Visible light blind near-infrared flexible organic photoelectric detector and preparation method and application thereof

Abstract

The invention discloses a visible light blind near-infrared flexible organic photoelectric detector and a preparation method and application thereof. The visible light blind near-infrared flexible organic photoelectric detector comprises a light filtering layer, a flexible substrate and a near-infrared detection part, the filter layer and the near-infrared detection component are located on the two opposite sides of the flexible substrate. The visible light blind near-infrared flexible organic photoelectric detector comprises a light filtering layer, a flexible substrate and a near-infrared detection part, realizes extremely low dark current of 0.048 nA / cm < 2 > on the basis of keeping light current equivalent to that of traditional OPDs, and has strong visible light interference resistance and near-infrared band detection ratio equivalent to that of the traditional OPDs.

Description

Technical Field

[0001] The present invention belongs to the technical field of near-infrared photoelectric detectors, and in particular relates to a visible light blind near-infrared flexible organic photoelectric detector and a preparation method and application thereof. Background Art

[0002] Contactless human-machine interfaces (C-HMIs) based on near-infrared organic photodetectors (NIR-OPDs) enable interaction with electronic devices without physical contact. However, current C-HMIs often suffer from low perception accuracy of finger height, position, trajectory, and movement speed, limited detection range, or long response time.

[0003] As the core sensing element of C-HMI, NIR-OPDs are responsible for converting optical signals such as user gestures and physiological information into electrical signals. The detection range, gesture and physiological information recognition accuracy, anti-ambient light interference ability, and adaptability to extreme environments of NIR-OPDs directly affect the application and promotion of C-HMI. Among them, dark current density is an important indicator affecting NIR-OPDs. Dark current density refers to the intrinsic current generated by NIR-OPDs in the absence of light. It is usually caused by thermally excited carriers or defects per unit area. Dark current density affects many performances of NIR-OPDs, including dynamic range and specific detection rate. Low dark current density is crucial for NIR-OPDs. Currently, the responsiveness of NIR-OPDs is mainly improved by introducing a heterojunction structure composed of two different semiconductor materials. In the process of realizing the present invention, the inventors found that the existing technology has at least the following problems: visible light interference cannot be avoided, disordered microstructures or trap states lead to higher dark current and lower carrier mobility, low device sensitivity, and slow response speed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a visible light blind near-infrared flexible organic photodetector and its preparation method and application in response to the above-mentioned deficiencies in the existing technology. The visible light blind near-infrared flexible organic photodetector can effectively avoid visible light interference and has extremely low dark current and high sensitivity.

[0005] Compared with the prior art, the present invention has the following advantages:

[0006] 1. The present invention comprises a visible light blind near-infrared flexible organic photodetector comprising a filter layer, a flexible substrate and a near-infrared detection component. While maintaining a near-infrared photoresponse comparable to that of conventional OPDs, it can achieve a photoresponse of 0.048 nA / cm 2 It has extremely low dark current, strong resistance to visible light interference and near-infrared band detection rate comparable to traditional OPDs.

[0007] 2. The visible light blind near-infrared flexible organic photodetector of the present invention has stable mechanical properties and can withstand more than 1,000 bends, and the sensitivity indicators remain unchanged after bending.

[0008] 3. The present invention also provides a flexible optical non-contact human-machine interface based on the above-mentioned visible light blind near-infrared flexible organic photodetector. In addition to having the above-mentioned ultra-low dark current, resistance to visible light interference and wide light response range, it has a cutoff frequency of 1.32MHz, a fast response speed, and a distance resolution of up to 10μm, which is significantly higher than the resolution of existing non-contact human-machine interfaces.

[0009] 4. The present invention also provides a flexible optical non-contact human-machine interface based on the above-mentioned visible light blind near-infrared flexible organic photodetector, which can realize real-time motion capture and can provide real-time feedback of physiological data when applied to non-contact human heart rate and respiratory monitoring, and the data is reliable.

[0010] 5. The flexible optical non-contact human-machine interface of the present invention has a light response attenuation of less than 0.5% in 45,000 optical switching cycles, has long-term stability, and can be used in various extreme working conditions such as high temperature, high humidity, high ambient light intensity, and underwater, and has a wide range of application scenarios.

[0011] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of the visible light blind near-infrared flexible organic photodetector of the present invention;

[0013] Figure 2 This is a schematic diagram of the flexible optical non-contact human-machine interface structure of the present invention;

[0014] Figure 3 Schematic diagram of the dark current test results of the Vis-blind NIR OPD of Example 1;

[0015] Figure 4 Schematic diagram of the Vis-blind NIR OPD light response test results of Example 1;

[0016] Figure 5 Schematic diagram of the test results of the Vis-blind NIR OPD's anti-visible light interference ability in Example 1;

[0017] Figure 6 Schematic diagram of the specific detectivity test results of the Vis-blind NIR OPD of Example 1;

[0018] Figure 7Schematic diagram of the LDR test results of the Vis-blind NIR OPD of Example 1;

[0019] Figure 8 Schematic diagram of the instantaneous photoresponse behavior of the Vis-blind NIR OPD in self-powered mode of Example 1;

[0020] Figure 9 Schematic diagram of the Vis-blind NIR OPD cutoff frequency test results of Example 1;

