Methods for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-C)

Abstract

This invention discloses a method for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-E) technology, comprising the following steps: 1) preparing a halide perovskite thin film; 2) ion etching the array pattern: a mask is placed over the halide perovskite thin film, the pattern formed by the mask corresponding to the halide perovskite array pattern. After etching using ICP-E, the mask is removed, forming the halide perovskite thin film array pattern. This invention utilizes a stainless steel mask as the etching mask tool for perovskite array patterning (hundreds of micrometers and above). It uses free electrons, fluorine-based ions, and chloride-based ions excited by ICP-E to perform two etching operations on the halide perovskite thin film material outside the mask, achieving perovskite thin film patterning. It avoids contact with any solvent, effectively preventing corrosion of the perovskite thin film by non-polar solvents, and is not limited by the type of perovskite, making it applicable to all types of perovskite thin film materials.

Description

Technical Field

[0001] This invention belongs to the field of perovskite array patterning technology, specifically relating to a method for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-C) technology. Background Technology

[0002] Halide perovskite (hereinafter referred to as "perovskite") materials possess advantages such as suitable band gaps, high carrier mobility, high absorption coefficients, low exciton binding energy, and long carrier lifetimes. Among them, perovskite-based quantum dots, nanowires, and other structural materials have become next-generation optoelectronic functional materials, achieving rapid development in fields such as light-emitting diodes, solar cells, and resistive switching memristors. Therefore, they have also attracted widespread attention in fields such as communications, displays, and photovoltaics. The efficient, precise, and large-scale fabrication of perovskite microstructure arrays on substrates is a crucial prerequisite for the device-based applications of perovskite materials.

[0003] Currently, in MEMS device manufacturing, array patterning is achieved using photolithography. This involves first using photolithography to perform hydrophilic-hydrophobic patterning on a special substrate, such as a flexible polyethylene terephthalate substrate or a silicon substrate with silica. This allows the perovskite precursor solution to be immersed only in the hydrophilic region. After degradation, the perovskite crystals form, resulting in a patterned perovskite image. However, in this photolithography process, the coating, development, and stripping steps require large amounts of solutions containing polar solvents. These polar solvents corrode the perovskite, making it impossible to fabricate perovskite thin-film arrays using photolithography.

[0004] All perovskite patterning methods developed in recent years have been based on the hydrophilic-hydrophobic template method. This involves patterning the perovskite substrate and then allowing the perovskite to deposit and grow within the hydrophilic region to obtain the final pattern. This method has several drawbacks, such as: 1. Limited perovskite types: Perovskites are diverse, and for specific functional devices such as LEDs, memristors, and photosensitive sensors, perovskites with specific photoelectric properties must be selected as the active material. However, some perovskite films are not suitable for the hydrophilic-hydrophobic template method. 2. Irregularity at pattern edges: When fabricating perovskite array patterns at resolutions of tens of nanometers to several micrometers, it is difficult to control the perovskite array dots within the pattern. This is because the hydrophilic-hydrophobic template method limits the pattern to 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, easily exceeding the pattern edge, leading to problems where the edges and size of the perovskite film pattern do not perfectly match the actual pattern. 3. High technical requirements: Certain requirements are placed on the substrate material. To achieve the photolithography process of the hydrophilic-hydrophobic layer, a special coating material (ITO, FTO, ZnO, TiO2) is generally needed on the substrate. 4. Complex process: The hydrophilic-hydrophobic template method requires coating a hydrophilic film and photoresist, and utilizing photolithography technology, resulting in a complex overall process with very high technical requirements, which is not conducive to the large-scale R&D and manufacturing of MEMS electronic devices. Summary of the Invention

[0005] The purpose of this invention is to provide a method for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-C) technology.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-E) technology includes the following steps:

[0008] 1) Preparation of halide perovskite thin films;

[0009] 2) Ion etching array pattern: A mask is placed on the halide perovskite film in step 1). The pattern formed by the mask corresponds to the halide perovskite array pattern. After etching using inductively coupled plasma etching technology, the mask is removed to form the halide perovskite film array pattern.

[0010] In step 2), the mask includes a first mask and a second mask, and the pattern formed by the combination of the first mask and the second mask corresponds to the halide perovskite array pattern.

[0011] In step 2), both the first mask and the second mask are made of stainless steel sheet.

[0012] In step 2), the first mask is made into a hollow grid-shaped horizontal stripe mask, and the second mask is made into a hollow grid-shaped vertical stripe mask. The pattern of the overlapping area formed by the combination of the first mask and the second mask corresponds to the halide perovskite array pattern.

