TWI803193B - Organic-inorganic hybrid piezoelectric film - Google Patents

Abstract

The present invention provides an organic-inorganic hybrid piezoelectric film, comprising poly (vinylidene fluoride-co-trifluoroethylene), poly (methyl methacrylate), which is a polymer with amorphous phase, and zinc oxide. The organized stacking of PVDF-TrFE lamellae is evolved through the thin films with two dispersion behaviors of zinc oxide columnar crystals. The organic-inorganic hybrid piezoelectric film of the present invention offers a strategy to greatly enhance the piezoelectric performance of the whole film.

Description

Organic-inorganic composite piezoelectric film

The invention relates to an organic-inorganic composite piezoelectric film, in particular to an organic-inorganic composite piezoelectric film using novel polymers and inorganic materials.

The piezoelectric effect means that when a material is stimulated by external stress, the material will deform and cause uneven distribution of charges in the material; when the charge is unevenly distributed inside the material, a potential difference will be generated inside the material to drive The effect of electromigration of external leads. In this regard, the piezoelectric film prepared by polymer has the characteristics of light weight and flexibility, thus increasing the scope of application of the piezoelectric film, such as various wearable sensors on the human body.

However, the piezoelectric properties of current polymer materials are lower than those of inorganic materials, and the ferroelectric polymer polycrystalline material developed as a flexible piezoelectric film, due to inconsistent crystal orientation and small dipole moment, the piezoelectric The performance cannot meet the needs of the application.

Therefore, the prior art tried to improve the overall piezoelectric properties of the film by mixing inorganic piezoelectric crystal phases to form an organic-inorganic hybrid piezoelectric material; The piezoelectric properties of hybrid thin films are a bottleneck.

In addition, nanostructures with specific orientations are also desired for many applications, but direct preparation of oriented crystal forms remains a major challenge.

[Prior Technical Literature] 〔Patent Document〕

[Patent Document 1] Chinese Publication CN109449299A

Therefore, in order to improve the piezoelectric performance of polymer films, the present invention aims to regulate the distribution of inorganic precursors, and convert the precursors into zinc oxide columnar crystals at low temperature by hydrothermal method, and explore a new crystal phase growth. Guide mechanism to optimize the structure of mixed crystal phase film and develop multifunctional organic-inorganic composite piezoelectric film.

The present invention regulates the distribution of inorganic precursors by regulating the distribution of ferroelectric polymer polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) and amorphous phase polymer polymethyl methacrylate (PMMA) in the film ; and then convert the precursors into zinc oxide (ZnO) columnar crystals at low temperature by hydrothermal method to develop an organic-inorganic composite piezoelectric film with PVDF-TrFE ordered plate crystals/standing ZnO columnar crystal arrays, to Improve the overall piezoelectric effect of the film.

Specifically, the present invention provides an organic-inorganic composite piezoelectric film comprising poly Vinylidene fluoride-trifluoroethylene (PVDF-TrFE), polymethyl methacrylate (PMMA) and zinc oxide; wherein, the organic-inorganic composite piezoelectric film has an ordered plate crystal array, and the zinc oxide has a columnar crystal structure.

Further, the preparation method of the organic-inorganic composite piezoelectric film may include the following steps: (A) configuring a mixed solution of zinc acetate and PMMA; (B) ultrasonically vibrating the mixed solution; (C) adding PVDF to the mixed solution -TrFE, forming a ternary mixed solution; (D) forming a film on a substrate by spin-coating the ternary mixed solution; (E) heating the film to 60° C. at a heating rate of 1° C. per minute to 130°C, and hold the temperature for 0 to 4 hours; (F) add the film, hexamethylenetetramine, zinc acetate and deionized water into the hydrothermal kettle, and place the hydrothermal kettle in an oven for two-stage holding temperature; (G) taking out the film after holding the temperature to obtain the organic-inorganic composite piezoelectric film.

Further, the weight ratio of the PVDF-TrFE to the PMMA in step (C) may be 9:1.

Further, the solvent of the mixed solution in step (A) may be tetrahydrofuran or butanone.

Further, the concentration of the zinc acetate in step (A) may be 0.05wt% to 0.1wt%.

Further, the total concentration of the ternary mixed solution in step (C) may be 0.6wt%.

Further, the conditions of the spin coating in step (D) can be: firstly, the rotation speed is 500 rpms for 20 seconds, and then the rotation speed is 2000 rpms for 30 seconds.

