A method for patterning perovskite thin films using reactive ion etching (RIE) dry etching.

Abstract

This invention discloses a method for patterning perovskite thin films using reactive ion etching (RIE) technology, comprising the following steps: 1) substrate / substrate cleaning; 2) perovskite film deposition; and 3) reactive ion beam etching of the perovskite thin film. This invention is the first to propose using reactive ion beam etching for perovskite, offering a new process strategy for perovskite array patterning. Furthermore, this dry etching process avoids solvent corrosion of perovskite and is not limited by the type of perovskite, making it applicable to all types of perovskite thin film materials. Compared to the previously proposed template method for perovskite patterning, it is simpler. Secondly, the reactive ion beam etching equipment is simple in structure, inexpensive, and compatible with all MEMS-scale manufacturing plants, significantly reducing manufacturing costs. It is applicable to any substrate material, broadening the compatibility for manufacturing various functional materials.

Description

Technical Field

[0001] This invention belongs to the field of perovskite thin film patterning preparation technology, specifically relating to a method for patterning perovskite thin films using reactive ion etching technology with dry etching. Background Technology

[0002] Perovskite materials possess advantages such as suitable band gap, high carrier mobility, high absorption coefficient, low exciton binding energy, and long carrier lifetime. Quantum dots, nanowires, and other structural materials based on perovskites have become a new generation of optoelectronic functional materials, achieving rapid development in fields such as light-emitting diodes, solar cells, and resistive switching memristors. Therefore, they have received widespread attention in fields such as communications, displays, and photovoltaics.

[0003] Patterning functional material thin films is a crucial step in the fabrication of micro / nanoelectronic devices, typically achieved using microelectromechanical systems (MEMS) fabrication techniques. Common methods for thin film patterning include coating the thin film or substrate surface with photoresist, then patterning the photoresist using techniques such as laser direct writing, ultraviolet exposure, or electron beam lithography. A development step exposes the areas of the thin film to be removed on the film surface, or the areas of the substrate to be deposited on the substrate surface, revealing the pattern. Further processes such as lift-off, etching, or deposition are then employed. For etching and deposition, further removal of the photoresist is still required. Another patterning method involves directly etching the functional material thin film surface using a mask. Dry etching includes chemically-based reactive ion etching (RIE), physically-based ion beam etching (IBE), and a combination of both (RIBE) physicochemical etching techniques.

[0004] Perovskite thin films are highly sensitive to photoresists and developers, and are easily corroded by the solvents in these liquid chemicals. Therefore, the design of perovskite thin film patterning processes must avoid direct contact with liquid chemicals such as photoresists and developers. Thus, perovskite thin film patterning technology remains a challenge. One solution is to directly bond a photomask to the perovskite film surface and perform dry etching to remove the uncovered areas of the perovskite film outside the photomask, thereby forming a pattern. However, to date, there are no reports of similar solutions. The reasons for this technical difficulty are roughly as follows: 1. Dry etching processes ultimately require the reaction products to become gaseous and be expelled from the reaction chamber, but the presence of heavy metal elements such as Pb and Cs in perovskite films makes it difficult to form gaseous products; 2. There is no corresponding template that can be used to form perovskite array point patterns.

[0005] For dry etching in current MEMS processes, reactive ion etching (RIE) is the most mainstream method, offering high etching rates, higher selectivity than IBE, and controllable parameters. It is commonly used in MEMS processes for etching Si-based films such as Si, SiO2, SiNx, and SiC, whose main components are Si, O, C, and N. However, perovskite films contain Pb, halogens (Cl, Br, I), C, O, and H, including the heavy metal Pb, which increases the difficulty of RIE etching. This differs significantly from existing Si-based thin film etching technologies; therefore, no reactive ion beam etching schemes for perovskite thin films have been reported to date.

