the organic short-wave infrared image sensor ranges from 64 to 2048×64 to 2048, and the pixel size ranges from 1 μm to 500 μm.

[0101] The present invention provides a method for preparing an organic shortwave infrared image sensor according to any one of the above technical solutions, comprising:

[0102] A) Cleaning a TFT substrate or a CMOS substrate;

[0103] B) depositing an anode interface layer, a photosensitive active layer, a cathode interface layer, and a metal electrode in sequence on the cleaned TFT substrate or CMOS substrate, and encapsulating the substrate;

[0104] or

[0105] A cathode interface layer, a photosensitive active layer, an anode interface layer and a metal electrode are sequentially deposited on the cleaned TFT substrate or CMOS substrate, and then packaged.

[0106] The preparation method of the organic short-wave infrared image sensor of the present invention first cleans the TFT substrate or CMOS substrate; preferably, specifically, ultrasonic cleaning is performed in sequence using secondary deionized water, isopropyl alcohol, secondary water, acetone, and isopropyl alcohol, and then drying in a blast oven.

[0107] The processing of the photodiode takes the upright structure as an example: an anode interface layer, a photosensitive active layer, a cathode interface layer and a metal electrode are sequentially deposited on the cleaned TFT substrate or CMOS substrate, and then packaged.

[0108] The present invention does not limit the specific method of deposition, which can be solution deposition, including deposition by spin coating, with a rotation speed of 500 rpm to 8000 rpm;

[0109] Deposition is performed by doctor blade coating, wherein the substrate heating temperature is from room temperature to 100 degrees Celsius and the doctor blade scanning speed is 20 mm / s to 100 mm / s;

[0110] It can also be evaporation, including evaporation of the anode / cathode interface layer, evaporation of the photosensitive layer, and evaporation of the electrode.

[0111] Particularly preferably, an anode interface layer having a thickness ranging from 2 to 100 nm is formed on the cleaned TFT substrate or CMOS substrate; an active layer having a thickness ranging from 50 to 1000 nm is formed by solution deposition; a cathode interface layer having a thickness ranging from 2 to 100 nm is formed; silver, aluminum, or gold having a thickness ranging from 10 to 300 nm is evaporated, or PEDOT:PSS (PH1000) having a thickness ranging from 30 to 300 nm is spin-coated on a PDMS substrate, and then transferred onto the cathode interface layer by surface tension.

[0112] Packaging: Ultra-white glass and UV-curing adhesive are used to encapsulate the pixel area of ​​the array to block air.

[0113] Integration with the readout circuit: Pre-print ACF conductive glue at the pins of the flexible printed circuit and the readout circuit, and then hot-press the device with the flexible printed circuit and the readout circuit under a hot press.

[0114] The thickness of the specific layer of the present invention has been clearly described above and will not be repeated here.

[0115] The processing of the photodiode takes the inverted structure as an example: a cathode interface layer, a photosensitive active layer, an anode interface layer and a metal electrode are sequentially deposited on the cleaned TFT substrate, and then packaged.

[0116] Compared with the prior art, the present invention has the following beneficial effects:

[0117] 1. Existing short-wave infrared image sensor arrays are all based on inorganic semiconductor materials as the photosensitive layer. The image sensor array disclosed in the present invention adopts an organic photodiode structure, and the photosensitive layer is processed by a solution method from organic electron donors and electron acceptors that respond to short-wave infrared light.

[0118] 2. The present invention directly deposits the layers of the organic short-wave infrared photodetector onto a TFT array substrate, eliminating the need for pixelation of the organic photosensitive layer. A commercial readout circuit system is then used to obtain an imaging array. The process is simple and easy, and is suitable for high-yield preparation.

[0119] 3. Due to the limitation of the energy gap law, organic short-wave infrared photodetectors usually have low responsivity and high dark current. After integration with the field effect transistor array substrate, they usually have low signal-to-noise ratio, which affects the imaging contrast. The present invention achieves high device performance through low trap density active layer materials, high charge blocking ability interface layer materials, and high-quality film forming technology. The imaging array developed based on the present invention can obtain more than 0.3AW -1 The responsiveness is less than 10 –9 A cm –2 The dark current is small, and the wide linear dynamic range is more than 130dB, the blind pixel rate is less than 1%, and it can achieve 10μW cm –2 Clear imaging effect in low light.