[0021] Figure 10 Schematic diagram of the bending stability test results of the Vis-blind NIR OPD of Example 1;

[0022] Figure 11 Schematic diagram of the test results of Flex-PCI for approaching and moving away objects in Example 2;

[0023] Figure 12 Schematic diagram of the Flex-PCI distance sensitivity test results of Example 2;

[0024] Figure 13 Schematic diagram of the Flex-PCI spatial resolution test results of Example 2;

[0025] Figure 14 This is a schematic diagram of the fast response speed test results of the Flex-PCI self-powered mode in Example 2;

[0026] Figure 15 Schematic diagram of the Flex-PCI object motion speed test principle of Example 2;

[0027] Figure 16 This is a schematic diagram of Flex-PCI detecting human physiological information according to Example 2;

[0028] Figure 17 This is a schematic diagram of the working stability test results of Flex-PCI in extreme environments according to Example 2;

[0029] Figure 18 This is the Flex-PCI bending test state of Example 2;

[0030] Figure 19 Output signal of the Flex-PCI bending test of Example 2;

[0031] Figure 20 Schematic diagram of the test results of sliding gestures in the bent state of Flex-PCI in Example 2;

[0032] Figure 21Schematic diagram of the distance sensitivity test results of the Flex-PCI bending state in Example 2;

[0033] Figure 22 This is the Flex-PCI underwater test state of Example 2;

[0034] Figure 23 This is a schematic diagram of the test results of the Flex-PCI underwater test output signal in Example 2;

[0035] Figure 24 This is a schematic diagram of the Flex-PCI underwater sliding gesture test results of Example 2;

[0036] Figure 25 Schematic diagram of the Flex-PCI underwater distance sensitivity test in Example 2;

[0037] Figure 26 Schematic diagram of Flex-PCI in Example 2 detecting physiological information of the human body in various extreme states;

[0038] Figure 27 Schematic diagram of photocurrent changes under various extreme states of Flex-PCI in Example 2;

[0039] Figure 28 Schematic diagram of the fast Fourier transform of the test results of detecting human physiological information under various extreme conditions of Flex-PCI in Example 2;

[0040] Figure 29 Schematic diagram of the long-term stability test results of Flex-PCI in Example 2. DETAILED DESCRIPTION

[0041] The following will be combined with the embodiments of this application to clearly and completely describe the technical solution. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] In the following description, the term "and / or" is used to describe the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. A and B can be singular or plural.

[0043] In the following description, the terms "include", "comprising", "having" and "containing" are open-ended terms, meaning including but not limited to.

[0044] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and 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.

[0045] It will be understood by those skilled in the art that the numerical ranges in the examples of the present application are to be understood as also specifically disclosing each intermediate value between the upper and lower limits of the ranges. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also included in the present application. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0046] Unless otherwise indicated, the technical / scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which this application belongs. Although this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of any conflict with any incorporated document, the content of this specification shall prevail.

[0047] The technical principle adopted by the present invention is: by arranging a filter layer and a near-infrared detection component on both sides of the flexible substrate, the low dark current of the near-infrared detection component and the absorption and filtering of visible light in the near-infrared light region are achieved, thereby obtaining a visible light-blind near-infrared flexible organic photodetector with extremely low dark current and high resistance to visible light interference.

[0048] On the one hand, a visible light blind near-infrared flexible organic photodetector is provided, comprising a filter layer, a flexible substrate and a near-infrared detection component; the filter layer and the near-infrared detection component are located on opposite sides of the flexible substrate.

[0049] The filter layer and the near-infrared detection component are located on opposite sides of the flexible substrate. The filter layer is electrically isolated from the active layer in the near-infrared detection component, which can prevent the filter layer from participating in the dynamic activities of charges in the detector and interfering with near-infrared detection, thereby achieving extremely low dark current and strong resistance to visible light interference of the flexible organic photodetector.

[0050] In some embodiments, the near-infrared detection component includes, from the closest to the flexible substrate to the furthest away from the flexible substrate, an ITO transparent electrode layer, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, a MoO xIn some specific embodiments, the thickness of the ZnO electron transport layer is 30 nm; and / or the thickness of the PFNBr interface modification layer is 10 nm; and / or the thickness of the active layer is 150 nm; and / or the MoO x The hole transport layer has a thickness of 3 nm; and / or the Ag electrode layer has a thickness of 100 nm; and / or the filter layer has a thickness of 1 μm; and / or the filter layer material includes PC with a mass ratio of 1:1. 71 BM and PCE-10.

[0051] On the other hand, a flexible optical non-contact human-machine interface is provided, comprising the above-mentioned visible light blind near-infrared flexible organic photodetector, wherein the ZnO electron transport layer, PFNBr interface modification layer, active layer, MoO x The hole transport layer and the Ag electrode layer are concentric hollow structures.

[0052] By setting the flexible substrate and near-infrared detection components into a hollow array structure, infrared light can pass through the interface without attenuation, be reflected by the moving object, and be detected by the visible light-blind near-infrared flexible organic photodetector. This can maximize the collection of light reflected from moving objects, such as moving fingers, and has high sensitivity and can effectively reduce the optical crosstalk effect.