[0006] Regarding the development of perovskite thin film patterning technology, there have been a few reports since 2015. For example, the most popular approach is the hydrophilic-hydrophobic template method for fabricating perovskite array patterns. This involves using octadecylsilane trichlorosilane (OTS) to hydrophobize the SiO2 / Si substrate, controlling the perovskite precursor solution to wet and grow within the hydrophobically treated patterned areas, thereby achieving perovskite patterning. Light-emitting diodes have been developed using a similar approach. In this hydrophilic-hydrophobic template method, Al2O3 is added as an aid to form a large-scale perovskite array.

[0007] The hydrophilic-hydrophobic template method for patterning perovskite thin films involves first forming hydrophobic and hydrophilic regions on a substrate. Then, a one-step or two-step spin-coating deposition method is used, where the spin-coated perovskite precursor solution covers only the wettable hydrophilic regions. After heating, a perovskite thin film crystallizes only in the wetted areas, forming a pattern. Disadvantages: 1. There are many types of perovskites. For materials used in specific functional devices (LEDs, memristors, photosensitive devices, etc.), perovskites with specific photoelectric properties must be selected as the active material. However, hydrophilic-hydrophobic template methods are not suitable for most perovskite films; 2. When fabricating perovskite array patterns with a resolution of tens of nanometers to several micrometers, it is difficult to control the perovskite array points within the pattern. This is because the hydrophilic-hydrophobic template method limits the pattern on which the perovskite precursor solution adheres, and then the perovskite continues to grow on the pattern. Typically, the perovskite grain size is tens to hundreds of micrometers, which can easily exceed the edge of the pattern, resulting in the edge and size of the perovskite film pattern not being completely consistent with the pattern; 3. There are certain requirements for the substrate material. To achieve the photolithography process of the hydrophilic-hydrophobic layer, it is generally necessary to cover the substrate with a special coating material (ITO, FTO, ZnO, TiO2) before performing the hydrophilic-hydrophobic template process. This template process requires coating a hydrophilic film and photoresist, and utilizing photolithography technology, which leads to a very high overall process complexity and technical requirements, which is not conducive to the large-scale development of MEMS electronic devices. Summary of the Invention

[0008] The purpose of this invention is to provide a method for patterning perovskite thin films using reactive ion etching (RIE) dry etching. This invention achieves patterning of perovskite thin films using RIE dry etching, avoiding contact with any solvent and preventing damage to the perovskite film due to non-polar solvents. Because the RIE etching is performed in a high-vacuum environment, it avoids the problem of prolonged contact between the perovskite film and water molecules in the air during patterning, which could lead to performance degradation or failure. The technical solution of this invention has low requirements for process equipment and is easily compatible with MEMS processes.

[0009] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0010] A method for patterning perovskite thin films using reactive ion etching (RIE) dry etching technology includes the following steps: 1) substrate / base cleaning; 2) perovskite film deposition; 3) reactive ion beam etching of the perovskite thin film; wherein, the reactive ion beam etching method in step 3) is as follows:

[0011] a. First, a rigid mask with a pre-designed pattern is placed on the surface of the perovskite thin film. The mask and the perovskite thin film substrate are then fixed together using adhesive resin or spring clips. If the position of the mask on the etched pattern on the perovskite thin film needs to be corrected, an alignment operation is performed using a substrate transfer platform. The pre-designed rigid mask is placed on the perovskite thin film surface according to the alignment marks. First, a coarse alignment of the substrate is performed, with an accuracy error <50μm. Then, a fine alignment of the substrate is performed, with an alignment error <5μm. After the mask is aligned, the mask and the perovskite thin film substrate are fixed together using adhesive resin or spring clips. The adhesive resin buffers the micro-movements between the mask and the perovskite thin film substrate; the pressure exerted by the spring clips on the mask and substrate prevents misalignment. The specific method used depends on the precision of the etched pattern. If the etched pattern precision is high, both methods are used; if the etched pattern precision is low, only the spring clips are needed. Both can prevent misalignment between the mask and the perovskite thin film substrate, thus improving the accuracy of the perovskite thin film etching pattern.

