Single-structure-based optoelectronic / frictional hybrid nanogenerator and preparation method thereof

Abstract

The application discloses a single-structure-based photoelectric / friction hybrid nanogenerator and a preparation method thereof. 0.1 MA 0.2 FA 0.7 PbI3 composite film. Through material design of the positive friction layer, the application increases the dielectric constant of the perovskite composite film and constructs a Schottky junction in the film, thereby not only satisfying the function of simultaneously collecting light energy and solar energy through a single structure, but also effectively increasing the surface charge density of the positive friction layer, so that the output performance of the hybrid nanogenerator is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of new energy, and relates to energy collection, in particular to a photoelectric / frictional electricity hybrid nanogenerator based on a single structure and a preparation method thereof. BACKGROUND

[0002] In the mechanical energy collection technology, the frictional nanogenerator is concerned due to its high power density, high conversion efficiency, low processing cost, wide material selection range and the like.

[0003] The frictional nanogenerator (TENG) can successfully collect the mechanical energy ubiquitous in nature and human life through the principle of contact electrification and electrostatic induction, and convert it into electrical energy. At present, researchers mainly optimize the structure, inject charges, increase the dielectric constant, construct the Schottky junction and excite light to improve the output performance of the frictional nanogenerator. In addition to the ubiquitous mechanical energy, light energy is another kind of clean energy. In the current research, the photovoltaic cell (PVC) is the most stable and reliable device for converting light energy into electrical energy, and the research on the frictional nanogenerator for collecting light energy is less. In order to meet the indicators of energy collection and output performance of the frictional nanogenerator, it is urgent to develop a hybrid nanogenerator capable of simultaneously collecting light energy and mechanical energy. In the existing reports, the mechanical energy and light energy are mostly collected by a single component and outputted through an external circuit, which is not feasible in the later large-scale development and device miniaturization.

[0004] In general, the traditional photoelectric / frictional electricity hybrid nanogenerator mainly collects electrical energy and mechanical energy by different components, and then the collected energy is rectified through an external circuit and stacked together in series or parallel. The device structure is complex, the preparation process is complicated, the preparation cost is high, and it is not conducive to the later large-scale production and device miniaturization. At the same time, there is a certain loss of energy in the process of stacking the collected mechanical energy and light energy through the external circuit, which makes the conversion efficiency of the hybrid nanogenerator low, the output power low and the stability poor. SUMMARY

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a photoelectric / frictional electricity hybrid nanogenerator based on a single structure and a preparation method thereof, so as to realize the simultaneous collection of light energy and mechanical energy by a single structure.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A single-structure-based photoelectric / friction hybrid nanogenerator, comprising a positive electrode part and a negative electrode part, the positive electrode part comprising a first substrate, a positive electrode and an electron transport layer, and a positive friction layer arranged in sequence; the negative electrode part comprising a negative friction layer, a negative electrode and a second substrate arranged in sequence; the positive friction layer is opposite to the negative friction layer and has a spacing therebetween; the positive friction layer is Ag NWs@BaTiO3 / Cs 0.1 MA 0.2 FA 0.7 PbI3 composite film.

[0008] The application also provides a preparation method of the single-structure-based photoelectric / friction hybrid nanogenerator, comprising the following steps:

[0009] Step 1, preparation of the positive electrode part

[0010] Preparation of the positive electrode and the electron transport layer on the first substrate in sequence;

[0011] The molar ratio of each element in Cs 0.1 MA 0.2 FA 0.7 PbI3, CsI, MAI, FAI and PbI2 are taken and dissolved in DMF to prepare a perovskite precursor solution I, Ag NWs@BaTiO3 nanoparticles are added to the perovskite precursor solution I, and ultrasonic stirring is performed to form a precursor solution II; the precursor solution II is scraped and coated on the electron transport layer, and then annealing is performed to obtain the positive friction layer, and the preparation of the positive electrode part is completed;

[0012] Step 2, preparation of the negative electrode part

[0013] Step 3, assembly of the hybrid nanogenerator

[0014] Lead wires are drawn from the positive electrode and the negative electrode respectively, and the assembly is completed.

