Flexible barium zirconate photoelectric film and preparation method and application thereof

Abstract

The invention discloses a flexible barium zirconate photoelectric film and a preparation method and application thereof. The preparation method of the flexible barium zirconate photoelectric film comprises the following steps: preparing a water-soluble strontium aluminate sacrificial layer on a substrate; depositing barium zirconate on the water-soluble strontium aluminate sacrificial layer by adopting a sol-gel method or a radio frequency magnetron sputtering method to obtain a barium zirconate film grown on the sacrificial layer; and immersing the barium zirconate film grown on the sacrificial layer and the flexible substrate into water, and transferring the barium zirconate film to the flexible substrate after the sacrificial layer is dissolved to obtain the flexible barium zirconate photoelectric film. Water-soluble strontium aluminate is used as a sacrificial layer, the BZO film is prepared by a sol-gel method or a radio frequency magnetron sputtering method, and the obtained BZO film has good photoelectric properties, crystallinity and thermal stability and is suitable for being applied to high-performance photoelectric devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of photoelectric materials, and in particular relates to a flexible barium zirconate photoelectric film and a preparation method and application thereof. Background Art

[0002] Optoelectronic devices are playing an increasingly important role in modern communications, sensing, energy, and other fields. With the increasing demand for efficient and high-performance optoelectronic devices, the selection and preparation of optoelectronic materials are crucial for improving device performance. Barium zirconium oxide (BaZrO3, BZO), a material with a high dielectric constant, excellent thermal stability, and a strong electro-optical effect, is widely used in the optoelectronics field. In particular, BZO thin films have become a research hotspot due to their excellent electrical and optical properties and thermal stability in high-performance optoelectronic devices such as photodetectors, photodiodes, and solar cells.

[0003] In optoelectronic devices, the photoelectric conversion efficiency, response speed, and long-term stability of materials are crucial. The high dielectric constant of BZO thin films gives them a significant advantage in improving the electro-optical performance of devices. Their good thermal stability and high-temperature resistance enable them to maintain excellent performance even in high-frequency and high-power operating environments. These characteristics make BZO thin films have broad application prospects in high-performance optoelectronic devices. However, despite the excellent optoelectronic properties of BZO thin films, the lattice mismatch between the film and the substrate material still exists in actual preparation. In particular, during the epitaxial growth process on common substrates (such as SrTiO3), the quality and performance of BZO films are difficult to effectively guarantee.

[0004] Therefore, how to achieve the preparation of high-quality BZO films, especially solving the lattice mismatch problem while maintaining the high photoelectric conversion efficiency and thermal stability of the films, remains a challenge in the research and development of optoelectronic devices. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the purpose of the present invention is to provide a flexible barium zirconate photoelectric film and its preparation method and application, so as to solve the problem that the existing BZO film has lattice mismatch during the preparation process, resulting in a decrease in film quality.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions: In a first aspect, the present invention provides a method for preparing a flexible barium zirconate photoelectric film, comprising the following steps: (1) Preparing a water-soluble strontium aluminate sacrificial layer on a substrate; (2) depositing barium zirconate on a water-soluble strontium aluminate sacrificial layer by a sol-gel method or a radio frequency magnetron sputtering method to obtain a barium zirconate film grown on the sacrificial layer; (3) Immersing the product of step (2) and the flexible substrate in water, and after the sacrificial layer is dissolved, transferring the barium zirconate film onto the flexible substrate to obtain a flexible barium zirconate photoelectric film.

[0007] Preferably, in step (1), the water-soluble strontium aluminate sacrificial layer is prepared by a sol-gel method or a radio frequency magnetron sputtering method.

[0008] Preferably, in step (1), the substrate is a strontium titanate single crystal substrate with a (100) crystal orientation.

[0009] Preferably, in step (2), the sol-gel method includes the following steps: dissolving a barium source and a zirconium source in a solvent to obtain a barium zirconate precursor solution; coating the barium zirconate precursor solution on a water-soluble strontium aluminate sacrificial layer to obtain a barium zirconate film; and annealing the barium zirconate film to obtain a barium zirconate film grown on the sacrificial layer.