[0053] In some preferred embodiments, there are multiple hollow structures, and the multiple hollow structures are evenly spaced. In some preferred embodiments, the multiple hollow structures are evenly spaced at n×n intervals.

[0054] In another aspect, a method for preparing the above-mentioned visible light-blind near-infrared flexible organic photodetector is provided, comprising:

[0055] Step 1: pretreating the ITO-covered PET flexible substrate; in some specific embodiments, the pretreating comprises irradiating the ITO-covered PET flexible substrate with UV light for 15 minutes; the ITO-covered PET flexible substrate is covered with ITO on one side; the pretreated flexible substrate is used as a substrate, and a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer are provided on one side. x The functional layers of the hole transport layer and the Ag electrode layer are provided with a filter layer on the other side to obtain a visible light blind near-infrared flexible organic photodetector; the ITO-covered PET flexible substrate is cleaned and surface treated by UV light, which is beneficial for the subsequent coating of the film layer;

[0056] Step 2: providing a ZnO electron transport layer on the pretreated flexible substrate by spin coating; in some preferred embodiments, providing the ZnO electron transport layer comprises: spin coating a slurry containing nano-ZnO on the pretreated flexible substrate, and heat treating it at 120° C. in an air environment for 10 minutes to obtain a ZnO electron transport layer; the ZnO electron transport layer has a thickness of 30 nm; in some specific embodiments, the slurry containing nano-ZnO is prepared by dispersing nano-ZnO particles in n-butanol, the concentration of the nano-ZnO particles in the nano-ZnO slurry is 15 mg / mL, and the particle size of the nano-ZnO particles is 10 nm;

[0057] Step 3: providing a PFNBr interface modification layer on the ZnO electron transport layer by spin coating; in some preferred embodiments, providing the PFNBr interface modification layer comprises: transferring the flexible substrate covered with the ZnO electron transport layer into a nitrogen-filled glove box, and spin coating a 0.5 mg / mL PFN-Br methanol solution on the ZnO electron transport layer to obtain a PFNBr interface modification layer; the thickness of the PFNBr interface modification layer is 10 nm; the function of the PFN-BrPFNBr interface modification layer is to modify the interface properties of the ZnO electron transport layer;

[0058] Step 4: setting an active layer on the PFNBr interface modification layer; in some preferred embodiments, setting the active layer includes: dissolving PM6 and Y6-4Se in chloroform to obtain a donor-acceptor mixed slurry; spin-coating the donor-acceptor mixed slurry on the PFNBr interface modification layer, and heat-treating it at 110°C for 5 minutes to obtain an active layer; the thickness of the active layer is 150 nm; the mass ratio of PM6 and Y6-4Se is 1:1.2; the total concentration of PM6 and Y6-4Se in the donor-acceptor mixed slurry is 15.4 mg / mL; in some preferred embodiments, the donor-acceptor mixed slurry further includes 0.5% by mass of chloronaphthalene; in the present invention, the preferred donor-acceptor mixed slurry also includes chloronaphthalene, which can regulate the phase separation morphology of the donor and the acceptor in the active layer and improve the photoelectric performance;

[0059] Step 5: Set MoO on the active layer in sequence x Hole transport layer and Ag electrode layer complete the setting of functional layer; in some preferred embodiments, MoO x The hole transport layer and the Ag electrode layer include: MoO x and Ag are deposited on the active layer in sequence; MoO x The thickness of the hole transport layer is 3 nm, and the thickness of the Ag electrode layer is 100 nm. The vacuum degree of the evaporation deposition coating is 2×10 -5 pa;

[0060] Step 6: Prepare a filter layer on the pre-treated flexible substrate; in some preferred embodiments, preparing the filter layer includes: 71 BM and PCE-10 were dissolved in chlorobenzene to obtain a filter slurry; the PC 71 The mass ratio of BM and PCE-10 is 1:1. 71 The total concentration of BM and PCE-10 is 40 mg / mL. A filter slurry is applied to the pretreated flexible substrate on one side of the non-functional layer by spin coating to form a filter layer. The filter layer has a thickness of 1 μm. By providing the filter layer on the non-functional layer of the pretreated flexible substrate, visible light is absorbed and filtered out.

[0061] On the other hand, a method for preparing the flexible optical non-contact human-machine interface based on the visible light blind near-infrared flexible organic photodetector is provided, comprising:

[0062] Step 1: pretreating the ITO-covered PET flexible substrate; in some specific embodiments, the pretreating comprises irradiating the ITO-covered PET flexible substrate with UV light for 15 minutes; the ITO-covered PET flexible substrate is covered with ITO on one side; the pretreated flexible substrate is used as a substrate, and a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer are provided on one side. x The functional layers of the hole transport layer and the Ag electrode layer are provided with a filter layer on the other side to obtain a visible light blind near-infrared flexible organic photodetector; the ITO-covered PET flexible substrate is cleaned and surface treated by UV light, which is beneficial for the subsequent coating of the film layer;