Further, in step (E), the film can be heated at a rate of 1°C per minute to 100°C to 130°C, and hold the temperature for 0 to 4 hours.

Further, in step (E), the film can be heated to 60°C to 130°C at a rate of 1°C per minute, and kept at the temperature for 2 hours.

Further, the condition for the two-stage temperature holding in step (F) may be: firstly hold the temperature at 50°C for 15 minutes, then rise to 90°C and hold the temperature for 15 minutes.

The addition of inorganic materials in the present invention can improve the piezoelectric properties of the overall film, thereby increasing the efficiency of converting mechanical energy into electrical energy, so it can also become a new choice for energy supply; in addition, the present invention utilizes two polymers with different affinity to regulate The distribution of inorganic materials in the thin film significantly improves and enhances the piezoelectric properties of the overall thin film.

[Figure 1] Observation of PMMA of PVDF-TrFE/PMMA thin film of (a) Example 1, (b) Example 2, (c) Example 3, (d) Example 4, (e) Example 6 by TEM Regional evolution.

[Figure 2] (a) SEM images of the organic-inorganic composite piezoelectric thin film of (a) Example 6 and (b) Example 8.

[Figure 3] SEM images of PVDF-TrFE/PMMA thin films in (a) Example 7, (b) Example 9, and (c) Example 11.

[Figure 4] SEM images of (a) Embodiment 6, (b) Embodiment 11, and (c) Embodiment 19 organic-inorganic composite piezoelectric thin films.

[Figure 5] Observation by TEM of (a) Example 14, (b) Example 17, (c) Example 18 Evolution of PMMA domains of PVDF-TrFE/PMMA thin films.

[Fig. 6] SEM image of the organic-inorganic composite piezoelectric thin film of Example 17.

[Fig. 7] In Example 6, the piezoelectric properties of PVDF-TrFE/PMMA film and PVDF-TrFE/PMMA/ZnO organic-inorganic composite piezoelectric film are compared.

[Figure 8] Measurement of the piezoelectric response of the organic-inorganic composite piezoelectric thin film in Example 6; from left to right are the morphology, PFM amplitude, and PFM phase.

[Figure 9] The left figure is the PFM phase diagram of the organic-inorganic composite piezoelectric thin film of Example 6, and the right figure is the analysis result.

[Fig. 10] The left picture is the PFM topography of the organic-inorganic composite piezoelectric thin film of Example 6, the middle picture is the PFM phase diagram, and the right picture shows the numerical change on the red line of the PFM phase diagram.

The preparation steps, identification methods and analysis results of the present invention are described below by means of exemplary embodiments. It should be noted that the following exemplary embodiments are only used to illustrate the present invention, but not to limit the scope of the present invention.

Embodiment 1: Preparation of Organic-Inorganic Piezoelectric Composite Films

The experimental materials in Embodiment 1 of the present invention include the following: polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE, molecular weight 450,000Da, source: Piezotech Arkema); polymethyl methacrylate (PMMA, molecular weight 35,000Da, source: Acros organics); Zinc acetate dihydrate (Zn(Ac) ₂ .2H ₂ O, molecular weight 183.48g/mol, source: Sigma-Aldrich); Tetrahydrofuran (THF, source: Sigma-Aldrich); Butanone (MEK, source: Sigma-Aldrich); Hexamethylenetetramine (Source: Alfa Aesar)

Embodiment one

The preparation method of the organic-inorganic piezoelectric composite film includes the following: (A) configure a mixed solution of PVDF-TrFE and PMMA with a total concentration of 0.5wt%, and the solvent is tetrahydrofuran (THF); wherein the weight ratio of PVDF-TrFE and PMMA is 9: 1; (B) add 0.1wt% zinc acetate to the mixed solution; (C) ultrasonically oscillate the mixed solution for 12 hours, so that the precursor crystal grains are evenly dispersed in the solution; (D) the mixed solution A thin film is formed on a substrate by means of spin coating; the parameters of the spin coater are: the rotational speed of the first step is 500 rpms for 20 seconds. The second step rotates at 2000rpms for 30 seconds; (E) heats the film to a holding temperature of 60°C at a rate of 1°C per minute, and holds the temperature for 2 hours to form a PVDF-TrFE/PMMA film; (F) Add the film, 0.08 grams of hexamethylenetetramine, 0.077 grams of zinc acetate and 40 milliliters of deionized water into the hydrothermal kettle, place the hydrothermal kettle in an oven, keep the temperature at 50°C for 15 minutes and then raise it to 90°C Hold the temperature for 15 minutes; (G) Take out the film after holding the temperature to obtain PVDF-TrFE/PMMA/ZnO organic-inorganic composite piezoelectric film.

