Stretchable near-infrared organic photoelectric detector and preparation method thereof

Abstract

The invention provides a stretchable near-infrared organic photoelectric detector and a preparation method thereof, and relates to the technical field of photoelectric detectors, the stretchable near-infrared organic photoelectric detector sequentially comprises a stretchable transparent substrate, a bottom stretchable transparent anode layer, a hole transport layer, an organic active layer, an electron transport layer and a top stretchable cathode layer from bottom to top; the bottom stretchable transparent anode layer material comprises a conductive polymer solution PEDOT: PSS, a polar solvent DMSO and a deep eutectic solvent. On the basis of ensuring the detection performance of the photoelectric detector, the mechanical stretchability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic detectors, and particularly to a stretchable near-infrared organic optoelectronic detector and a preparation method thereof. Background Art

[0002] The medical and health field is undergoing a profound transformation from early diagnostic devices to continuously innovative smart wearable technologies with the help of emerging technologies. Especially in non-invasive monitoring, real-time health tracking, and personalized treatment, etc., optoelectronic detectors (PDs) have become important tools for medical and health diagnosis due to their high sensitivity and precise response to optical signals. Near-infrared light (NIR, 780 nm - 2526 nm) optoelectronic detectors are particularly prominent in this field because near-infrared light has low absorption and scattering in human tissues, can penetrate skin, muscle, and even bone tissues, and is suitable for non-invasive vital signs monitoring and long-term physiological data monitoring.

[0003] Compared with traditional rigid optoelectronic detectors based on inorganic crystal materials (such as Si, Ge, and InGaAs, etc.), emerging organic semiconductor-based optoelectronic detectors (OPDs) benefit from the advantages of lightweight, low cost, adjustable detection wavelength, and high flexibility of organic materials, and have gradually become an important research direction in the medical and health field. In particular, near-stretchable infrared optoelectronic detectors with reasonable device designs can achieve non-invasive real-time monitoring of human physiological signals on the premise of closely fitting the human skin and adapting to various dynamic movements of the body, providing important technical support for wearable health monitoring devices. However, in related technologies, there are few studies on stretchable optoelectronic detectors in the near-infrared range. How to improve the mechanical stretchability while ensuring the detection performance of optoelectronic detectors is an urgent problem to be solved in this field. Summary of the Invention

[0004] In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide a stretchable near-infrared organic optoelectronic detector and a preparation method thereof to improve the mechanical stretchability while ensuring the detection performance of the optoelectronic detector.

[0005] To achieve the above purpose, according to some embodiments, in a first aspect of the present invention, there is provided a stretchable near-infrared organic optoelectronic detector, which sequentially includes a stretchable transparent substrate, a bottom stretchable transparent anode layer, a hole transport layer, an organic active layer, an electron transport layer, and a top stretchable cathode layer from bottom to top; the material of the bottom stretchable transparent anode layer includes a conductive polymer solution PEDOT:PSS, a polar solvent DMSO, and a deep eutectic solvent.

[0006] In some embodiments, the conductive polymer solution PEDOT:PSS is PH1000.

[0007] In some embodiments, the deep eutectic solvent includes any one of choline chloride: urea, choline chloride: ethylene glycol, choline chloride: glycerol, choline chloride: lactic acid, choline chloride: glycolic acid, choline chloride: levulinic acid, and choline chloride: p-toluenesulfonic acid; preferably, the deep eutectic solvent is choline chloride: p-toluenesulfonic acid.

[0008] In some embodiments, the organic active layer is a blend structure composed of a polymeric donor material PM6, a polymeric small molecule acceptor material PY-IT, and an elastomeric material SEBS.

[0009] In some embodiments, 1-chloronaphthalene is further included in the organic active layer.

[0010] In some embodiments, the range of the elastomeric material SEBS in the total mass of the organic active layer is 5%-50%, and the range of 1-chloronaphthalene in the volume of the organic active layer solution is 0.5%-2%; preferably, the elastomeric material SEBS accounts for 38% of the total mass of the organic active layer, and 1-chloronaphthalene accounts for 1.5% of the volume of the organic active layer solution.

[0011] In some embodiments, the electron transport layer material is PNDIT-F3N-Br.

[0012] In some embodiments, the material of the hole transport layer is PEDOT:PSS; preferably, a fluorosurfactant FS-30 is further added to the hole transport layer; preferably, the range of the fluorosurfactant FS-30 in the total volume of the hole transport layer solution is 0.1%-1%.

