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

Abstract

The application discloses a visible-light-blind near-infrared flexible organic photodetector and a preparation method and application thereof, and the visible-light-blind near-infrared flexible organic photodetector 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 the opposite sides of the flexible substrate. The visible-light-blind near-infrared flexible organic photodetector containing the filter layer, the flexible substrate and the near-infrared detection component has an extremely low dark current of 0.048nA / cm 2 on the basis of keeping a photoelectric current equivalent to that of a conventional OPD, has strong anti-visible-light interference performance and a near-infrared waveband detection ratio equivalent to that of the conventional OPD.

Description

Technical Field

[0001] This invention belongs to the field of near-infrared photodetector technology, specifically relating to a visible-blind near-infrared flexible organic photodetector, its preparation method, and its application. Background Technology

[0002] Non-contact 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 drawbacks such as low accuracy in sensing 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, resistance to ambient light interference, and adaptability to extreme environments of NIR-OPDs directly affect the application and promotion of C-HMI. Among these, 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, usually caused by thermally excited carriers or defects per unit area. Dark current density affects many performance characteristics of NIR-OPDs, including dynamic range and specific detectivity. Low dark current density is crucial for NIR-OPDs. Currently, the responsivity of NIR-OPDs is mainly improved by introducing a heterojunction structure composed of two different semiconductor materials. In the process of realizing this invention, the inventors found that the prior art has at least the following problems: it cannot avoid visible light interference; disordered microstructure or trapped 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 address the shortcomings of the prior art by providing a visible light blind near-infrared flexible organic photodetector, its preparation method and application. This 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. This invention comprises a visible-blind near-infrared flexible organic photodetector, including a filter layer, a flexible substrate, and a near-infrared detection component, achieving a near-infrared light response of 0.048 nA / cm while maintaining a near-infrared light response comparable to traditional OPDs. 2 It has extremely low dark current, strong resistance to visible light interference, and near-infrared band detectivity comparable to traditional OPDs.

[0007] 2. The visible-blind near-infrared flexible organic photodetector of the present invention has stable mechanical properties, can withstand more than 1,000 bends, and its 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, fast response speed and 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 in non-contact human heart rate and respiration monitoring, with reliable data.

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

[0011] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the visible light blind near-infrared flexible organic photodetector structure 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 This is a schematic diagram of the dark current test results of Vis-blind NIR OPD in Example 1;

[0015] Figure 4 This is a schematic diagram of the Vis-blind NIR OPD photoresponse test results in Example 1;

[0016] Figure 5 This is a schematic diagram of the test results of the Vis-blind NIR OPD's resistance to visible light interference in Example 1;

[0017] Figure 6 This is a schematic diagram of the specific detectivity test results of the Vis-blind NIR OPD in Example 1;

[0018] Figure 7This is a schematic diagram of the LDR test results of the Vis-blind NIR OPD in Example 1;

[0019] Figure 8 This is a schematic diagram of the instantaneous photodynamic response behavior of the Vis-blind NIR OPD in self-powered mode in Example 1;

[0020] Figure 9 This is a schematic diagram of the Vis-blind NIR OPD cutoff frequency test results in Example 1;

[0021] Figure 10 This is a schematic diagram of the Vis-blind NIR OPD bending stability test results for Example 1;

[0022] Figure 11 This is a schematic diagram of the Flex-PCI test results for object approach and distance in Example 2;

[0023] Figure 12 This is a schematic diagram of the Flex-PCI distance sensitivity test results in Example 2;

[0024] Figure 13 This is a schematic diagram of the Flex-PCI spatial resolution test results in Example 2;

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

[0026] Figure 15 This is a schematic diagram illustrating the principle of Flex-PCI object motion speed testing in Example 2;

[0027] Figure 16 This is a schematic diagram of the detection of human physiological information by Flex-PCI in Example 2;

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

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

[0030] Figure 19 This is the output signal of the Flex-PCI bending test in Example 2;

[0031] Figure 20 This is a schematic diagram illustrating the behavior of a sliding gesture test result in the Flex-PCI bending state in Example 2;

[0032] Figure 21This is a schematic diagram of the distance sensitivity test results of Flex-PCI under bending conditions in Example 2;

[0033] Figure 22 This is the underwater test status of Flex-PCI in 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 swipe gesture test results in Example 2;

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

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

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

[0039] Figure 28 This is a schematic diagram of the fast Fourier transform of the test results for detecting human physiological information under various extreme conditions of Flex-PCI in Example 2.