Embodiment two

Except changing the holding temperature in step (E) to 80°C, other steps are the same as in Example 1.

Embodiment three

Except changing the holding temperature in step (E) to 100°C, other steps are the same as in Example 1.

Embodiment Four

Except changing the holding temperature in step (E) to 110°C, other steps are the same as in Example 1.

Embodiment five

Except changing the holding temperature in step (E) to 120°C, other steps are the same as in Example 1.

Embodiment six

Except changing the holding temperature in step (E) to 125°C, other steps are the same as in Example 1.

Embodiment seven

Except changing the holding temperature in step (E) to 130°C, other steps are the same as in Example 1.

Embodiment Eight

Except changing the temperature holding time into 4 hours in the embodiment six step (E), other steps are the same as embodiment six.

Embodiment nine

Except that temperature holding time is changed into 0 hour in the embodiment seven steps (E), promptly do not hold temperature, cool down immediately, other steps are with embodiment seven.

Embodiment ten

Except changing the temperature holding time into 10 minutes in the embodiment seven step (E), other steps are the same as embodiment seven.

Embodiment Eleven

Except that the temperature holding time in step (E) of embodiment seven was changed to 30 minutes, other steps were the same as embodiment seven.

Embodiment 12 to 18

Except changing solvent into MEK in step (A), other steps are respectively the same as embodiment 1 to embodiment 7.

Embodiment nineteen

Except changing the temperature holding time into 1 hour in the embodiment seven step (E), other steps are the same as embodiment seven.

Embodiment 2: Identification and Analysis of PVDF-TrFE/PMMA Films in Examples 1 to 7

The analytical instruments used in the present invention include the following: Transmission electron microscope (Transmission electron microscope, TEM), model: JEM-1400 Transmission electron microscope, JEOL; Atomic Force Microscope (Atomic Force Microscope, AFM), model: J XE-100, Park system., the maximum scanning range: 50 μm (x, y direction scanning), 12 μm (z direction scanning); high-resolution thermal field emission scanning electron microscope (Field-Emission Scanning Electron Microscope, SEM), resolution: 1.2nm ( 30KV), 1.5nm(15KV), 3nm(1KV), magnification: x25 to x1,000,000, accelerating voltage: 0.5kV to 30kV, current: ~pA to 200nA; differential scanning thermal analyzer, model: Q2000; Multipurpose X-Ray Thin-Film Micro Area Diffractometer (XRD), Model: D8 Discover with GADDS (Bruker AXS Gmbh, Karlsruhe, Germany); Lock-in Amplifier (Lock-in Amplifier) , Label: J Park.

First, carry out PVDF-TrFE/PMMA/Zn(Ac) ₂ for Examples 1 to 7. Discussion on the evolution of the amorphous PMMA region in the 2H ₂ O mixed system, that is, the identification analysis of the PVDF-TrFE/PMMA film. Observed by TEM, after mixing zinc acetate, slowly heating up to different temperatures and holding the temperature will cause differences in the film structure, and the results are shown in Figure 1. First, at a holding temperature of 60°C, it was observed that PVDF-TrFE formed fine plate crystals grown from parallel substrates of molecular chains, and the previously mixed PMMA components that could not be crystallized were separated from the crystallized regions. In addition, smaller PMMA regions will gradually merge into larger PMMA regions, resulting in a decrease in the overall number of PMMA regions and an increase in the diameter of PMMA regions.

At a holding temperature of 80°C, the PVDF-TrFE plate crystals grow further, and the PMMA components will be further separated and aggregated into many smaller PMMA regions, increasing the number of PMMA regions. However, the average diameter of the PMMA domains did not change significantly at this time.

At a holding temperature of 100°C, the PVDF-TrFE plate crystals begin to thicken and grow, and the growth process of the PVDF-TrFE plate crystals will exert a compressive stress on the surrounding PMMA region. Since the glass transition temperature of PMMA has been reached, the components of PMMA begin to redistribute locally when pushed by isodirectional stress from the surroundings.

At a holding temperature of 110℃, PMMA and Zn(Ac) ₂ . 2H ₂ O has a better affinity with each other, so the PMMA molecules originally between the plate crystals tend to diffuse to the PMMA region and Zn(Ac) ₂ . 2H ₂ O mixed, resulting in a further increase in the diameter of the PMMA domain.