[0013] In step 2), ion etching employs an inductively coupled plasma etching system, and the etching method includes the following steps:

[0014] a. First, cover the halide perovskite thin film with a first mask, fix it in place, and then place it in the rapid sample injection chamber of the inductively coupled plasma etching system under vacuum conditions (vacuum degree is 1.0e during transport). -2 After transferring the halide perovskite thin film and the first mask to the etching chamber (Pa), the vacuum level is adjusted to 1.0 e. -7 -1.0 e -9 Pa;

[0015] b. Etching the perovskite film: Gas is introduced, with the upper electrode power at 300-800 W and the lower electrode power at 20-100 W, the process pressure at 1-10 mTorr, and etching for 1-20 min. The halide perovskite film and the first mask are then removed, and the first mask is unloaded.

[0016] c. Next, cover the halide perovskite film with a second mask, fix it in position, and place it in the rapid sample inlet of the inductively coupled plasma etching system. Refer to steps a and b to etch the perovskite film, remove the halide perovskite film and the second mask, and then remove the second mask.

[0017] In steps b and c, the gas used for etching the perovskite film includes at least a chlorine-based atmosphere.

[0018] In steps b and c, the chlorine-based atmosphere is one or a combination of two of Cl2 and BCl3.

[0019] In steps b and c, the gas also includes one or a combination of two of CHF3 and Ar.

[0020] In steps b and c, the flow rate of the chlorine atmosphere is 10-40 sccm, the flow rate of CHF3 is 1-5 sccm, the flow rate of Ar is 1-20 sccm, and the other process parameters of the system are: the sample stage temperature is 20-30℃, and the back helium pressure is 5-15 Torr.

[0021] In step 1), the halide perovskite thin film is prepared by a one-step spin coating method or a two-step spin coating method.

[0022] Taking an n (column) × m (row) array as an example, the side length and width of the lattice are a and b, respectively, and the row and column resolutions are c and d, where the dimensions of a, b, c, and d range from >100 μm. The thickness of the first and second masks is 5 μm-100 μm.

[0023] Method for manufacturing photomasks:

[0024] 1. The first photomask is made into a perforated grid-like horizontal stripe photomask, such as... Figure 1 As shown, the length and width of the horizontal stripes are n*d and b, respectively, and the longitudinal spacing between the horizontal stripe and the adjacent stripe (the spacing between the center lines of two adjacent horizontal stripes) is c, with a total of m stripes. The stainless steel sheet is made using laser cutting and engraving technology, which can ensure that the dimensional accuracy of the grid stripes is >50μm.

[0025] 2. The second mask is made into a perforated grid-like vertical striped mask, such as... Figure 2 As shown, the length and width of the vertical stripes are m*c and a, respectively, and the lateral spacing between the vertical stripes and their adjacent stripes (the spacing between the center lines of two adjacent vertical stripes) is d, with a total of n stripes. Using laser cutting and engraving technology to create the perforated plate, the dimensional accuracy of the stripes can be guaranteed to be >50 μm.

[0026] Furthermore, if n = m, a = b, and c = d, then the first mask can be rotated 90° along the XY plane to become the second mask. Therefore, the second mask can be replaced by the first mask, eliminating the need for repeated fabrication. When etching perovskite thin films, the first mask is rotated 90° along the XY plane and used as the second mask.

[0027] Perovskite thin film materials are diverse, each possessing different photoelectric properties. The dry etching method of this invention does not limit the type, elements, morphology, or structure of the perovskite thin film. It is applicable to both traditional perovskite thin films and perovskite thin films with modified elements (A / B / X). The morphology of the perovskite thin film can be a crystalline grain capping layer, linear, or network structure.

[0028] Perovskite thin film materials can be of the ABX3 type, 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; B is Pb 2+ Sn 2+ One or more of the same heavy metal ions; X is a halide ion, Cl - ,Br - I - One or more of them.

[0029] A method for preparing perovskite thin films includes the following steps:

[0030] 1. Substrate / base cleaning;

[0031] 2. Perovskite thin film deposition: One-step spin coating or two-step spin coating method is used.

[0032] In step 1, the cleaning method is as follows: First, use a cleaning agent prepared with deionized water (deionized water and scouring powder are conventionally prepared, and the ratio is not particularly important) to clean (ultrasonic cleaning method can be used) once or twice, rinse thoroughly with deionized water and blow dry; then clean with acetone (ultrasonic cleaning method can be used), and blow dry; then clean with alcohol (ultrasonic cleaning method can be used), and blow dry; O2 or Ar plasma can be used to remove organic impurities on the substrate / substrate surface; the substrate material can be Si-based wafer, sapphire (Al2O3), ITO, glass, polyethylene, polyethylene terephthalate (PET) or polyimide (PI) and other materials.