[0120] Experimental results show that based on organic photodiodes constructed with active donor-acceptor materials that respond to short-wave infrared, solution deposition onto a TFT array substrate or a CMOS substrate can achieve an array with a pixel specification range of 64 to 2048×64 to 2048 and a pixel size range of 5μm to 500μm. The array can obtain wide-spectrum imaging of visible light, near-infrared light, and short-wave infrared light, and perform low-light imaging, demonstrating the practical application prospects of the organic short-wave infrared image sensor array provided by the present invention.

[0121] It should be understood that the order of steps or the order in which certain actions are performed are not important as long as the present invention remains operable. Additionally, two or more steps or actions may be performed simultaneously.

[0122] The use of any and all examples or exemplary language, such as "such as" or "including," herein is intended merely to better illustrate the invention and does not limit the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0123] In addition, the numerical ranges and parameters used to define the present invention are approximate values. The relevant numerical values ​​in the specific examples have been presented as accurately as possible. However, any numerical value inherently inevitably contains standard deviations due to individual testing methods. Therefore, unless otherwise expressly stated, all ranges, amounts, values, and percentages used in this disclosure should be understood to be modified by the word "about." As used herein, "about" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specified value or range.

[0124] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0125] Some cases are described in the embodiments and comparative examples of the present invention, wherein the embodiments illustrate certain implementations of the present invention. However, this does not mean that the effects of the present invention can only be achieved in these cases.

[0126] To further illustrate the present invention, an organic short-wave infrared image sensor and a preparation method thereof provided by the present invention are described in detail below with reference to embodiments.

[0127] Example 1

[0128] Fabrication of organic shortwave infrared imaging array

[0129] 1. Cleaning and treatment of the substrate: The patterned TFT panel was ultrasonically cleaned in distilled water, isopropyl alcohol, and acetone for 10 minutes, transferred to a 100°C oven and dried for 15 minutes. Before use, it was treated with UV-ozone for 10 minutes and set aside.

[0130] 2. The structure of short-wave infrared imaging array device is as shown in the attached figure. Figure 1 The device structure of the photodiode is shown in the attached Figure 2 Preparation of the CuSCN anode interface layer, active layer, and electrode vacuum evaporation deposition: CuSCN powder was dissolved in dipropyl sulfide solvent at a concentration of 20 mg / mL and stirred at room temperature for 2 hours. In a nitrogen glove box, 50 μL of the solution was pipetted onto a substrate and spin-coated at 3000 rpm. The film was then treated at 150°C for 15 minutes and stored for later use. The thickness of the anode interface layer was determined to be 30 nm using a step profiler.

[0131] Compound PM6 and receptor molecule 1 (FM7, shown in the figure) were weighed in a 1:1.5 mass ratio in a 1.5 mL sample vial. A 16 mg / mL solution was prepared using chloroform as the drying solvent. The mixed solution was stirred at 500 rpm at 55°C for 1.5 hours. After cooling to room temperature, 0.5% by volume of chloronaphthalene was added and stirring continued for 0.5 hours. Using a pipette, 45 μL of the mixed solution was dropped onto a substrate and spin-coated at 2500 rpm to form a film. The wet film was thermally annealed at 130°C for 10 minutes. The thickness of the functional layer was measured using a step profiler and found to be 145 nm.

[0132] Weigh the compound PFN-Br into a 1.5 mL vial and prepare a 0.5 mg / mL solution using methanol to dry the solvent. Stir at room temperature for 2 hours. Use a pipette to drop 65 μL of the solution onto the substrate and spin-coat it at 3000 rpm to form a film.

[0133] Place the substrate on the metal mask and transfer it to the vacuum coating machine. Evacuate the chamber until the pressure is lower than 2×10- 4 Pa, using thermal evaporation method at a speed of 1nm / s 100nm Al electrode. The cross-sectional scanning electron microscope image of the prepared device is shown in the attached Figure 3 shown.

[0134] 3. Packaging: Use a pipette to take 3 μL of UV-curing glue and evenly apply it to the edge of the ultra-white glass sheet. Then cover it with the pixel area of ​​the short-wave infrared light detection array and cure it with UV light for 15 seconds.

[0135] 4. Hot pressing of flexible printed circuits

[0136] Clean the pin areas of the TFT panel and the flexible printed circuit with anhydrous ethanol. Pre-press the ACF conductive adhesive using a hot press at 100°C and 90 Pa. Continue hot pressing for 20 seconds at 120°C and 140 Pa.

