Rollable dielectric energy storage film capacitor with high energy storage density and preparation method thereof

Abstract

The invention belongs to the technical field of dielectric film capacitors, and particularly relates to a flexible dielectric energy storage film capacitor with high energy storage density and a preparation method thereof. The dielectric energy storage film capacitor comprises a single crystal ferroelectric oxide film layer, single crystal paraelectric oxide films epitaxially grown on two sides of the single crystal ferroelectric oxide film layer, and dielectric polymer layers located on the outer sides of the two layers of single crystal paraelectric oxide films, the single crystal paraelectric oxide films are SrTiO3, the single crystal ferroelectric oxide films are BaZr0. 2Ti0. 8O3 or (Ba0. 85Ca0. 15) (Zr0. 10Ti0. 90) O3, and the dielectric polymer layers are arranged on the outer sides of the two layers of single crystal paraelectric oxide films. The dielectric polymer layer is polyetherimide PEI or polyimide PI, the dielectric energy storage characteristic of the composite film capacitor is effectively improved, and a new research idea is developed for developing the dielectric energy storage film capacitor which is high in energy storage density and can be curled.

Description

Technical Field

[0001] This invention belongs to the field of dielectric thin-film capacitor technology, specifically relating to a high-energy-density, rollable dielectric energy storage thin-film capacitor and its preparation method. Background Technology

[0002] Dielectric capacitors are characterized by high power density, fast charging and discharging speed, and good cycle stability, making them an indispensable energy storage component in electronic power and pulse power systems. However, their relatively low energy density and operating temperature make it difficult to meet the requirements of next-generation electronic power systems for high-energy-density dielectric energy storage capacitors that can operate stably under high field strength and high temperature conditions.

[0003] Single-crystal ferroelectric oxide thin films typically exhibit high energy density and good temperature stability, achieving up to 100 J / cm². -3 Energy storage density. Interface engineering is one of the effective ways to improve the energy storage density of oxide thin films. By constructing stacked epitaxial heterostructures, including paraelectric / ferroelectric, ferroelectric / antiferroelectric, and ferroelectric / ferroelectric heterostructures, the introduced 2D-2D interfaces can hinder carrier movement and electrical tree propagation, thereby improving the polarization intensity and breakdown strength of oxide thin films, and thus significantly increasing their energy density. To date, the energy storage performance of single-crystal ferroelectric oxide thin films far exceeds that of organic dielectric materials and organic / inorganic composite dielectric materials. However, they are usually bound to rigid substrates, and their poor mechanical flexibility and high substrate cost greatly limit their applications.

[0004] Polymer dielectric materials possess good mechanical flexibility and can be mass-produced, but their energy storage density is typically low. Adding inorganic fillers such as nanoparticles, nanowires, and nanosheets to organic polymers to construct organic / inorganic composite materials can improve their energy storage density to some extent. However, due to problems such as the tendency of inorganic fillers to agglomerate, high leakage conductivity, and large surface energy differences between inorganic fillers and polymers, most existing organic / inorganic composite materials are prone to breakdown at low fields, and the low breakdown field strength significantly limits the improvement of energy storage performance.

[0005] Constructing sandwich-structured organic / inorganic composite films is another effective way to improve the energy storage performance of polymers and prepare high-performance dielectric energy storage capacitors. Inorganic films, due to their large dielectric constant and high polarization intensity, can significantly improve the energy density of dielectric energy storage capacitors. Furthermore, the depolarization field generated at the organic / inorganic interface can further enhance the breakdown strength and energy density of the capacitor. However, the preparation processes of inorganic and polymer films are usually quite different, especially for single-crystal films, whose preparation temperatures are as high as 700-800℃, making it difficult to combine the two. Currently, research on sandwich-structured composite films mainly focuses on the composite of different types of pure organic films and polymer composites filled with low-dimensional inorganic fillers. Research on sandwich-structured inorganic / organic composite films, especially rollable, high-energy-density single-crystal inorganic / organic film composites and related capacitors, is still scarce. Summary of the Invention

[0006] Objective of the invention: To provide a high-energy-density, rollable dielectric energy storage film capacitor and its preparation method, so as to solve the technical problems of low energy density, poor high-temperature resistance, and difficulty in making existing film capacitors flexible.

[0007] Technical solution: A high-energy-density, rollable dielectric thin-film capacitor comprises: a single-crystal ferroelectric oxide thin film layer, single-crystal paraelectric oxide thin films epitaxially grown on both sides of the single-crystal ferroelectric oxide thin film layer, and a dielectric polymer layer located outside the two single-crystal paraelectric oxide thin films, wherein the single-crystal paraelectric oxide thin film is SrTiO3 and the single-crystal ferroelectric oxide thin film is BaZr. 0.2 Ti 0.8 O3 or (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3, the dielectric polymer layer is polyetherimide (PEI) or polyimide (PI).

[0008] A method for fabricating a high-energy-density, rollable dielectric thin-film capacitor includes the following steps: Step 1.1: Using pulsed laser deposition technology, grow an epitaxial, highly crystalline Sr3Al2O6 sacrificial layer on a SrTiO3 single-crystal substrate. Then, deposit epitaxial multilayer heterostructures of SrTiO3 paraelectric / BaZr with varying thickness ratios on the sacrificial layer. 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric single crystal oxide thin film; Step 1.2: Dissolve the Sr3Al2O6 sacrificial layer to prepare self-supporting SrTiO3 paraelectric / BaZr 0.2 Ti 0.8O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film; Step 1.3: Prepare a polyetherimide solution and use a spin-coating process to prepare a PEI polymer film on a platinum-plated silicon wafer; Step 1.4: Use a hot-pressing process to bond self-supporting SrTiO3 paraelectric / BaZr 0.2 Ti 0.8 Transfer of O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film onto PEI polymer film; Step 1.5: Use a hot-pressing process to bond the upper PEI polymer film with the self-supporting SrTiO3 paraelectric / BaZr... 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure composite film was used to prepare a rollable film capacitor.

