A flexible self-healing touch screen based on a perovskite-graphene heterojunction

Abstract

The present invention discloses a flexible self-healing touch screen and a mobile terminal device based on a perovskite-graphene heterojunction, comprising components stacked in the following order: (a) a flexible transparent substrate, (b) a perovskite photovoltaic layer disposed on the substrate, (c) a graphene conductive layer covering the perovskite photovoltaic layer, and (d) a self-healing functional layer embedded in the graphene conductive layer. It further includes an energy management module electrically connected to the graphene conductive layer, which includes an energy storage unit composed of a micro-supercapacitor and a lithium-ion battery connected in parallel, and a power distribution chip integrated with an adaptive algorithm. Through the optimization of the formation of a continuous and defect-free heterojunction interface between the graphene conductive layer and the perovskite photovoltaic layer, the present invention has a photoelectric conversion efficiency of 25.6% (under AM 1.5G illumination), which is 40% higher than that of traditional ITO electrodes. At the same time, the present invention also has more prominent self-healing ability and more intelligent power supply management.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible electronic devices, and particularly to a flexible self-healing touch screen based on a perovskite-graphene heterojunction. The touch screen integrates a perovskite photovoltaic layer, a graphene conductive layer, a dynamic self-healing functional layer and an intelligent energy management module, and is applicable to flexible display scenarios such as wearable devices and foldable mobile phones. It can significantly improve the environmental adaptability and service life of devices through self-power supply and self-healing mechanisms. Background Art

[0002] As an important display electronic device, touch screens are widely used in industrial and consumer electronic products, especially in mobile terminal devices such as smart phones, tablets, wearable devices, etc. However, traditional touch screens are easily damaged in flexible applications, resulting in display failure and difficult to repair, which greatly limits the reliability of devices and the user experience. In addition, traditional touch screens have high energy consumption and cannot meet the battery life requirements of portable devices. To solve the battery life problem when charging is inconvenient, Infinix, a brand under Transsion Holdings Co., Ltd., and BOE Technology Group Co., Ltd. jointly launched the first perovskite photovoltaic charging mobile phone, which is provided with a perovskite photovoltaic layer on the back to utilize its high energy conversion efficiency to achieve self-power supply function and effectively extend the battery life of the device. However, in terms of touch screen charging, it is still blank. Therefore, people have never stopped applying perovskite in consumer electronic products.

[0003] 1. Application of Perovskite-Graphene Heterojunction

[0004] Due to its high light absorption coefficient and adjustable bandgap characteristics, perovskite materials are widely used in photovoltaic devices. Graphene, due to its high conductivity and flexibility, is often used as a transparent electrode material in combination with perovskite. However, in the prior art, the interface between perovskite and graphene often has defects due to lattice mismatch, affecting the carrier transport efficiency.

[0005] 2. Limitations of Self-Healing Materials

[0006] Most self-healing materials for existing flexible electronic devices adopt microcapsules or dynamic covalent bond designs. For example, polyurethane microcapsules encapsulating a conductive polymer repair agent can respond to mechanical damage, but the conductivity recovery rate after repair is usually less than 80%. In addition, the glass transition temperature ( ) range of the dynamic covalent bond network is narrow (40 - 60 °C), making it difficult to meet the repair requirements in high or low temperature environments.

[0007] 3. Energy Management Challenges of Flexible Touch Screens

[0008] Traditional flexible touchscreens rely on external power sources, with limited energy density and battery life. Although perovskite photovoltaic layers can power the device, their output power is significantly affected by ambient light and mechanical deformation. Existing energy management algorithms mostly use fixed-mode control and cannot adjust the power supply strategy in real time, resulting in overload or insufficient power supply in strong light or high-load scenarios.

[0009] Summary of Technical Problems:

[0010] 1. Interface defects and insufficient mechanical durability: Interface defects in the perovskite-graphene heterojunction lead to a decline in the photoelectric conversion efficiency, and the flexible substrate is prone to fracture during repeated bending.

[0011] 2. Low self-healing efficiency: Existing self-healing materials have a low conductivity recovery rate and a limited operating temperature range.

[0012] 3. Poor adaptability of energy management: Traditional algorithms cannot dynamically respond to changes in multiple parameters such as light, pressure, and device deformation, resulting in unstable power supply. Summary of the Invention

[0013] In view of the above technical problems, the object of the present invention is to provide a novel flexible touchscreen, which significantly improves the photoelectric conversion efficiency, mechanical durability, and environmental adaptability by optimizing the perovskite-graphene interface structure, introducing highly efficient self-healing materials, and developing intelligent energy management algorithms, thereby achieving stable and reliable energy supply.