[0013] In some embodiments, the top stretchable cathode layer is eutectic gallium-indium liquid metal.

[0014] In a second aspect of the present invention, there is provided a method for preparing the above-mentioned stretchable near-infrared organic optoelectronic detector, including:

[0015] Spin-coating a prepared TPU solution on the glass surface and heating and curing to obtain a stretchable transparent substrate;

[0016] In an air atmosphere, spin-coating the bottom anode electrode solution on the stretchable substrate treated in an ultraviolet-ozone environment, annealing, etching the pattern, and using a low-adhesion tape to paste and protect the common electrode part to obtain a bottom stretchable transparent anode layer;

[0017] Treat the bottom stretchable transparent anode layer in an ultraviolet-ozone environment, and then spin-coat the hole transport layer material on the surface twice and anneal in an air atmosphere to obtain a hole transport layer;

[0018] In an air atmosphere, scrape-coat the active layer material on the hole transport layer and anneal in an inert gas atmosphere to obtain an organic active layer;

[0019] In an inert gas atmosphere, the electron transport layer solution is spin-coated on the organic active layer to obtain the electron transport layer.

[0020] Tear off the low-adhesion tape, cover with a patterned mask, spray and coat the top electrode solution on the electron transport layer to obtain a top stretchable cathode layer consistent with the mask pattern. Finally, the fabricated device is peeled off from the glass surface.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The present invention provides a stretchable near-infrared organic optoelectronic detector and a preparation method thereof. A low-cost and low-toxic deep eutectic solvent is introduced into the conductive polymer solution PEDOT:PSS (PH1000), which synergistically enhances the stretchability and conductivity of the electrode layer. The obtained optoelectronic detector has high stretchability and high specific detectivity in the near-infrared light range, and the device structure and preparation process are simple, which is convenient for mass production.

[0023] The present invention introduces a low-cost thermoplastic elastomer SEBS into the all-polymer organic active layer, which can effectively reduce the rigidity of the active layer while maintaining the high specific detectivity of the device in the near-infrared range. At the same time, the organic active layer is prepared by an environmentally friendly and halogen-free solvent blade coating process, which not only conforms to the trend of environmental protection and sustainable development, but also provides a more economical and efficient solution for industrial mass production, which is beneficial to the stretchable application of organic optoelectronic detectors.

[0024] Advantages of additional aspects of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The specification drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0026] Figure 1 It is a schematic structural diagram of the optoelectronic detector provided by the present invention;

[0027] Figure 2 It is a graph of crack initiation strain and resistance data of the stretchable transparent electrode prepared in Examples 1-7;

[0028] Figure 3 It is a physical diagram of the optoelectronic detector provided by the present invention under different tensile strains;

[0029] Figure 4 It is a dark current-voltage curve graph of the optoelectronic detector prepared in Example 8 of the present invention during the stretching process;

[0030] Figure 5 This is the external quantum efficiency graph of the photodetector prepared in Example 8 of the present invention during the stretching process;

[0031] Figure 6 This is the responsivity graph of the photodetector prepared in Example 8 of the present invention during the stretching process;

[0032] Figure 7 This is the noise current spectrum graph of the photodetector prepared in Example 8 of the present invention during the stretching process;

[0033] Figure 8 This is the specific detectivity graph of the photodetector prepared in Example 8 of the present invention during the stretching process. Detailed implementation manners

[0034] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0035] In the present invention, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only relational terms determined for the convenience of describing the structural relationship of each component or element of the present invention, and do not specifically refer to any component or element of the present invention, and should not be construed as a limitation to the present invention.

[0036] Glossary of terms:

[0037] PEDOT:PSS, a conductive polymer composite material, usually used as the electrode material or hole transport layer material of an organic photodetector.

[0038] PM6, a wide-bandgap polymer material, mainly used as the donor material of an organic photodetector.

[0039] PY-IT, a polymeric small molecule material, mainly used as the acceptor material of an organic photodetector.

[0040] SEBS, a commercial thermoplastic elastomer material, which can be used as the third component to improve the stretching performance of the active layer blend system of an organic photodetector.

[0041] PNDIT-F3N-Br, a polymer material, mainly used as the electron transport layer material of an organic solar cell.