[0010] Preferably, the barium source is barium acetate, and the zirconium source is zirconium acetylacetonate; the molar ratio of the barium source to the zirconium source is 1:(1-2); and the concentration of the barium zirconate precursor solution is 0.6-0.8 mol / L.

[0011] Preferably, the annealing treatment conditions include: pre-annealing at 300-350° C. for 3-5 min, then heating to 750-1000° C. at a rate of 5-10° C. / min, and keeping the temperature for 1-2 h.

[0012] Preferably, in step (2), the radio frequency magnetron sputtering method includes the following steps: placing a water-soluble strontium aluminate sacrificial layer in a vacuum chamber of a magnetron sputtering apparatus, using barium zirconate as a target, introducing an inert gas, and sputtering barium zirconate; wherein the sputtering conditions are: substrate temperature of 200°C, sputtering power of 110W, sputtering pressure of 0.2Pa, and inert gas flow rate of 60SCCM; annealing the barium zirconate film after sputtering at 750-1000°C to obtain a barium zirconate film grown on the sacrificial layer.

[0013] Preferably, in step (3), the flexible substrate is one of flexible materials such as polyimide, PET / PEN, PDMS, polyurethane, etc.

[0014] In a second aspect, the present invention provides a flexible barium zirconate photoelectric film, which is prepared by the preparation method described in the first aspect.

[0015] In a third aspect, the present invention provides a flexible optoelectronic device comprising the flexible barium zirconate optoelectronic film described in the second aspect.

[0016] The beneficial effects of the present invention are: (1) The present invention uses water-soluble strontium aluminate as a sacrificial layer and adopts the sol-gel method or radio frequency magnetron sputtering method to prepare barium zirconate (BZO) thin films. The obtained BZO thin films have good optoelectronic properties, crystallinity and thermal stability, and are suitable for the application of high-performance optoelectronic devices. It overcomes the lattice mismatch problem existing in the preparation of BZO thin films by existing processes.

[0017] (2) The present invention uses water-soluble strontium aluminate (SAO) as a sacrificial layer. SAO not only alleviates the lattice mismatch but also facilitates the subsequent transfer of the BZO film. After the BZO film is deposited, the SAO sacrificial layer can be removed by a simple water dissolution process, thereby achieving lossless transfer of the BZO film from the hard substrate to the flexible substrate. This process is not only simple to operate and environmentally friendly, but also avoids the use of high-temperature annealing or toxic chemical solvents, greatly simplifying the film transfer process.

[0018] (3) The preparation method of the present invention is a sol-gel method or a magnetron sputtering method. This method is simple to operate, has a short preparation cycle, low raw material cost, low-cost equipment, and a simple preparation environment. Compared with the pulsed laser deposition method, the cost is greatly reduced. In addition, the preparation efficiency of the pulsed laser deposition method is limited and can only remain in the experimental stage. The preparation method of the present invention can be industrialized for large-scale production and has good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments are briefly introduced below.

[0020] Figure 1 This is a flow chart for preparing the flexible barium zirconate photoelectric film provided by the present invention.

[0021] Figure 2 is the XRD pattern of SAO prepared in Example 1-2.

[0022] Figure 3 It is the XRD pattern of BZO prepared in Example 1 and Examples 3-4.

[0023] Figure 4 This is the absorption spectrum of BZO prepared in Example 1.

[0024] Figure 5 is the Raman spectrum of BZO prepared in Example 1. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] An embodiment of the present invention provides a method for preparing a flexible barium zirconate photoelectric film, comprising the following steps: (1) A water-soluble strontium aluminate sacrificial layer is prepared on a substrate by a sol-gel method or a radio frequency magnetron sputtering method.