At a holding temperature of 125°C, it can be further observed that the number of amorphous PMMA domains decreases significantly, and the diameter of PMMA domains increases. However, when the temperature is higher than 125°C, the opposite phenomenon will occur. The increase of temperature will weaken Zn(Ac) ₂ . Between 2H ₂ O and Zn(Ac) ₂ . Affinity between 2H ₂ O and PMMA. Therefore, PMMA and Zn(Ac) ₂ . 2H ₂ O will incline to diffuse between plate crystals to increase the disorder of the finishing system. Therefore, when the temperature is higher than 125 °C, the driving force for the film development changes from an enthalpy-dominated behavior to an entropy-dominated behavior.

From the above results, it can be deduced that the precipitation of zinc acetate grains in the PMMA region, at 125 ° C The following will guide PMMA molecules to gather during the temperature-sustaining process, because of the affinity between the zinc acetate grains, the establishment of the interaction between the zinc acetate grains will release more enthalpy. Therefore, the diffusion of PMMA components driven by the interaction will cause the enlargement of the PMMA area. But above 125°C, due to the increase of chaos, the zinc acetate grains tend to disperse between plate crystals, resulting in the reduction and disappearance of some PMMA regions, which increases the chaos of the overall system.

Embodiment 3: Identification and Analysis of Embodiment 6 and Embodiment 8 Organic-inorganic Composite Piezoelectric Film

Observed by SEM, the results are shown in Figure 2. When growing ZnO columnar crystals by the hydrothermal method, it was found that the morphology of the grown ZnO columnar crystals was different when the film was kept at 125°C for different times. In the hybrid film grown at 125°C for 2 hours, the diameter of ZnO columnar crystals is relatively large and the number is small; while in the hybrid film grown at 125°C for 4 hours, the diameter of ZnO columnar crystals is smaller and smaller. There are many. Therefore, it is inferred that more and more zinc acetate grains gather in the PMMA region as the temperature is maintained at 125°C. In the case of simultaneous conversion of multiple zinc acetate seeds into zinc oxide, the developed zinc oxide columnar crystals are smaller.

It can be deduced from the above results that PMMA and zinc acetate tend to mix together because PMMA and zinc acetate have a better affinity. The zinc acetate located between the plate crystals near the PMMA region tends to diffuse further into the PMMA region due to its own aggregation tendency to release heat and reduce free energy.

Embodiment 4: Identification and Analysis of PVDF-TrFE/PMMA Films in Examples 7, 9, and 11

Then, the effects of different holding times at 130°C and the formation of PVDF-TrFE plate crystal arrays on the regional distribution of zinc acetate and PMMA were discussed. As shown in Figure 3, it was observed from the SEM results that When the temperature is slowly raised to 130°C, it is cooled down immediately (without holding the temperature). At this time, the PVDF-TrFE plate crystals are randomly oriented, and the zinc acetate grains are distributed in the PMMA area. After slowly raising the temperature to 130°C, hold the temperature for 30 minutes and then cool it down. At this time, the formation of an ordered array of PVDF-TrFE plate crystals can be observed. When the temperature is slowly raised to 130°C, and then cooled down after holding the temperature for 2 hours, not only the orderly arrangement of PVDF-TrFE plate crystals develops, but also the compression of the PMMA area with the growth of the plate crystals causes the PMMA area to gradually disappear. The evolution of such a polymer composition distribution presumably will make the zinc acetate grains distributed between the PVDF-TrFE plate crystals.

Embodiment 4: Identification and Analysis of Organic-inorganic Composite Piezoelectric Films in Examples 6, 11, and 19

The SEM identification and analysis results of Examples six, eleven, and nineteen organic-inorganic composite piezoelectric thin films are shown in Figure 4. This experimental result shows that, with the difference of thermal history, thin film structures of different hybrid materials can be developed, and PMMA The distribution of ingredients. And by adjusting the distribution of PMMA components, the distribution of zinc acetate grains with better affinity with PMMA in the film can be adjusted.

From the above results, it can be deduced that at a holding temperature of 130℃, the interaction force between PMMA and zinc acetate is not enough to make PMMA tend to aggregate only with zinc acetate. At this time, PVDF-TrFE/PMMA/Zn(Ac) ₂ . 2H ₂ O tends to mix together to get the highest disorder, thereby reducing the free energy.