[0009] Furthermore, step 1.1 is implemented as follows: Step 1.1.1: An epitaxial layer of 40 nm thick Sr3Al2O6 is grown on a 001 oriented SrTiO3 single crystal substrate using pulsed laser deposition technology. The cavity vacuum degree before deposition is 3 × 10⁻⁶. -4 Below Pa, the temperature of the SrTiO3 single crystal substrate is 750~770℃, the heating rate is 20℃ / min, the oxygen pressure is 20Pa, and the laser energy density is 1.8~2.3J / cm². 2 The laser frequency was 5 Hz, the growth time was 5 min, and the target spacing between the SrTiO3 single crystal substrate and the Sr3Al2O6 ceramic target was 6 cm, thus preparing the Sr3Al2O6 / SrTiO3 heterostructure. Step 1.1.2: A 50 nm thick SrTiO3 epitaxial film is grown on a Sr3Al2O6 / SrTiO3 heterostructure using pulsed laser deposition technology. The SrTiO3 single crystal substrate temperature is 650~700℃, the heating rate is 20℃ / min, the oxygen pressure is 15 Pa, and the laser energy density is 1.5~2 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6cm, thus preparing a SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure. Step 1.1.3: A 50 nm thick BaZr layer is grown on the SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure using pulsed laser deposition technology. 0.2 Ti 0.8 O3 epitaxial thin film, wherein the SrTiO3 single crystal substrate temperature is 750~800℃, the heating rate is 20℃ / min, the oxygen pressure is 20Pa, and the laser energy density is 1.5~2J / cm². 2The laser frequency was 3Hz, the growth time was 10min, and the SrTiO3 single crystal substrate was mixed with BaZr. 0.2 Ti 0.8 With an O3 ceramic target spacing of 6 cm, BaZr was prepared. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure; Step 1.1.4: Apply pulsed laser deposition technology to BaZr. 0.2 Ti 0.8 A 50 nm thick SrTiO3 epitaxial film was grown on an O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure. The SrTiO3 single crystal substrate temperature was 650–700 °C, the heating rate was 20 °C / min, the oxygen pressure was 15 Pa, and the laser energy density was 1.5–2 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6cm, thus preparing SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure.

[0010] Furthermore, step 1.2 is implemented as follows: Step 1.2.1: Cut polydimethylsiloxane (PDMS) of appropriate size and attach it to SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure surface.

[0011] Step 1.2.2: Place it in deionized water and wait 6-24 hours until the Sr3Al2O6 sacrificial layer is completely dissolved, then SrTiO3 / BaZr 0.2 Ti 0.8 O3 / SrTiO3 heterostructures were detached from the SrTiO3 single-crystal substrate to prepare self-supporting single-crystal oxide films.

[0012] Furthermore, step 1.3 is implemented as follows: 1.3.1 Weigh an appropriate amount of PEI granules and place them in a glass bottle. Add N,N-dimethylformamide solution and heat and stir at 50~70℃ for 4~8 hours to prepare a PEI solution of 0.1~0.4g / ml. 1.3.2 Place the PEI solution in a vacuum drying oven, degas under vacuum for 10-30 minutes, and then let it stand for 0.5-2 hours; 1.3.3. At a rotation speed of 700~2000 rpm, pour an appropriate amount of PEI solution and spin-coat it onto a silicon wafer for 10~30s. Then, dry it in an oven at 80~120℃ for 12~26 hours to obtain a PEI polymer film of 2~6 micrometers.

[0013] Furthermore, step 1.4 is implemented as follows: 1.4.1, Paraelectrically converting self-supporting SrTiO3 / BaZr 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film is attached to the surface of PEI polymer film, clamped with a fixture, and placed in a vacuum drying oven and kept at 200~300 degrees Celsius for 30~90 minutes. 1.4.2 After the holding time is reached, the sample is removed from the oven and cooled. After cooling to room temperature, the sample is removed from the fixture, and the PDMS film is peeled off to obtain SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / PEI / Si composite thin film.

[0014] Furthermore, step 1.5 is implemented as follows: 1.5.1 Peel off the PEI polymer film spin-coated onto the silicon wafer surface and attach it to the SrTiO3 / BaZr... 0.2 Ti 0.8 The surface of the O3 / SrTiO3 / PEI / Si composite film is clamped with a fixture and placed in a vacuum drying oven. It is kept at 200~300 degrees Celsius for 30~90 minutes to combine the upper PEI polymer film with the self-supporting single crystal oxide film. 1.5.2 After cooling to room temperature, PEI / SrTiO3 / BaZr 0.2 Ti 0.8 A composite film with an O3 / SrTiO3 / PEI / Si sandwich multilayer heterostructure was peeled off from a silicon wafer to obtain a rollable, flexible dielectric energy storage capacitor.

[0015] A method for fabricating a high-energy-density, rollable dielectric thin-film capacitor includes the following steps: Step 2.1: Epitaxial growth of well-crystallized La on a SrTiO3 single-crystal substrate using pulsed laser deposition technology. 0.7 Sr 0.3 A MnO3 sacrificial layer is formed on which an epitaxial multilayer heterostructure SrTiO3 / (Ba) is deposited. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 single crystal oxide thin film; Step 2.2, Dissolve La 0.7 Sr 0.3 MnO3 sacrificial layer, preparation of self-supporting SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 multilayer heterostructure film; Step 2.3: Prepare the PI solution and use spin coating to prepare a PI polymer film on a platinum-plated silicon wafer; Step 2.4: Use a hot pressing process to bond the self-supporting SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 Transfer of O3 / SrTiO3 multilayer heterostructure film onto PI polymer film; Step 2.5: Use a hot-pressing process to bond the upper PI polymer film with the self-supporting SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 A rollable capacitor was prepared by compositing O3 / SrTiO3 multilayer heterogeneous thin films.

[0016] Furthermore, step 2.1 is implemented as follows: Step 2.1.1: Epitaxially grow a 20 nm thick La on a 001 oriented SrTiO3 single crystal substrate using pulsed laser deposition technology. 0.7 Sr 0.3 The MnO3 sacrificial layer, wherein the pre-deposition cavity vacuum is 3×10⁻⁶. -4 The conditions for the SrTiO3 single crystal substrate were: temperature 600–700 °C, heating rate 20 °C / min, oxygen pressure 10 Pa, and laser energy density 1.2–1.8 J / cm². 2 The laser frequency was 5 Hz, the growth time was 5 min, and the target spacing between the SrTiO3 single crystal substrate and the Sr3Al2O6 ceramic target was 6 cm. La was then prepared. 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; Step 2.1.2: Using pulsed laser deposition technology on La 0.7 Sr 0.3 A 50 nm thick SrTiO3 epitaxial film was grown on a MnO3 / SrTiO3 heterostructure. The SrTiO3 single crystal substrate temperature was 650–700 °C, the heating rate was 20 °C / min, the oxygen pressure was 15 Pa, and the laser energy density was 1.5–2 J / cm². 2The laser frequency was 3 Hz, the growth time was 10 min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6 cm, thus preparing SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; Step 2.1.3: Apply pulsed laser deposition technology to SrTiO3 / La 0.7 Sr 0.3 A 50 nm thick layer of (Ba) was grown on a MnO3 / SrTiO3 heterostructure. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The SrTiO3 epitaxial thin film was prepared with a SrTiO3 single crystal substrate at a temperature of 750-800℃, a heating rate of 20℃ / min, an oxygen pressure of 25 Pa, and a laser energy density of 1.5-2 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the SrTiO3 single crystal substrate was mixed with (Ba) 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The target spacing of the O3 ceramic target was 6 cm, and (Ba) was prepared. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; Step 2.1.4: Using pulsed laser deposition technology on (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 A 50 nm thick SrTiO3 epitaxial film was grown on a MnO3 / SrTiO3 heterostructure. The SrTiO3 single crystal substrate temperature was 650–700 °C, the heating rate was 20 °C / min, the oxygen pressure was 15 Pa, and the laser energy density was 1.5–2 J / cm². 2 The laser frequency was 3 Hz, the growth time was 10 min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6 cm. SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3MnO3 / SrTiO3 heterostructure.