[0014] To achieve the above object, the present invention adopts the following technical solutions:

[0015] A flexible self-healing touchscreen based on a perovskite-graphene heterojunction, comprising the following components stacked in sequence:

[0016] (a) A flexible transparent substrate made of polyimide (PI) or polyethylene terephthalate (PET), with a thickness of 10-50 μm and a surface treated by plasma;

[0017] (b) A perovskite photovoltaic layer disposed on the substrate, the material of which is formamidinium lead iodide perovskite ( ) or methylammonium lead bromide perovskite ( ), with a thickness of 200-500 nm and a surface modified with graphene quantum dots to improve the light absorption efficiency;

[0018] (c) A graphene conductive layer covering the perovskite photovoltaic layer, which is directly grown by chemical vapor deposition (CVD) method, with a sheet resistance ≤50 Ω / sq and a transmittance ≥90%, and forms a heterojunction structure with the perovskite layer;

[0019] (d) A self-healing functional layer embedded in the graphene conductive layer, which is a thermoreversible polymer network containing dynamic covalent bonds or a conductive polymer repair agent encapsulated in microcapsules, wherein the dynamic covalent bond is a Diels-Alder bond, the glass transition temperature of the thermoreversible polymer network is 60-80 °C, and the rupture threshold of the microcapsules is 0.5-2.0 MPa;

[0020] (e) An energy management module electrically connected to the graphene conductive layer, including an energy storage unit composed of a parallel-connected micro-supercapacitor and a lithium-ion battery, and a power distribution chip integrated with an adaptive algorithm. The algorithm calculates the real-time power supply of the touch electrode through the following formula:

[0021]

[0022] Wherein:

[0023] : The real-time power supply of the touch electrode, unit ;

[0024] L: The illuminance value collected by the ambient light sensor, ;

[0025] F: The feedback value of the touch pressure sensor, ;

[0026] : The reference power of the operation mode, defined as follows:

[0027]

[0028] , : The dynamic weight coefficient, satisfying , and is updated every 30 seconds according to the following formula:

[0029]

[0030] α: The power adjustment factor, with a value range of [0.8, 1.2].

[0031] In an embodiment of the present invention, in order to improve conductivity and interface stability, the graphene conductive layer is a few-layer graphene film with a double-layer AB stacking structure, the layer spacing is 0.34 ± 0.02 nm, and a methane / hydrogen mixed gas is used during CVD growth, with a methane volume concentration of 5-15% and a growth temperature of 1000-1050 °C. Experiments have shown that the interlayer sliding mechanism of the double-layer structure can disperse stress. In the bending test with a curvature radius of 5 mm for 100,000 times, the increase in sheet resistance is ≤ 8% (≥ 30% for the traditional single-layer structure).

[0032] Further, in the microcapsule-encapsulated conductive polymer repair agent, the mass ratio of polypyrrole to polyaniline is 3:1 to 1:1, the wall thickness of the microcapsule is 10-15% of the core diameter, and the spatial distribution density of the microcapsules in the graphene conductive layer is . In addition, the repair agent can be rapidly released after the microcapsules rupture, form a conductive network with the graphene layer, restore the conductivity to more than 90% of the initial value, and significantly extend the service life of the device.

[0033] Further, the plasma treatment adopts a radio frequency glow discharge mode, and the power density is . After the treatment, the oxygen element content on the surface of the substrate increases by 8-12 at%, and the interfacial binding energy with the perovskite layer is ≥ . This treatment not only improves the interfacial adhesion force but also optimizes the charge transfer efficiency, enabling the device to maintain stable performance in high-temperature and high-humidity environments, effectively reducing the failure rate, and extending the service life.

[0034] In a specific embodiment of the present invention, the weight coefficient update function further includes a resistance compensation term:

[0035]

[0036] Among them, is the initial sheet resistance of the graphene conductive layer, is the real-time monitored sheet resistance, with the unit of Ω / sq. By introducing the resistance compensation term, the system can adjust the power supply strategy in real time to ensure that the touch electrode maintains efficient response in different environments. Experiments show that this improvement increases the touch sensitivity by 20%, and under extreme temperature and humidity conditions, the failure rate is reduced by 15%, further improving the reliability and user experience of the device.

[0037] To solve the interface damage that may be caused by insufficient power supply or circuit overload triggered by instantaneous overload, when it is detected that Δω>0.8 and lasts for more than 10 seconds, the emergency power supply protocol is activated:

[0038]

[0039] Among them, τ = 30 s, which is the time constant; is the real-time output power of the perovskite layer, with the unit .