[0015] Compared with the prior art, the application dopes Ag NWs@BaTiO3 nanoparticles in Cs 0.1 MA 0.2 FA 0.7 PbI3 halide, increases the dielectric constant of the perovskite composite film, constructs a Schottky junction in the film, not only meets the function of simultaneously collecting light energy and solar energy through a single structure, but also effectively increases the surface charge density of the positive friction layer, thereby improving the output performance of the hybrid nanogenerator. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the single-structure photoelectric / friction hybrid nanogenerator of the application.

[0017] Figure 2 is a schematic diagram of the separation and migration of surface friction charge and photo-generated electron-hole pairs.

[0018] Figure 3 is a preparation flow chart of the composite positive friction layer of the application. DETAILED DESCRIPTION

[0019] The embodiments of the application will be described in detail below with reference to the accompanying drawings and examples.

[0020] As described above, the traditional hybrid nanogenerator collects electrical energy and mechanical energy through different components, which is complex in structure and has large energy loss, and the output power and stability are difficult to meet the actual demand.

[0021] Therefore, the purpose of the application is to construct a high-output single-structure optoelectronic / friction hybrid friction nanogenerator. Halide perovskite has the characteristics of adjustable band gap, long carrier diffusion length, high carrier mobility and long lifetime, and is a good candidate material for modern photonics and optoelectronics. At the same time, halide perovskite can exhibit excellent triboelectric properties due to its special structure and electronic properties, spontaneous polarization and significant dielectric properties. Among them, organic-inorganic hybrid halide perovskite has significant advantages in single-structure optoelectronic / friction hybrid nanogenerator due to its diversified composition and low processing temperature.

[0022] The single-structure optoelectronic / friction hybrid nanogenerator of the application includes a positive electrode part and a negative electrode part. As shown in Figure 1 , the positive electrode part includes a first substrate 1, a positive electrode 2 and an electron transport layer 3, a positive friction layer 4, which are sequentially attached and arranged. The negative electrode part includes a negative friction layer 5, a negative electrode 6 and a second substrate 8, which are sequentially attached and arranged. The positive friction layer 4 is opposite to the negative friction layer 5 and has a necessary spacing between them. In the application, the positive friction layer 4 is Ag NWs@BaTiO3 / Cs 0.1 MA 0.2 FA 0.7 PbI3 composite film, that is, Ag NWs@BaTiO3 nanoparticles are doped in Cs 0.1 MA 0.2 FA 0.7 PbI3.

[0023] According to the structure, the specific process of the optoelectronic / friction hybrid nanogenerator of the application is as follows:

[0024] Triboelectricity: when the positive friction layer 4 and the negative friction layer 5 are in contact, the surface of the friction layer 5 is negatively charged due to the larger electron affinity of the material of the friction layer 5, and the surface of the positive friction layer 4 is positively charged; when the two friction layers are separated, an equal amount of opposite charges appears between the two electrodes due to electrostatic induction, and a potential difference is generated between the two electrodes, and the electrons flow through the external circuit to generate current.

[0025] Photovoltaic: light will generate a large number of electron-hole pairs on the surface of the positive friction layer 4, and the generated electrons are then transported away from the surface of the positive friction layer 4 due to the presence of the electron transport layer, leaving excess holes on the surface of the positive friction layer 4, thereby increasing the surface charge density.

[0026] The present application increases the dielectric constant of the composite film while constructing Ag NWs@BaTiO3 Schottky junction inside the film by designing the material of the positive friction layer 4, that is, forming a Schottky junction by Ag NWs and BaTiO3, due to the difference in work function between the two, a large amount of positive charges are accumulated on the side of BaTiO3 through electron flow, thereby increasing the surface charge density of BaTiO3 and the surface of the composite film, that is, increasing the surface charge density of the positive friction layer, thereby improving the output performance of the triboelectric nanogenerator. At the same time, the large dielectric constant of BaTiO3 (1500 at room temperature) significantly improves the dielectric constant of the composite film, increases the capacitance and charge transfer density of the composite film, and makes the hybrid nanogenerator have high electrical output performance.