[0017] Furthermore, step 2.2 is implemented as follows: Step 2.2.1: Cut PDMS to an appropriate size and attach it to SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure surface; Step 2.2.2: Apply the attached SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 The MnO3 / SrTiO3 heterostructure was placed in a KI+HCl etching solution and left for 6-24 hours until La 0.7 Sr 0.3 After the MnO3 sacrificial layer completely dissolves, SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 A self-supporting single-crystal oxide thin film was prepared by detaching the MnO3 / SrTiO3 heterostructure from the SrTiO3 single-crystal substrate.

[0018] Furthermore, step 2.3 is implemented as follows: 2.3.1. Place an appropriate amount of PI solution in a vacuum drying oven, degas under vacuum for 10-30 minutes, and then let it stand for 0.5-2 hours. 2.3.2. At a speed of 1000~2500 rpm, pour an appropriate amount of PI solution and spin-coat it onto a silicon wafer for 10~30s. Then, dry it in an oven at 80~120℃ for 12~26 hours to obtain a PI film of 2~6 micrometers.

[0019] Furthermore, step 2.4 is implemented as follows: 2.4.1. Attach the self-supporting single-crystal oxide film to the surface of the PI polymer film, clamp it with a fixture, place it in a vacuum drying oven, and keep it at 250~350℃ for 30~90 minutes. 2.4.2 After the holding time is reached, the sample is removed from the oven and cooled. After cooling to room temperature, the sample is removed from the fixture, and the PDMS film is peeled off to obtain SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / PI / Si composite thin film.

[0020] Furthermore, step 2.5 is implemented as follows: 2.5.1 Peel off the PI polymer film spin-coated onto the silicon wafer surface and attach it to the SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The surface of the O3 / SrTiO3 / PI / Si composite film is clamped with a fixture and placed in a vacuum drying oven, and kept at 250~350 degrees Celsius for 30~90 minutes to composite the upper PI polymer film with the self-supporting single crystal oxide film. 2.5.2 After cooling to room temperature, PI / SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 A composite film with a sandwich-like multilayer heterostructure of O3 / SrTiO3 / PI / Si was peeled off from a silicon wafer to obtain a rollable, flexible dielectric energy storage capacitor.

[0021] Beneficial effects: The method of this invention employs a method of dissolving the sacrificial layer to prepare a self-supporting oxide multilayer heterostructure single-crystal thin film, which is then composited with a polymer using a hot-pressing process. This composite is further peeled off from a silicon wafer to prepare a flexible, rollable dielectric energy storage thin-film capacitor with multi-scale interfaces of organic / inorganic and inorganic / inorganic structures. The inorganic / inorganic interface of the introduced multilayer heterostructure self-supporting oxide single-crystal thin film can significantly improve the polarization intensity and breakdown field strength of the composite film. Furthermore, the depolarization field generated at the organic / inorganic interface can further enhance the breakdown field strength of the composite film, effectively improving the dielectric energy storage characteristics of the composite thin-film capacitor. This opens up new research avenues for developing high-energy-density, rollable dielectric energy storage thin-film capacitors.

[0022] The thin-film capacitor fabricated using this method combines the flexibility of polymer dielectric materials with the ultra-flexibility and ultra-elasticity of self-supporting single-crystal oxide thin films, exhibiting excellent mechanical flexibility to meet the demands of flexible and integrated applications. The introduced self-supporting single-crystal inorganic oxide thin film possesses a large dielectric constant and high polarization intensity, significantly improving the energy storage density of the dielectric energy storage thin-film capacitor. Furthermore, the depolarization field generated at the organic / inorganic and inorganic / inorganic interfaces after introducing the single-crystal inorganic oxide heterostructure also greatly enhances the polarization, breakdown strength, and energy storage density of the thin-film capacitor. Simultaneously, the dielectric energy storage thin-film capacitor fabricated using this method exhibits good temperature stability, making it suitable for applications requiring stable operation under high field strength and high temperature conditions. Experimental results demonstrate that this dielectric energy storage capacitor simultaneously possesses high breakdown strength, high energy storage density, good mechanical flexibility, and good temperature stability, making it promising for widespread application in next-generation electronic power systems, electric vehicles, and new energy power generation. This opens up new research avenues for developing high-energy-density, rollable dielectric energy storage thin-film capacitors. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the dielectric energy storage thin-film capacitor based on a sandwich multilayer heterostructure provided in an embodiment of this application, where 1 is a SrTiO3 single-crystal paraelectrooxide thin film, and 2 is a BaZr... 0.2 Ti 0.8 O3 or (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 single-crystal ferroelectric oxide thin film, 3 is Sr3Al2O6 or La 0.7 Sr 0.3 4 is a MnO3 sacrificial layer, 5 is a SrTiO3 single crystal substrate, and 6 is a PEI or PI dielectric polymer layer.

[0025] Figure 2 This is a photograph of a rollable dielectric energy storage film capacitor prepared according to Example 1 of this application, wherein 1 is a rollable film capacitor and 2 is a capillary used for support when the film capacitor is rolled.

[0026] Figure 3 The energy storage density of the dielectric energy storage film capacitor based on a sandwich multilayer heterostructure prepared in Example 1 of this application at 150°C. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0029] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing and simplifying the invention, and should not be construed as limiting the invention. Furthermore, the use of ordinal numbers (e.g., "first and second," etc.) is for distinguishing objects and is not limited to this order, and should not be construed as indicating or implying relative importance.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly, encompassing both direct connection and indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0031] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0033] This application provides a high-energy-density, rollable dielectric thin-film capacitor, comprising: a single-crystal ferroelectric oxide thin film layer, single-crystal paraelectric oxide thin films bonded to both sides of the single-crystal ferroelectric oxide thin film layer, and a dielectric polymer layer located outside the two single-crystal paraelectric oxide thin films, wherein the single-crystal paraelectric oxide thin film is SrTiO3, and the single-crystal ferroelectric oxide thin film is BaZr. 0.2 Ti 0.8 O3 or (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3, the dielectric polymer layer is PEI or PI. Physical products are as follows: Figure 2 .

[0034] like Figure 1 This application also provides a method for fabricating a high-energy-density, rollable dielectric thin-film capacitor, which includes the following steps: Step 1.1: Growing an epitaxial, well-crystallized Sr3Al2O6 sacrificial layer on a SrTiO3 single-crystal substrate using pulsed laser deposition technology, and depositing epitaxial multilayer heterostructures of SrTiO3 paraelectric / BaZr with different thickness ratios on the sacrificial layer. 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric single-crystal oxide thin film; Steps 1 and 2: Dissolve the Sr3Al2O6 sacrificial layer to prepare self-supporting SrTiO3 paraelectric / BaZr 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film; Step 1.3: Prepare polyetherimide (PEI) solution and prepare PEI polymer film on platinum-plated silicon wafer using spin coating process; Step 1.4: Apply self-supporting SrTiO3 paraelectric / BaZr... 0.2 Ti 0.8 Step 1.5: Transfer the O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film onto the PEI polymer film using a hot-pressing process. 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure composite film was used to prepare a rollable capacitor.