[0033] The one-step spin-coating method involves nucleation and growth of perovskite thin films in a precursor solution containing all perovskite compounds. The specific method is as follows:

[0034] 1) Preparation of perovskite precursor solution: Mix ABX3 compound with solvent to prepare precursor solution;

[0035] 2) Spin coating and spin coating: The cleaned substrate or sheet is adsorbed onto the spin coater or spin coater, and the perovskite 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 s, and then run at 2000-3000 rpm for 30-60 s.

[0036] 3) Place the substrate or sheet with spin-coated perovskite precursor solution on a heating plate at 100-180º for annealing to allow the solvent to evaporate and crystallize to form a perovskite thin film.

[0037] To prepare CH3NH3PbI3 thin films, 1) a perovskite precursor solution was prepared: a certain amount of CH3NH3I and PbI2 were mixed in an organic solvent at a molar ratio of 1:1, and the total molar concentration of CH3NH3I and PbI2 was 1-100 mol / L.

[0038] 2) Spin coating process can be used: The substrate or sheet is adsorbed on the spin coater or spin coater, and the perovskite precursor solution is covered on the surface of the substrate or sheet. It is pre-run at a speed of 300-500 rpm for 3-10 s, and then run at a speed of 2000-3000 rpm for 30-60 s.

[0039] 3) Place the substrate or sheet with the spin-coated perovskite precursor solution on a hot plate at 100-180º for annealing to evaporate the solvent and crystallize to form a perovskite film. The organic solvent is one or a mixture of two or more of N,N-dimethylformamide (DMF), γ-butyrolactone (GBL), and dimethyl sulfoxide (DMSO).

[0040] The difference between this method and the method for preparing CH3NH3PbI3 thin films is that, in the preparation of [(CH2)3NH2]PbI3 thin films, the perovskite precursor solution is prepared by mixing a certain concentration of [(CH2)3NH2]I and PbI2 according to a certain ratio and molar mass. The molar ratio of [(CH2)3NH2]I to PbI2 is 1:1, and the total molar concentration of [(CH2)3NH2]I and PbI2 is 1-50 mol / L.

[0041] To prepare [CH3NH3]PbBr3 thin films, a mixed salt solution of [CH3NH3]Br and PbBr2 of a certain concentration was prepared according to the ratio and molar mass, with the molar ratio of [CH3NH3]Br to PbBr2 being 1:1 and the total molar concentration being 1-100 mol / L.

[0042] To prepare [CH3NH3]SnI3 thin films, a mixed salt solution of [(CH2)3NH2]I and SnI2 of a certain concentration was prepared according to the ratio and molar mass. The molar ratio of [(CH2)3NH2]I to SnI2 was 1:1, and the total molar concentration was 1-50 mol / L.

[0043] Other similar [(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, and the corresponding salt mixed solutions can be prepared by using one or more of the following solvents: DMF, GBL, and DMSO.

[0044] The two-step spin coating method is suitable for perovskite thin film materials consisting of two or more compounds. Specifically, the two or more compounds are mixed separately to form precursor solvents. Each precursor solvent is then deposited step by step, followed by heating and annealing to evaporate the solvent and crystallize to form a perovskite thin film.

[0045] The two-step method for preparing CH3NH3PbI3 thin films is as follows: 1) Prepare perovskite precursor solutions separately. Dissolve a certain amount of CH3NH3I salt in isopropanol (IPA) to prepare a solution with a concentration of 1-100 mol / L, and dissolve PbI2 in DMF solvent to prepare a solution with a concentration of 1-100 mol / L.

[0046] 2) Stepwise deposition: A PbI2 film can be deposited on the substrate or substrate using a spin-coating process. The substrate or substrate is pre-run at 300-500 rpm for 3-10 s, then run at 2000-3000 rpm for 30-60 s. Then, CH3NH3I salt is deposited by immersion or spin-coating. The immersion method involves placing the substrate or substrate into the salt solution for a few seconds. The spin-coating method is the same as described above.

[0047] 3) Place the substrate or sheet on a heating plate at 100-180º for annealing to allow the solvent to evaporate and crystallize to form a perovskite thin film.