[0012] b. Place the perovskite thin film substrate with a mask on its surface into the reactive ion beam etching chamber. The reactive etching process parameters are as follows: the process gas is a mixed atmosphere of CF4 and CHF3, the CF4 flow rate is set to 30 sccm, the CHF3 flow rate is set to 10 sccm, the electrode power is 80 W, the gas pressure is 3 Pa, and the time is 5-10 s. Under the action of the high-energy high-frequency magnetic field of the electrode, the mixed process gas is excited to generate free matrix F. - and H + When an unmasked perovskite film comes into contact with the free substrate, it undergoes a corrosion reaction, generating gas which is then expelled from the reaction chamber, as shown in the following reaction formula:

[0013] CF4→CF x + +CF y -

[0014] CF4+e-→CF X +CF y +F - +e -

[0015] CF x + +e-→CF x

[0016] CHF3→CF x +H + +e -

[0017] CHF3+e - →CHF2+F -

[0018] When an unmasked perovskite film comes into contact with the free substrate, it undergoes a corrosion reaction, generating gas which is then expelled from the reaction chamber; the reaction is as follows:

[0019] Taking CH3NH3PbI3 as an example, the reaction occurs as follows:

[0020] CH3NH3 + H + → CH x (gas) + NH x (gas)

[0021] Pb 2+ + F - → PbF2 (g)

[0022] I - + H+ → HI (g)

[0023] Taking CH3NH3PbBr3 as an example, the reaction equation is as follows:

[0024] CH3NH3 + H + → CH x (gas) + NH x (gas)

[0025] Pb 2+ + F - → PbF2 (g)

[0026] Br - + H+→ HBr (g)

[0027] iii. Taking CsPbI3 as an example, the reaction equation is as follows:

[0028] Cs + + F - → CsF (g)

[0029] Pb 2+ + F - → PbF2 (g)

[0030] I - + H+ → HI (g)

[0031] iv. Taking [CH3NH3]SnI3 as an example, the reaction occurs as follows:

[0032] CH3NH3 + H + → CH x (gas) + NH x (gas)

[0033] Sn + + F - → SnF (g)

[0034] I - + H+ → HI (g)

[0035] c. After reactive ion beam etching is complete, the perovskite thin film substrate and mask can be removed. If secondary etching is required, repeat steps a and b above.

[0036] As a further preferred embodiment of the present invention, in step a., the material of the hard mask is selected from stainless steel, silicon dioxide, silicon nitride and silicon wafer.

[0037] As a further preferred embodiment of the present invention, in step 1), the material of the substrate / base is selected from one of Si-based wafers, sapphire (Al2O3), ITO, glass, polyethylene, polyethylene terephthalate (PET), and polyimide (PI).

[0038] As a further preferred embodiment of the present invention, in step 1), the cleaning process involves first washing with deionized water once or twice and then drying, then washing with acetone and drying, and finally washing with alcohol and drying. Then, O2 / Ar plasma is used to remove the surface organic impurities. Ultrasonic cleaning is used during each cleaning process to ensure more thorough cleaning.

[0039] As a further preferred embodiment of the present invention, in step 2), the perovskite film is ABX3, wherein A can be NH4. + [(CH3)NH4] +[(CH2)3NH2] + [NH2(CH)NH2] + [(CH3)2NH2] + [(C2H5)NH3] + [C(NH2)3] + [(CH3)4N] + One or more organic groups, or Cs + 、Rb + K + One or more metal ions; wherein B is Pb 2+ Sn 2+ One or more heavy metal ions; X is a halogen element: Cl, Br, I, one or more.