[0040] To improve the conductivity recovery rate and temperature adaptability, the crosslinking density of the dynamic covalent bonds in the thermoreversible polymer network is to , and the repair efficiency satisfies:

[0041]

[0042] Among them, is the conductivity of the graphene conductive layer after self-healing treatment, is the conductivity in the original undamaged state, in S / m; is the glass transition temperature of the thermoreversible polymer network, T is the applied external heating temperature, in °C.

[0043] The present invention also provides a mobile terminal device, comprising the above-mentioned flexible self-repairing touch screen, and the energy management module is integrated with the terminal battery system through a reversible plug interface.

[0044] Furthermore, in order to solve the problems of communication delay and low power management of existing communication equipment, the communication interface between the energy management module and the terminal motherboard adopts Protocol, data transmission rate ≥ 400 kbps, and has the following collaborative control logic:

[0045]

[0046] in: : The state of charge of the terminal battery, ranging from 0-100%; : The safe output power of the perovskite photovoltaic layer is calculated as follows:

[0047]

[0048] is the real-time output power of the perovskite layer, in units .

[0049] Furthermore, the device housing is provided with a deformation sensor array linked to the self-healing functional layer, with a sensor spacing of ≤500 μm. When a bend with a curvature radius r<5 mm is detected, the following compensation mechanism is triggered:

[0050]

[0051] in, , is the change in curvature radius, unit: mm; is the radius of curvature of the device in the initial planar state, defined as . By introducing the deformation sensor array and dynamic compensation mechanism, the device can still maintain stable touch performance under complex deformation, effectively extending its service life. Experimental verification shows that this mechanism increases the bending tolerance by 30%, significantly enhancing the durability of the device and user satisfaction.

[0052] Due to the adoption of the above scheme, the beneficial effects of the present invention are as follows:

[0053] 1. Through the optimization of the continuous and defect-free heterojunction interface formed by the graphene conductive layer and the perovskite photovoltaic layer, the photoelectric conversion efficiency reaches 25.6% (under AM 1.5G illumination), which is 40% higher than that of the traditional ITO electrode; the surface-modified graphene quantum dots extend the light absorption range to 300 - 800 nm, and the peak external quantum efficiency (EQE) reaches 92%.

[0054] 2. It has outstanding self-healing ability. The dynamic covalent bond network (Tg = 60 - 80 °C) or microcapsule repair agent can repair cracks with a depth ≤ 50 μm within 5 minutes, the conductivity recovery rate ≥ 90%, and the interfacial resistance recovers to within 95% of the initial value. The repair temperature range is also wider.

[0055] 3. Energy management is more intelligent. The adaptive algorithm adjusts the power supply in real time based on the environmental light (L), touch pressure (F), and device deformation ( ), the touch response delay ≤ 10 ms, and the false touch rate ≤ 2%.

[0056] In addition, the mechanical durability, extreme environment adaptability, and user experience of this device are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic exploded view of the structure of the present invention;

[0058] In the figure, 1. Flexible transparent substrate; 2. Perovskite photovoltaic layer; 3. Graphene conductive layer; 4. Self-healing functional layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0060] Example 1

[0061] As Figure 1 shown, a flexible self-healing touch screen based on a perovskite-graphene heterojunction includes a flexible transparent substrate 1, a perovskite photovoltaic layer 2, a graphene conductive layer 3, and a self-healing functional layer 4 stacked in the following order. The perovskite photovoltaic layer 2 is disposed on the flexible transparent substrate 1, and the material is formamidinium lead iodide perovskite ( (), with a thickness of 300 nm, the surface of the perovskite light - emitting layer 2 is decorated with graphene quantum dots with a particle size of 10 nm to improve the light absorption efficiency. The graphene conductive layer 3 covers the perovskite photovoltaic layer 2. The graphene conductive layer 3 is directly grown in a bilayer AB by chemical vapor deposition (CVD) method, with a sheet resistance ≤ 50 Ω / sq and a light transmittance ≥ 90%, and forms a heterojunction structure with the perovskite layer. The self - healing functional layer 4 is embedded in the graphene conductive layer 3. The self - healing functional layer is a micro - capsule repair agent (polypyrrole:polyaniline = 2:1, wall thickness ratio 12%), with a rupture threshold of 1.5 MPa and a distribution density (SEM statistics).

[0062] The energy management module is electrically connected to the graphene conductive layer 3. The energy management module includes an energy storage unit composed of a parallel - connected micro - supercapacitor and a lithium - ion battery, and a power distribution chip integrated with an adaptive algorithm. The adaptive algorithm calculates the real - time power supply of the touch electrode through the following formula:

[0063]

[0064] Among them, is the real - time power supply of the touch electrode, with the unit ; L is the illuminance value collected by the ambient light sensor, ; F is the feedback value of the touch pressure sensor, ; is the reference power of the operation mode, defined as follows:

[0065]

[0066] 、 are dynamic weight coefficients, satisfying , and are updated every 30 seconds according to the following formula:

[0067]

[0068] α is a power adjustment factor, with a value range of [0.8, 1.2]. The weight coefficient update function includes a resistance compensation term:

[0069]

[0070] Among them, is the initial sheet resistance of the graphene conductive layer, with the unit Ω / sq; is the real - time monitored sheet resistance, with the unit Ω / sq; when it is detected that and it lasts for more than 10 seconds, activate the emergency power supply protocol:

[0071]

[0072] Among them, τ = 30 s is the time constant; is the real-time output power of the perovskite layer, with the unit .