[0035] Optionally, step 1.1 is implemented as follows: Step 1.1.1, a 40 nm thick Sr3Al2O6 sacrificial layer is epitaxially grown on a (001) oriented SrTiO3 single crystal substrate using pulsed laser deposition technology. The cavity vacuum degree before deposition is 3 × 10⁻⁶. -4 The conditions were: SrTiO3 single crystal substrate temperature 770℃, heating rate 20℃ / min, oxygen pressure 20Pa, and laser energy density 2.2J / cm².2 The laser frequency was 5 Hz, the growth time was 5 min, and the target spacing between the SrTiO3 single crystal substrate and the Sr3Al2O6 ceramic target was 6 cm, thus preparing an Sr3Al2O6 / SrTiO3 heterostructure. Step 1.1.2: A 50 nm thick SrTiO3 epitaxial film was grown on the Sr3Al2O6 / SrTiO3 heterostructure using pulsed laser deposition. The SrTiO3 single crystal substrate temperature was 700 °C, the heating rate was 20 °C / min, the oxygen pressure was 15 Pa, and the laser energy density was 1.6 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6cm, thus preparing a SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure. Step 1.1.3: A 50nm thick BaZr layer was grown on the SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure using pulsed laser deposition. 0.2 Ti 0.8 O3 epitaxial thin film. The SrTiO3 single crystal substrate temperature was 800℃, the heating rate was 20℃ / min, the oxygen pressure was 20 Pa, and the laser energy density was 1.8 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the SrTiO3 single crystal substrate was mixed with BaZr. 0.2 Ti 0.8 With an O3 ceramic target spacing of 6 cm, BaZr was prepared. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure; Step 1.1.4: Pulsed laser deposition technology is used to deposit BaZr... 0.2 Ti 0.8 A 50 nm thick SrTiO3 epitaxial film was grown on an O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure. The SrTiO3 single-crystal substrate was grown at a temperature of 700 °C, a heating rate of 20 °C / min, an oxygen pressure of 15 Pa, and a laser energy density of 1.6 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6cm, thus preparing SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure.

[0036] Optionally, step 1.2 is implemented as follows: Step 1.2.1, cutting polydimethylsiloxane (PDMS) of appropriate size and attaching it to SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure surface; Step 1.2.2: Place it in deionized water and wait 6~24 hours until the Sr3Al2O6 sacrificial layer is completely dissolved, then the SrTiO3 / BaZr 0.2 Ti 0.8 A self-supporting single-crystal oxide thin film was prepared by detaching the O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure from the SrTiO3 single-crystal substrate.

[0037] Optionally, step 1.3 is implemented as follows: 1.3.1 Weigh an appropriate amount of PEI particles and place them in a glass bottle. Add N,N-dimethylformamide (DMF) solution and heat and stir at 50~70℃ for 4~8 hours to prepare a PEI solution of 0.1~0.4g / ml; 1.3.2 Place the PEI solution in a vacuum drying oven and degas under vacuum for 10~30 minutes, then let it stand for 0.5~2 hours; 1.3.3 At a speed of 700~2000 rpm, pour an appropriate amount of PEI solution and spin-coat it onto a silicon wafer (Si) for 10~30s. Dry it in an oven at 80~120℃ for 12~26 hours to obtain a PEI polymer film of 2~6 micrometers.

[0038] Optionally, step 1.4 is implemented as follows: 1.4.1. The self-supporting single-crystal oxide film is attached to the PEI surface, clamped with a fixture, and placed in a vacuum drying oven at 200-300 degrees Celsius for 30-90 minutes; 1.4.2. After the holding time is reached, the sample is removed from the oven and cooled. After cooling to room temperature, the sample is removed from the fixture, and the PDMS film is peeled off to obtain SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / PEI / Si composite thin film.

[0039] Optionally, step 1.5 is implemented as follows: 1.5.1, peel off the PEI polymer film spin-coated onto the silicon wafer surface and attach it to the SrTiO3 / BaZr... 0.2 Ti 0.8The surface of the O3 / SrTiO3 / PEI / Si composite film is clamped with a fixture and placed in a vacuum drying oven at 200~300 degrees Celsius for 30~90 minutes to composite the upper PEI polymer film with the self-supporting single crystal oxide film; 1.5.2, after cooling to room temperature, the PEI / SrTiO3 / BaZr... 0.2 Ti 0.8 A composite film with an O3 / SrTiO3 / PEI / Si sandwich multilayer heterostructure was peeled off from a silicon wafer to obtain a rollable, flexible dielectric energy storage capacitor.

[0040] This application embodiment also provides another method for fabricating a high-energy-density, rollable dielectric energy storage thin-film capacitor, the method comprising the following steps: Step 2.1, growing epitaxially crystalline La on a SrTiO3 single-crystal substrate using pulsed laser deposition technology. 0.7 Sr 0.3 A MnO3 sacrificial layer is formed on which an epitaxial multilayer heterostructure SrTiO3 / (Ba) is deposited. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 single crystal oxide thin film; Step 2.2, dissolving La 0.7 Sr 0.3 MnO3 sacrificial layer, preparation of self-supporting SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 Step 2.3: Prepare a polyimide (PI) solution and spin-coate a PI polymer film onto a platinum-plated silicon wafer; Step 2.4: Apply a hot-pressing process to the self-supporting SrTiO3 / (BaO3 / SrTiO3) multilayer heterostructure film. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 Step 2.5: Transfer the upper PI polymer film onto the PI polymer film using a hot-pressing process. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 A rollable capacitor was prepared by compositing O3 / SrTiO3 multilayer heterogeneous thin films.