[0042] Crack initiation strain: The strain at which cracks first form under the applied stress.

[0043] External quantum efficiency (EQE): The ratio of the number of electrons collected by the electrode per unit time to the number of incident photons when a photodetector is irradiated with light of a specific wavelength.

[0044] Responsivity (R): It is used to describe the sensitivity of a photodetector to a signal, and it describes the relationship between the output signal and the input signal of the detector. When the EQE is known, R can be calculated through the following formula:

[0045]

[0046] In the formula, λ is the wavelength.

[0047] Noise current (i n ): When a photodetector detects an optical signal, it will be interfered by environmental noise and the detector's own noise signal. The detector's own noise is also called internal noise, and its appearance causes fluctuations in the current signal. Therefore, the noise current is usually used to measure the magnitude of the noise.

[0048] Specific detectivity (D * *): One of the performance parameters of a photodetector, which characterizes the ability of the device to distinguish a signal from noise. When R and i n are known, D* can be calculated through the following formula:

[0049] D*(λ) = R(AB) 1 / 2 / i n = R(A) 1 / 2 / S n

[0050] In the formula, A is the effective area of the device, B is the bandwidth, and S n is the noise current spectral density.

[0051] An embodiment of the present invention provides a stretchable near-infrared organic photodetector. As Figure 1 shown, the photodetector sequentially includes a stretchable transparent substrate, a bottom stretchable transparent anode layer, a hole transport layer, an organic active layer, an electron transport layer, and a top stretchable cathode layer from bottom to top; the material of the bottom stretchable transparent anode layer includes a conductive polymer solution PEDOT:PSS, a polar solvent DMSO, and a deep eutectic solvent.

[0052] In some embodiments, the stretchable transparent substrate material is thermoplastic polyurethane (TPU).

[0053] The material of the bottom stretchable transparent anode layer includes a conductive polymer solution PEDOT:PSS (PH1000), a polar solvent DMSO, and a deep eutectic solvent, and DMSO and the deep eutectic solvent are used to modify the PH1000 solution.

[0054] Traditional high-performance electrode materials (such as ITO, Ag, or Au) are prone to cracking under mechanical deformation and are not suitable for use as the electrode layer of intrinsically stretchable near-infrared organic optoelectronic detectors. For stretchable bottom transparent electrodes, some emerging materials, such as silver nanowires, graphene, and conductive polymers, have been explored. Among them, the conductive polymer PEDOT:PSS (PH1000) has received extensive attention due to its environmental friendliness and excellent flexibility. So far, some teams have modified PH1000 using polar solvents, surfactants, and inorganic acids in order to enhance the conductivity or mechanical flexibility of PH1000. However, it is still difficult to simultaneously improve the conductivity and stretchability of the electrodes using these methods.

[0055] A class of ionic compounds existing in liquid form, called ionic liquids, will trigger ion exchange between the mixture solutions after being incorporated into PH1000, thereby synergistically improving the electrical and mechanical properties of the electrode solution. Deep eutectic solvents are considered to be a subset of ionic liquids and are generally composed of a hydrogen bond donor and a hydrogen bond acceptor that interact through strong hydrogen bonds, and can be used as a conductivity enhancer and plasticizer for PH1000. Compared with traditional ionic liquids, as an emerging green solvent, deep eutectic solvents have the same certain properties as them, and also have advantages such as low cost, low toxicity, and biodegradability.

[0056] As a further preference, the deep eutectic solvent includes any one of choline chloride:urea, choline chloride:ethylene glycol, choline chloride:glycerol, choline chloride:lactic acid, choline chloride:glycolic acid, choline chloride:levulinic acid, and choline chloride:p-toluenesulfonic acid. To synergistically improve the stretchability and conductivity of the bottom electrode, the preferred deep eutectic solvent is choline chloride:p-toluenesulfonic acid.

[0057] In some embodiments, in the bottom stretchable transparent anode layer, the range of DMSO in the total volume of the electrode solution (i.e., PH1000 + DMSO + choline chloride:p-toluenesulfonic acid) is 1% - 5%, and the range of choline chloride:p-toluenesulfonic acid in the total volume of the electrode solution is 0.3% - 1.2%. Preferably, the content of choline chloride:p-toluenesulfonic acid in the bottom electrode solution is 1%, and the content of DMSO is 5%, denoted as m 2 -PH1000.