[0040] Figure 29 This is a schematic diagram of the long-term stability test results of Flex-PCI in Example 2. Detailed Implementation

[0041] The technical solution will now be clearly and completely described with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0042] In the following description, the term "and / or" is used to describe the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. A and B can be singular or plural.

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

[0044] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may 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 this application.

[0045] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0046] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0047] The technical principle adopted in this invention is as follows: by setting filter layers and near-infrared detection components on both sides of the flexible substrate, the low dark current of the near-infrared detection components 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 one hand, a visible-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 charge activity in the detector and interfering with the near-infrared detection. This achieves extremely low dark current and strong resistance to visible light interference in the flexible organic photodetector.

[0050] In some embodiments, the near-infrared detection component comprises, from near the flexible substrate to far away from the flexible substrate, the following layers in sequence: an ITO transparent electrode layer, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer. xHole transport layer and Ag electrode layer. In 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 thickness of the MoO layer is... 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 comprises PC in a mass ratio of 1:1. 71 BM and PCE-10.

[0051] On another front, a flexible optical non-contact human-machine interface is provided, comprising the aforementioned visible-blind near-infrared flexible organic photodetector, wherein the ZnO electron transport layer, PFNBr interface modification layer, active layer, and MoO are described. 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 moving objects, and be detected by a 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 the effect of high sensitivity and effective reduction of optical crosstalk effects.

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

[0054] Furthermore, a method for fabricating the aforementioned visible-blind near-infrared flexible organic photodetector is provided, comprising:

[0055] Step 1: Pre-treat the ITO-covered PET flexible substrate; in some specific embodiments, the pre-treatment includes irradiating the ITO-covered PET flexible substrate with UV light for 15 minutes; the ITO in the ITO-covered PET flexible substrate is single-sided; using the pre-treated flexible substrate as a base, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer are formed on one side. x The hole transport layer and Ag electrode layer are functional layers, and a filter layer is set 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 irradiation, which is beneficial for subsequent coating layers.

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

[0057] Step 3: A PFNBr interface modification layer is formed on the ZnO electron transport layer by spin coating. In some preferred embodiments, forming the PFNBr interface modification layer includes: transferring a flexible substrate covering the ZnO electron transport layer to a glove box filled with nitrogen, and spin coating a PFN-Br methanol solution with a concentration of 0.5 mg / mL onto the ZnO electron transport layer to obtain the PFNBr interface modification layer; the thickness of the PFNBr interface modification layer is 10 nm; the function of the PFN-Br interface modification layer is to modify the interface properties of the ZnO electron transport layer.

[0058] Step 4: Set 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 onto the PFNBr interface modification layer, and heat-treating at 110℃ for 5 min to obtain the active layer; the thickness of the active layer is 150 nm; 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; in some preferred embodiments, the donor-acceptor mixed slurry also includes 0.5% chloronaphthalene by mass; in this invention, the preferred donor-acceptor mixed slurry also includes chloronaphthalene, which can regulate the phase separation morphology of the donor and acceptor in the active layer and improve photoelectric performance;

[0059] Step 5: Sequentially place MoO2 on the active layer. x A hole transport layer and an Ag electrode layer complete the functional layer setup; in some preferred embodiments, a MoO layer is also provided. x The hole transport layer and Ag electrode layer include: MoO2 deposited by evaporation deposition. x Ag and MoO are deposited sequentially on the active layer; x The hole transport layer has a thickness of 3 nm, and the Ag electrode layer has a thickness of 100 nm; the vacuum degree of the evaporation deposition coating is 2 × 10⁻⁶. -5 pa;