[0041] Optionally, step 2.1 is implemented as follows: Step 2.1.1, using pulsed laser deposition technology, a 20nm thick La layer is epitaxially grown on a (001) oriented SrTiO3 single crystal substrate. 0.7 Sr0.3 MnO3 sacrificial layer, in which the pre-deposition cavity vacuum is 3×10 -4 The conditions were: SrTiO3 single crystal substrate temperature 700℃, heating rate 20℃ / min, oxygen pressure 10 Pa, and laser energy density 1.5 J / cm². 2 The laser frequency was 5 Hz, the growth time was 5 min, and the target spacing between the SrTiO3 single crystal substrate and the Sr3Al2O6 ceramic target was 6 cm. La was then prepared. 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; Step 2.1.2, using pulsed laser deposition technology on La 0.7 Sr 0.3 A 50 nm thick SrTiO3 epitaxial film was grown on a MnO3 / SrTiO3 heterostructure. The SrTiO3 single-crystal substrate was grown at a temperature of 700 °C, a heating rate of 20 °C / min, an oxygen pressure of 15 Pa, and a laser energy density of 1.6 J / cm². 2 The laser frequency was 3 Hz, the growth time was 10 min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6 cm, thus preparing SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; Step 2.1.3: MnO3 / SrTiO3 heterostructure is deposited using pulsed laser deposition technology. 0.7 Sr 0.3 A 50 nm thick layer of (Ba) was grown on a MnO3 / SrTiO3 heterostructure. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 SrTiO3 epitaxial thin film. The SrTiO3 single crystal substrate temperature was 800℃, the heating rate was 20℃ / min, the oxygen pressure was 25 Pa, and the laser energy density was 1.6 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the SrTiO3 single crystal substrate was mixed with (Ba) 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The target spacing of the O3 ceramic target was 6 cm, and (Ba) was prepared. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; Step 2.1.4: Using pulsed laser deposition technology on (Ba 0.85 Ca 0.15 (Zr) 0.10Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 A 50 nm thick SrTiO3 epitaxial film was grown on a MnO3 / SrTiO3 heterostructure. The SrTiO3 single-crystal substrate was grown at a temperature of 700 °C, a heating rate of 20 °C / min, an oxygen pressure of 15 Pa, and a laser energy density of 1.6 J / cm². 2 The laser frequency was 3 Hz, the growth time was 10 min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6 cm. SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure.

[0042] Optionally, step 2.2 is implemented as follows: Step 2.2.1, cut PDMS of appropriate size and attach it to SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure surface; Step 2.2.2: Immerse it in KI+HCl etching solution and wait 6~24 hours until La 0.7 Sr 0.3 After the MnO3 sacrificial layer completely dissolves, SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 A self-supporting single-crystal oxide thin film was prepared by detaching the MnO3 / SrTiO3 heterostructure from the SrTiO3 single-crystal substrate.

[0043] Optionally, step 2.3 is implemented as follows: 2.3.1. Take an appropriate amount of PI solution and place it in a vacuum drying oven. After vacuum degassing for 10-30 minutes, let it stand for 0.5-2 hours; 2.3.2. At a speed of 1000-2500 rpm, pour an appropriate amount of PI solution and spin-coat it onto a silicon wafer (Si) for 10-30 seconds. Then, dry it in an oven at 80-120°C for 12-26 hours to obtain a PI / Si film of 2-6 micrometers.

[0044] Optionally, step 2.4 is implemented as follows: 2.4.1. The self-supporting single-crystal oxide film is attached to the PI surface, clamped with a fixture, and placed in a vacuum drying oven at 250~350 degrees Celsius for 30~90 minutes; 2.4.2. After the holding time is reached, the sample is removed from the oven and cooled. After cooling to room temperature, the sample is removed from the fixture, and the PDMS film is peeled off to obtain SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / PI / Si composite thin film.

[0045] Optionally, step 2.5 is implemented as follows: 2.5.1, peel off the PI polymer film spin-coated on the silicon wafer surface and attach it to the SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The surface of the O3 / SrTiO3 / PI / Si composite film is clamped with a fixture and placed in a vacuum drying oven at 250~350 degrees Celsius for 30~90 minutes to composite the upper PI polymer film with the self-supporting single crystal oxide film; 2.5.2, after cooling to room temperature, the PI / SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 A composite film with a sandwich-like multilayer heterostructure of O3 / SrTiO3 / PI / Si was peeled off from a silicon wafer to obtain a rollable, flexible dielectric energy storage capacitor.

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and not for limitation.

[0047] Example 1 This application provides a method for fabricating a high-energy-density, rollable dielectric thin-film capacitor, the method comprising the following steps: Step 101: Growth of epitaxial, highly crystalline single-crystal oxide thin films using pulsed laser deposition: A 40 nm thick Sr3Al2O6 sacrificial layer is epitaxially grown on a (001) oriented SrTiO3 single-crystal substrate using pulsed laser deposition, wherein the cavity vacuum degree before deposition is 3 × 10⁻⁶. -4 The conditions were: SrTiO3 single crystal substrate temperature 770℃, heating rate 20℃ / min, oxygen pressure 20Pa, and laser energy density 2.2J / cm². 2A Sr3Al2O6 / SrTiO3 heterostructure was prepared by using a laser with a frequency of 5 Hz, a growth time of 5 min, and a target spacing of 6 cm between the SrTiO3 single crystal substrate and the Sr3Al2O6 ceramic target. A 50 nm thick SrTiO3 epitaxial film was then grown on the Sr3Al2O6 / SrTiO3 heterostructure using pulsed laser deposition (PLD). The SrTiO3 single crystal substrate temperature was 700 °C, the heating rate was 20 °C / min, the oxygen pressure was 15 Pa, and the laser energy density was 1.6 J / cm². 2 A SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure was prepared by using a laser frequency of 3Hz, a growth time of 10min, and a target spacing of 6cm between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target. A 50nm thick BaZr ablation layer was then grown on the SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure using pulsed laser deposition. 0.2 Ti 0.8 O3 epitaxial thin film, wherein the SrTiO3 single crystal substrate temperature is 800℃, the heating rate is 20℃ / min, the oxygen pressure is 20Pa, and the laser energy density is 1.8J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the SrTiO3 single crystal substrate was mixed with BaZr. 0.2 Ti 0.8 With an O3 ceramic target spacing of 6 cm, BaZr was prepared. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure; BaZr was deposited using pulsed laser deposition technology. 0.2 Ti 0.8 A 50 nm thick SrTiO3 epitaxial film was grown on an O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure. The SrTiO3 single crystal substrate was grown at a temperature of 700 °C, a heating rate of 20 °C / min, an oxygen pressure of 15 Pa, and a laser energy density of 1.6 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6cm, thus preparing SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure.

[0048] Step 102: Dissolve the Sr3Al2O6 sacrificial layer to prepare self-supporting SrTiO3 paraelectric / BaZr 0.2 Ti 0.8O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film: A PDMS support layer of appropriate size is cut and attached to SrTiO3 / BaZr 0.2 Ti 0.8 The surface of the SrTiO3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure was placed in deionized water and left for 24 hours until the Sr3Al2O6 sacrificial layer was completely dissolved. 0.2 Ti 0.8 A self-supporting single-crystal oxide thin film was prepared by detaching the O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure from the SrTiO3 single-crystal substrate.

[0049] Step 103: Prepare polyetherimide (PEI) solution and prepare PEI polymer film on platinum-plated silicon wafer using spin coating: Weigh an appropriate amount of PEI particles into a glass bottle, add N,N-dimethylformamide (DMF) solution, heat and stir at 50~70℃ for 6 hours to prepare a 0.2 g / ml PEI solution; Place the PEI solution in a vacuum drying oven, vacuum degas for 30 minutes, and let it stand for 2 hours; At a speed of 1500 rpm, pour an appropriate amount of PEI solution and spin coat it onto the silicon wafer for 12 seconds using spin coating, then dry it in an oven at 80℃ for 12 hours to obtain a 2-micron PEI polymer film.