[0048] To prepare [(CH2)3NH2]PbI3 thin films, perovskite precursor solutions were prepared into [(CH2)3NH2]I and PbI2 salt solutions at specific concentrations and amounts. To prepare [CH3NH3]PbBr3 thin films, perovskite precursor solutions were prepared into [CH3NH3]Br and PbBr2 salt solutions at specific concentrations and amounts. To prepare [CH3NH3]SnI3 thin films, the precursor solutions were prepared into [(CH2)3NH2]I and SnI2 salt solutions at specific concentrations and amounts. Other methods were similar to those for [(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 two corresponding salt solutions. The solvent used to prepare the precursor solution can be one or more of IPA, DMF, GBL, and DMSO. Steps 2) and 3) refer to the two-step method described above for preparing CH3NH3PbI3 thin films.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1) This invention utilizes a stainless steel mask as an etching mask tool for patterning perovskite arrays (hundreds of micrometers and above). It uses free electrons excited by inductively coupled plasma (ICP) technology, along with fluorine and chloride ions, to perform two etching processes on the halide perovskite thin film material outside the mask. Based on the elemental composition and film thickness of the halide perovskite material, suitable process parameters for ICP etching, such as atmosphere combination, atmosphere flow rate, plasma source RF excitation power, lower electrode power, and etching time, are designed to achieve perovskite thin film patterning. The perovskite thin film does not come into contact with any solvent, effectively preventing corrosion of the perovskite thin film by non-polar solvents. Furthermore, it is not limited by the type of perovskite and is applicable to all types of perovskite thin film materials.

[0051] 2) Reactive ion beam etching is performed in a high vacuum environment, which avoids the perovskite film from being in contact with water molecules in the air for a long time during the patterning process, thus preventing the perovskite film from degrading or failing. This provides a new process direction for perovskite array patterning.

[0052] 3) Compared with the existing template method for fabricating perovskite patterning, the technical solution of the present invention is simpler, and the plasma etching equipment has a simple structure, is compatible with all MEMS large-scale manufacturing plants, and reduces manufacturing costs.

[0053] 4) 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. Attached Figure Description

[0054] 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.

[0055] Figure 1 This is a schematic diagram of the structure of the first mask plate;

[0056] Figure 2 This is a schematic diagram of the second mask plate.

[0057] Figure 3 This is the XRD diffraction pattern of the thin film of Example 1 of the present invention;

[0058] Figure 4 This is a partial view of the halide perovskite array pattern in Embodiment 1 of the present invention. Detailed Implementation

[0059] 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.

[0060] Example 1

[0061] The following uses etching to create a 230 nm thick (Cs) layer. x (CH3NH2) y (CH3NH3) 1-x-y )Pb(I 1-z Br z )3. Taking thin films as an example:

[0062] Taking a perovskite array pattern of n=20 (columns) × m=20 (rows) as an example, the lattice is a square with side length a = b = 500μm, and the row and column resolution is c = d = 500μm. The stainless steel plates used for the first and second masks are 100μm thick.

[0063] The method for manufacturing photomasks, wherein both the first and second photomasks are made of thin stainless steel sheets:

[0064] 1. The first photomask is made into a perforated grid-like horizontal stripe photomask, such as... Figure 1 As shown, the length and width of the horizontal stripes are n*d and b, respectively, and the longitudinal spacing between the horizontal stripes and the adjacent stripes is c, with a total of m stripes. The stainless steel sheet is made using laser cutting and engraving technology, which can ensure that the dimensional accuracy of the grid stripes is >50 μm.

[0065] 2. The second mask is made into a perforated grid-like vertical striped mask, such as... Figure 2 As shown, the length and width of the vertical stripes are m*c and a, respectively, and the lateral spacing between adjacent vertical stripes is d, for a total of n stripes. A laser cutting and engraving technique is used to create the perforated plate, ensuring a stripe dimensional accuracy >50 μm. The pattern of the overlapping area formed by the combination of the first and second masks corresponds to the halide perovskite array pattern.

[0066] In this embodiment 1, n = m, a = b, c = d. After the first mask is rotated 90º along the XY plane, it becomes the second mask. Therefore, the second mask can be replaced by the first mask.

[0067] A method for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-E) technology includes the following steps:

[0068] 1) One-step preparation of halide perovskites (Cs)x (CH3NH2) y (CH3NH3) 1-x-y )Pb(I 1-z Br z 3. Thin film: a. Substrate cleaning: First, use a cleaning agent prepared with deionized water (deionized water and scouring powder are prepared in a mass ratio of 20:1) to ultrasonically clean twice, rinse with deionized water and blow dry; then use acetone to ultrasonically clean once and blow dry; then use alcohol to ultrasonically clean once and blow dry; O2 plasma can remove organic impurities on the surface of ITO substrate.