[0073] The following makes a more detailed comparison and description of the present invention in combination with different materials and preparation methods.

[0074] I. Preparation and performance testing of a flexible self-healing touch screen of a perovskite-graphene heterojunction:

[0075] 1. Material and structure preparation

[0076] Substrate treatment:

[0077] A 50-μm-thick polyimide (PI) film is used and treated by oxygen plasma (power density , treatment time 90 s), and the surface roughness is reduced from the initial 25 nm to 8 nm, and the interfacial binding energy is increased from to (AFM test).

[0078] Perovskite photovoltaic layer:

[0079] Deposited by spin coating layer (thickness 300 nm), and the surface is modified with graphene quantum dots with a particle size of 10 nm, and the light absorption efficiency is increased by 28% (UV-Vis test, 400 - 800 nm band).

[0080] Graphene conductive layer:

[0081] Grow bilayer AB-stacked graphene by CVD method (methane concentration 10%, temperature 1020 °C), with a sheet resistance of 40 Ω / sq and a light transmittance of 92% (four-probe method and spectrophotometer test).

[0082] Self-healing functional layer:

[0083] Microcapsule repair agent (polypyrrole:polyaniline = 2:1, wall thickness ratio 12%), rupture threshold 1.5 MPa, distribution density (SEM statistics).

[0084] The performance test and data comparison are shown in Table 1.

[0085] Table 1

[0086]

[0087] As can be seen from Table 1, compared with the traditional ITO-based touch screen, the present invention has a greatly improved photoelectric conversion efficiency, a small increase in resistance after 100,000 bends, and its performance is far superior to that of the traditional ITO-based touch screen.

[0088] II. Dynamic Power Supply Verification of the Adaptive Algorithm:

[0089] 1. Experimental Setup

[0090] Test Scenario: Simulate the combined working conditions of strong light ( ), high voltage (F = 3.5 N), and bending (r = 5 mm).

[0091] Algorithm Parameters: , , α = 1.1, update period 30 seconds.

[0092] 2. The data is recorded as shown in Table 2.

[0093] Table 2

[0094]

[0095] 3. Comparative Analysis

[0096] Traditional fixed algorithm (without compensation), overloading occurred 11 times within 90 seconds, and the overloading incidence rate in the same scenario was 12.3%;

[0097] The adaptive algorithm of the present invention has an overloading incidence rate of 0%, and the utilization rate of photovoltaic energy is increased from 65% to 88%.

[0098] III. Self - repair Test under Extreme Environments

[0099] 1. Test Conditions

[0100] Low - temperature repair: In an environment of - 20°C, apply a pressure of 1.0 MPa to simulate cracks;

[0101] High - temperature repair: In an environment of 100°C, record the repair time.

[0102] 2. The results are compared as shown in Table 3

[0103] Table 3

[0104]

[0105] IV. Durability Test of the Reversible Plug - in Interface

[0106] 1. Experimental Method

[0107] Insertion and extraction life test: 100,000 insertion and extraction cycles, frequency 5 times / minute;

[0108] Deformation test: Bend with a curvature radius of 5 mm, record the change in contact resistance.

[0109] 2. The data is recorded as shown in Table 4

[0110] Table 4

[0111]

[0112] V. Low - battery Endurance Test of Mobile Terminals

[0113] 1. Test Scenario

[0114] : Continuous touch operation (game mode, 120 Hz sampling rate);

[0115] Photovoltaic Input: , simulating cloudy - day environment.

[0116] 2. Test Results

[0117] For the present invention: The endurance time is 2.8 hours and the touch function is normal;

[0118] For the traditional solution: The endurance time is 2.0 hours and the touch function is down - clocked by 50%.

[0119] VI. Low - battery Cooperative Control and Communication Test

[0120] 1. Experimental Setup

[0121] Test device: A foldable mobile phone equipped with the touch screen of the present invention, with the initial value of SOC set to 25%, and continuously running the game mode until SOC = 15%.

[0122] Communication Protocol: Interface, with a rate of 400 kbps; The control group uses the SPI protocol with a rate of 100 kbps.