[0063] Step 2: providing a ZnO electron transport layer on the pretreated flexible substrate by spin coating; in some preferred embodiments, providing the ZnO electron transport layer comprises: spin coating a slurry containing nano-ZnO on the pretreated flexible substrate, and heat treating it at 120° C. in an air environment for 10 minutes to obtain a ZnO electron transport layer; the ZnO electron transport layer has a thickness of 30 nm; in some specific embodiments, the slurry containing nano-ZnO is prepared by dispersing nano-ZnO particles in n-butanol, the concentration of the nano-ZnO particles in the nano-ZnO slurry is 15 mg / mL, and the particle size of the nano-ZnO particles is 10 nm;

[0064] Step 3: providing a PFNBr interface modification layer on the ZnO electron transport layer by spin coating; in some preferred embodiments, providing the PFNBr interface modification layer comprises: transferring the flexible substrate covered with the ZnO electron transport layer into a nitrogen-filled glove box, and spin coating a 0.5 mg / mL PFN-Br methanol solution on the ZnO electron transport layer to obtain a PFNBr interface modification layer; the thickness of the PFNBr interface modification layer is 10 nm; the function of the PFN-BrPFNBr interface modification layer is to modify the interface properties of the ZnO electron transport layer;

[0065] Step 4: setting an active layer on the PFNBr interface modification layer; in some preferred embodiments, setting the active layer includes: dissolving PM6 and Y6-4Se in chloroform to obtain a donor-acceptor mixed slurry; spin-coating the donor-acceptor mixed slurry on the PFNBr interface modification layer, and heat-treating it at 110°C for 5 minutes to obtain an active layer; the thickness of the active layer is 150 nm; the mass ratio of PM6 and Y6-4Se is 1:1.2; the total concentration of PM6 and Y6-4Se in the donor-acceptor mixed slurry is 15.4 mg / mL; in some preferred embodiments, the donor-acceptor mixed slurry further includes 0.5% by mass of chloronaphthalene; in the present invention, the preferred donor-acceptor mixed slurry also includes chloronaphthalene, which can regulate the phase separation morphology of the donor and the acceptor in the active layer and improve the photoelectric performance;

[0066] Step 5: In MoO x A plurality of hollow silver electrodes were evaporated and deposited on the hole transport layer. After evaporation and deposition of 16 hollow silver electrodes, the ZnO electron transport layer, PFNBr interface modification layer, active layer and MoO in the hollow area of ​​the hollow silver electrode were x The hole transport layer is removed; in some preferred embodiments, the number of the hollow silver electrodes is 16, and the 16 hollow silver electrodes are in the MoO x The hole transport layer is evenly distributed in a 4×4 array. The outer size of each hollow silver electrode is 2mm×2mm, the hollow area size is 1mm×1mm, and the effective area of ​​each hollow silver electrode is 3mm. 2 ; The thickness of each hollow silver electrode is 300 nm; the method of setting the hollow silver electrode is prepared by a mask containing 16 hollow areas; in some specific embodiments, the method of removing the layers at the hollow area is to erase with acetone;

[0067] Step 6: Prepare a filter layer on the pre-treated flexible substrate; in some preferred embodiments, preparing the filter layer includes: 71 BM and PCE-10 were dissolved in chlorobenzene to obtain a filter slurry; the PC 71 The mass ratio of BM and PCE-10 is 1:1. 71The total concentration of BM and PCE-10 is 40 mg / mL. A filter slurry is applied to the pretreated flexible substrate on one side of the non-functional layer by spin coating to form a filter layer. The filter layer has a thickness of 1 μm. By providing the filter layer on the non-functional layer of the pretreated flexible substrate, visible light is absorbed and filtered out.

[0068] The method also includes removing the ZnO electron transport layer, PFNBr interface modification layer, active layer, MoO x A hole transport layer ensures that near-infrared light can pass through the device.

[0069] The flexible optical non-contact human-machine interface prepared by the above method can achieve light response within 30 cm, with high distance sensitivity and spatial resolution. It can be used as a human physiological information detection device to monitor human physiological information such as pulse and heart rate. It can be used in extreme environments such as high temperature, high humidity and high ambient light intensity, and has significant anti-bending and long-term working stability.

[0070] On the other hand, a method for applying the above-mentioned flexible optical non-contact human-machine interface is provided, including making the distance between the moving object to be detected and the flexible optical non-contact human-machine interface ≤5 cm; in some specific embodiments, the application method includes making the distance between the moving object to be detected and the filter layer of the flexible optical non-contact human-machine interface ≤5 cm.

[0071] The present invention has been subjected to a series of experiments before the application is filed. Some of the experimental results are listed below to further describe the invention in detail, and the following embodiments are used to describe the invention in detail.

[0072] Example 1

[0073] This embodiment provides a visible light blind near-infrared flexible organic photodetector, comprising a filter layer, a flexible substrate, and a near-infrared detection component. The filter layer and the near-infrared detection component are located on opposite sides of the flexible substrate. The near-infrared detection component comprises, from the closest to the flexible substrate to the furthest away from the flexible substrate, an ITO transparent electrode layer, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, a MoO x Hole transport layer and Ag electrode layer. Figure 1 shown.