[0040] As a further preferred embodiment of the present invention, in step 2), the perovskite film is prepared by a one-step or two-step method; the one-step method involves nucleating and growing a perovskite film in a precursor solution containing all perovskite compounds; the two-step method involves mixing two precursor solution solvents separately, gradually depositing various precursor solutions, initially spin-coating one precursor solution, and depositing the other by immersion or spin-coating, followed by heating and annealing to evaporate the solvent and crystallize the perovskite into a film.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1) The dry etching perovskite process of the present invention avoids the corrosion of perovskite by solvents and is not limited by the type of perovskite, and is applicable to all types of perovskite thin film materials.

[0043] 2) This invention is the first to propose using reactive ion beam etching technology to etch perovskites, providing a new process strategy for perovskite array patterning.

[0044] 3) Compared with the previously proposed template method for fabricating perovskite patterning, it is simpler. Secondly, the reactive ion beam etching equipment has a simple structure, is inexpensive, and is compatible with all MEMS large-scale manufacturing plants, which greatly reduces manufacturing costs.

[0045] 4) The solution proposed in this invention is applicable to any substrate or base material, such as glass or PET plastic substrates with ITO, FTO, ZnO, TiO2 substrates; thus broadening the compatibility for manufacturing various functional materials.

[0046] 5) The perovskite substrate etched by the proposed method of this invention can produce array points with resolutions ranging from hundreds of micrometers to tens of nanometers, depending on the resolution of the mask. Attached Figure Description

[0047] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, 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.

[0048] Figure 1 Optical microscope image of a stainless steel mask plate;

[0049] Figure 2 It is a perovskite thin film through-hole array etched using a through-hole mask. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described in detail below. However, the following embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0051] There are many types of perovskite thin film materials, each with different photoelectric properties. In the dry etching method of this invention, no requirements are placed on the type or elements of the perovskite thin film. The perovskite used is ABX3, where A can be NH4. + [(CH3)NH4] + [(CH2)3NH2] + [NH2(CH)NH2] + [(CH3)2NH2] + [(C2H5)NH3] + [C(NH2)3] + [(CH3)4N] + Single or multiple organic groups, or Cs + 、Rb + K + One or more metal ions; wherein B is Pb 2+ Sn 2+ One or more of the same heavy metal ions; X is a halogen element: one or more of Cl, Br, and I. This invention provides a method for preparing perovskite thin films using a one-step or two-step method.

[0052] One method involves nucleation and growth of a perovskite thin film in a precursor solution containing all perovskite compounds. Taking the preparation of CH3NH3PbI3 as an example, the first step is to prepare the precursor solution: a certain amount of CH3NH3I and PbI2 are mixed in a molar ratio of 1:1 in one or more solvents such as N,N-dimethylformamide (DMF), γ-butyrolactone (GBL), and / or dimethyl sulfoxide (DMSO), with a total molar concentration of 1–100 mol / mL. The second step can be a spin-coating process, where the substrate or sheet is adsorbed onto a spin coater or spin coater, and the precursor solution is covered on the surface of the substrate or sheet. The spin coater is pre-run at 300–500 rpm for 3–10 seconds, and then run at 2000–3000 rpm for 30–60 seconds. The third step is to place the substrate or sheet with the spin-coated perovskite precursor solution on a heating plate at 100–180 degrees Celsius for annealing treatment, so that the solvent evaporates and crystallization forms a perovskite thin film.

[0053] For example, to prepare a [(CH2)3NH2]PbI3 thin film, the precursor solution is prepared by mixing a certain concentration and quantity of [(CH2)3NH2]I and PbI2 according to the specified proportion and molar mass. For preparing a [CH3NH3]PbBr3 thin film, a certain concentration and quantity of [CH3NH3]Br and PbBr2 is prepared according to the specified proportion and molar mass, using the same solvent. For preparing a [CH3NH3]SnI3 thin film, a certain concentration and quantity of [(CH2)3NH2]I and SnI2 is prepared according to the specified proportion and molar mass. Other preparations are similar to [(CH2)3NH2]PbBr... 3-a-b I a Cl b Perovskites with mixed elemental compositions at the A, B, or X sites can be prepared by analogy to the above method, using corresponding salt mixture solutions. The solvent used to prepare the precursor solution can be one or a mixture of two of DMF, GBL, and / or DMSO. The second step of coating the substrate or sheet with the perovskite precursor solution and the third step of crystallizing the perovskite film are the same as above.