Embodiment 5: Identification and analysis of PVDF-TrFE/PMMA thin films in Examples 14, 17, and 18

Using TEM to observe the effect of slowly heating up to different temperatures and holding the temperature on the film structure after mixing zinc acetate, the results are shown in Figure 5. Among them, it was observed that when the temperature was slowly increased to 100°C and the temperature was maintained, the PVDF-TrFE plate crystals began to thicken and grow, and the diameter of the PMMA region became larger and the number decreased. heat up At a higher temperature of 125°C and 130°C, it is found that in the process of continuous thickening and growth of plate crystals, the PMMA area also increases similarly, so it is inferred that the temperature rises above 100°C. After mixing zinc acetate, PMMA Regions are still merging with each other.

Embodiment 6: Identification Analysis of Example 17 Organic-inorganic Composite Piezoelectric Film

As shown in Figure 6, in Example 17, the sample after holding the temperature at 125°C was subjected to the hydrothermal method to grow zinc oxide columnar crystals, and through the mechanism of PMMA region fusion, the density of columnar crystals in the PMMA region was increased to promote Crystal growth has a certain orientation.

Embodiment 7: Measurement of piezoelectric properties of PVDF-TrFE/PMMA thin films in Examples 1 to 7

The influence of different holding temperatures on the piezoelectric properties of PVDF-TrFE/PMMA films was investigated. First measure the piezoelectric coefficient, and the results are shown in Table 1. When the temperature is kept at 60°C, a considerable proportion of PVDF-TrFE molecules have not yet crystallized, so the piezoelectric performance is not good. It was observed that with the rise of the holding temperature, more and more PVDF-TrFE molecules participated in the crystallization, and the piezoelectric constant of the film also increased, and had the highest piezoelectric effect at 125°C, and a voltage of 39.86pm/V was obtained. electric constant. Holding the temperature at 130°C will result in a substantial drop in the piezoelectric constant.

Next, the plate crystal size of PVDF-TrFE perpendicular to the substrate dimension was measured, and the results are shown in Table 2. According to the observation by atomic force microscope, as the temperature rises to a higher temperature, the plate crystal size perpendicular to the substrate dimension continues to increase, and has the largest increase at 125°C. Observation shows that the measured piezoelectric constant is related to the size of the crystal, and larger crystals have better piezoelectric performance.

Next, the small angle X-ray scattering (SAXS) experiment was used to investigate the influence of holding temperature at different temperatures on the arrangement of the plate crystal stacking pitch. It was found that with the rise of the holding temperature, the arrangement spacing of plate crystals also increased. The plate crystal thickness (Lc) at different temperatures was further calculated, and it was found that there was a maximum plate crystal thickness (Lc) at 125°C, and the plate crystal thickness (Lc) decreased after holding the temperature at 130°C, as shown in Table 3 It is shown as the change of plate crystal thickness (Lc) and amorphous region (La) thickness and plate crystal stacking distance (L) in the PVDF-TrFE/PMMA hybrid system. Therefore, it can be inferred that the reason for the decay of the piezoelectric constant at 130°C is related to the partial melting of the PVDF-TrFE plate crystal.

Embodiment 8: Measurement of piezoelectric properties of PVDF-TrFE/PMMA thin films in Examples 7, 9 and 11

Observe the influence of different time on the piezoelectric constant at the holding temperature of 130°C. The results are shown in Table 4; it can be found that the piezoelectric properties of the film are improved at the initial holding temperature of 130°C. As the temperature increases, the slab crystal gradually melts, causing the piezoelectric response to attenuate by half after holding the temperature for one hour.

Embodiment 9: Measurement of piezoelectric properties of PVDF-TrFE/PMMA thin films in Embodiment 7 and Embodiment 18

Then, the effects of the phase distribution thin films formed by volatilization of different solvents on the piezoelectric properties after the same holding temperature are discussed. The film coated with solvent MEK was kept at 130°C for 2 hours, compared with the film coated with solvent THF at 130°C for 2 hours, it was found that the piezoelectric property of the film formed by volatilization of MEK solvent was less than The films formed by the evaporation of THF solvent are shown in Table 5.

Embodiment 10: In Example 6, the piezoelectric properties of PVDF-TrFE/PMMA film and PVDF-TrFE/PMMA/ZnO organic-inorganic composite piezoelectric film are compared

The influence of ZnO columnar crystal growth on the piezoelectric properties of thin film after hydrothermal method was investigated. It was observed that after adding ZnO columnar crystals to form an organic-inorganic hybrid film, the overall piezoelectric constant of the film was 52pm/V, which was higher than that of the original PVDF-TrFE plate crystals held at 125°C, as shown in Figure 7 and Table 6. Show.