[0074] This embodiment also provides a method for preparing the above-mentioned visible light-blind near-infrared flexible organic photodetector, comprising:

[0075] Step 1: Pre-treating the ITO-covered PET flexible substrate;

[0076] Step 101: Place an ITO-coated PET flexible substrate with a size of 30×30 mm in a UV-ozone generator and irradiate with UV light for 15 minutes; the UV-ozone generator is purchased from Jelight; the ITO-coated PET flexible substrate is purchased from Advanced Election Technology Co., Ltd.;

[0077] Step 2: providing a ZnO electron transport layer on the pretreated flexible substrate;

[0078] Step 201: spin-coating a nano-ZnO slurry on a pretreated flexible substrate and heat-treating it at 120° C. in air for 10 minutes to obtain a ZnO electron transport layer; the ZnO electron transport layer has a thickness of 30 nm; the nano-ZnO slurry is prepared by dispersing nano-ZnO particles in n-butanol; the mass percentage of the nano-ZnO particles in the nano-ZnO slurry is 15 mg / mL, and the particle size of the nano-ZnO particles is 10 nm;

[0079] Step 3: Setting a PFNBr interface modification layer on the ZnO electron transport layer;

[0080] Step 301: Transfer the flexible substrate covered with the ZnO electron transport layer to a nitrogen-filled glove box, and spin-coat a 0.5 mg / mL PFN-Br methanol solution onto the ZnO electron transport layer to form a PFNBr interface modification layer. The thickness of the PFNBr interface modification layer is 10 nm, and the PFN-Br is purchased from Luminescence Technology Corp.

[0081] Step 4: Setting an active layer on the PFNBr interface modification layer;

[0082] Step 401, PM6, Y6-4Se and chloronaphthalene are dissolved in chloroform to obtain a donor-acceptor mixed slurry; the mass ratio of PM6 to Y6-4Se is 1:1.2; the total concentration of PM6 and Y6-4Se in the donor-acceptor mixed slurry is 15.4 mg / mL, and the mass percentage of chloronaphthalene is 0.5%; the chloronaphthalene is 1-chloronaphthalene, purchased from Sigma Aldirch; the PM6 is purchased from Solarmer Material (Beijing) Inc.; the Y6-4Se is synthesized according to the method disclosed in Song, G. et al. Extending se substitution to the limit: From 5s to 5se in high-efficiency non-fullerene acceptors. Chem. Commun. 59, 10307-10310 (2023);

[0083] Step 402: spin-coat the donor-acceptor mixed slurry on the PFNBr interface modification layer, and heat-treat it at 110° C. for 5 minutes to obtain an active layer; the active layer has a thickness of 150 nm;

[0084] Step 5: Set MoO on the active layer in sequence x Hole transport layer and Ag electrode layer;

[0085] Step 501: MoO x Deposited on the active layer to obtain MoO x Hole transport layer, in MoO x 16 Ag electrodes were evaporated and deposited on the hole transport layer to obtain the Ag electrode layer, which completed the ZnO electron transport layer, PFNBr interface modification layer, active layer, MoO x The setting of the functional layer of hole transport layer and Ag electrode layer; MoO x The thickness of the hole transport layer is 3 nm, and the thickness of each Ag electrode is 100 nm. The vacuum degree of the evaporation deposition is 2×10 -5 pa;MoO x Purchased from SigmaAldrich; in the Ag electrode layer, each silver electrode has an area of ​​0.04 mm 2 , 16 silver electrodes are evenly distributed in a 4×4 array, and the size of each silver electrode is 2mm×2mm;

[0086] Step 6: Prepare a filter layer on the pretreated flexible substrate to obtain a visible-blind near-infrared flexible organic photodetector, which is labeled as Vis-blind NIR OPD;

[0087] Step 601: PC 71 BM and PCE-10 were dissolved in chlorobenzene to obtain a filter slurry; the PC 71 The mass ratio of BM and PCE-10 is 1:1. 71 The total concentration of BM and PCE-10 was 40 mg / mL; PCE-10 was purchased from 1-Material Inc.; PC 71 BM was purchased from American Dye Source, Inc.;

[0088] Step 602 : Spin-coat a filter slurry on the non-functional layer side of the pre-treated flexible substrate to obtain a filter layer. The filter layer has a thickness of 1 μm.

[0089] Example 2

[0090] This embodiment provides a flexible optical non-contact human-machine interface, including a filter layer, a flexible substrate, and a near-infrared detection component. The filter layer and the near-infrared detection component are located on opposite sides of the flexible substrate. The near-infrared detection component is a concentric hollow structure. The number of the hollow structures is 16, and the 16 hollow structures are evenly spaced in a 4×4 array. It is named Flex-PCI and has a structure as shown below. Figure 2 shown.

[0091] This embodiment also provides a method for preparing the flexible optical non-contact human-machine interface, comprising:

[0092] Steps 1 to 4 are the same as the method for preparing a visible light blind near-infrared flexible organic photodetector in Example 1;

[0093] Step five is to deposit MoO by evaporation deposition coating. x Deposited on the active layer to obtain MoO x Hole transport layer, in MoO x 16 hollow silver electrodes are evaporated and deposited on the hole transport layer; the 16 hollow silver electrodes are formed on the MoO x The hole transport layer is evenly distributed in a 4×4 array. The outer size of each hollow silver electrode is 2mm×2mm, the hollow area size is 1mm×1mm, and the effective area of ​​each hollow silver electrode is 3mm. 2 ; The thickness of each hollow silver electrode is 300nm; The method of setting the hollow silver electrode is prepared by a mask containing 16 hollow areas;

[0094] After evaporation deposition of 16 hollow silver electrodes, the ZnO electron transport layer, PFNBr interface modification layer, active layer and MoO x The hole transport layer was removed, and then the filter layer was prepared according to step 6 of Example 1. The method for removing each layer in the hollow area was to erase it with acetone.