[0054] The two-step method for preparing perovskite thin films involves mixing two precursor solvents separately, gradually depositing various precursor liquids, initially spin-coating one precursor liquid, and depositing the other by immersion or spin-coating, followed by heating and annealing to evaporate the solvent and crystallize the perovskite to form a film. Taking the two-step preparation of CH3NH3PbI3 as an example, the specific method is as follows: First, prepare precursor solutions by dissolving a certain amount of CH3NH3I salt in isopropanol (IPA) to form a solution with a concentration of 1-100 mol / mL, and dissolving PbI2 in DMF solvent to form a solution with a concentration of 1-100 mol / mL. Second, perform stepwise deposition by spin-coating on the substrate or substrate. The substrate or substrate can be pre-run at 300-500 rpm for 3-10 seconds, then run at 2000-3000 rpm for 30-60 seconds. Then, deposit CH3NH3I salt using either an immersion process or a spin-coating process. The immersion process involves immersing the substrate or substrate in the salt solution for several seconds, while the spin-coating process can use the former method. Third, place the substrate or substrate on a heating plate at 100-180 degrees Celsius for annealing to evaporate the solvent and crystallize to form a perovskite thin film.

[0055] For example, to prepare a [(CH2)3NH2]PbI3 thin film, the precursor solution is prepared with two salt solutions of [(CH2)3NH2]I and PbI2 at specific amounts and concentrations; to prepare a [CH3NH3]PbBr3 thin film, the precursor solution is prepared with two salt solutions of [CH3NH3]Br and PbBr2 at specific amounts and concentrations; to prepare a [CH3NH3]SnI3 thin film, the precursor solution is prepared with two salt solutions of [(CH2)3NH2]I and SnI2 at specific amounts and concentrations; other similar preparations are prepared with the same method as [(CH2)3NH2]PbBr... 3-a-b I a Cl b Perovskites with mixed elemental compositions at the A, B, or X sites can be prepared in the same manner as described above, using two corresponding salt solutions. The solvent used to prepare the precursor solution can be one or a mixture of two of IPA, DMF, GBL, and / or DMSO. The second step of coating the substrate or sheet with the perovskite precursor solution and the third step of crystallizing the perovskite film are the same as above.

[0056] The reactive ion beam etching scheme of this invention is applicable to both conventional perovskite thin films and perovskite thin films with modified element sites (A / B / X). The morphology of the perovskite thin film can be a crystalline grain capping layer, linear, or network structure. In summary, the dry etching scheme for perovskite thin films does not impose any limitations on the type, element, morphology, or structure of the perovskite.

[0057] Example 1

[0058] This embodiment presents a method for patterning perovskite thin films using reactive ion etching (RIE) dry etching technology, specifically demonstrating the dry etching of pores in [(CH₂)₃NH₂]PbBrI₂ perovskite thin films. The specific fabrication method of the array includes the following steps:

[0059] 1) Use a glass substrate with an ITO coating as the perovskite thin film substrate; sequentially use deionized water for ultrasonic cleaning once or twice and then blow dry, acetone for ultrasonic cleaning and then blow dry, alcohol for ultrasonic cleaning and then blow dry, and then use O2 / Ar plasma to remove the adhesive and remove organic impurities from the surface.