[0060] Step 6: Fabricate a filter layer on the pretreated flexible substrate; in some preferred embodiments, fabricating the filter layer includes: applying PC... 71 BM and PCE-10 are miscible in chlorobenzene to obtain a filter paste; the PC 71 The mass ratio of BM to PCE-10 is 1:1, and the PC in the filter paste... 71 The total concentration of BM and PCE-10 is 40 mg / mL. The filter paste is coated onto the non-functional layer side of the pretreated flexible substrate by spin coating to obtain a filter layer. The thickness of the filter layer is 1 μm. By setting the filter layer on the non-functional layer side of the pretreated flexible substrate, visible light is absorbed, thereby achieving the purpose of filtering and removing visible light.

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

[0062] Step 1: Pre-treat the ITO-covered PET flexible substrate; in some specific embodiments, the pre-treatment includes irradiating the ITO-covered PET flexible substrate with UV light for 15 minutes; the ITO in the ITO-covered PET flexible substrate is single-sided; using the pre-treated flexible substrate as a base, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer are formed on one side. x The hole transport layer and Ag electrode layer are functional layers, and a filter layer is set 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 irradiation, which is beneficial for subsequent coating layers.

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

[0064] Step 3: A PFNBr interface modification layer is formed on the ZnO electron transport layer by spin coating. In some preferred embodiments, forming the PFNBr interface modification layer includes: transferring a flexible substrate covering the ZnO electron transport layer to a glove box filled with nitrogen, and spin coating a PFN-Br methanol solution with a concentration of 0.5 mg / mL onto the ZnO electron transport layer to obtain the PFNBr interface modification layer; the thickness of the PFNBr interface modification layer is 10 nm; the function of the PFN-Br interface modification layer is to modify the interface properties of the ZnO electron transport layer.

[0065] Step 4: Set 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 onto the PFNBr interface modification layer, and heat-treating at 110℃ for 5 min to obtain the active layer; the thickness of the active layer is 150 nm; 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; in some preferred embodiments, the donor-acceptor mixed slurry also includes 0.5% chloronaphthalene by mass; in this invention, the preferred donor-acceptor mixed slurry also includes chloronaphthalene, which can regulate the phase separation morphology of the donor and acceptor in the active layer and improve photoelectric performance;

[0066] Step 5, in MoO x Multiple hollow silver electrodes were evaporated and deposited on the hole transport layer. After evaporating and depositing 16 hollow silver electrodes, the ZnO electron transport layer, PFNBr interface modification layer, active layer, and MoO were then deposited in the hollow regions of the hollow silver electrodes. x Hole transport layer removal; in some preferred embodiments, the number of hollow silver electrodes is 16, and the 16 hollow silver electrodes are in MoO x Hollow silver electrodes are evenly distributed in a 4×4 array on the hole transport layer. Each hollow silver electrode has an external dimension of 2mm×2mm and a hollow region dimension of 1mm×1mm, with an effective area of ​​3mm². 2 Each hollow silver electrode has a thickness of 300 nm; the hollow silver electrodes are fabricated using a mask containing 16 hollow regions; in some specific embodiments, the layers at the hollow regions are removed by wiping with acetone.

[0067] Step 6: Fabricate a filter layer on the pretreated flexible substrate; in some preferred embodiments, fabricating the filter layer includes: applying PC... 71 BM and PCE-10 are miscible in chlorobenzene to obtain a filter paste; the PC 71 The mass ratio of BM to PCE-10 is 1:1, and the PC in the filter paste... 71The total concentration of BM and PCE-10 is 40 mg / mL. The filter paste is coated onto the non-functional layer side of the pretreated flexible substrate by spin coating to obtain a filter layer. The thickness of the filter layer is 1 μm. By setting the filter layer on the non-functional layer side of the pretreated flexible substrate, visible light is absorbed, thereby achieving the purpose of filtering and removing visible light.