[0137] Example 2

[0138] Absorption spectrum and electrochemical band gap measurement of short-wave infrared receptor materials

[0139] In order to verify that the electron acceptor material in the photoactive layer has the property of absorbing short-wave infrared light, the absorption spectrum of the electron acceptor material was collected by a PerkinElmer Lambda 35 UV-visible spectrometer using UV-visible-near infrared absorption spectroscopy. Figure 4 The film state shown has an absorption peak at 1105 nm and a maximum absorption wavelength at 1300 nm. Cyclic voltammograms were measured on a CHI660a electrochemical workstation to characterize its electrochemical band gap. The working electrode was a glassy carbon electrode and a platinum wire was used as the counter electrode. All measurements were performed in 0.1 mol / L acetonitrile. -1 The measurement was carried out in tetra-n-butylammonium hexafluorophosphate solution. Ferrocene was used as the internal reference and the voltage was set at 100 mV s -1 The material is cast onto the working electrode at a scan rate of Figure 5 Its lowest unoccupied molecular orbital (LUMO) energy level is -4.37 eV, and its highest occupied molecular orbital (HOMO) energy level is -5.68 eV.

[0140] Example 3

[0141] Basic performance test of shortwave infrared imaging array

[0142] To ensure that the short-wave infrared imaging array has high imaging clarity and high signal-to-noise ratio, the Keithley 2635B digital source meter was used to measure the current-voltage (JV) characteristic curve of the photodetector device of the short-wave infrared imaging array component in the dark state. The dark state JV characteristic curve of the device is shown in Figure 6 The actual noise current inside is tested by LEN-2000 low frequency noise test system, and the noise frequency spectrum is Figure 7 The QE quantum efficiency test system is used to measure the external quantum efficiency of the device and calculate the responsivity curve of the corresponding band. The responsivity-wavelength characteristic curve of the device is shown in Figure 8 At 0V, its dark current is 9.08×10 -9 A cm -2 , the noise current is 1.37×10 -13 A Hz -1 / 2， Responsivity is 0.32AW -1 The calculated specific detection rate is 7.44×10 11 Jones. This shows that it has sufficient performance foundation to meet the needs of short-wave infrared imaging.

[0143] Example 4

[0144] Linear dynamic range testing of shortwave infrared imaging arrays

[0145] The depth of field of a short-wave infrared imaging array is determined by the linear dynamic range of the component. The linear dynamic range describes the ability of the photodetector to detect weak light signals and describes the range of light intensity over which the device maintains a linear response. The linear dynamic range of the component is tested by the CEL-PD291 photodetection performance test system. Figure 9 Its linear response light intensity dynamic range spans eight orders of magnitude, reaching 123dB.

[0146] Example 5

[0147] Dynamic response parameter test of shortwave infrared imaging array

[0148] The two parameters, response time and cutoff frequency, together determine the photodetector's ability to handle high-frequency and rapidly changing optical signals. Response time refers to the time required for a photodetector to respond to changes in the optical signal. Response time is usually determined by the detector's electrical and optical properties. A shorter response time means the detector can respond faster to changes in the optical signal. Response time is analyzed by measuring rise time and fall time. The former refers to the time interval for a signal to rise from 10% to 90% of its maximum value, and the latter refers to the time interval for a signal to decay from 90% to 10%. Figure 10 As shown in the figure, the rise time and fall time are 25 microseconds and 35 microseconds respectively. The cutoff frequency refers to the highest frequency that the photodetector can effectively respond to. It is usually the upper limit of the signal frequency that the device can respond to. Above this frequency, the response of the detector will be significantly reduced. It reflects the detector's ability to respond to rapidly changing optical signals, such as Figure 11 As shown, the cutoff frequency of the device is 12000Hz.

[0149] Example 6

[0150] Blind Element Rate Test of Short-Wave Infrared Imaging Array

[0151] Blind pixels are pixels in an image sensor that are not functioning properly, unable to sense light signals or generate valid electrical signals. These pixels do not contribute any useful information to image acquisition, resulting in "dead" or "blind" spots in the image. The blind pixel rate is a key indicator of sensor quality. A high blind pixel rate indicates a high number of failed pixels in the sensor, which can affect imaging and result in missing or distorted images. We tested the blind pixel rate of a shortwave infrared imaging array in low light conditions and found it to be 1.1%.

[0152] Example 7

[0153] Imaging demonstration of the shortwave infrared imaging array

[0154] In dark conditions, 990nm LED light is used to illuminate the image. Figure 12 The image shown here features the logo of the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. It has clear edge contours and imaging details.