[0027] A water-soluble strontium aluminate (Sr3Al2O6) sacrificial layer was prepared by a sol-gel method: an aluminum source and a strontium source were dissolved in a solvent to obtain an SAO precursor solution; the SAO precursor solution was coated on a substrate to produce an SAO thin film; and the SAO thin film was annealed to obtain a SAO sacrificial layer grown on the substrate. The aluminum source was aluminum acetylacetonate, and the strontium source was strontium acetate. The molar ratio of the aluminum source to the strontium source was 2:3, and the concentration of the SAO precursor solution was 0.5-0.6 mol / L. Annealing conditions included a pre-annealing at 150-200°C for 3-5 minutes, followed by a pre-annealing at 200-250°C for 3-5 minutes to volatilize organic matter in the colloid and remove it from the film. Finally, the temperature was increased at a rate of 5-10°C / min to 800-850°C and held at that temperature for 1-2 hours. After proper annealing treatment, the crystal quality of the SAO film is optimized, ensuring that it can be removed smoothly during the subsequent film transfer process.

[0028] Preparation of water-soluble strontium aluminate Sr3Al2O6 (SAO) sacrificial layer by radio frequency magnetron sputtering: Place the substrate in the vacuum chamber of the magnetron sputtering instrument and evacuate to 10 -4 Pa, an inert gas is introduced, and a strontium aluminate sacrificial layer is sputtered on the substrate using strontium aluminate as a target; the sputtering conditions are: substrate temperature of 200°C, sputtering power of 110W, sputtering pressure of 0.2Pa, and inert gas flow rate of 60SCCM; the substrate after sputtering is annealed at 700-800°C to obtain a strontium aluminate thin film sacrificial layer grown on the substrate.

[0029] (2) Barium zirconate is deposited on a water-soluble strontium aluminate sacrificial layer by a sol-gel method or a radio frequency magnetron sputtering method to obtain a barium zirconate film grown on the sacrificial layer.

[0030] Barium zirconate (BZO) thin films are prepared by a sol-gel method: a barium source and a zirconium source are dissolved in a solvent to obtain a barium zirconate precursor solution. This barium zirconate precursor solution is then coated (by spin coating or dipping) onto a water-soluble sacrificial layer of strontium aluminate to produce a barium zirconate thin film. The barium zirconate thin film is then annealed to obtain a barium zirconate thin film grown on the sacrificial layer. The barium source is barium acetate, and the zirconium source is zirconium acetylacetonate. The molar ratio of the barium source to the zirconium source is 1:1-2, and the concentration of the barium zirconate precursor solution is 0.6-0.8 mol / L. Annealing conditions include a pre-annealing step at 300-350°C for 3-5 minutes, followed by a heating rate of 5-10°C / min to 750-1000°C and a holding time of 1 hour. The sol-gel method effectively controls the composition, thickness, and crystallinity of BZO thin films, making it suitable for optoelectronic devices requiring high-quality films.

[0031] Preparation of barium zirconate (BZO) thin film by radio frequency magnetron sputtering: a water-soluble strontium aluminate sacrificial layer was placed in the vacuum chamber of the magnetron sputtering instrument and evacuated to 10 -4 Pa, an inert gas is introduced, and a barium zirconate film is sputtered onto the sacrificial layer using barium zirconate as the target. The sputtering conditions are: substrate temperature of 300°C, sputtering power of 100W, sputtering pressure of 0.2Pa, and inert gas flow rate of 60 SCCM. The sputtered barium zirconate film is annealed at 750-1000°C to obtain a barium zirconate film grown on the sacrificial layer. The sputtering process is optimized to ensure uniformity and high quality of the BZO film. RF magnetron sputtering is suitable for large-area deposition and can produce high-quality BZO films at relatively low temperatures.

[0032] (3) The product of step (2) and the flexible substrate are placed in water. After the sacrificial layer is dissolved, the barium zirconate film is transferred to the flexible substrate to obtain a flexible barium zirconate photoelectric film. By dissolving the SAO sacrificial layer, the BZO film can be smoothly separated from the original substrate and transferred to the flexible substrate. The transferred BZO film still maintains its original excellent photoelectric properties and thermal stability, and is suitable for the application of flexible optoelectronic devices.

[0033] To make the purpose, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below. Unless otherwise specified, the various reagents and raw materials used in the present invention are commercially available products or products that can be prepared by known methods.