[0050] Step 104: Use a hot-pressing process to bond the self-supporting SrTiO3 paraelectric / BaZr 0.2 Ti 0.8 Transfer of O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film onto PEI polymer film: A self-supporting single-crystal oxide film was attached to the PEI surface, clamped with a fixture, and placed in a vacuum drying oven at 230℃ for 30 minutes; after the holding time was reached, the sample was removed from the oven and cooled to room temperature. The sample was then removed from the fixture, and the PDMS film was peeled off to obtain SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / PEI / Si composite thin film.

[0051] Step 105: Use a hot-pressing process to bond the upper PEI polymer film with the self-supporting SrTiO3 paraelectric / BaZr... 0.2 Ti 0.8 Fabrication of a rollable capacitor using a multilayer heterogeneous composite of O3 ferroelectric and SrTiO3 paraelectric thin films: A PEI polymer film spin-coated onto a silicon wafer is peeled off and attached to an SrTiO3 / BaZr... 0.2 Ti 0.8The surface of the O3 / SrTiO3 / PEI / Si composite film was clamped with a fixture and placed in a vacuum drying oven at 230℃ for 30 minutes to composite the upper PEI polymer film with the self-supporting single-crystal oxide film. After cooling to room temperature, the PEI / SrTiO3 / BaZr composite film was then laminated. 0.2 Ti 0.8 A composite film with an O3 / SrTiO3 / PEI / Si sandwich multilayer heterostructure was peeled off from a silicon wafer to obtain a rollable, flexible dielectric energy storage film capacitor. The energy storage density of the prepared dielectric energy storage film capacitor at 150℃ is as follows: Figure 3 As shown, at 635 MV·m -1 7.18 J·cm can be achieved under an electric field. -3 Energy storage density.

[0052] Example 2 This application also provides another method for fabricating a high-energy-density, rollable dielectric energy storage film capacitor, the method comprising the following steps: Step 201: Deposit an epitaxial multilayer heterostructure SrTiO3 / (Ba) using pulsed laser deposition technology. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 LaO3 / SrTiO3 single crystal oxide thin film: A 20 nm thick LaO3 / SrTiO3 single crystal thin film was epitaxially grown on a 001 oriented SrTiO3 single crystal substrate using pulsed laser deposition technology. 0.7 Sr 0.3 MnO3 sacrificial layer, in which the pre-deposition cavity vacuum is 3×10 -4 The conditions were: SrTiO3 single crystal substrate temperature 700℃, heating rate 20℃ / min, oxygen pressure 10 Pa, and laser energy density 1.5 J / cm². 2 The laser frequency was 5 Hz, the growth time was 5 min, and the target spacing between the SrTiO3 single crystal substrate and the Sr3Al2O6 ceramic target was 6 cm. La was then prepared. 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; La was deposited using pulsed laser deposition technology. 0.7 Sr 0.3 A 50 nm thick SrTiO3 epitaxial film was grown on a MnO3 / SrTiO3 heterostructure. The SrTiO3 single crystal substrate was grown at a temperature of 700 °C, a heating rate of 20 °C / min, an oxygen pressure of 15 Pa, and a laser energy density of 1.6 J / cm². 2 The laser frequency was 3 Hz, the growth time was 10 min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6 cm, thus preparing SrTiO3 / La 0.7 Sr0.3 MnO3 / SrTiO3 heterostructure; pulsed laser deposition technique was used to deposit MnO3 / La... 0.7 Sr 0.3 A 50 nm thick layer of (Ba) was grown on a MnO3 / SrTiO3 heterostructure. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The SrTiO3 epitaxial thin film was prepared with a SrTiO3 single crystal substrate at a temperature of 800℃, a heating rate of 20℃ / min, an oxygen pressure of 25Pa, and a laser energy density of 1.6J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the SrTiO3 single crystal substrate was mixed with (Ba) 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The target spacing of the O3 ceramic target was 6 cm, and (Ba) was prepared. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; pulsed laser deposition technique was used to deposit (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 A 50 nm thick SrTiO3 epitaxial film was grown on a MnO3 / SrTiO3 heterostructure. The SrTiO3 single crystal substrate was grown at a temperature of 700 °C, a heating rate of 20 °C / min, an oxygen pressure of 15 Pa, and a laser energy density of 1.6 J / cm². 2 The laser frequency was 3 Hz, the growth time was 10 min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6 cm. SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure.

[0053] Step 202, Dissolve La 0.7 Sr 0.3 Self-supporting SrTiO3 / (Ba) was prepared using a MnO3 sacrificial layer. 0.85 Ca 0.15 (Zr)0.10 Ti 0.90 SrTiO3 / SrTiO3 multilayer heterostructure film: PDMS of appropriate size is cut and attached to SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure surface; immerse it in KI+HCl etching solution and wait 24 hours until La 0.7 Sr 0.3 After the MnO3 sacrificial layer completely dissolves, SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 A self-supporting single-crystal oxide thin film was prepared by detaching the MnO3 / SrTiO3 heterostructure from the SrTiO3 single-crystal substrate.

[0054] Step 203: Prepare a polyimide (PI) solution and prepare a PI polymer film on a platinum-plated silicon wafer using a spin-coating process: Place an appropriate amount of PI solution in a vacuum drying oven, remove bubbles under vacuum for 30 minutes, and let it stand for 2 hours; at a speed of 2000 rpm, pour an appropriate amount of PI solution and spin-coat it on the silicon wafer for 15 seconds, then dry it in an oven at 120°C for 18 hours to obtain a 3-micron PI polymer film.

[0055] Step 204: Use a hot pressing process to bond the self-supporting SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 Transfer of SrTiO3 / SrTiO3 multilayer heterostructure film onto PI polymer film: A self-supporting single-crystal oxide film was attached to the PI surface, clamped with a fixture, and placed in a vacuum drying oven at 280℃ for 45 minutes; after the holding time was reached, the sample was removed from the oven and cooled to room temperature. The sample was then removed from the fixture, and the PDMS film was peeled off to obtain SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / PI / Si composite thin film.

[0056] Step 205: Use a hot-pressing process to bond the upper PI polymer film with the self-supporting SrTiO3 / (Ba 0.85 Ca 0.15(Zr) 0.10 Ti 0.90 Fabrication of a rollable capacitor using SrTiO3 / SrTiO3 multilayer heterogeneous thin film composite: The PI polymer film spin-coated onto the surface of a silicon wafer is peeled off and attached to a SrTiO3 / (Ba) composite. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The surface of the PI / SrTiO3 / PI / Si composite film was clamped with a fixture and placed in a vacuum drying oven at 280℃ for 45 minutes to composite the upper PI polymer film with the self-supporting single-crystal oxide film. After cooling to room temperature, the PI / SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 A composite film with a sandwich-like multilayer heterostructure of O3 / SrTiO3 / PI / Si was peeled off from a silicon wafer to obtain a rollable, flexible dielectric energy storage capacitor.