[0155] Example 8

[0156] The photoactive layer of the imaging array is prepared using common and efficient electron donors including chemical structures such as Figure 13 The chemical structure of the electron acceptor whose absorption spectrum peak is in the short-wave infrared region is as follows: Figure 14 .

[0157] Comparative Example 1

[0158] The photoactive layer for preparing imaging arrays requires a short-wave infrared response exceeding 0.1 AW. –1 , as shown below, the BTQ-1 has a lower responsiveness, such as Figure 13 The responsivity at 1000nm is only 0.0034AW -1 The imaging results of the stamp of the main building of the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, are very poor. It is almost difficult to distinguish the outline and details in the stamp. Figure 14 .

[0159]

[0160] Comparative Example 2

[0161] The imaging array requires the integration of photodiodes and field effect transistor array substrates to achieve high resolution and high definition imaging. We use single pixel points with stepper motors for imaging. Figure 15The experimental setup is described, in which a mask labeled "NIR" is placed between the LED light and the detector. The mask can be adjusted along the X and Y axes, allowing for precise measurements. As the mask moves, the photocurrent at each coordinate is recorded. However, real-time imaging such as Figure 16 .

[0162] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An organic short-wave infrared image sensor, characterized in that: include: A substrate and an organic photodiode disposed on the substrate electrode layer; The substrate includes a TFT substrate or a CMOS substrate; Organic photodiodes include: The positive device structure with ITO or conductive metal as the anode is sequentially deposited including the anode interface layer, photosensitive active layer, cathode interface layer and metal electrode; or Based on an inverted device structure with ITO or conductive metal as the cathode, a cathode interface layer, a photosensitive active layer, an anode interface layer and a metal electrode are deposited in sequence.

2. The organic shortwave infrared image sensor according to claim 1, characterized in that: The TFT substrate includes: a glass substrate, a gate electrode arranged on the glass substrate, a source / drain electrode, an insulating filling layer, and a transparent electrode layer connected to the source / drain electrode through the insulating filling layer; the CMOS substrate includes: a pixel array, a column circuit, an output buffer, a current reference, and a row and column control.

3. The organic shortwave infrared image sensor according to claim 1, characterized in that: The material of the photosensitive active layer includes a donor material and an acceptor material; the mass ratio of the donor material to the acceptor material is 200:1 to 1:200; The donor material is selected from the following structures:

4. The organic shortwave infrared image sensor according to claim 3, characterized in that: The receptor material is selected from the following structures; Wherein, m, n, and f are natural numbers ranging from 1 to 50. Wherein, m is a positive integer ≥ 1; n is a natural number from 1 to 50. Preferred receptor materials are as follows:

5. The organic shortwave infrared image sensor according to claim 1, characterized in that: The anode interface layer includes CuSCN, Poly-TPD, PEDOT:PSS (4083), PEDOT:PSS (CH8000), and X-IFTPA for upright devices; MoO for inverted devices x 、NiO x , VO x , transfer polymer donors P3HT, PM6, PBDB-T, PTB7-Th.

6. The organic shortwave infrared image sensor according to claim 1, characterized in that: The cathode interface layer includes: PFN-Br, PDINO, PDINN, PFN, Ca, LiF, n-PT7, n-PT8 or n-PT9 for upright devices; For inverted devices: ZnO, SnO2 or NDI-A (PCy2).

7. The organic shortwave infrared image sensor according to claim 1, characterized in that: The metal electrode is selected from aluminum, silver, gold, silver nanowire, PEDOT:PSS (PH1000) or gallium-indium alloy.

8. The organic shortwave infrared image sensor according to claim 1, wherein: The pixel specification of the organic short-wave infrared image sensor ranges from 64 to 2048×64 to 2048, and the pixel size ranges from 1 μm to 500 μm.

9. A method for preparing an organic shortwave infrared image sensor according to any one of claims 1 to 8, characterized in that: include: A) Cleaning a TFT substrate or a CMOS substrate; B) depositing an anode interface layer, a photosensitive active layer, a cathode interface layer, and a metal electrode in sequence on the cleaned TFT substrate or CMOS substrate, and encapsulating the substrate; or A cathode interface layer, a photosensitive active layer, an anode interface layer and a metal electrode are sequentially deposited on the cleaned TFT substrate or CMOS substrate, and then packaged.

10. The preparation method according to claim 9, characterized in that The thickness of the anode interface layer is 2-100 nm; the thickness of the photosensitive active layer is 50-1000 nm; the thickness of the cathode interface layer is 2-100 nm; and the thickness of the metal electrode is 10-300 nm.

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