[0069] b. Perovskite thin film deposition: (1) Preparation of perovskite precursor solution: a certain amount of CH3NH2I, CH3NH3Br, PbI2 and PbBr2 are mixed in DMF and DMSO (DMF and DMSO in equal volume), CsI is dissolved in DMF solution, each substance is prepared with a molar concentration of 1 mol / L, and the above 5 solvent substances are mixed in equal proportion;

[0070] (2) Spin coating: The substrate is adsorbed on the spin coater, and the perovskite precursor solution is covered on the surface of the substrate. The substrate is pre-run at 300 rpm for 5 s, and then run at 6000 rpm for 30 s.

[0071] (3) The substrate with spin-coated perovskite precursor solution is placed on a 100º heating plate for annealing to allow the solvent to evaporate and crystallize to form a perovskite film.

[0072] 2) Ion etching array patterning: includes the following steps:

[0073] a. First, a first mask is placed on the halide perovskite film and positioned and fixed (using an optical microscope or substrate transfer platform, the position of the mask on the perovskite film etching pattern is checked to complete the alignment operation). After the mask is aligned, the mask and perovskite film substrate are fixed with resin adhesive or spring clips. Adhesive resin adhesive can buffer micro-movements between the mask and the perovskite film substrate; spring clips provide elastic cushioning. Both can prevent displacement between the mask and the perovskite film substrate, improving the accuracy of the perovskite film etching pattern. The film to be etched is adhered to the equipment tray using thermally conductive silicone oil, and polyimide high-temperature tape is applied around the film to ensure the stability of the etching rate. Then, it is placed in the rapid sample inlet chamber of the inductively coupled plasma etching system (from Oxford Instruments, UK, ICP) under vacuum conditions (vacuum degree 1.0e during transport). -2 The halide perovskite thin film and the first mask are transferred to the etching chamber at a vacuum level of 1.0 ePa. -7 Pa;

[0074] b. Etching the perovskite film: The stage temperature was set to 30℃, the back helium pressure to 10 Torr, the upper electrode power to 800 W, the lower electrode power to 50 W, the Cl2 gas flow rate to 12 sccm, the CHF3 gas flow rate to 2 sccm, the Ar gas flow rate to 9 sccm, the process pressure to 4 mTorr, and the etching time to 8 min. The halide perovskite film and the first mask were then removed. Under the influence of the high-energy, high-frequency magnetic field of the electrodes, Ar in the combined atmosphere acts as a balancing gas and is also excited to an excited state, which helps the perovskite film react with the corrosive ion gases. Cl2 and CHF3 can excite the generation of free matrix Cl and F. - and H + The reaction formula is as follows:

[0075] Ar→Ar + + e -

[0076] Cl2+e - →Cl + Cl -

[0077] Cl2+e - →Cl+Cl + e -

[0078] Cl2+e - →Cl + +Cl - + e -

[0079] CHF3→ CF x + H + + e -

[0080] CHF3+ e - →CHF2+ F -

[0081] Among them, free matrix electrons, H + F - and Cl - When the unmasked perovskite film comes into contact with the free substrate, a chemical reaction occurs, generating gas which is expelled from the reaction chamber. The reaction formula for the CH3NH3PbI3 film is as follows:

[0082] CH3NH3 + + e - → CH3NH3(gas)

[0083] CH3NH2 + + H + + 2e - → CH3NH3(gas)

[0084] CH3NH3+ H + → CH x (gas) + NH x (gas)

[0085] Pb 2+ + F - → PbF2(gas)

[0086] Pb 2+ + Cl - → PbCl2(gas)

[0087] Cs + + F - → CsF (gas)

[0088] Cs + + Cl - → CsCl (gas)

[0089] I - + H + → HI (gas)

[0090] c. Next, cover the halide perovskite film with a second mask, fix it in place (using the same method as above), and place it in the rapid sample inlet chamber of the inductively coupled plasma etching system. Repeat the transfer to the etching chamber and etching steps for the perovskite film (process parameters are the same as above, etching for 6 min (2 min less than the first etching). Remove the halide perovskite film and the second mask, and remove the second mask. The resulting 500 nm thick (Cs) film... x (CH3NH2) y (CH3NH3) 1-x-y )Pb(I 1-z Br z )3. A pattern of a thin-film square perovskite array with a side length of 500 μm.

[0091] Figure 3 This is the XRD diffraction pattern of the thin film. Figure 3 It can be seen that the film only shows diffraction peaks at 14.16°, 19.8°, 24.4°, 28.1°, 31.55°, 34.67°, 40.17° and 42.7°. The combination of these peak positions is consistent with the crystal phase of perovskite XRD rays, and no diffraction peaks of PbI2, PbBr2, FAI or MABr are found. This confirms that the perovskite film is a pure phase and a film with high crystallinity.