[0057] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-energy-density, rollable dielectric thin-film capacitor, characterized in that, include: A single-crystal ferroelectric oxide thin film layer, a single-crystal paraelectric oxide thin film epitaxially grown on both sides of the single-crystal ferroelectric oxide thin film layer, and a dielectric polymer layer located outside the two single-crystal paraelectric oxide thin films, wherein the single-crystal paraelectric oxide thin film is SrTiO3 and the single-crystal ferroelectric oxide thin film is BaZr. 0.2 Ti 0.8 O3 or (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3, the dielectric polymer layer is polyetherimide (PEI) or polyimide (PI).

2. A method for preparing a high-energy-density, rollable dielectric thin-film capacitor, characterized in that, Includes the following steps: Step 1.1: Using pulsed laser deposition technology, grow an epitaxial, highly crystalline Sr3Al2O6 sacrificial layer on a SrTiO3 single-crystal substrate. Then, deposit epitaxial multilayer heterostructures of SrTiO3 paraelectric / BaZr with varying thickness ratios on the sacrificial layer. 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric single crystal oxide thin film; Step 1.2: Dissolve the Sr3Al2O6 sacrificial layer to prepare self-supporting SrTiO3 paraelectric / BaZr 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film; Step 1.3: Prepare a polyetherimide solution and use a spin-coating process to prepare a PEI polymer film on a platinum-plated silicon wafer; Step 1.4: Use a hot-pressing process to bond self-supporting SrTiO3 paraelectric / BaZr 0.2 Ti 0.8 Transfer of O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film onto PEI polymer film; Step 1.5: Use a hot-pressing process to bond the upper PEI polymer film with the self-supporting SrTiO3 paraelectric / BaZr... 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure composite film was used to prepare a rollable film capacitor.

3. The method for preparing a high-energy-density, rollable dielectric energy storage film capacitor according to claim 2, characterized in that, Step 1.1 is implemented as follows: Step 1.1.1: An epitaxial layer of 40 nm thick Sr3Al2O6 is grown on a 001 oriented SrTiO3 single crystal substrate using pulsed laser deposition technology. The cavity vacuum degree before deposition is 3 × 10⁻⁶. -4 Below Pa, the temperature of the SrTiO3 single crystal substrate is 750~770℃, the heating rate is 20℃ / min, the oxygen pressure is 20Pa, and the laser energy density is 1.8~2.3J / cm². 2 The laser frequency was 5 Hz, the growth time was 5 min, and the target spacing between the SrTiO3 single crystal substrate and the Sr3Al2O6 ceramic target was 6 cm, thus preparing the Sr3Al2O6 / SrTiO3 heterostructure. Step 1.1.2: A 50 nm thick SrTiO3 epitaxial film is grown on a Sr3Al2O6 / SrTiO3 heterostructure using pulsed laser deposition technology. The SrTiO3 single crystal substrate temperature is 650~700℃, the heating rate is 20℃ / min, the oxygen pressure is 15 Pa, and the laser energy density is 1.5~2 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6cm, thus preparing a SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure. Step 1.1.3: A 50 nm thick BaZr layer is grown on the SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure using pulsed laser deposition technology. 0.2 Ti 0.8 O3 epitaxial thin film, wherein the SrTiO3 single crystal substrate temperature is 750~800℃, the heating rate is 20℃ / min, the oxygen pressure is 20Pa, and the laser energy density is 1.5~2J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the SrTiO3 single crystal substrate was mixed with BaZr. 0.2 Ti 0.8 With an O3 ceramic target spacing of 6 cm, BaZr was prepared. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure; Step 1.1.4: Apply pulsed laser deposition technology to BaZr. 0.2 Ti 0.8 A 50 nm thick SrTiO3 epitaxial film was grown on an O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure. The SrTiO3 single crystal substrate temperature was 650–700 °C, the heating rate was 20 °C / min, the oxygen pressure was 15 Pa, and the laser energy density was 1.5–2 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6cm, thus preparing SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure.

4. The method for preparing a high-energy-density, rollable dielectric energy storage film capacitor according to claim 2, characterized in that, Step 1.2 is implemented as follows: Step 1.2.1: Cut polydimethylsiloxane (PDMS) of appropriate size and attach it to SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / Sr3Al2O6 / SrTiO3 heterostructure surface; Step 1.2.2: Place it in deionized water and wait 6-24 hours until the Sr3Al2O6 sacrificial layer is completely dissolved, then SrTiO3 / BaZr 0.2 Ti 0.8 O3 / SrTiO3 heterostructures were detached from the SrTiO3 single-crystal substrate to prepare self-supporting single-crystal oxide films.

5. The method for preparing a high energy density rollable dielectric energy storage film capacitor according to claim 2, characterized in that, Step 1.3 is implemented as follows: 1.3.1 Weigh an appropriate amount of PEI granules and place them in a glass bottle. Add N,N-dimethylformamide solution and heat and stir at 50~70℃ for 4~8 hours to prepare a PEI solution of 0.1~0.4g / ml. 1.3.2 Place the PEI solution in a vacuum drying oven, degas under vacuum for 10-30 minutes, and then let it stand for 0.5-2 hours; 1.3.

3. At a rotation speed of 700~2000 rpm, pour an appropriate amount of PEI solution and spin-coat it onto a silicon wafer for 10~30s. Then, dry it in an oven at 80~120℃ for 12~26 hours to obtain a PEI polymer film of 2~6 micrometers.

6. The method for preparing a high energy density rollable dielectric energy storage film capacitor according to claim 2, characterized in that, Step 1.4 is implemented as follows: 1.4.1, Paraelectrically converting self-supporting SrTiO3 / BaZr 0.2 Ti 0.8 O3 ferroelectric / SrTiO3 paraelectric multilayer heterostructure film is attached to the PEI surface, clamped with a fixture, and placed in a vacuum drying oven and kept at 200~300 degrees Celsius for 30~90 minutes; 1.4.2 After the holding time is reached, the sample is removed from the oven and cooled. After cooling to room temperature, the sample is removed from the fixture, and the PDMS film is peeled off to obtain SrTiO3 / BaZr. 0.2 Ti 0.8 O3 / SrTiO3 / PEI / Si composite thin film.