[0034] Example 1 A method for preparing a flexible barium zirconate photoelectric film comprises the following steps: S1. Preparation of a Water-Soluble Strontium Aluminate (Sr3Al2O6) Sacrificial Layer by Sol-Gel Method S1.1. Prepare the SAO precursor solution: Dissolve strontium acetate and aluminum acetylacetonate in a propionic acid aqueous solution (propionic acid:water ratio:9:1). Heat and stir at 80°C for 5 h, then age for 1 day to obtain the SAO precursor solution. The ratio of strontium acetate, aluminum acetylacetonate, propionic acid, and water is 0.6 g:0.6 g:9 mL:1 mL.

[0035] S1.2. Cleaning the substrate: Take a (100) strontium titanate single crystal substrate, first ultrasonically clean the substrate with acetone for 15 minutes, then ultrasonically clean it with alcohol for 10 minutes, and then ultrasonically clean it with deionized water for 10 minutes to remove impurities on the substrate, and finally blow it dry with nitrogen to obtain a clean substrate.

[0036] S1.3. Prepare a SAO thin film: Place the cleaned substrate obtained in S1.2 in the center of a spin coater. Spin coat the SAO precursor solution obtained in S1.1 onto the cleaned substrate at 6000 rpm / min. Perform a pre-annealing step after each thin film coating. Repeat the spin coating and pre-annealing steps five times. Pre-annealing conditions are: first, hold at 150°C for 5 minutes, then hold at 230°C for 5 minutes to volatilize the organic matter in the colloid and remove it from the film. After spin coating and pre-annealing, increase the temperature to 800°C at a rate of 5°C / min and hold for 1 hour to form a uniform SAO thin film on the substrate.

[0037] S2. Preparation of Barium Zirconate (BZO) Thin Films by Sol-Gel Method S2.1. Prepare the BZO precursor solution: Dissolve barium acetate and zirconium acetylacetonate in propionic acid, heat and stir at 80°C for 5 h, and then age for 1 day to obtain the BZO precursor solution. The ratio of barium acetate, zirconium acetylacetonate, and propionic acid is 0.7 g:1.4 g:10 mL.

[0038] S2.2. Prepare a BZO thin film: Place the SAO thin film substrate obtained in S1 in the center of a spin coater. Spin-coat the BZO precursor solution obtained in S2.1 onto the SAO thin film substrate at 6000 rpm / min. Perform a pre-annealing step after each layer of film. Repeat the spin-coating and pre-annealing steps five times. The pre-annealing conditions are: hold at 300°C for 5 minutes. After the spin-coating and pre-annealing steps are complete, increase the temperature to 750°C at a rate of 5°C / min and hold for 1 hour to form a uniform BZO thin film on the SAO film.

[0039] S2.3. BZO thin film transfer: The product of step S2.2 and the flexible substrate polyimide are immersed in water. After the SAO sacrificial layer is dissolved, the BZO film is transferred to the polyimide substrate to obtain a flexible barium zirconate photoelectric film.

[0040] Example 2 The preparation method of the flexible barium zirconate photoelectric film in this embodiment is basically the same as that in Example 1, except that the annealing temperature in step S1.3 is 700°C.

[0041] Example 3 The preparation method of the flexible barium zirconate photoelectric film in this embodiment is basically the same as that in Example 1, except that the annealing temperature in step S2.2 is 850°C.

[0042] Example 4 The preparation method of the flexible barium zirconate photoelectric film in this embodiment is basically the same as that in Example 1, except that the annealing temperature in step S2.2 is 1000°C.

[0043] Example 5 A method for preparing a flexible barium zirconate photoelectric film comprises the following steps: S1. Preparation of a Water-Soluble Strontium Aluminate (Sr3Al2O6) Sacrificial Layer by Radio Frequency Magnetron Sputtering S1.1. Cleaning the substrate: Take a strontium titanate single crystal substrate with a (100) crystal orientation, first ultrasonically clean the substrate with acetone for 15 minutes, then ultrasonically clean it with alcohol for 10 minutes, and then ultrasonically clean it with deionized water for 10 minutes to remove impurities on the substrate, and finally blow it dry with nitrogen to obtain a clean substrate.