[0027] At the same time, the Ag NWs@BaTiO3 particles form a Schottky junction in the halide perovskite film, which not only improves the surface charge density of the perovskite film, but also successfully avoids the reaction of Ag with Cs 0.1 MA 0.2 FA 0.7 PbI3, and Ag is lower in cost than other noble metals (Au, Pt). The output performance of the hybrid nanogenerator is improved while the preparation cost of the device is reduced.

[0028] Therefore, the present application can realize the collection of light energy and mechanical energy through a single structure while ensuring the output performance of the hybrid triboelectric nanogenerator. At the same time, the overall structural design greatly simplifies the device structure and reduces the preparation cost, and the present application improves the overall output performance and stability of the device.

[0029] In an embodiment of the present application, the first substrate 1 and the second substrate 8 are both ITO glass substrates, the positive electrode 2 is an ITO electrode, the electron transport layer 3 is a SnO2 electron transport layer, and the material of the negative friction layer 5 is polyvinylidene fluoride. The negative electrode 6 is an Al electrode.

[0030] In this embodiment, the materials of each part are mostly existing materials, raw materials are easy to obtain, and the process is mature, thus the stability of the device and cost control can be ensured. Illumination can generate a large number of electron-hole pairs on the perovskite surface. In this embodiment, the generated electrons are immediately transported away from the perovskite surface due to the existence of the SnO2 electron transport layer, thereby avoiding recombination with the rubbing positive charge, leaving a large number of holes on the perovskite surface. These positively charged holes are superimposed with the existing rubbing positive charge, thereby increasing the surface charge density and improving the output performance of the hybrid nanogenerator. A model diagram is shown in FIG. 1. Figure 2

[0031] At the same time, polyvinylidene fluoride has a large electron affinity, a strong spontaneous polarization and good polarization stability, and is a very promising triboelectric material. A polyvinylidene fluoride film can be prepared by a spin coating method, which greatly simplifies the preparation process.

[0032] In an embodiment of the present application, the doping amount of Ag NWs@BaTiO3 is 0-1% in terms of mole percentage, and is not 0.

[0033] In this embodiment, the preferable doping amount of Ag NWs@BaTiO3 is limited, and 0.25%, 0.5%, 0.75%, 1% can be selected in specific experiments, and 0% is used as a comparative example. The selection of this doping amount is for two purposes: one is to increase the dielectric constant of the composite material, and the other is to construct a Schottky junction to increase the surface charge density of the composite material, thereby increasing the output performance of the nanogenerator. However, if the amount is too large, the presence of AgNWs may cause charge leakage, which may reduce the output performance of the nanogenerator.

[0034] In an embodiment of the present application, the thickness of the positive rubbing layer 4 is 500-600 nm, and the thickness of the negative rubbing layer 5 is 50-100 μm.

[0035] In this embodiment, the preferable thicknesses of the positive rubbing layer 4 and the negative rubbing layer 5 are limited. According to literature reports and experiments, the positive rubbing layer 4 (perovskite layer) prepared by doctor blading usually has a thickness of 400-500 nm, and the thickness of the negative rubbing layer is less than 50 μm, which is easy to curl during annealing.

[0036] In an embodiment of the present application, a foam adhesive buffer layer 7 is arranged between the negative electrode 6 and the second substrate 8.

[0037] In this embodiment, the foam adhesive buffer layer 7 has a certain elasticity, which can increase the effective contact area between polyvinylidene fluoride and the positive rubbing layer 4, and improve the electrical output performance of the hybrid nanogenerator.

[0038] The present application also provides a preparation method of the photoelectric / triboelectric hybrid nanogenerator based on a single structure, which comprises the following steps:​

[0039] Step 1, preparation of the positive electrode part

[0040] The positive electrode 2 and the electron transport layer 3 are prepared on the first substrate 1, which is a mature prior art.