The above results show that the addition of ZnO columnar crystals can significantly improve the piezoelectric properties of the film, and as shown in Figure 8, the piezoelectric contributors are mainly PVDF-TrFE plate crystals found through the PFM amplitude image.

Embodiment 11: Observing the effect of mutual phase polarization between the organic crystal phase and the inorganic crystal phase in the organic-inorganic composite piezoelectric film of Embodiment 6 by PFM

The left figure of Figure 9 is the PFM phase diagram of the organic-inorganic composite piezoelectric thin film of Example 6, and the effect of mutual polarization between the organic crystal phase and the inorganic crystal can be observed; the observation results are analyzed as the right figure of Figure 9, showing Due to the mutual polarization force between the PVDF-TrFE plate crystal and zinc oxide, the polymer region has a piezoelectric response about 3-5 times higher than the original (the piezoelectric coefficient d ₃₃ of the polymer region is about 100pm /V), and this effect will decrease with increasing distance from ZnO.

Further observe and analyze the analysis results of the mutual polarization effect of the organic-inorganic composite piezoelectric thin film in Example 6. The left picture in Figure 10 is the PFM topography, the bright area is the inorganic crystal phase, and the dark area is the high score Sub-plate crystal; the middle picture is the PFM phase diagram, and the numerical changes on the red line are shown in the right picture. It can be observed that there is a 180-degree phase difference between the inorganic crystal phase and the organic crystal phase, indicating that the two crystal phases have opposite dipole moment directions.

Accordingly, it shows that the present invention can significantly improve the piezoelectric properties of the organic-inorganic composite piezoelectric film due to the successful preparation of the phase difference between the two crystal phases and the interaction between the two crystal phases.

Claims (9)

An organic-inorganic composite piezoelectric film is characterized by comprising polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE), polymethyl methacrylate (PMMA) and zinc oxide; the organic-inorganic composite piezoelectric film has an ordered plate crystal array, the zinc oxide has a columnar crystal structure; the preparation method of the organic-inorganic composite piezoelectric film comprises the following steps: (A) configuring a mixed solution of zinc acetate and PMMA; (B) ultrasonically vibrating the mixed solution; ( C) adding PVDF-TrFE to the mixed solution; (D) forming a thin film on a substrate by spin-coating the mixed solution after adding PVDF-TrFE in step (C); (E) forming the thin film at each Heat to 60°C to 130°C at a heating rate of 1°C per minute, and hold the temperature for 0 to 4 hours; (F) add the film, hexamethylenetetramine, zinc acetate and deionized water into the hydrothermal kettle, and the The hydrothermal kettle is placed in an oven for two-stage temperature maintenance; (G) taking out the temperature-maintained film to obtain the organic-inorganic composite piezoelectric film. The organic-inorganic composite piezoelectric thin film according to claim 1, wherein the weight ratio of the PVDF-TrFE to the PMMA in step (C) is 9:1. The organic-inorganic composite piezoelectric thin film according to claim 1, wherein the solvent of the mixed solution in step (A) is tetrahydrofuran or butanone. The organic-inorganic composite piezoelectric thin film according to Claim 1, wherein the total concentration of the mixed solution after adding PVDF-TrFE in step (C) is 0.6wt%. The organic-inorganic composite piezoelectric film as described in claim 1, wherein, in step (A), the acetic acid The concentration of zinc is 0.05wt% to 0.1wt%. The organic-inorganic composite piezoelectric thin film as described in claim 1, wherein the spin-coating condition in step (D) is as follows: 20 seconds at a rotational speed of 500 rpms, and 30 seconds at a rotational speed of 2000 rpms. The organic-inorganic composite piezoelectric thin film according to claim 1, wherein in step (E), the thin film is heated to 100°C to 130°C at a rate of 1°C per minute, and the temperature is maintained for 0 to 4 hours. The organic-inorganic composite piezoelectric thin film according to Claim 1, wherein in step (E), the thin film is heated to 60°C to 130°C at a rate of 1°C per minute, and kept at the temperature for 2 hours. The organic-inorganic composite piezoelectric thin film as described in Claim 1, wherein the condition for the two-stage temperature holding in step (F) is: first hold the temperature at 50°C for 15 minutes, then rise to 90°C and hold the temperature for 15 minutes.

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