[0095] Performance evaluation

[0096] 1Vis-blind NIR OPD key performance indicators

[0097] 1.1 Dark current density and responsivity

[0098] The photoelectric test of the Vis-blind NIR OPD of Example 1 was carried out, and the following results were obtained: Figure 3 The dark current-voltage curve is shown in FIG. 1 . According to the dark current-voltage curve, it can be seen that the Vis-blind NIR OPD of the present invention exhibits a dark current of 0.048 nA / cm 2 The ultra-low dark current of the Vis-blind NIR OPD of Example 1 is as follows: Figure 4As shown, it has a responsivity of 0.33 A / W at a wavelength of 850 nm, which is comparable to the responsivity of conventional OPDs without a filter layer (0.36 A / W). It can be seen that the Vis-blind NIR OPD of the present invention has the characteristics of low noise current and high sensitivity; wherein the conventional OPDs without a filter layer are the organic photodetectors prepared according to steps 1 to 5 of Example 1.

[0099] 1.2 Anti-visible light interference capability

[0100] At a light intensity of 5 mW / cm², the photocurrent of the Vis-blind NIR OPD of Example 1 was measured using 450 nm, 550 nm, 850 nm and 950 nm wavelength light as the incident light. The results are as follows: Figure 5 As shown in the figure, the photocurrent ratio of the Vis-blind NIR OPD to 850nm near-infrared light and 550nm visible light is as high as 186:1, which has strong resistance to visible light interference.

[0101] 1.3 Detection Rate and LDR

[0102] The results of the Vis-blind NIR OPD ratio detection rate measurement of Example 1 are as follows: Figure 6 As shown in the figure, it can be seen that the Vis-blind NIR OPD of Example 1 has a detection rate of more than 10 12 Jones, LDR test results are as follows Figure 7 As shown, it can be seen that the LDR of the Vis-blind NIR OPD of Example 1 is greater than 149 dB, indicating that the Vis-blind NIR OPD of the present invention has high specific detectivity and LDR.

[0103] 1.4 Response Speed

[0104] The transient photoresponse behavior of the Vis-blind NIR OPD of Example 1 under 850nm LED illumination in self-powered mode is shown in FIG. Figure 8 As shown, its response time is 580ns. The -3dB frequency is Figure 9 As shown, the cutoff frequency f of the Vis-blind NIR OPD of the present invention is -3dB The ultra-fast response speed is 1.32MHz, which far exceeds the human reaction time (300-600ms).

[0105] 1.5 Bending stability

[0106] The Vis-blind NIR OPD of Example 1 was bent 1000 times, and the curvature radius after bending was 7.5 mm. The performance test results after bending were as follows: Figure 10 As shown, the noise spectral density S n, responsivity, specific detectivity, f -3dB The ratio of the linear dynamic range (LDR) to that before bending is stable at about 1.0, and each parameter remains basically unchanged, indicating that the Vis-blind NIR OPD of the present invention has excellent anti-bending stability.

[0107] 2 Key indicators of the Flex-PCI device in Example 2

[0108] 2.1Flex-PCI wide detection range (0.5-30 cm)

[0109] The Flex-PCI was placed with the filter layer on top and the silver electrode layer on the bottom. A planar light source with a wavelength of 850nm and a power of 8.3mW / cm was placed underneath. 2 , place your hand on top of Flex-PCI and test the light response of Flex-PCI to your finger at different distances. The results are as follows Figure 11 As shown, Figure 11 The photovoltage close to Flex-PCI is the photovoltage of Flex-PCI when the distance between the finger and Flex-PCI is 0.5 cm, and the photovoltage far from Flex-PCI is the photovoltage of Flex-PCI when the distance between the finger and Flex-PCI is 5 cm. It can be seen that as the finger approaches and moves away from Flex-PCI, the photovoltage shows significantly different changes. When the finger approaches Flex-PCI, the photovoltage increases significantly, and when the finger moves away from Flex-PCI, the photovoltage drops sharply.

[0110] 2.2 Distance Sensitivity and Spatial Resolution of Flex-PCI

[0111] Using the palm as the detection source, the distance sensitivity of Flex-PCI to the palm in the range of 0.5 to 30 cm was tested. The distance sensitivity S = ΔI / Δd, where ΔI is the change in photocurrent in μA and Δd is the displacement of the palm in cm. The results are as follows: Figure 12 As shown. Figure 12 It can be seen that when the distance between the palm and Flex-PCI is 1.5cm, the differential value of the photocurrent with distance reaches its peak. At this time, the distance sensitivity is the highest, up to 26.83uA / cm. The photocurrent change is approximately linear within 1.505cm±0.005cm (e.g. Figure 13 The distance resolution obtained by the test is 10μm, which is significantly higher than the resolution of existing non-contact human-machine interfaces.