[0123] Trigger Conditions for Control Logic:

[0124]

[0125]

[0126] 2. Data recording and comparison are shown in Table 5.

[0127] Table 5

[0128]

[0129] 3. Comparison Results

[0130] Low - battery endurance improvement: By dynamically adjusting the power - supply weight (0.7:0.3), the endurance of the touch function is extended by 40%;

[0131] Advantages of high - speed communication: The protocol reduces the data - transmission delay to 1 / 4 of SPI, and the bit - error rate drops by 25 times;

[0132] Safety power management: The dynamic amplitude limiting algorithm prevents circuit overload, and no overload events are measured.

[0133] VII. Deformation Sensor and Compensation Mechanism Test

[0134] 1. Experimental Setup

[0135] Sensor array: MEMS piezoresistive sensors with a 500 μm pitch, covering the device housing;

[0136] Bending test: The radius of curvature r = 5 mm (critical value) and r = 3 mm (extreme value), continuous bending 100,000 times;

[0137] Compensation algorithm:

[0138]

[0139] 2. Data recording and comparison are shown in Table 6.

[0140] Table 6

[0141]

[0142] 3. Comparison Results

[0143] Real-time deformation compensation: For every 1 mm increase, α increases by 2% (e.g., when r = 5 mm, α + 10%), and the power fluctuation is suppressed to ±3%;

[0144] Extreme bending protection: When r = 3 mm, the microcapsule rupture rate is reduced by 23%, and the conductivity recovery rate after repair is still ≥88%;

[0145] High-precision sensing: The sensor error is ≤0.1 mm, far better than the traditional solution (±1.0 mm).

[0146] Example 2: Preparation and Repair Performance Test of Dynamically Covalent Thermoreversible Polymer Networks

[0147] 1. Material Preparation and Test Methods

[0148] 1.1 Preparation of Thermoreversible Polymer Networks

[0149] Raw materials:

[0150] Monomers: Furan-based acrylate (FA) and maleimide (MI), molar ratio 1:1;

[0151] Crosslinking agent: Four-armed polyethylene glycol (PEG-4MA, molecular weight 2000 Da);

[0152] Dynamic covalent bond: Diels-Alder bond (DA bond).

[0153] Synthesis steps:

[0154] (a) Pre-polymerize FA and MI at 60 °C for 30 minutes to form a linear prepolymer;

[0155] (b) Add PEG-4MA (10% of the total mass) and crosslink at 80 °C for 2 hours to form a three-dimensional network;

[0156] (c) The crosslinking density is measured by the swelling method as .

[0157] 1.2 Performance testing

[0158] Repair temperature range: -20 °C to 100 °C;

[0159] Conductivity testing: The conductivity before and after repair is measured by the four-probe method ( );

[0160] Mechanical testing: The tensile strength after repair is measured by a universal testing machine (ASTM D638).

[0161] 2. Experimental results and data comparison

[0162] 2.1 The repair efficiency and temperature adaptability are shown in Table 7

[0163] Table 7

[0164]

[0165] 2.2 The mechanical properties comparison is shown in Table 8

[0166] Table 8

[0167]

[0168] 3. Comparison results

[0169] Compared with the traditional solution, the present invention has the following advantages:

[0170] 3.1 Wide temperature range repair advantage, effective within -20 °C to 100 °C, covering the extreme environment requirements;

[0171] 3.2 High conductivity recovery rate: ≥90% at room temperature, ≥88% after 10 cycles;

[0172] 3.3 Low bending modulus: 1.2 GPa (far lower than 2.5 GPa in the comparative example), adapting to the deformation requirements of flexible devices;

[0173] 3.4 Precise control of crosslinking density: , balance the repair speed and mechanical strength.

[0174] Example 3: Influence of the thickness change of the perovskite photovoltaic layer on the present invention

[0175] According to the method and conditions of Example 1, perovskite photovoltaic layers with thicknesses of 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, and 600 nm were prepared respectively, and their electro-optical properties were tested. The test data are compared as shown in Table 9:

[0176] Table 9

[0177]

[0178] Comparison result:

[0179] When the thickness of the perovskite photovoltaic layer is 200 - 500 nm, the light absorption efficiency ≥ 82%, and the interfacial binding energy ≥ , and the resistance fluctuation after bending is small; while when the thickness is too thin (such as 100 nm) or too thick (such as 600 nm), the light absorption efficiency < 75%, and the interfacial binding energy < , and the resistance fluctuation after bending is large.

[0180] Example 4: Influence of the change of the microcapsule rupture threshold on the present invention

[0181] Examples of preparing a microcapsule self-healing functional layer with rupture thresholds of 0.5 MPa (wall thickness ratio 8%), 1.0 MPa (wall thickness ratio 10%), 1.5 MPa (wall thickness ratio 12%), and 2.0 MPa (wall thickness ratio 15%) were prepared; at the same time, comparative examples with 0.3 MPa (wall thickness ratio 6%) and 2.5 MPa (wall thickness ratio 15%) were prepared.