[0058] In the embodiments of the present invention, the hole transport layer material uses PEDOT:PSS (AI4083).

[0059] In some embodiments, a fluorosurfactant FS-30 is added to the hole transport layer to increase wettability, and the range of FS-30 in the total volume of the hole transport layer solution (AI4083 + FS-30) is 0.1% - 1%.

[0060] The active layer is a blend structure composed of a polymer donor material PM6, a polymeric small molecule acceptor material PY-IT, and an elastomer material SEBS.

[0061] Blend films of all-polymer systems composed of polymer donors and polymer acceptors have high molecular weights and flexible chain segments, making them the most promising candidates for constructing excellent and durable intrinsically stretchable organic photodetectors. Insulating elastomer materials can provide mechanical buffering and effectively relieve the damage of stress to the active layer, thus becoming a potential third component in the active layer of intrinsically stretchable organic photodetectors.

[0062] In some embodiments, the range of SEBS in the total mass of the active layer materials (donor + acceptor + SEBS) is 5% - 50%. In addition, 1-chloronaphthalene is used as an additive for regulating the morphology of the blend film, and its range in the volume of the active layer solution is 0.5% - 2%. Preferably, SEBS accounts for 38% of the total mass of the active layer, and the content of 1-chloronaphthalene in the active layer solution is 1.5%.

[0063] The electron transport layer material is PNDIT-F3N-Br.

[0064] The top stretchable cathode layer is eutectic gallium-indium liquid metal (EGaIn), which contains 70 - 80 wt% gallium and 20 - 30 wt% indium, and is further preferably 75.5 wt% gallium and 24.5 wt% indium.

[0065] On the other hand, the present invention provides a method for preparing a stretchable near-infrared organic photodetector, comprising the following steps:

[0066] (1) Cleaning a transparent glass sheet.

[0067] (2) Spin-coating a prepared TPU solution on the surface of the smooth transparent glass sheet obtained in step (1), and heating and curing to obtain a stretchable transparent substrate.

[0068] (3) Under an air atmosphere, spin-coating the bottom anode electrode solution on the stretchable substrate treated in an ultraviolet-ozone environment, annealing, and etching the pattern with a 532 nm green laser, and pasting the common electrode part with a low-adhesion tape for protection to obtain a stretchable transparent anode layer.

[0069] (4) Treating the stretchable transparent anode layer in an ultraviolet-ozone environment, and then spin-coating the hole transport layer on its surface twice and annealing under an air atmosphere to obtain the hole transport layer.

[0070] (5) Scraping the active layer material on the hole transport layer under an air atmosphere, and annealing in an inert gas glove box to obtain the organic active layer.

[0071] (6) Continue to spin-coat the electron transport layer solution on the active layer in an inert gas glove box to obtain the electron transport layer.

[0072] (7) Tear off the tape, cover with a patterned mask, spray and coat the top electrode solution on the electron transport layer to obtain a top stretchable cathode layer consistent with the mask pattern. Finally, peel the device from the rigid glass surface to obtain the intrinsic stretchable near-infrared organic optoelectronic detector, and test its optoelectronic detection performance and stretchability.

[0073] In some embodiments, the concentration of the stretchable substrate TPU solution prepared in step (2) is 150 - 350 mg / mL, the spinning speed on the white glass slide is 500 - 2000 rpm, the heating and curing temperature is 60 - 110 °C, and the heating and curing time is 0.5 - 3 h.

[0074] Preferably, spin-coat the TPU solution with a concentration of 300 mg / mL that has been stirred overnight on the white glass slide at a speed of 800 rpm, and heat and cure at 80 °C for 1 h.

[0075] In some embodiments, the treatment time of the stretchable substrate prepared in step (3) in the ultraviolet-ozone environment is 10 - 20 min, the spinning speed of the transparent anode layer is 1000 - 4000 rpm, the annealing temperature is 80 - 120 °C, the annealing time is 10 - 30 min, the laser etching frequency is 100000 - 150000 Hz, and the power factor is 10% - 30%.

[0076] Preferably, in an air atmosphere, spin-coat the anode layer solution on the surface of the stretchable substrate treated in the ultraviolet-ozone environment for 15 min at a speed of 3000 rpm, anneal at 90 °C for 20 min, and pattern the electrode layer with a laser with a frequency of 100000 Hz and a power factor of 10%.