[0060] 2) Deposition of [(CH2)3NH2]PbBrI2 perovskite thin films using a two-step method:

[0061] The first step is to prepare the precursor solution: a certain amount of [(CH2)3NH2]Br and [(CH2)3NH2]I are mixed in DMSO solvent at a molar ratio of 1:1, with a total molar concentration of 1 mol / mL; a certain amount of PbI2 is dissolved in DMF solvent to form a 1 mol / mL solution. The second step is to perform stepwise deposition: a PbI2 film is deposited on an ITO substrate using a spin-coating process. The substrate is pre-run at 400 rpm for 3-10 seconds, then at 3000 rpm for 50 seconds. The substrate with the PbI2 film is then immersed in a mixed salt of [(CH2)3NH2]Br and [(CH2)3NH2]I for 15 seconds, then removed and dried. The third step is to place the substrate or sheet on a 120°C heating plate for annealing to evaporate the solvent and crystallize to form a perovskite thin film.

[0062] 3) Reactive ion beam etching of perovskite thin films:

[0063] a. Made of 50µm thick stainless steel with through holes The mask of the array (e.g.) Figure 1 (Optical microscope image of stainless steel mask); The alignment operation is completed using a substrate transfer platform, and the mask with the through-hole pattern is brought into contact with the surface of the perovskite film; First, the substrate is coarsely aligned with an accuracy error of <50μm, and then the substrate is finely aligned with an alignment error of <5μm; After the mask is aligned, the mask and the perovskite film substrate are fixed with spring clips.

[0064] b. Place the perovskite thin film substrate with a mask on its surface into the reactive ion beam etching chamber. The reactive etching process parameters are as follows: the process gas is a mixed atmosphere of CF4 and CHF3, the CF4 flow rate is set to 30 sccm, the CHF3 flow rate is set to 10 sccm, the electrode power is 80 W, the gas pressure is 3 Pa, and the time is 5-10 s. Under the action of the high-energy, high-frequency magnetic field of the electrode, the mixed process gas is excited to generate free matrix F. -and H + When an unmasked perovskite film comes into contact with the free substrate, it undergoes a corrosion reaction, generating gas which is then expelled from the reaction chamber, as shown in the following reaction formula:

[0065] CF4→CF x + +CF y -

[0066] CF4+e-→CF X +CF y +F - +e -

[0067] CF x + +e-→CF x

[0068] CHF3→CF x +H + +e -

[0069] CHF3+e - →CHF2+F -

[0070] When a perovskite film without a mask comes into contact with the free substrate, it undergoes a corrosion reaction, generating gas which is then expelled from the reaction chamber, as shown in the following reaction formula:

[0071] Taking [(CH2)3NH2]PbBrI2 as an example, the reaction occurs as follows:

[0072] (CH2)3NH2 + + H + → CH x (gas) + NH x (gas)

[0073] Pb 2+ + F - → PbF2 (g)

[0074] Br - + H+→ HBr (g)

[0075] I - + H+ → HI (g)

[0076] c. After reactive ion beam etching is complete, remove the perovskite thin film substrate and mask, as follows: Figure 2 After etching, a perovskite thin film aperture array is formed according to the mask pattern, thereby realizing the patterning of the perovskite thin film.

[0077] Example 2

[0078] This embodiment describes a method for patterning perovskite thin films using reactive ion etching (RIE) dry etching, similar to Embodiment 1, except that [(CH2)3NH2]PbBrI2 is replaced with CH3NH3PbBr3.

[0079] Taking CH3NH3PbBr3 as an example, the reaction equation is as follows:

[0080] CH3NH3 + + H + → CH x (gas) + NH x (gas)

[0081] Pb 2+ + F - → PbF2 (g)

[0082] Br - +H+→HBr(g).

[0083] Example 3

[0084] This embodiment describes a method for patterning perovskite thin films using reactive ion etching (RIE) dry etching, similar to Embodiment 1, except that [(CH2)3NH2]PbBrI2 is replaced with CsPbI3.

[0085] Taking CsPbI3 as an example, the reaction occurs as follows:

[0086] Cs + + F - → CsF (g)

[0087] Pb 2+ + F - → PbF2 (g)

[0088] I - +H+→HI(g).