[0041] Then the positive rubbing layer 4 is prepared. Specifically, Cs 0.1 MA 0.2 FA 0.7 The molar ratio of each element in PbI3 is taken by using CsI, MAI, FAI and PbI2, dissolved in a certain amount of DMF to prepare a perovskite precursor solution I, then Ag NWs@BaTiO3 nanoparticles are added to the perovskite precursor solution I, and the precursor solution II is formed by ultrasonic stirring; the precursor solution II is scraped on the electron transport layer 3, and then annealing is performed to obtain the positive rubbing layer 4 on the electron transport layer 3, and at this time the preparation of the positive electrode part is completed.

[0042] Step 2, preparation of the negative electrode part

[0043] That is, the negative electrode 6 and the negative rubbing layer 5 are prepared on the second substrate 8, which is a mature prior art.

[0044] Step 3, assembly of the hybrid nanogenerator

[0045] The wires are drawn from the positive electrode 2 and the negative electrode 6 respectively, and the assembly is completed.

[0046] The above preparation process is basically a mature process, so that only an organic-inorganic hybrid perovskite thin film is used as a positive rubbing layer and a light absorption material, compared with other photoelectric / rubbing hybrid nanogenerators, the preparation process of the device is simplified, and the preparation cost of the device is reduced. Cs 0.1 MA 0.2 FA 0.7 The perovskite PbI3 has a long carrier diffusion length and a high carrier mobility, and is a very ideal optoelectronic material; at the same time, its excellent dielectric performance also shows excellent rubbing characteristics, and the hybrid nanogenerator can significantly improve its electrical output performance while simultaneously collecting light energy and mechanical energy.

[0047] In an embodiment of the present application, the first substrate 1 is selected as an ITO glass substrate, and the area is designed as 4*4cm 2 , and the square resistance is designed as 10Ω / □ (here, "□" represents square). It is ultrasonically cleaned with cleaning agent, deionized water, acetone and alcohol for about 20 minutes, and then dried with N2 gun, and then transferred to a UV-ozone cleaning machine for surface treatment for about 20 minutes to improve its hydrophilicity.

[0048] The electron transport layer 3 is selected as SnO2, and a SnO2 hydrogel with a mass concentration of about 15% is diluted with deionized water to about 5%, and then is spin-coated on the surface-treated ITO glass substrate, with the spin-coating parameters being 3000 rpm, 45 s, and finally being annealed at 120-150°C for 15-30 minutes to complete the preparation of the electron transport layer 3.

[0049] To perform the blade coating of the precursor solution II, the ITO glass substrate with the electron transport layer 3 is vacuum-adsorbed on a blade coating platform, and then the precursor solution II is blade-coated on the electron transport layer at a speed of 80-100 mm / s at 100-120°C in air, preferably at 100°C and 100 mm / s, and then is annealed at 100-120°C for 10-15 minutes, preferably at 100°C for 10 minutes. The detailed process is shown in Figure 3 .

[0050] Further preferably, in the preparation of the perovskite precursor solution I, CsI:MAI:FAI:PbI2 is dissolved in 1 mL of DMF at a molar ratio of 1:2:7:10, and is stirred at 70-75°C for 12-18 h, preferably at 70°C for 12 h, to obtain the perovskite precursor solution I with a concentration of 1 mol / L. After obtaining the perovskite precursor solution I, it is filtered with a 0.22 μm filter to remove the undissolved part. Then Ag NWs@BaTiO3 nanoparticles are added, and are stirred and ultrasonically treated at 70-75°C for 6-8 h, preferably at 70°C for 6 h.

[0051] In an embodiment of the present application, a preparation method of Ag NWs@BaTiO3 nanoparticles is also provided, as shown in the following steps:

[0052] Ag NWs and PVP are added to deionized water, and are stirred at room temperature, and then are filtered, collected, and dried to obtain Ag@PVP particles.