[0077] In some embodiments, the treatment time of the stretchable transparent anode layer prepared in step (4) in the ultraviolet-ozone environment is 5 - 25 min, and then spin-coat and anneal the hole transport layer twice on its surface at a speed of 800 - 2000 rpm, an annealing temperature of 80 - 120 °C, and an annealing time of 10 - 30 min.

[0078] Preferably, in an air atmosphere, spin-coat the hole transport layer solution on the surface of the stretchable transparent anode layer treated in the ultraviolet-ozone environment for 17 min at a speed of 1200 rpm, and anneal at 100 °C for 20 min.

[0079] In some embodiments, the stirring temperature of the organic active layer solution (with o-xylene as the solvent) in step (5) is 45 - 100 °C, and the stirring time is 1.5 - 10 h. The specific steps of spin-coating the organic active layer in an air atmosphere include: a spin-coating speed of 10 - 40 mm / s, a single droplet volume of 10 - 40 μL, a substrate temperature of 60 - 100 °C, and annealing at 60 - 150 °C for 5 - 20 min in an inert gas glove box.

[0080] Preferably, the organic active layer solution is stirred at 80 °C for 8 h, and the active layer material is spin-coated on the hole transport layer in an air atmosphere. The spin-coating speed is 25 mm / s, the single droplet volume is 20 μL, the substrate temperature is 80 °C, and annealing is carried out at 100 °C for 10 min in an inert gas atmosphere. The inert atmosphere is nitrogen. It should be noted that other gases capable of achieving an inert atmosphere can also be used.

[0081] In some embodiments, in step (6), a PNDIT-F3N-Br solution with a concentration of 0.5 - 1.5 mg / mL is spin-coated onto the active layer at a rotation speed of 1000 - 4000 rpm.

[0082] Preferably, a 0.7 mg / mL PNDIT-F3N-Br solution is spin-coated onto the active layer in an inert gas glove box at a spin-coating speed of 3000 rpm. The solvent used for the electron transport layer is preferably methanol, which will not affect the active layer.

[0083] In some embodiments, in step (7), the mass content of gallium in the eutectic gallium-indium alloy is 70% - 80%, and the mass content of indium is 20% - 30%. A certain proportion of gallium and indium are heated and blended, and then sprayed onto the electron transport layer.

[0084] Preferably, 75.5 wt% of gallium and 24.5 wt% of indium are heated at 150 °C for 1 h to obtain a liquid metal. The heating temperature and time are not particularly limited as long as the effect of sufficient blending can be achieved, and then it is sprayed onto the electron transport layer.

[0085] Preferably, the thickness of the stretchable transparent substrate is ~50 μm, the thickness of the bottom stretchable transparent anode layer is ~140 nm, the thickness of the hole transport layer is ~73 nm, the thickness of the electron transport layer is ~8 nm, and the thickness of the top stretchable electrode layer is ~40 μm.

[0086] Example 1

[0087] Smooth transparent white glass slides are ultrasonically cleaned with absolute ethanol and dried with nitrogen.

[0088] The 300 mg / mL TPU solution (with DMF as the solvent) that has been stirred overnight is spin-coated on the surface of the obtained smooth, transparent glass slide at a speed of 800 rpm and heated and cured at 80 °C for 1 h. By heating and curing, a stretchable transparent substrate is prepared.

[0089] In an air atmosphere, the bottom anode electrode solution containing 1% by volume of choline chloride:urea (ChCl:Urea) is spin-coated on the obtained stretchable transparent substrate that has been treated in a UV-ozone environment for 15 min at a speed of 1000 rpm and annealed at 90 °C for 20 min to prepare a stretchable bottom electrode layer.

[0090] The obtained stretchable transparent substrate and the bottom electrode layer (bottom stretchable transparent anode layer) are peeled off from the surface of the rigid glass substrate. As Figure 2 shown, the crack initiation strain value is measured to be 40% and the resistance is 55627 Ω.

[0091] Example 2

[0092] The smooth, transparent glass slide is ultrasonically cleaned with absolute ethanol and dried with nitrogen.

[0093] The 300 mg / mL TPU solution that has been stirred overnight is spin-coated on the surface of the obtained smooth, transparent glass slide at a speed of 800 rpm and heated and cured at 80 °C for 1 h. By heating and curing, a stretchable transparent substrate is prepared.