[0068] This method also includes removing the ZnO electron transport layer, PFNBr interface modification layer, active layer, and MoO from the hollow region. x The 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 30cm, 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 applied to extreme environments such as high temperature, high humidity and high ambient light intensity, and has significant resistance to 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 ensuring that the distance between the moving object to be detected and the flexible optical non-contact human-machine interface is ≤5cm; in some specific embodiments, the application method includes ensuring that the distance between the moving object to be detected and the filter layer of the flexible optical non-contact human-machine interface is ≤5cm.

[0071] Prior to the application for this invention, a series of experiments were conducted. Some of the experimental results are listed below to provide a more detailed description of the invention. The following is a detailed description in conjunction with the embodiments.

[0072] Example 1

[0073] This embodiment provides a visible-blind near-infrared flexible organic photodetector, 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, from the closest to the flexible substrate to the furthest away from the flexible substrate, sequentially includes: an ITO transparent electrode layer, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer. x Hole transport layer and Ag electrode layer. For example... Figure 1 As shown.

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

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

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

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

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

[0079] Step 3: Set 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 glove box filled with nitrogen, and spin-coat a PFN-Br methanol solution with a concentration of 0.5 mg / mL onto the ZnO electron transport layer to obtain 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: Set an active layer on the PFNBr interface modification layer;

[0082] Step 401: PM6, Y6-4Se, and chloronaphthalene are mixed 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 sesubstitution 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 mixture onto the PFNBr interface modification layer, and heat-treat at 110°C for 5 min to obtain the active layer; the thickness of the active layer is 150 nm.

[0084] Step 5: Sequentially place MoO2 on the active layer. x Hole transport layer and Ag electrode layer;

[0085] Step 501: Apply MoO2 by evaporation deposition. x MoO is deposited on the active layer to obtain x Hole transport layer, in MoO x Sixteen Ag electrodes were evaporated and deposited on the hole transport layer to obtain the Ag electrode layer, completing the process of forming a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer. x The functional layers of the hole transport layer and the Ag electrode layer; MoO x The hole transport layer is 3 nm thick, and each Ag electrode is 100 nm thick; the vacuum degree of the evaporation deposition is 2 × 10⁻⁶. -5 pa;MoO x Purchased from Sigma-Aldrich; in the Ag electrode layer, each silver electrode has an area of ​​0.04 mm². 2 Sixteen silver electrodes are evenly distributed in a 4×4 array, and each silver electrode measures 2mm×2mm.

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

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

[0088] Step 602: On one side of the non-functional layer of the pretreated flexible substrate, a filter paste is coated onto the pretreated flexible substrate by spin coating to obtain a filter layer; the thickness of the filter layer is 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, and there are 16 hollow structures. These 16 hollow structures are evenly distributed in a 4×4 array, named Flex-PCI, and the structure is as follows. Figure 2 As shown.

[0091] This embodiment also provides a method for fabricating the above-mentioned flexible optical non-contact human-machine interface, including:

[0092] Steps one through four are the same as those in Example 1 for preparing the visible-blind near-infrared flexible organic photodetector;

[0093] Step five involves depositing a film of MoO through evaporation deposition. x MoO is deposited on the active layer to obtain x Hole transport layer, in MoO x Sixteen hollow silver electrodes were evaporated and deposited on the hole transport layer; the 16 hollow silver electrodes were deposited on MoO. x Hollow silver electrodes are evenly distributed in a 4×4 array on the hole transport layer. Each hollow silver electrode has an external dimension of 2mm×2mm and a hollow region dimension of 1mm×1mm, with an effective area of ​​3mm². 2 Each hollow silver electrode has a thickness of 300 nm; the hollow silver electrodes are fabricated using a mask containing 16 hollow regions.

[0094] After evaporating and depositing 16 hollow silver electrodes, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer were added to the hollow regions of the hollow silver electrodes. x The hole transport layer was removed, and then the filter layer was prepared according to step six of Example 1; the method for removing each layer in the hollow region was to wipe it off with acetone.