[0053] Ag@PVP particles, anhydrous ethanol, barium ethoxide, tetra-n-butyl titanate, and deionized water are mixed, and are stirred at room temperature, and then are filtered, washed, collected, and dried to obtain Ag NWs@BaTiO3 nanoparticles.

[0054] Preferably, in the present embodiment, the diameter of the Ag NWs is 20-30 nm, the amount of the Ag NWs is 2-3 g, and the amount of the PVP is 7-8 g; further preferably, the amounts are 3 g and 8 g, respectively, and the amount of the deionized water is preferably 160 mL. After mixing, the stirring is performed at 300 rpm at room temperature for 24-48 hours; and the drying condition is preferably 75-100°C for 30-45 minutes.

[0055] Preferably, in the present embodiment, the amount of Ag@PVP particles is 2-3 g, the amount of anhydrous ethanol is 100-150 g, the amount of barium ethoxide is 2.7-4.1 g, the amount of titanium tetrabutoxide is 0.66-1 g, and the amount of deionized water is 0.9-1.4 g, and further preferably 3 g, 150 g, 4.1 g, 1 g, and 1.4 g, respectively. After mixing, stirring at 300 rpm at room temperature for 48-72 hours; the drying conditions are 75-100°C for 1-2 hours.

[0056] In an embodiment of the present application, the preparation of the negative friction layer 5, 2-3 g (preferably 2 g) of polyvinylidene fluoride particles is dissolved in 10-15 mL (preferably 10 mL) of DMF, and stirred at 65-70°C for 24-36 h (preferably 65°C for 24 h) to prepare a polyvinylidene fluoride precursor solution; the polyvinylidene fluoride precursor solution is spin-coated on a Si substrate (2000 rpm-30 s), and after annealing at 100-150°C for 30-60 minutes (preferably 100°C for 30 minutes), it is peeled off for standby use. Among them, the Si substrate here is used as a template for preparing the thin film, and is not the substrate of the device.

[0057] In an embodiment of the present application, the assembly of the hybrid nanogenerator, the polyvinylidene fluoride negative friction layer is cut into a size of 4*4 cm 2 , and an aluminum tape is attached to its surface as an electrode, and the aluminum tape is attached to the foam double-sided tape on one side, and finally fixed on the second substrate 8; two wires are led out from the aluminum tape and the ITO of the first substrate 1, respectively, i.e. the assembly of the device is completed.

Claims

1. A preparation method of a single-structure-based photoelectric / friction hybrid nanogenerator, the single-structure-based photoelectric / friction hybrid nanogenerator comprising a positive electrode part and a negative electrode part, the positive electrode part comprising a first substrate (1), a positive electrode (2), and an electron transport layer (3), a positive friction layer (4) arranged in sequence; the negative electrode part comprising a negative friction layer (5), a negative electrode (6), and a second substrate (8) arranged in sequence; the positive friction layer (4) is opposite to the negative friction layer (5) and has a spacing therebetween; the positive friction layer (4) is Ag NWs@BaTiO3 / Cs 0.1 MA 0.2 FA 0.7 PbI3 composite film; characterized in that Comprising the following steps: Step 1, preparation of the positive electrode part Prepared on the first substrate (1) in turn positive electrode (2) and electron transport layer (3) ; Cs 0.1 MA 0.2 FA 0.7 The molar ratio of each element in PbI3, CsI, MAI, FAI and PbI2 are taken and dissolved in DMF to prepare perovskite precursor solution I, Ag NWs@BaTiO3 nanoparticles are added to the perovskite precursor solution I, and ultrasonic stirring is formed to form precursor solution II; The precursor solution II is scraped on the electron transport layer (3), and then annealed to obtain the positive rubbing layer (4), and the preparation of the positive electrode part is completed; Step 2, preparation of the negative electrode part Step 3, assembly of hybrid nanogenerator Lead wire is drawn from the positive electrode (2) and the negative electrode (6) respectively, and the assembly is completed. 2.The method of claim 1, wherein the single-structured optoelectronic / frictional hybrid nanogenerator is prepared by the steps of: The first substrate (1) and the second substrate (8) are ITO glass substrates, the positive electrode (2) is an ITO electrode, the electron transport layer (3) is a SnO2 electron transport layer, the material of the negative rubbing layer (5) is polyvinylidene fluoride, and the negative electrode (6) is an Al electrode.