[0044] S1.2 Place the cleaned substrate in step S1.1 into the vacuum chamber of the magnetron sputtering coating machine and heat it while evacuating the vacuum until the vacuum degree reaches 10 -4 After 1 Pa, argon gas was introduced, and pre-sputtering was performed on the substrate using strontium aluminate as the target. After the pre-sputtering was completed, the baffle was opened, the chamber pressure was adjusted to 2 Pa, and the main sputtering began. After the sputtering was completed, a sacrificial layer of strontium aluminate thin film was grown on the substrate. The main sputtering conditions were: substrate temperature of 200°C, sputtering power of 110W, sputtering pressure of 0.2Pa, argon flow rate of 60SCCM, and sputtering time of 5 hours. After the sputtering was completed, the substrate was annealed at 800°C to obtain a sacrificial layer of strontium aluminate thin film grown on the substrate.

[0045] S2. Preparation of Barium Zirconate (BZO) Thin Films by Radio Frequency Magnetron Sputtering S2.1. Preparation of BZO thin film: Place the water-soluble strontium aluminate sacrificial layer prepared in step S1 into the vacuum chamber of a magnetron sputtering coating machine and heat while evacuating the chamber until the vacuum reaches 10 -4After 100 Pa, argon gas was introduced, and pre-sputtering was performed on the sacrificial layer using barium zirconate as the target. After the pre-sputtering was completed, the baffle was opened, the chamber pressure was adjusted to 2 Pa, and the main sputtering began. After the sputtering was completed, a barium zirconate film grown on the SAO sacrificial layer was obtained. The main sputtering conditions were substrate temperature of 300°C, sputtering power of 100W, sputtering pressure of 0.2Pa, inert gas flow rate of 60SCCM, and sputtering time of 5 hours. The barium zirconate film after sputtering was annealed at 750°C to obtain a barium zirconate film grown on the sacrificial layer.

[0046] S2.2. BZO thin film transfer: The product of step S2.1 and the flexible substrate polyimide are immersed in water. After the SAO sacrificial layer is dissolved, the BZO film is transferred to the polyimide substrate to obtain a flexible barium zirconate photoelectric film.

[0047] Example 6 The method for preparing the flexible barium zirconate photoelectric film in this embodiment is basically the same as that in Example 4, except that the sputtering power in step S2.1 is 90W.

[0048] Example 7 The method for preparing the flexible barium zirconate photoelectric film in this embodiment is basically the same as that in Example 4, except that the sputtering power in step S2.1 is 110W.

[0049] Material characterization and performance testing Figure 2 1-2 is the XRD pattern of the SAO prepared in Example 1-2. It can be seen that the embodiment of the present invention successfully prepared a SAO film with good crystallinity.

[0050] Figure 3 3-4 are XRD patterns of the BZO prepared in Example 1 and Examples 3-4. It can be seen that the BZO thin films prepared in the examples of the present invention have a good crystalline structure.

[0051] Figure 4This is the absorption spectrum of BZO prepared in Example 1. It can be seen that the material shows significant absorption characteristics at 3.5 eV, 4.1 eV and 5.8 eV. The absorption feature at 3.5 eV is formed by the synergistic effect of heterojunction interface stress and oxygen vacancies, reflecting the unique electronic structure modulation in the film. The leading applications corresponding to the 3.5 eV absorption peak include photocatalysis, proton conductors, UV shielding and near-UV detection. The application directions corresponding to the 4.1 eV absorption peak are deep ultraviolet optoelectronic devices, transparent conductive films and high dielectric application scenarios. The absorption peak at 5.8 eV is the intrinsic band gap absorption peak of BaZrO3, and the absorption peak at 4.1 eV is the defect state absorption peak of BaZrO3. Through the synergistic effect of interface stress and oxygen vacancies, multi-band light response is achieved in a single material, which is expected to meet the multifunctional needs of new energy, environment and advanced electronic devices.