[0094] In an air atmosphere, the bottom anode electrode solution containing 1% by volume of choline chloride:ethylene glycol (ChCl:EG) is spin-coated on the obtained stretchable transparent substrate that has been treated in a UV-ozone environment for 15 min at a speed of 1000 rpm and annealed at 90 °C for 20 min to prepare a stretchable bottom electrode layer.

[0095] The obtained stretchable transparent substrate and the bottom electrode layer are peeled off from the surface of the rigid glass substrate. As Figure 2 shown, the crack initiation strain value is measured to be 24% and the resistance is 25228 Ω.

[0096] Example 3

[0097] The smooth, transparent glass slide is ultrasonically cleaned with absolute ethanol and dried with nitrogen.

[0098] The 300 mg / mL TPU solution that has been stirred overnight is spin-coated on the surface of the obtained smooth, transparent glass slide at a speed of 800 rpm and heated and cured at 80 °C for 1 h. By heating and curing, a stretchable transparent substrate is prepared.

[0099] In an air atmosphere, a bottom anode electrode solution containing 1% by volume of choline chloride: glycerol (ChCl:GLY) was spin-coated on the obtained stretchable transparent substrate treated in an ultraviolet-ozone environment for 15 minutes at a rotation speed of 1000 rpm and annealed at 90 °C for 20 minutes to prepare a stretchable bottom electrode layer.

[0100] The obtained stretchable transparent substrate and the bottom electrode layer were peeled off from the surface of the rigid glass substrate, as Figure 2 shown, and the crack initiation strain value was measured to be 30% and the resistance was 27323 Ω.

[0101] Example 4

[0102] A smooth transparent white glass sheet was ultrasonically cleaned with absolute ethanol and dried with nitrogen.

[0103] A 300 mg / mL concentration of TPU solution stirred overnight was spin-coated on the surface of the obtained smooth transparent white glass sheet at a rotation speed of 800 rpm and heated and cured at 80 °C for 1 h. By heating and curing, a stretchable transparent substrate was prepared.

[0104] In an air atmosphere, a bottom anode electrode solution containing 1% by volume of choline chloride: lactic acid (ChCl:LAC 1 ) was spin-coated on the obtained stretchable transparent substrate treated in an ultraviolet-ozone environment for 15 minutes at a rotation speed of 1000 rpm and annealed at 90 °C for 20 minutes to prepare a stretchable bottom electrode layer.

[0105] The obtained stretchable transparent substrate and the bottom electrode layer were peeled off from the surface of the rigid glass substrate, as Figure 2 shown, and the crack initiation strain value was measured to be 26% and the resistance was 3802 Ω.

[0106] Example 5

[0107] A smooth transparent white glass sheet was ultrasonically cleaned with absolute ethanol and dried with nitrogen.

[0108] A 300 mg / mL concentration of TPU solution stirred overnight was spin-coated on the surface of the obtained smooth transparent white glass sheet at a rotation speed of 800 rpm and heated and cured at 80 °C for 1 h. By heating and curing, a stretchable transparent substrate was prepared.

[0109] In an air atmosphere, a bottom anode electrode solution containing 1% by volume of choline chloride: glycolic acid (ChCl:GAC) was spin-coated on the obtained stretchable transparent substrate treated in an ultraviolet-ozone environment for 15 minutes at a rotation speed of 1000 rpm and annealed at 90 °C for 20 minutes to prepare a stretchable bottom electrode layer.

[0110] The obtained stretchable transparent substrate and the bottom electrode layer were peeled off from the surface of the rigid glass substrate, asFigure 2 As shown, the measured crack initiation strain value is 48%, and the resistance is 81820 Ω.

[0111] Example 6

[0112] The smooth transparent glass sheet was ultrasonically cleaned with absolute ethanol and dried with nitrogen.

[0113] The TPU solution with a concentration of 300 mg / mL that had been stirred overnight was spin-coated on the surface of the obtained smooth transparent glass sheet at a rotation speed of 800 rpm and heated and cured at 80 °C for 1 h. By heating and curing, a stretchable transparent substrate was prepared.

[0114] In an air atmosphere, the bottom anode electrode solution containing 1% by volume of choline chloride: levulinic acid (ChCl:LAC 2 ) was spin-coated on the obtained stretchable transparent substrate treated in an ultraviolet-ozone environment for 15 min at a rotation speed of 1000 rpm and annealed at 90 °C for 20 min to prepare a stretchable bottom electrode layer.