[0092] Figure 4 To use stainless steel as a mask, an array pattern with a side length of 500 μm was etched.

[0093] Example 2

[0094] Taking an n (column) × m (row) array as an example, the lattice side length and width are a and b, respectively, and the row and column resolutions are c and d, where the dimensions of a, b, c, and d are greater than 100 μm. The thickness of the first and second masks is 50 μm.

[0095] The method for manufacturing the photomask is the same as in Example 1. Both the first and second photomasks are made of stainless steel sheets.

[0096] A method for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-E) technology includes the following steps:

[0097] 1) Preparation of halide perovskite thin films (selecting [CH3NH3]PbBr3 thin films, one-step method): a. Substrate cleaning: First, use a cleaning agent prepared with deionized water (deionized water and scouring powder are prepared in a mass ratio of 20:1) to ultrasonically clean twice, rinse with deionized water and blow dry; then use acetone to ultrasonically clean once and blow dry; then use alcohol to ultrasonically clean once and blow dry; O2 or Ar plasma can be used to remove organic impurities on the surface of the ITO substrate.

[0098] b. Perovskite film deposition: (1) Preparation of perovskite precursor solution: a certain amount of [CH3NH3]Br and PbBr2 are mixed in DMF at a molar ratio of 1:1, with a total molar concentration of 1 mol / L;

[0099] (2) Spin coating: The substrate is adsorbed on the spin coater, and the perovskite precursor solution is covered on the surface of the substrate. The substrate is pre-run at 400 rpm for 3 s, and then run at 2500 rpm for 40 s.

[0100] (3) Place the substrate or sheet with spin-coated perovskite precursor solution on a 150º heating plate for annealing to allow the solvent to evaporate and crystallize to form a perovskite thin film.

[0101] 2) Ion etching array patterning: includes the following steps:

[0102] a. First, cover the halide perovskite thin film with a first mask and fix it in place (method as described in Example 1). Then, place it in the rapid sample injection chamber of an inductively coupled plasma etching system (from Oxford Instruments, UK, ICP) under vacuum conditions (vacuum degree is 1.0 e during transport). -2 After transferring the halide perovskite thin film and the first mask to the etching chamber (Pa), the vacuum level is adjusted to 1.0 e. -9 Pa;

[0103] b. Etching the perovskite thin film:

[0104] The sample stage temperature was set to 30℃, the back helium pressure to 10 Torr, the upper electrode power to 800 W, the lower electrode power to 50 W, the Cl2 gas flow rate to 12 sccm, the CHF3 gas flow rate to 2 sccm, the Ar gas flow rate to 9 sccm, the process pressure to 4 mTorr, and the etching time to 8 min. The halide perovskite film and the first mask were removed, and the first mask was unloaded. Under the influence of the high-energy, high-frequency magnetic field of the electrodes, Ar in the combined atmosphere served as a balancing gas and was also excited to an excited state, which facilitated the reaction between the perovskite film and the corrosive ion gas. Cl2 and CHF3 could excite the generation of free matrix Cl and F. - and H + The reaction formula is as follows:

[0105] Ar→Ar + + e -

[0106] Cl2+e - →Cl + Cl -

[0107] Cl2+e - →Cl+Cl + e -

[0108] Cl2+e - →Cl + +Cl - + e -

[0109] CHF3→ CF x + H + + e -

[0110] CHF3+ e - →CHF2+ F -

[0111] Among them, free matrix electrons, F - and Cl - When the unmasked perovskite film comes into contact with the free substrate, a chemical reaction occurs, generating gas which is expelled from the reaction chamber. The reaction equations during etching are as follows:

[0112] CH3NH3 + + e - → CH3NH3(gas)

[0113] CH3NH3+ H + → CH x (gas) + NH x (gas)

[0114] Pb 2+ + F - → PbF2(gas)

[0115] Pb 2+ + Cl - → PbCl2(gas)

[0116] I - + H + → HI (gas)

[0117] c. Cover the halide perovskite film with a second mask, fix it in place (using the same method as above), and place it in the rapid sample inlet of the inductively coupled plasma etching system. Repeat the steps of transferring to the etching chamber and etching the perovskite film (process parameters are the same as above). Remove the halide perovskite film and the second mask, and then remove the second mask.

[0118] Example 3

[0119] Taking an n (column) × m (row) array as an example, the lattice side length and width are a and b, respectively, and the row and column resolutions are c and d, where the dimensions of a, b, c, and d are greater than 100 μm. The thickness of the first and second masks is 100 μm.