[0095] Performance Evaluation

[0096] 1. Vis-blind NIR OPD Key Performance Indicators

[0097] 1.1 Dark current density and responsivity

[0098] Photoelectric testing was performed on the Vis-blind NIR OPD of Example 1, and the results were as follows: Figure 3 The dark current-voltage curve shown indicates that the Vis-blind NIR OPD of this invention exhibits 0.048 nA / cm² in self-powered mode. 2 Ultra-low dark current. The Vis-blind NIR OPD photoresponse 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. The conventional OPDs without a filter layer are the organic photodetectors prepared according to steps one to five of Example 1.

[0099] 1.2 Visible light interference resistance

[0100] Under an illumination intensity of 5 mW / cm², the photocurrent of the Vis-blind NIR OPD in Example 1 was measured using incident light at wavelengths of 450 nm, 550 nm, 850 nm, and 950 nm. The results are as follows: Figure 5 As shown, the Vis-blind NIR OPD has a photocurrent ratio of up to 186:1 for 850nm near-infrared light and 550nm visible light, demonstrating strong resistance to visible light interference.

[0101] 1.3 Specific detectivity and LDR

[0102] The results of the Vis-blind NIR OPD specific detectivity measurement for Example 1 are as follows: Figure 6 As shown, the Vis-blind NIR OPD specific detectivity of Example 1 exceeds 10. 12 Jones, LDR test results are as follows Figure 7 As shown, the LDR of the Vis-blind NIR OPD in Example 1 is >149 dB. This indicates that the Vis-blind NIR OPD of the present invention has high specific detectivity and LDR.

[0103] 1.4 Response Speed

[0104] The instantaneous time response behavior of the Vis-blind NIR OPD in Example 1 under 850nm LED illumination in self-powered mode is as follows: Figure 8 As shown, its response time is 580ns. The -3dB frequency is as follows... Figure 9 As shown, the Vis-blind NIR OPD cutoff frequency f of the present invention -3dB With a clock speed of 1.32MHz, this ultrafast response time far exceeds 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 radius of curvature after bending was 7.5 mm. The performance test results after bending are as follows: Figure 10 As shown, the noise spectral density S nResponse rate, specific detectivity, f -3dB The ratio of linear dynamic range (LDR) to that before bending remained stable at around 1.0, and all parameters remained basically unchanged, indicating that the Vis-blind NIR OPD of the present invention has excellent bending stability.

[0107] 2. Key Indicators of Flex-PCI Devices in Example 2

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

[0109] The Flex-PCI was positioned with the filter layer on top and the silver electrode layer on the bottom, and a planar light source with a wavelength of 850nm and a power of 8.3mW / cm² was placed below it. 2 By placing a hand above the Flex-PCI, the light response of the Flex-PCI to the finger at different distances was tested, and the results are as follows. Figure 11 As shown, Figure 11 The photovoltage near the Flex-PCI is the photovoltage of the Flex-PCI when the finger is 0.5cm away from the Flex-PCI, and the photovoltage far away from the Flex-PCI is the photovoltage of the Flex-PCI when the finger is 5cm away from the Flex-PCI. It can be seen that the photovoltage shows significantly different changes as the finger approaches and moves away from the Flex-PCI. When the finger approaches the Flex-PCI, the photovoltage increases significantly, and when the finger moves away from the Flex-PCI, the photovoltage decreases 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 within the range of 0.5–30 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. According to Figure 12 It can be seen that when the distance between the palm and the Flex-PCI is 1.5cm, the differential value of the photocurrent as a function of distance reaches its peak, at which point the distance sensitivity is highest, reaching 26.83uA / cm. Within 1.505cm ± 0.005cm, the photocurrent changes approximately linearly (e.g., Figure 13 As shown in the figure, the distance resolution obtained from the test is 10μm, which is significantly higher than the resolution of existing non-contact human-machine interfaces.