[0115] The obtained stretchable transparent substrate and the bottom electrode layer were peeled off from the surface of the rigid glass substrate. As Figure 2 shown, the measured crack initiation strain value is 34%, and the resistance is 275 Ω.

[0116] Example 7

[0117] The smooth transparent glass sheet was ultrasonically cleaned with absolute ethanol and dried with nitrogen.

[0118] The TPU solution with a concentration of 300 mg / mL that had been stirred overnight was spin-coated on the surface of the obtained smooth transparent glass sheet at a rotation speed of 800 rpm and heated and cured at 80 °C for 1 h. By heating and curing, a stretchable transparent substrate was prepared.

[0119] In an air atmosphere, the bottom anode electrode solution containing 1% by volume of choline chloride: p-toluenesulfonic acid (ChCl:PTSA) was spin-coated on the obtained stretchable transparent substrate treated in an ultraviolet-ozone environment for 15 min at a rotation speed of 1000 rpm and annealed at 90 °C for 20 min to prepare a stretchable bottom electrode layer.

[0120] The obtained stretchable transparent substrate and the bottom electrode layer were peeled off from the surface of the rigid glass substrate. As Figure 2 shown, the measured crack initiation strain value is 58%, and the resistance is 82 Ω.

[0121] Example 8

[0122] The smooth transparent glass sheet was ultrasonically cleaned with absolute ethanol and dried with nitrogen.

[0123] Preparation of stretchable substrate: A 300 mg / mL TPU solution stirred overnight was spin-coated on the surface of the obtained smooth, transparent glass slide at a speed of 800 rpm and cured by heating at 80 °C for 1 h to obtain a stretchable transparent substrate.

[0124] Preparation of stretchable transparent anode layer: In an air atmosphere, a solution prepared by mixing PH1000, choline chloride:p-toluenesulfonic acid, and DMSO was spin-coated on the obtained stretchable transparent substrate treated in a UV-ozone environment for 15 min at a speed of 3000 rpm and annealed at 90 °C for 20 min. Among them, the volume fraction of choline chloride:p-toluenesulfonic acid in the solution was 1%, the volume fraction of DMSO was 5%, and the electrode layer was patterned by laser etching with a 532 nm green laser with a frequency of 100000 Hz and a power factor of 10%. Then, the common electrode part was protected by pasting with a low-adhesion tape to obtain a stretchable transparent anode layer.

[0125] Preparation of hole transport layer: Two layers of PEDOT:PSS hole transport layer solution were spin-coated on the surface of the stretchable transparent anode layer treated in a UV-ozone environment for 17 min. The spin-coating conditions for both layers were 1200 rpm, and annealing was carried out at 100 °C for 20 min.

[0126] Preparation of organic active layer: The organic active layer solution with a mass ratio of 38% SEBS was stirred at 80 °C for 8 h and spin-coated on the hole transport layer in an air atmosphere. The spin-coating speed was 25 mm / s, the volume of each droplet was 20 μL, the substrate temperature was 80 °C, and annealing was carried out at 100 °C for 10 min in an inert gas atmosphere.

[0127] Preparation of electron transport layer: A 0.7 mg / mL PNDIT-F3N-Br solution dissolved in methanol was spin-coated on the active layer in a glove box filled with inert gas at a speed of 3000 rpm.

[0128] Preparation of stretchable cathode layer: 75.5 wt% gallium and 24.5 wt% indium were heated at 150 °C for 1 h to obtain liquid metal. For the convenience of testing, the pasted low-adhesion tape was torn off to expose the stretchable transparent anode layer, a customized patterned mask was covered, and the top electrode solution was sprayed and covered on the electron transport layer to obtain a top stretchable cathode layer consistent with the mask pattern, thus obtaining a stretchable organic optoelectronic detector.

[0129] The prepared stretchable optoelectronic detector was peeled off from the glass, and the device was stretched using a stretching fixture to test the dark current-voltage curve and external quantum efficiency curve during the stretching process, and the responsivity and specific detectivity were calculated therefrom.

[0130] Figure 3Figure 0 shows the physical pictures of the intrinsic stretchable near-infrared organic optoelectronic detector provided in Embodiment 8 of the present invention under 0%, 60% and 180% strain, indicating that the fabricated device can be easily stretched.