[0112] 2.3 Fast response speed in self-powered mode (1.6μs)

[0113] Place your palm 1cm away from the Flex-PCI, with an 850nm LED placed below the Flex-PCI, to simulate the instantaneous light response behavior of the Flex-PCI in a real application scenario. The results are as follows: Figure 14 As shown in the figure, the response time of Flex-PCI in self-powered mode is 1.6μs, which has a significantly improved response speed compared to the existing non-contact human-machine interface.

[0114] Table 1 Comparison of detection distance and response speed between Flex-PCI of Example 2 and existing contactless human-machine interface

[0115]

[0116]

[0117] 3 Application indicators

[0118] 3.1 Object movement speed test

[0119] like Figure 15 As shown, a finger is moved parallel to the Flex-PCI device at a speed of 43 mm / s at a distance of 1 cm from the device, so that the finger moves from channel 1 (CH1) to channel 13 (CH13) of the device. The near-infrared light reflected by the finger is detected by the Flex-PCI. The movement speed of the finger is calculated to be 41.3 mm / s based on the response sequence of each channel in the Flex-PCI, and the error with the actual speed is within 4%, indicating that the Flex-PCI device of the present invention can achieve real-time motion capture.

[0120] 3.2Flex-PCI detection of human physiological information

[0121] Place a planar light source with a wavelength of 850nm and a power of 8.3mW / cm below the Flex-PCI. 2 , so that the fingertip hovers 1cm above the Flex-PCI device. The light emitted by the planar light source passes through the hollow part of the Flex-PCI and shines on the finger, which is reflected by the finger. The light intensity signal of the fingertip pulse that changes with time is determined based on the reflected light response. The waveform of the light intensity signal shows obvious periodic changes, with clear systolic peaks, dicrotic notch peaks and diastolic peaks, such as Figure 16As shown. It shows that the Flex-PCI device of the present invention can realize the measurement of repeatable photoplethysmography (PPG). The above absorption waveform is analyzed by SDPTG, and it can be seen that the absorption wave can be clearly divided into four systolic waves and one diastolic wave, including: a wave, a positive wave in early systole; b wave, a negative wave in early systole; c wave, a reinforcing wave in late systole; d wave, a weakening wave in late systole; e wave, a positive wave in early diastole. Combined with Fourier transform for time-frequency conversion, the respiratory and heart rate frequencies are decomposed. As a result, two obvious peaks can be observed, located at 0.39Hz and 0.98Hz, respectively, corresponding to a respiratory rate of 23 times / minute (brpm) and a heart rate of 58 times / minute (bpm), indicating that the Flex-PCI device of the present invention can be used for non-contact human heart rate and respiratory monitoring.

[0122] 3.3 Application of Flex-PCI in extreme environments

[0123] 3.3.1 Application effect in extreme environments

[0124] To simulate an extreme environment of high temperature and high humidity, the Flex-PCI was placed in a closed acrylic box. The humidity in the acrylic box was changed by spraying water into the box. Alternatively, an electric heater was used to increase the temperature in the acrylic box, or the acrylic box was placed in a refrigerator to lower the temperature. A thermometer and hygrometer were placed next to the Flex-PCI to monitor changes in temperature and humidity in real time. To simulate high ambient light intensity, a white light emitting lamp was placed above the Flex-PCI. The distance between the white light and the Flex-PCI was changed to control the visible light intensity on the surface of the Flex-PCI. The optical power meter was used to monitor the test results. Figure 17 The results show that the temperature range is 0-85.0℃, the relative humidity is 22.4%-97.9%, and the ambient light intensity is 0.1-4.8mW / cm 2 Under the conditions of , the light intensity of the Flex-PCI device remains basically unchanged, and the light response fluctuation is less than 5%, showing stability and repeatability.

[0125] 3.3.2 Bending state

[0126] Flex-PCI devices according to Figure 18 The curvature radius after bending is about 7.5mm. The curved surface is illuminated by an 850nm LED light source with a switching frequency of 0.05Hz. The output signal shows a change pattern that is basically consistent with the change of the light source (such as Figure 19 When a finger is swiped across the surface of the curved Flex-PCI device, the device exhibits a rapid and continuous response, which is basically consistent with the optical response behavior in the flat state, as shown in Figure 2. Figure 20As the palm approaches the surface of the bent Flex-PCI device, as the distance between the palm and the surface of the Flex-PCI device decreases, the Flex-PCI device exhibits a significant optical response, and its optical response behavior is consistent with that in the unbent state, as shown in Figure 2. Figure 21 shown.