[0182] Under the condition that other conditions of Example 1 remain unchanged, the data comparison is shown in Table 10 below:

[0183] Table 10

[0184]

[0185] Comparison result:

[0186] When the microcapsule rupture threshold is 0.5 - 2.0 MPa, the conductivity recovery rate of the present invention ≥ 88%, and the cycle life ≥ 80,000 times; when the microcapsule rupture threshold is too low (such as 0.3 MPa) or too high (such as 2.5 MPa), the conductivity recovery rate ≤ 75%.

[0187] Example 5: Preparation and performance test of methylammonium lead bromide perovskite ( )

[0188] 1. Material preparation and test method

[0189] 1.1 Preparation of Photovoltaic Layer

[0190] Raw Materials:

[0191] Methylamine ( ), Lead Bromide ( ), and Dimethyl Sulfoxide (DMSO) Solvent;

[0192] Graphene Quantum Dots (GQDs, particle size 5 - 20 nm).

[0193] Process Steps:

[0194] (a) Dissolve and in DMSO at a molar ratio of 1:3 and stir at room temperature for 24 hours to form a precursor solution;

[0195] (b) Deposit layers on a PI substrate by spin coating (rotation speed 3000 rpm, time 30 seconds), with thicknesses of 200 nm, 300 nm, 400 nm, and 500 nm respectively;

[0196] (c) Surface Modification: Spray graphene quantum dots (concentration 0.1 mg / mL), with a coverage rate ≥ 95% (verified by SEM).

[0197] 1.2 Performance Testing

[0198] Light Absorption Efficiency: UV - Vis Spectrophotometer (wavelength 300 - 800 nm);

[0199] Carrier Lifetime: Time - Resolved Photoluminescence Spectroscopy (TRPL);

[0200] Bending Stability: Conductivity test (four - probe method) after bending 100,000 times with a curvature radius of 5 mm.

[0201] 2. Experimental Results and Data Comparison

[0202] 2.1 Light Absorption and Carrier Lifetime

[0203] Table 11: Data Table of Light Absorption and Carrier Lifetime with Different Thicknesses

[0204]

[0205] 2.2 Bending Stability Test Data are Shown in Table 12 as Follows.

[0206] Table 12

[0207]

[0208] 3. Comparison Results

[0209] As shown in Table 12, under the condition that other conditions remain unchanged, both the light absorption efficiency and carrier lifetime of the photovoltaic layer are significantly higher than those of the traditional solution (ITO electrode). In the thickness range of 200 to 500 nm, the light absorption efficiency is ≥81%, and the conductivity retention rate after bending is ≥82%. Its optimal thickness is 300 nm.

[0210] Example 6: Preparation and performance testing of a double-layer AB stacked graphene conductive layer

[0211] 1. Material preparation and testing methods

[0212] 1.1 Preparation of graphene conductive layer

[0213] CVD process parameters:

[0214] Substrate: copper foil (99.8% purity, 25 μm thick);

[0215] Gas mixing ratio: methane ( ), volume concentration 5%, 10%, 15%, hydrogen ( ), balanced;

[0216] Growth temperature: 1000 °C, 1025 °C, 1050 °C;

[0217] Growth time: 30 minutes.

[0218] Transfer process: PMMA-assisted wet transfer to the surface of the perovskite layer, and the interface is annealed (200 °C, argon protection).

[0219] 1.2 Structure characterization and performance testing

[0220] Interlayer structure: Transmission electron microscopy (TEM) is used to analyze the layer spacing and stacking mode;

[0221] Electrical properties: Four-probe method is used to measure the sheet resistance, and Hall effect is used to test the carrier mobility;

[0222] Optical properties: Ultraviolet-visible spectrophotometer is used to measure the transmittance;

[0223] Mechanical stability: The change rate of sheet resistance after 100,000 bends (curvature radius 5 mm).

[0224] 2. Experimental results and data comparison

[0225] 2.1 Process parameter optimization is shown in Table 13.

[0226] Table 13:

[0227]

[0228] 2.2 Mechanical stability test is shown in Table 14

[0229] Table 14

[0230]

[0231] 3. Technical effect analysis

[0232] 3.1 Advantages of double-layer AB stacking:

[0233] Carrier mobility improvement: The carrier mobility of the double-layer AB stacking ( ) is 48.6% higher than that of the single layer ( ) due to the formation of additional transport channels by π-π coupling between layers;

[0234] Enhanced mechanical stability: The double-layer structure disperses stress through interlayer sliding, and the resistance increase after bending is only 7.5% (32% for the single layer).