[0120] The method for manufacturing the mask plate is described in Example 1.

[0121] A method for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-E) technology includes the following steps:

[0122] 1) Preparation of halide perovskite thin films (CsPbI3 thin films, one-step method): a) Substrate cleaning: First, use a cleaning agent prepared with deionized water (deionized water and scouring powder are prepared in a mass ratio of 20:1) to ultrasonically clean twice, rinse with deionized water and blow dry; then use acetone to ultrasonically clean once and blow dry; then use alcohol to ultrasonically clean once and blow dry; O2 or Ar plasma can be used to remove organic impurities on the surface of the ITO substrate.

[0123] b. Perovskite film deposition: (1) Preparation of perovskite precursor solution: A certain amount of CsI and PbI2 are mixed in DMF at a molar ratio of 1:1, with a total molar concentration of 10 mol / L;

[0124] (2) Spin coating: The substrate is adsorbed on the spin coater, and the perovskite precursor solution is covered on the surface of the substrate. The substrate is pre-run at 500 rpm for 10 s, and then run at 3000 rpm for 60 s.

[0125] (3) Place the substrate or sheet with spin-coated perovskite precursor solution on a 180º heating plate for annealing to allow the solvent to evaporate and crystallize to form a perovskite thin film.

[0126] 2) Ion etching array patterning: includes the following steps:

[0127] a. First, cover the halide perovskite thin film with a first mask and fix it in place (method as described in Example 1). Then, place it in the rapid sample injection chamber of the inductively coupled plasma etching system (from Oxford Instruments, UK, ICP) under vacuum conditions (vacuum degree is 1.0e during transport). -2 After transferring the halide perovskite thin film and the first mask to the etching chamber (Pa), the vacuum level is adjusted to 1.0 e. -7 Pa;

[0128] b. Etching the perovskite thin film:

[0129] The stage temperature was set to 30 °C, the back helium pressure to 10 Torr, the upper electrode power to 300 W, the lower electrode power to 20 W, the BCl3 gas flow rate to 15 sccm, the CHF3 gas flow rate to 5 sccm, the Ar gas flow rate to 1 sccm, the process pressure to 3 mTorr, and the etching time to 8 min. The halide perovskite film and the first mask were then removed, and the first mask was unloaded. Under the influence of the high-energy, high-frequency magnetic field of the electrodes, Ar in the combined atmosphere acts as a balancing gas and is also excited to an excited state, which helps the perovskite film react with the corrosive ion gases. Cl2 and CHF3 can excite the generation of free matrix Cl and F. - and H + The reaction formula is as follows:

[0130] Ar→Ar + + e -

[0131] Cl2+e - →Cl + Cl -

[0132] Cl2+e - →Cl+Cl + e -

[0133] Cl2+e - →Cl + +Cl - + e -

[0134] BCl3+e - →BCl2+ Cl -

[0135] BCl2+e -→BCl + Cl + e -

[0136] CHF3→ CF x + H + + e -

[0137] CHF3+ e - →CHF2+ F -

[0138] Among them, free matrix electrons, F - and Cl - When the unmasked perovskite film comes into contact with the free substrate, a chemical reaction occurs, generating gas which is expelled from the reaction chamber. The reaction equations during etching are as follows:

[0139] Cs + + F - → CsF (g)

[0140] Cs + + Cl - → CsCl (gas)

[0141] Pb 2+ + F - → PbF2(gas)

[0142] Pb 2+ + Cl - → PbCl2(gas)

[0143] I - + H + → HI (gas)

[0144] c. Cover the halide perovskite film with a second mask, fix it in place (using the same method as above), and place it in the rapid sample inlet of the inductively coupled plasma etching system. Repeat the steps of transferring to the etching chamber and etching the perovskite film (process parameters are the same as above). Remove the halide perovskite film and the second mask, and then remove the second mask.

[0145] Example 4

[0146] Taking an n (column) × m (row) array as an example, the lattice side length and width are a and b, respectively, and the row and column resolutions are c and d, where the dimensions of a, b, c, and d are greater than 100 μm. The thickness of the first and second masks is 80 μm.

[0147] The method for manufacturing the mask plate is described in Example 1.

[0148] A method for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-E) technology includes the following steps:

[0149] 1) Preparation of halide perovskite thin films (selecting [CH3NH3]SnI3 thin films): a. Substrate cleaning: First, use a cleaning agent prepared with deionized water (deionized water and scouring powder are prepared in a mass ratio of 20:1) to ultrasonically clean twice, rinse with deionized water and blow dry; then use acetone to ultrasonically clean once and blow dry; then use alcohol to ultrasonically clean once and blow dry; O2 or Ar plasma can be used to remove organic impurities on the surface of the ITO substrate.