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

[0113] With a palm placed 1 cm away from the Flex-PCI, and an 850nm LED placed below it, the instantaneous photonic response behavior of the Flex-PCI in a real-world application scenario was simulated. The results are as follows: Figure 14 As shown, the response time of Flex-PCI in self-powered mode is 1.6μs, which is a significant improvement in response speed compared to existing non-contact human-machine interfaces.

[0114] Table 1. Comparison of detection distance and response speed between Flex-PCI and existing non-contact human-machine interfaces in Example 2.

[0115]

[0116]

[0117] 3 Application Indicators

[0118] 3.1 Test of the speed of moving objects

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

[0120] 3.2 Flex-PCI for Detecting Human Physiological Information

[0121] A planar light source with a wavelength of 850nm and a power of 8.3mW / cm² is placed below the Flex-PCI. 2 The fingertip is held 1 cm above the Flex-PCI device. Light from a planar light source passes through the hollow part of the Flex-PCI and shines on the finger, where it is reflected. The light intensity signal of the fingertip pulse over time is determined based on the reflected light response. The waveform of the light intensity signal exhibits obvious periodic changes, with clear contraction peaks, dicrotic notch peaks, and diastolic peaks. Figure 16As shown, the Flex-PCI device of this invention can achieve repeatable photoplethysmography (PPG) measurement. Analysis of the absorption waveform using SDPTG reveals that the absorption wave can be clearly divided into four systolic waves and one diastolic wave, including: wave a, a positive wave in early systole; wave b, a negative wave in early systole; wave c, a re-enhancing wave in late systole; wave d, a re-decreasing wave in late systole; and wave e, a positive wave in early diastole. Time-frequency conversion using Fourier transform decomposes the respiratory and heart rate frequencies. Two distinct peaks are observed at 0.39 Hz and 0.98 Hz, corresponding to a respiratory rate of 23 breaths / minute (brpm) and a heart rate of 58 beats / minute (bpm), respectively. This indicates that the Flex-PCI device of this invention can be applied to non-contact human heart rate and respiratory monitoring.

[0122] 3.3 Application of Flex-PCI in Extreme Environments

[0123] 3.3.1 Application effect under extreme environments

[0124] To simulate extreme high-temperature and high-humidity environments, the Flex-PCI was placed in a sealed acrylic chamber. The humidity inside the chamber was adjusted by spraying water, or by using an electric heater to raise the temperature, or by placing the chamber in a refrigerator to lower it. A thermometer and hygrometer were placed next to the Flex-PCI to monitor temperature and humidity changes 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 varied to control the visible light intensity on the Flex-PCI surface, which was monitored using a power meter. The test results are as follows: Figure 17 As shown, the results indicate that the optimal operating conditions were achieved within a temperature range of 0–85.0℃, a relative humidity range of 22.4%–97.9%, and an ambient light intensity range of 0.1–4.8 mW / cm². 2 Under these conditions, the light intensity of the Flex-PCI device remains essentially unchanged, and the light response fluctuation is less than 5%, demonstrating stability and repeatability.

[0125] 3.3.2 Bending state

[0126] Flex-PCI devices according to Figure 18 The bending surface shown has a radius of curvature of approximately 7.5 mm after bending. When illuminated by an 850 nm LED light source with a switching frequency of 0.05 Hz, the output signal exhibits a variation pattern that is basically consistent with the change in the light source (e.g., ...). Figure 19 (As shown). When a finger is run across the surface of a curved Flex-PCI device, the device exhibits a fast and continuous response, which is essentially consistent with the light response behavior in a flat state, such as... Figure 20As shown, when a hand is brought close to the surface of a bent Flex-PCI device, the Flex-PCI exhibits a distinct light response as the distance between the hand and the device surface decreases. Its light response behavior is consistent with that in the unbent state, as shown... Figure 21 As shown.