3. The method for fabricating a photoelectric / triboelectric hybrid nanogenerator based on a single structure according to claim 1, characterized in that, In the positive rubbing layer (4), the doping amount of Ag NWs@BaTiO3 is 0-1% in mole percentage, and is not 0.

4. The method for fabricating a photoelectric / triboelectric hybrid nanogenerator based on a single structure according to claim 1, 2, or 3, characterized in that, The thickness of the positive rubbing layer (4) is 500-600 nm; the thickness of the negative rubbing layer (5) is 50-100 µm.

5. The method for fabricating a photoelectric / triboelectric hybrid nanogenerator based on a single structure according to claim 1, characterized in that, A foam rubber buffer layer (7) is arranged between the negative electrode (6) and the second substrate (8).

6. The method for fabricating a photoelectric / triboelectric hybrid nanogenerator based on a single structure according to claim 1, characterized in that, In the step 1, the first substrate (1) is an ITO glass substrate, which is ultrasonically cleaned with cleaning agent, deionized water, acetone and alcohol in turn, dried with N2 gun, and then transferred to an ultraviolet ozone cleaning machine for surface treatment to improve its hydrophilicity; The electron transport layer (3) is a SnO2 electron transport layer, and SnO2 hydrogel dispersion is spin-coated on the surface-treated ITO glass substrate, and then annealed at 120-150℃ for 15-30 minutes; In the preparation of the perovskite precursor solution I, stirring is carried out at 70-75℃ for 12-18h; in the preparation of the precursor solution II, stirring is carried out at 70-75℃ for 6-8h under ultrasonic; The precursor solution II is scraped on the electron transport layer (3) in air at a temperature of 100-120℃ and a speed of 80-100mm / s, and then annealed at 100-120℃ for 10-15 minutes.

7. The method for fabricating a single-structure photoelectric / triboelectric hybrid nanogenerator according to claim 1 or 6, characterized in that, In the step 1, Ag NWs@BaTiO3 nanoparticles are prepared by the following method: Ag NWs and PVP are added to deionized water, stirred at room temperature, and then filtered, collected and dried to obtain Ag@PVP particles; Ag@PVP particles, anhydrous ethanol, barium ethoxide, titanium tetrabutoxide and deionized water are mixed and stirred at room temperature, and then filtered, washed, collected and dried to obtain Ag NWs@BaTiO3 nanoparticles. 8.The method of claim 7, wherein the single-structured optoelectronic / frictional hybrid nanogenerator is prepared by the steps of, The diameter of the Ag NWs is 20-30nm; The amount of Ag NWs is 2-3g, and the amount of PVP is 7-8g; after mixing, stirring is carried out at room temperature for 24-48 hours; the drying condition is 75-100℃ for 30-45 minutes; The amount of Ag@PVP particles is 2-3 g, the amount of anhydrous ethanol is 100-150 g, the amount of barium ethoxide is 2.7-4.1 g, the amount of titanium tetrabutoxide is 0.66-1 g, and the amount of deionized water is 0.9-1.4 g. After mixing, stirring at room temperature for 48-72 hours; the drying condition is 75-100℃, 1-2 hours.

9. The method for fabricating a photoelectric / triboelectric hybrid nanogenerator based on a single structure according to claim 1, characterized in that, In the step 2, a polyvinylidene fluoride precursor solution is prepared by dissolving 2-3 g of polyvinylidene fluoride particles in 10-15 mL of DMF and stirring at 65-70℃ for 24-36 h; the polyvinylidene fluoride precursor solution is spin-coated on a Si substrate, and after annealing at 100-150℃ for 30-60 minutes, it is peeled off for standby use.

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