[0235] 3.2 Process parameter verification:

[0236] Methane concentration of 5 - 15%: Too low concentration (such as 3%) leads to discontinuous graphene, and too high concentration (such as 20%) generates multi-layer disordered structures;

[0237] Temperature of 1000 - 1050 °C: When the temperature is lower than 950 °C, the graphene crystal domain size < 10 μm (carrier mobility < 3000 ).

[0238] Example 7: Preparation and performance test of microcapsule repair agent

[0239] 1. Material preparation and test method

[0240] 1.1 Preparation of microcapsule repair agent

[0241] Core material composition: Polypyrrole (PPy) and polyaniline (PANI), with mass ratios of 3:1, 2:1, and 1:1 respectively;

[0242] Wall material: Polyurethane (PU), with wall thickness controlled at 10%, 12.5%, and 15% of the core diameter;

[0243] Process:

[0244] Microcapsules are synthesized by emulsion polymerization method, with core diameter of 10 μm (verified by laser particle size analyzer);

[0245] Adjust the emulsification speed (800 - 1200 rpm) and crosslinking time (2 - 6 hours) to control the distribution density at 500, 650, (statistical by SEM).

[0246] 1.2 Performance test

[0247] Rupture threshold: Compression test on universal testing machine (ASTM D5628);

[0248] Conductivity recovery rate: Measuring conductivity before and after repair by four-probe method ( );

[0249] Bending stability: Change in interface resistance after 100,000 bends (radius of curvature 5 mm) (GB / T 2423.34).

[0250] 2. Experimental results and data comparison

[0251] 2.1 The mass ratio and repair performance data are shown in Table 15.

[0252] Table 15

[0253]

[0254] 2.2 The influence of wall thickness and distribution density is shown in Table 16.

[0255] Table 16

[0256]

[0257] 3. Technical effect analysis

[0258] 3.1 Mass ratio optimization:

[0259] The mass ratio of 2:1 has the best comprehensive performance (conductivity recovery rate 92%, rupture threshold 2.0 MPa) because of the complementary conductivity of PPy and PANI;

[0260] The conductivity recovery rate of the over-proportion comparison (4:1 or 1:2) is ≤75%.

[0261] 3.2 Synergistic effect of wall thickness and distribution density:

[0262] Wall thickness 10 - 15%: Balancing the rupture threshold and the release efficiency of the repair agent (≥90%);

[0263] Distribution density : Too low density (<500) leads to uneven repair, and too high density (>800) affects flexibility (bending modulus >1.5 GPa).

[0264] Example 8: Optimization of plasma treatment process and interface performance testing

[0265] 1. Material preparation and treatment process

[0266] 1.1 Substrate treatment

[0267] Substrate material: 50 μm thick polyimide (PI) film;

[0268] Plasma equipment: Radio frequency glow discharge system (frequency 13.56 MHz, oxygen / argon mixed gas ratio 1:1);

[0269] Process parameters:

[0270] Power density: 、 、 (endpoints and intermediate values of the claim scope);

[0271] Processing time: Fixed at 90 seconds;

[0272] Gas flow rate: 20 sccm, chamber pressure 10 Pa.

[0273] 1.2 Perovskite layer deposition

[0274] Spin coating method for deposition layer (thickness 300 nm), untreated substrate as a comparative example.

[0275] 2. Performance testing and data comparison

[0276] 2.1 Surface property analysis is shown in Table 17.

[0277] Table 17

[0278]

[0279] 2.2 Photoelectric and mechanical properties are shown in Table 18.

[0280] Table 18

[0281]

[0282] 3. Technical effect analysis

[0283] 3.1 Oxygen element content and interfacial binding energy:

[0284] Power density When, the oxygen element increases by 8.5 - 11.8 at%, and the interfacial binding energy ≥ , significantly higher than the comparative example ( );

[0285] Risk of exceeding the scope: Power density results in surface carbonization, and the interfacial binding energy drops to , proving the technical necessity of the claim scope.

[0286] 3.2 Optimization of optoelectronic properties:

[0287] Optimal power density When the photoelectric conversion efficiency reaches 25.6%, the adhesion of the perovskite layer is improved due to the reduced surface roughness (4.8 nm) and the increased active sites of oxygen elements;

[0288] Power density and The efficiency is slightly lower, but still significantly better than the comparative example.

[0289] 3.3 Mechanical stability:

[0290] Power density After the treated substrate is bent, the resistance increase is only 7% because of the high interfacial binding energy ( ), which inhibits crack propagation.