[0127] 3.3.3 Underwater Applications

[0128] Flex-PCI devices are encapsulated in transparent flexible PET film, according to... Figure 22 The packaged device was placed in water, and the underwater Flex-PCI device was illuminated with an LED light source with a wavelength of 850nm and a switching frequency of 0.05Hz. The results are as follows. Figure 23 As shown, the output signal exhibits a variation pattern that is essentially consistent with the change in the light source underwater. When a finger is stroked across the surface of the underwater Flex-PCI device, the device displays a rapid and continuous response, similar to the photoresponse behavior of Flex-PCI devices in air (e.g., ...). Figure 24 As shown in the figure, the light response behavior exhibits a variation pattern that is basically consistent with that in air as the distance between the hand and the Flex-PCI device changes. That is, the Flex-PCI of this invention can achieve light response within a 30cm wide range underwater. Figure 25 As shown, this demonstrates that the Flex-PCI device of the present invention can be used underwater. Human physiological information was detected using the Flex-PCI device under the aforementioned bending, underwater, high temperature (80°C), or high humidity (RH = 95%) conditions. The testing method is consistent with the testing method for the device in its unbent state. Figure 26 The test results are as follows: Figure 27 and Figure 28 As shown, under the above operating conditions, the changes in photocurrent and amplitude of the Flex-PCI device are basically consistent with the test results in the unbent state, indicating that the Flex-PCI device of the present invention can still continuously and stably perform vital sign detection under extreme operating conditions.

[0129] 4. Long-term stability test

[0130] Using a light intensity of 240 μW / cm 2 The surface of the Flex-PCI device was illuminated by an LED light source with a wavelength of 850 nm and a frequency of 0.5 Hz, and its photoresponse was measured. The photoresponse behavior after 45,000 optical switching cycles was as follows: Figure 29 As shown in the results, the optical response attenuation 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 flexible optical non-contact human-machine interface, characterized in that, The invention includes a visible-blind near-infrared flexible organic photodetector, which 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 opposite sides of the flexible substrate. The near-infrared detection component comprises, from closest to the flexible substrate to furthest away from the flexible substrate, an ITO transparent electrode layer, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer. x Hole transport layer and Ag electrode layer; 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 thickness of the MoO layer is... 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 comprises PC in a mass ratio of 1:

1. 71 BM and PCE-10; the donor and acceptor in the active layer are PM6 and Y6-4Se, respectively; the ZnO electron transport layer, PFNBr interface modification layer, active layer, and MoO x The hole transport layer and the Ag electrode layer are concentric hollow structures.

2. A method for preparing the flexible optical non-contact human-machine interface as described in claim 1, characterized in that, The method for fabricating the visible-blind near-infrared flexible organic photodetector is characterized by comprising: Step 1: Pre-treat the ITO-covered PET flexible substrate; Step 2: A ZnO electron transport layer is formed on the pretreated flexible substrate by spin coating; Step 3: Spin-coating the PFN-Br methanol solution onto the ZnO electron transport layer to obtain the PFNBr interface modification layer; Step 4: Using PM6 and Y6-4Se as donor and acceptor, respectively, an active layer is set on the PFNBr interface modification layer; Step 5: Sequentially place MoO2 on the active layer. x Hole transport layer and Ag electrode layer; Step 6: Using PC71BM and PCE-10 as the main raw materials for the filter layer, a filter layer is prepared on the pretreated flexible substrate.

3. The flexible optical non-contact human-machine interface according to claim 1, characterized in that, The number of hollow structures is multiple, and the multiple hollow structures are evenly distributed at intervals.

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

5. The method according to claim 4, characterized in that, Also includes: After evaporation deposition of hollow silver electrodes, a ZnO electron transport layer, a PFNBr interface modification layer, an active layer, and a MoO layer are added to the hollow region of the hollow silver electrode. x Hole transport layer removed.

6. The method according to claim 4, characterized in that, Step one pre-treats the ITO-covered PET flexible substrate by UV irradiation; and / or, Step four's active layer material further includes chloronaphthalene; and / or, Step seven's filter layer material includes PC 71 The mass ratio of BM to PCE-10 is 1:

1.

7. A method for using the flexible optical non-contact human-machine interface as described in claim 1, characterized in that, This includes ensuring that the distance between the moving object to be detected and the flexible optical non-contact human-machine interface is ≤5cm.

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