7. The method for preparing a high energy density rollable dielectric energy storage film capacitor according to claim 2, characterized in that, Step 1.5 is implemented as follows: 1.5.1 Peel off the PEI polymer film spin-coated onto the silicon wafer surface and attach it to the SrTiO3 / BaZr... 0.2 Ti 0.8 The surface of the O3 / SrTiO3 / PEI / Si composite film is clamped with a fixture and placed in a vacuum drying oven. It is kept at 200~300 degrees Celsius for 30~90 minutes to combine the upper PEI polymer film with the self-supporting single crystal oxide film. 1.5.2 After cooling to room temperature, PEI / SrTiO3 / BaZr 0.2 Ti 0.8 A composite film with an O3 / SrTiO3 / PEI / Si sandwich multilayer heterostructure was peeled off from a silicon wafer to obtain a rollable, flexible dielectric energy storage capacitor.

8. A method for preparing a high-energy-density, rollable dielectric thin-film capacitor, characterized in that, Includes the following steps: Step 2.1: Epitaxial growth of well-crystallized La on a SrTiO3 single-crystal substrate using pulsed laser deposition technology. 0.7 Sr 0.3 A MnO3 sacrificial layer is formed on which an epitaxial multilayer heterostructure SrTiO3 / (Ba) is deposited. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 single crystal oxide thin film; Step 2.2, Dissolve La 0.7 Sr 0.3 MnO3 sacrificial layer, preparation of self-supporting SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 multilayer heterostructure film; Step 2.3: Prepare the PI solution and use spin coating to prepare a PI polymer film on a platinum-plated silicon wafer; Step 2.4: Use a hot pressing process to bond the self-supporting SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 Transfer of O3 / SrTiO3 multilayer heterostructure film onto PI polymer film; Step 2.5: Use a hot-pressing process to bond the upper PI polymer film with the self-supporting SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 A rollable capacitor was prepared by compositing O3 / SrTiO3 multilayer heterogeneous thin films.

9. The method for preparing a high energy density rollable dielectric energy storage film capacitor according to claim 8, characterized in that, Step 2.1 is implemented as follows: Step 2.1.1: Epitaxially grow a 20 nm thick La on a 001 oriented SrTiO3 single crystal substrate using pulsed laser deposition technology. 0.7 Sr 0.3 The MnO3 sacrificial layer, wherein the pre-deposition cavity vacuum is 3×10⁻⁶. -4 The conditions for the SrTiO3 single crystal substrate were: temperature 600–700 °C, heating rate 20 °C / min, oxygen pressure 10 Pa, and laser energy density 1.2–1.8 J / cm². 2 The laser frequency was 5 Hz, the growth time was 5 min, and the target spacing between the SrTiO3 single crystal substrate and the Sr3Al2O6 ceramic target was 6 cm. La was then prepared. 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; Step 2.1.2: Using pulsed laser deposition technology on La 0.7 Sr 0.3 A 50 nm thick SrTiO3 epitaxial film was grown on a MnO3 / SrTiO3 heterostructure. The SrTiO3 single crystal substrate temperature was 650–700 °C, the heating rate was 20 °C / min, the oxygen pressure was 15 Pa, and the laser energy density was 1.5–2 J / cm². 2 The laser frequency was 3 Hz, the growth time was 10 min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6 cm, thus preparing SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; Step 2.1.3: Apply pulsed laser deposition technology to SrTiO3 / La 0.7 Sr 0.3 A 50 nm thick layer of (Ba) was grown on a MnO3 / SrTiO3 heterostructure. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The SrTiO3 epitaxial thin film was prepared with a SrTiO3 single crystal substrate at a temperature of 750-800℃, a heating rate of 20℃ / min, an oxygen pressure of 25 Pa, and a laser energy density of 1.5-2 J / cm². 2 The laser frequency was 3Hz, the growth time was 10min, and the SrTiO3 single crystal substrate was mixed with (Ba) 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The target spacing of the O3 ceramic target was 6 cm, and (Ba) was prepared. 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure; Step 2.1.4: Using pulsed laser deposition technology on (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 A 50 nm thick SrTiO3 epitaxial film was grown on a MnO3 / SrTiO3 heterostructure. The SrTiO3 single crystal substrate temperature was 650–700 °C, the heating rate was 20 °C / min, the oxygen pressure was 15 Pa, and the laser energy density was 1.5–2 J / cm². 2 The laser frequency was 3 Hz, the growth time was 10 min, and the target spacing between the SrTiO3 single crystal substrate and the SrTiO3 ceramic target was 6 cm. SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure.

10. The method for preparing a high energy density rollable dielectric energy storage film capacitor according to claim 8, characterized in that, Step 2.2 is implemented as follows: Step 2.2.1: Cut PDMS to an appropriate size and attach it to SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 MnO3 / SrTiO3 heterostructure surface; Step 2.2.2: Apply the attached SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 The MnO3 / SrTiO3 heterostructure was placed in a KI+HCl etching solution and left for 6-24 hours until La 0.7 Sr 0.3 After the MnO3 sacrificial layer completely dissolves, SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / La 0.7 Sr 0.3 A self-supporting single-crystal oxide thin film was prepared by detaching the MnO3 / SrTiO3 heterostructure from the SrTiO3 single-crystal substrate.

11. The method for preparing a high energy density rollable dielectric energy storage film capacitor according to claim 8, characterized in that, Step 2.3 is implemented as follows: 2.3.

1. Place an appropriate amount of PI solution in a vacuum drying oven, degas under vacuum for 10-30 minutes, and then let it stand for 0.5-2 hours. 2.3.

2. At a rotation speed of 1000~2500 rpm, pour an appropriate amount of PI solution and spin-coat it onto a silicon wafer for 10~30s. Then, dry it in an oven at 80~120℃ for 12~26 hours to obtain a PI / Si film of 2~6 micrometers.

12. The method for preparing a high energy density rollable dielectric energy storage film capacitor according to claim 8, characterized in that, Step 2.4 is implemented as follows: 2.4.

1. Attach the self-supporting single-crystal oxide film to the surface of the PI polymer film, clamp it with a fixture, place it in a vacuum drying oven, and keep it at 250~350 degrees Celsius for 30~90 minutes. 2.4.2 After the holding time is reached, the sample is removed from the oven and cooled. After cooling to room temperature, the sample is removed from the fixture, and the PDMS film is peeled off to obtain SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 O3 / SrTiO3 / PI / Si composite thin film.

13. The method for preparing a high energy density rollable dielectric energy storage film capacitor according to claim 8, characterized in that, Step 2.5 is implemented as follows: 2.5.1 Peel off the PI polymer film spin-coated onto the silicon wafer surface and attach it to the SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 The surface of the O3 / SrTiO3 / PI / Si composite film is clamped with a fixture and placed in a vacuum drying oven, and kept at 250~350 degrees Celsius for 30~90 minutes to composite the upper PI polymer film with the self-supporting single crystal oxide film. 2.5.2 After cooling to room temperature, PI / SrTiO3 / (Ba 0.85 Ca 0.15 (Zr) 0.10 Ti 0.90 A composite film with a sandwich-like multilayer heterostructure of O3 / SrTiO3 / PI / Si was peeled off from a silicon wafer to obtain a rollable, flexible dielectric energy storage capacitor.

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