Claims

1. A flexible self-healing touch screen based on perovskite-graphene heterojunction, characterized in that: Includes the following components stacked in order: (a) Flexible transparent substrate made of polyimide (PI) or polyethylene terephthalate (PET), with a thickness of 10-50 μm and a plasma-treated surface; (b) a perovskite photovoltaic layer disposed on the substrate, wherein the material of the perovskite photovoltaic layer is formamidinium lead iodide perovskite ( ) or methylamine lead bromide perovskite ( ), with a thickness of 200-500 nm, and the surface is modified with graphene quantum dots to improve light absorption efficiency; (c) a graphene conductive layer covering the perovskite photovoltaic layer, which is directly grown by chemical vapor deposition (CVD) and has a square resistance of ≤50 Ω / sq and a transmittance of ≥90%, and forms a heterojunction structure with the perovskite layer; (d) a self-healing functional layer embedded in the graphene conductive layer, which is a thermoreversible polymer network containing dynamic covalent bonds or a conductive polymer repair agent encapsulated in microcapsules, wherein the dynamic covalent bonds are Diels-Alder bonds, the glass transition temperature of the thermoreversible polymer network is 60-80°C, and the microcapsule rupture threshold is 0.5-2.0 MPa; (e) An energy management module electrically connected to the graphene conductive layer, comprising an energy storage unit composed of a micro supercapacitor and a lithium-ion battery connected in parallel, and a power distribution chip integrating an adaptive algorithm, wherein the algorithm calculates the real-time power supply of the touch electrode by the following formula: ； in: : Real-time power supply of touch electrode, unit ; L: illuminance value collected by the ambient light sensor, ; F: Touch pressure sensor feedback value, ; : Operation mode reference power, defined as follows: ； , : Dynamic weight coefficient, satisfying , and updated every 30 seconds according to the following formula: ； α: power adjustment factor, value range [0.8,1.2].

2. The flexible self-repairing touch screen according to claim 1, characterized in that: The graphene conductive layer is a few-layer graphene film with a double-layer AB stacking structure, with an interlayer spacing of 0.34±0.02 nm, and the CVD method uses a methane / hydrogen mixed gas with a methane volume concentration of 5-15% and a growth temperature of 1000-1050°C.

3. The flexible self-repairing touch screen according to claim 1, characterized in that: In the conductive polymer repair agent wrapped in the microcapsule, the mass ratio of polypyrrole to polyaniline is 3:1 to 1:1, the wall thickness of the microcapsule is 10-15% of the core material diameter, and the spatial distribution density of the microcapsule in the graphene conductive layer is .

4. The flexible self-repairing touch screen according to claim 1, characterized in that: The plasma treatment adopts radio frequency glow discharge mode with a power density of The oxygen content of the treated substrate surface increases by 8-12 at%, and the interface binding energy with the perovskite layer is ≥ .

5. The flexible self-repairing touch screen according to claim 1, characterized in that: The weight coefficient update function further includes a resistance compensation term: ； in: : Initial square resistance of graphene conductive layer, unit: Ω / sq; : Real-time monitoring of square resistance, unit Ω / sq.

6. The flexible self-repairing touch screen according to claim 5, characterized in that: When Δω>0.8 is detected and lasts for more than 10 seconds, the emergency energy supply protocol is activated: ； in: τ=30 s: time constant; : Real-time output power of the perovskite layer, unit .

7. The flexible self-repairing touch screen according to claim 1, characterized in that: The cross-linking density of dynamic covalent bonds in the thermoreversible polymer network is to , and the repair efficiency satisfies: ； in: : The conductivity of the graphene conductive layer after self-healing treatment, unit S / m; : conductivity in the original undamaged state, unit: S / m; : The glass transition temperature of the thermoreversible polymer network defined in claim 1, in °C; T: Applied external heating temperature, unit: °C.

8. A mobile terminal device, characterized in that: It comprises the flexible self-repairing touch screen as described in any one of claims 1 to 7, and the energy management module is integrated with the terminal battery system through a reversible plug interface.

9. The mobile terminal device according to claim 8, characterized in that: The communication interface between the energy management module and the terminal mainboard adopts Protocol, data transmission rate ≥ 400 kbps, and has the following collaborative control logic: ； in: : The state of charge of the terminal battery, ranging from 0-100%; : The safe output power of the perovskite photovoltaic layer is calculated as follows: ； : Real-time output power of the perovskite layer, unit .

10. The mobile terminal device according to claim 9, characterized in that: The device housing is provided with a deformation sensor array linked to the self-healing functional layer, with a sensor spacing of ≤500 μm. When a bend with a curvature radius r<5 mm is detected, the following compensation mechanism is triggered: ； in: : Change in curvature radius, unit: mm; : The radius of curvature of the device in the initial planar state, defined as .

Images