[0127] 3.3.3 Underwater Applications

[0128] The Flex-PCI device is encapsulated with transparent flexible PET film, according to Figure 22 As shown in the figure, the packaged device is placed in water and the Flex-PCI device is illuminated by an LED light source with a wavelength of 850nm and a switching frequency of 0.05Hz. The results are shown in the figure. Figure 23 As shown in the figure, it can be seen that the output signal shows a change pattern that is basically consistent with the change of the light source underwater. When a finger passes over the surface of the underwater Flex-PCI device, the device shows a rapid and continuous response, which is similar to the light response behavior of the Flex-PCI device in the air (such as Figure 24 As shown in the figure, as the distance between the hand and the Flex-PCI device changes, the light response behavior shows a change pattern that is basically consistent with that in the air, that is, the Flex-PCI of the present invention can achieve light response within a wide range of 30 cm underwater, as shown in the figure. Figure 25 As shown. This shows that the Flex-PCI device of the present invention can be used underwater. The Flex-PCI device in the above bending, underwater, high temperature (temperature is 80℃) or high humidity (RH=95%) is used to detect human physiological information. The test method is consistent with the test method of the device in the unbent state ( Figure 26 ), the test results are as follows Figure 27 and Figure 28 As shown, it can be seen that the photocurrent and amplitude changes of the Flex-PCI device under the above working conditions are basically consistent with the test results of the unbent state, indicating that the Flex-PCI device of the present invention can still continuously and stably perform vital signs detection under extreme working conditions.

[0129] 4. Long-term stability test

[0130] The light intensity was 240 μW / cm 2 The LED light source with a wavelength of 850nm and a frequency of 0.5Hz illuminates the surface of the Flex-PCI device and measures its light response. The light response behavior of 45,000 optical switching cycles is as follows: Figure 29 As shown in the results, it can be seen that the optical response decay is less than 0.5% after 45,000 optical switching cycles, indicating that the Flex-PCI device of the present invention has excellent long-term stability.

Claims

1. A visible light blind near infrared flexible organic photodetector, characterized in that: It comprises a filter layer, a flexible substrate and a near-infrared detection component; the filter layer and the near-infrared detection component are located on two opposite sides of the flexible substrate.

2. The visible light blind near-infrared flexible organic photodetector according to claim 1, characterized in that: The near infrared detection component includes, from close to the flexible substrate to far away from the flexible substrate, an ITO transparent electrode layer, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, a MoO x hole transport layer and Ag electrode layer.

3. The visible light blind near-infrared flexible organic photodetector according to claim 2, characterized in that: The thickness of the ZnO electron transport layer is 30 nm; and / or the thickness of the PFNBr interface modification layer is 10 nm; and / or the thickness of the active layer is 150 nm; and / or the MoO x The hole transport layer has a thickness of 3 nm; and / or the Ag electrode layer has a thickness of 100 nm; and / or the filter layer has a thickness of 1 μm; and / or the filter layer material includes PC with a mass ratio of 1:

1. 71 BM and PCE-10.

4. A method for preparing a visible light blind near-infrared flexible organic photodetector according to any one of claims 1 to 3, characterized in that: include: Step 1: Pre-treating the ITO-covered PET flexible substrate; Step 2: forming a ZnO electron transport layer on the pretreated flexible substrate by spin coating; Step 3: Spin-coat the PFN-Br methanol solution onto the ZnO electron transport layer to obtain a PFNBr interface modification layer; Step 4: Using PM6 and Y6-4Se as donor and acceptor, respectively, to set an active layer on the PFNBr interface modification layer; Step 5: Set MoO on the active layer in sequence x Hole transport layer and Ag electrode layer; Step 6: Using PC71BM and PCE-10 as main raw materials for the filter layer, a filter layer is prepared on the pre-treated flexible substrate.

5. A flexible optical non-contact human-machine interface, characterized in that: The visible light blind near infrared flexible organic photodetector as claimed in claim 2, wherein the ZnO electron transport layer, the PFNBr interface modification layer, the active layer, the MoO x The hole transport layer and the Ag electrode layer are concentric hollow structures.

6. The flexible optical non-contact human-machine interface according to claim 5, characterized in that: There are multiple hollow structures, and the multiple hollow structures are evenly spaced.

7. A method for preparing the flexible optical non-contact human-machine interface according to claim 5, characterized in that: include: Step 1: Pre-treating the ITO-covered PET flexible substrate; Step 2: forming a ZnO electron transport layer on the pretreated flexible substrate by spin coating; Step 3: Spin-coat the PFN-Br methanol solution onto the ZnO electron transport layer to obtain a PFNBr interface modification layer; Step 4: Using PM6 and Y6-4Se as donor and acceptor, respectively, to set an active layer on the PFNBr interface modification layer; Step 5: Set MoO on the active layer x hole transport layer; Step 6: In MoO x A hollow silver electrode is evaporated and deposited on the hole transport layer; Step 7: Using PC71BM and PCE-10 as main raw materials for the filter layer, a filter layer is prepared on the pre-treated flexible substrate.

8. The method according to claim 7, characterized in that Also includes: After evaporation deposition of the hollow silver electrode, the ZnO electron transport layer, PFNBr interface modification layer, active layer and MoO x The hole transport layer is removed.

9. The method according to claim 7, characterized in that In step 1, the ITO-covered PET flexible substrate is pretreated by UV light; and / or, in step 4, the active layer raw material further includes chloronaphthalene; and / or, in step 7, the filter layer raw material includes PC 71 The mass ratio of BM and PCE-10 was 1:

1.

10. A method for applying the flexible optical non-contact human-machine interface according to claim 5, characterized in that: The method includes ensuring that the distance between the moving object to be detected and the flexible optical non-contact human-machine interface is ≤5 cm.

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