[0089] Example 4

[0090] This embodiment describes a method for patterning perovskite thin films using reactive ion etching (RIE) dry etching, similar to Embodiment 1, except that [(CH2)3NH2]PbBrI2 is replaced with [CH3NH3]SnI3.

[0091] Taking [CH3NH3]SnI3 as an example, the reaction occurs as follows:

[0092] (CH2)3NH2 + + H +→ CH x (gas) + NH x (gas)

[0093] Sn + + F - → SnF (g)

[0094] I - +H+→HI(g).

[0095] In other embodiments, in step 1), the substrate material is selected from one of Si-based wafers, sapphire (Al2O3), ITO, polyethylene, polyethylene terephthalate (PET), and polyimide (PI), all of which can achieve the effects of the present invention.

[0096] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for patterning perovskite thin films using dry etching with reactive ion etching technology, characterized in that, Includes the following steps: 1) Substrate / base cleaning; 2) Perovskite film deposition; 3) Reactive ion beam etching of perovskite film; The reactive ion beam etching method in step 3) is as follows: a. First, cover the surface of the perovskite thin film with a cutout rigid mask with the corresponding pattern designed, and then use adhesive resin or spring clips to fix the mask and the perovskite thin film substrate. b. Place the perovskite thin film substrate with a mask on its surface into the reactive ion beam etching chamber. The reactive etching process parameters are: process gas is a mixture of CF4 and CHF3, CF4 flow rate is set to 30 sccm, CHF3 flow rate is set to 10 sccm, electrode power is 80 W, gas pressure is 3 Pa, and time is 5-10 s. Under the action of the high-energy, high-frequency magnetic field of the electrode, the mixed process gas excites and generates free matrix F. - and H + When a perovskite film without a mask comes into contact with the free substrate, it undergoes a corrosion reaction, generates gas, and is expelled from the reaction chamber. c. After the reactive ion beam etching is completed, the perovskite thin film substrate and mask can be removed. In step 2), the perovskite film is ABX3, where A is NH4. + [(CH3)NH4] + [(CH2)3NH2] + [NH2(CH)NH2] + [(CH3)2NH2] + [(C2H5)NH3] + [C(NH2)3] + [(CH3)4N] + One or more organic groups, or Cs + 、Rb + K + One or more metal ions; wherein B is Pb 2+ Sn 2+ One or more heavy metal ions; X is a halogen element: Cl, Br, I, or one or more of them.

2. The method for patterning perovskite thin films using dry etching with reactive ion etching technology according to claim 1, characterized in that, In step a., the material of the hard mask is selected from stainless steel, silicon dioxide, silicon nitride and silicon wafer.

3. The method for patterning perovskite thin films using dry etching with reactive ion etching technology according to claim 1, characterized in that, In step 1), the material of the substrate / base is selected from one of the following: Si-based wafer, sapphire (Al2O3), ITO, glass, polyethylene, polyethylene terephthalate (PET), and polyimide (PI).

4. The method for patterning perovskite thin films using dry etching with reactive ion etching technology according to claim 1, characterized in that, In step 1), the cleaning process involves first rinsing with deionized water once or twice and then drying, followed by rinsing with acetone and then drying, and finally rinsing with alcohol and then drying. Then, O2 / Ar plasma is used to remove the surface organic impurities. Ultrasonic cleaning is used during each cleaning process to ensure a more thorough cleaning.

5. The method for patterning perovskite thin films using dry etching with reactive ion etching technology according to claim 1, characterized in that, The deposited perovskite thin film is prepared by a one-step or two-step method. The one-step method involves nucleation and growth of a perovskite thin film in a precursor solution containing all perovskite compounds. The two-step method involves mixing two precursor solution solvents separately, gradually depositing various precursor solutions, initially spin-coating one precursor solution, and depositing the other by immersion or spin-coating, followed by heating and annealing to evaporate the solvent and crystallize the perovskite to form a film.

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