[0052] Figure 5 This is the Raman spectrum of BZO prepared in Example 1. It can be seen that there are obvious tetragonal BZO structural features in the film. The tetragonal phase characteristics of the Raman spectrum reveal the structural origin of the 3.5 eV / 4.1 eV peak in the absorption spectrum, that is, the joint contribution of interface stress (double peak) and oxygen vacancies (defect state peak) modulates the energy band of BZO. Located at about 130 cm -1 The peak at 1219 cm is attributed to the lattice vibration mode of the BZO perovskite structure. -1 and 1241 cm -1 The double peak is the strain-induced symmetry-breaking vibration mode in the tetragonal BaZrO3 phase, which originates from the bending vibration of the oxygen octahedron (ZrO6) in the BZO lattice. Figures 4 and 5 This indicates that the BZO film prepared by the method provided by the present invention has broad application prospects in the field of optoelectronic devices.

[0053] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For any details not described in individual embodiments, reference may be made to the description in other embodiments.

[0054] The above-described embodiments merely illustrate the implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for preparing a flexible barium zirconate photoelectric film, characterized in that: The following steps are involved: (1) Preparing a water-soluble strontium aluminate sacrificial layer on a substrate; (2) depositing barium zirconate on the water-soluble strontium aluminate sacrificial layer by a sol-gel method or a radio frequency magnetron sputtering method to obtain a barium zirconate film grown on the sacrificial layer; (3) Immersing the product of step (2) and the flexible substrate in water, and after the sacrificial layer is dissolved, transferring the barium zirconate film to the flexible substrate to obtain a flexible barium zirconate photoelectric film.

2. The method for preparing a flexible barium zirconate photovoltaic film according to claim 1, wherein: In step (1), the water-soluble strontium aluminate sacrificial layer is prepared by a sol-gel method or a radio frequency magnetron sputtering method.

3. The method for preparing a flexible barium zirconate photovoltaic film according to claim 1, wherein: In step (1), the substrate is a strontium titanate single crystal substrate with a (100) crystal orientation.

4. The method for preparing a flexible barium zirconate photovoltaic film according to claim 1, wherein: In step (2), the sol-gel method includes the following steps: dissolving a barium source and a zirconium source in a solvent to obtain a barium zirconate precursor solution; coating the barium zirconate precursor solution on the water-soluble strontium aluminate sacrificial layer to obtain a barium zirconate film; The barium zirconate film is annealed to obtain a barium zirconate film grown on the sacrificial layer.

5. The method for preparing a flexible barium zirconate photovoltaic film according to claim 4, wherein: The barium source is barium acetate, and the zirconium source is zirconium acetylacetonate; the molar ratio of the barium source to the zirconium source is 1:(1-2); and the concentration of the barium zirconate precursor solution is 0.6-0.8 mol / L.

6. The method for preparing a flexible barium zirconate photovoltaic film according to claim 4, wherein: The annealing treatment conditions include: pre-annealing at 300-350° C. for 3-5 min, then heating to 750-1000° C. at a rate of 5-10° C. / min, and keeping the temperature for 1-2 h.

7. The method for preparing a flexible barium zirconate photovoltaic film according to claim 1, wherein: In step (2), the radio frequency magnetron sputtering method includes the following steps: The water-soluble strontium aluminate sacrificial layer was placed in a vacuum chamber of a magnetron sputtering apparatus, and barium zirconate was sputtered using barium zirconate as a target under an inert gas. The sputtering conditions were as follows: substrate temperature of 300° C., sputtering power of 100 W, sputtering pressure of 2 Pa, and inert gas flow rate of 60 SCCM. The barium zirconate film after sputtering is annealed at 750-1000° C. to obtain a barium zirconate film grown on the sacrificial layer.

8. The method for preparing a flexible barium zirconate photovoltaic film according to claim 1, wherein: In step (3), the flexible substrate is one of polyimide, PET / PEN, PDMS, and polyurethane.

9. A flexible barium zirconate photoelectric film, characterized in that: The method is prepared according to any one of claims 1 to 8.

10. A flexible optoelectronic device, characterized in that: The flexible barium zirconate photovoltaic film as claimed in claim 9 is included.

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