[0131] As Figure 4 shown, during the process of the intrinsic stretchable near-infrared organic optoelectronic detector provided in Embodiment 8 experiencing a tensile strain from 0% to 180%, it maintains a relatively constant ultra-low dark current value (~1012 A) without substantial change under a 0 V bias.

[0132] As Figure 6 shown, with the weakening of the light collection ability as Figure 5 shown, the effective response of the intrinsic stretchable near-infrared organic optoelectronic detector provided in Embodiment 8 to the optical signal gradually decreases.

[0133] As Figure 7 shown, the noise current of the intrinsic stretchable near-infrared organic optoelectronic detector provided in Embodiment 8 does not change significantly with stretching.

[0134] As Figure 8 shown, the intrinsic stretchable near-infrared organic optoelectronic detector provided in Embodiment 8 still has a high D * value of 9.2×1011 Jones at 800 nm under 180% tensile strain.

[0135] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A stretchable near-infrared organic photodetector, characterized in that: From bottom to top, it includes a stretchable transparent substrate, a bottom stretchable transparent anode layer, a hole transport layer, an organic active layer, an electron transport layer, and a top stretchable cathode layer; the bottom stretchable transparent anode layer material includes a conductive polymer solution PEDOT:PSS, a polar solvent DMSO and a deep eutectic solvent.

2. The stretchable near-infrared organic photodetector according to claim 1, characterized in that: The conductive polymer solution PEDOT:PSS is PH1000.

3. The stretchable near-infrared organic photodetector according to claim 1, characterized in that: The deep eutectic solvent includes any one of choline chloride:urea, choline chloride:ethylene glycol, choline chloride:glycerol, choline chloride:lactic acid, choline chloride:glycolic acid, choline chloride:levulinic acid and choline chloride:p-toluenesulfonic acid; preferably, the deep eutectic solvent is choline chloride:p-toluenesulfonic acid.

4. The stretchable near-infrared organic photodetector according to claim 1, characterized in that: The organic active layer is a blended structure composed of a polymer donor material PM6, a polymer small molecule acceptor material PY-IT and an elastomer material SEBS.

5. The stretchable near-infrared organic photodetector according to claim 4, characterized in that: The organic active layer also includes 1-chloronaphthalene.

6. The stretchable near-infrared organic photodetector according to claim 5, characterized in that: The elastomeric material SEBS accounts for 5%-50% of the total mass of the organic active layer, and 1-chloronaphthalene accounts for 0.5%-2% of the volume of the organic active layer solution; preferably, the elastomeric material SEBS accounts for 38% of the total mass of the organic active layer, and 1-chloronaphthalene accounts for 1.5% of the volume of the organic active layer solution.

7. The stretchable near-infrared organic photodetector according to claim 1, characterized in that: The electron transport layer material is PNDIT-F3N-Br.

8. The stretchable near-infrared organic photodetector according to claim 1, characterized in that: The material of the hole transport layer is PEDOT:PSS; preferably, the hole transport layer is further added with fluorosurfactant FS-30; preferably, the fluorosurfactant FS-30 accounts for 0.1%-1% of the total volume of the hole transport layer solution.

9. The stretchable near-infrared organic photodetector according to claim 1, characterized in that: The top stretchable cathode layer is eutectic gallium-indium liquid metal.

10. A method for preparing a stretchable near-infrared organic photodetector, characterized in that: include: Spin-coat the prepared TPU solution on the glass surface and heat and cure it to obtain a stretchable transparent substrate; In an air atmosphere, the bottom anode electrode solution is spin-coated on a stretchable substrate treated in a UV-ozone environment, annealed, and patterned, and a low-viscosity tape is used to adhere the common electrode portion for protection to obtain a bottom stretchable transparent anode layer; The bottom stretchable transparent anode layer is treated in an ultraviolet-ozone environment, and then a hole transport layer material is spin-coated twice on the surface in an air atmosphere and annealed to prepare a hole transport layer; In an air atmosphere, coating an active layer material on the hole transport layer by scraping, and annealing in an inert gas atmosphere to obtain an organic active layer; In an inert gas atmosphere, spin coating an electron transport layer solution on the organic active layer to prepare an electron transport layer; The low-viscosity tape is torn off, a patterned mask is applied, and the top electrode solution is sprayed on the electron transport layer to obtain a top stretchable cathode layer consistent with the mask pattern. Finally, the obtained device is peeled off from the glass surface.

Images