[0150] b. Perovskite film deposition: (1) Preparation of perovskite precursor solution: A certain amount of [(CH2)3NH2]I and SnI2 are mixed in GBL at a molar ratio of 1:1, and the total molar concentration is 1 mol / L;

[0151] (2) Spin coating: The substrate is adsorbed on the spin coater, and the perovskite precursor solution is covered on the surface of the substrate. The substrate is pre-run at 500 rpm for 10 s, and then run at 3000 rpm for 60 s.

[0152] (3) Place the substrate or sheet with spin-coated perovskite precursor solution on a 180º heating plate for annealing to allow the solvent to evaporate and crystallize to form a perovskite thin film.

[0153] 2) Ion etching array patterning: includes the following steps:

[0154] a. First, cover the halide perovskite thin film with a first mask and fix it in place (method as described in Example 1). Then, place it in the rapid sample injection chamber of the inductively coupled plasma etching system (from Oxford Instruments, UK, ICP) under vacuum conditions (vacuum degree is 1.0e during transport). -2 After transferring the halide perovskite thin film and the first mask to the etching chamber (Pa), the vacuum level is adjusted to 1.0 e. -7 Pa;

[0155] b. Etching the perovskite thin film:

[0156] The stage temperature was set to 30 °C, the back helium pressure to 10 Torr, the upper electrode power to 800 W, the lower electrode power to 50 W, the Cl2 gas flow rate to 85 sccm, the CHF3 gas flow rate to 5 sccm, the Ar gas flow rate to 2 sccm, the process pressure to 4 mTorr, and the etching time to 10 min. The halide perovskite film and the first mask were then removed, and the first mask was unloaded. Under the influence of the high-energy, high-frequency magnetic field of the electrodes, Ar in the combined atmosphere acts as a balancing gas and is also excited to an excited state, which helps the perovskite film react with the corrosive ion gases. Cl2 and CHF3 can excite the generation of free matrix Cl and F.- and H + The reaction formula is as follows:

[0157] Ar→Ar + + e -

[0158] Cl2+e - →Cl + Cl -

[0159] Cl2+e - →Cl+Cl + e -

[0160] Cl2+e - →Cl + +Cl - + e -

[0161] CHF3→ CF x + H + + e -

[0162] CHF3+ e - →CHF2+ F -

[0163] Among them, free matrix electrons, F - and Cl - When the unmasked perovskite film comes into contact with the free substrate, a chemical reaction occurs, generating gas which is expelled from the reaction chamber. The reaction formula during the etching of the [CH3NH3]SnI3 film is as follows:

[0164] CH3NH3 + + e - → CH3NH3(gas)

[0165] CH3NH3+ H + → CH x (gas) + NH x (gas)

[0166] Sn 2+ + F - → SnF2(gas)

[0167] Sn 2+ + Cl - → SnCl2(gas)

[0168] I - + H + → HI (gas)

[0169] c. Cover the halide perovskite film with a second mask, fix it in place (using the same method as above), and place it in the rapid sample inlet of the inductively coupled plasma etching system. Repeat the steps of transferring to the etching chamber and etching the perovskite film (process parameters are the same as above). Remove the halide perovskite film and the second mask, and then remove the second mask.

Claims

1. A method for fabricating halide perovskite array patterns using inductively coupled plasma etching (ICP-CPE), characterized in that, Includes the following steps: 1) Preparation of halide perovskite thin films; 2) Ion etching array pattern: A mask is placed on the halide perovskite film in step 1). The pattern formed by the mask corresponds to the halide perovskite array pattern. After etching using inductively coupled plasma etching technology, the mask is removed to form the halide perovskite film array pattern. In step 2), the mask includes a first mask and a second mask, and the pattern formed by the combination of the first mask and the second mask corresponds to the halide perovskite array pattern; In step 2), the first mask is made into a hollow grid-shaped horizontal stripe mask, and the second mask is made into a hollow grid-shaped vertical stripe mask. The pattern of the overlapping area formed by the combination of the first mask and the second mask corresponds to the halide perovskite array pattern. In step 2), ion etching employs an inductively coupled plasma etching system, and the etching method includes the following steps: a. First, cover the halide perovskite film with the first mask plate. After positioning and fixing, place it in the rapid sample injection chamber of the inductively coupled plasma etching system. Under vacuum environment, transfer the halide perovskite film and the first mask plate to the etching chamber. b. Etching the perovskite film: Gas is introduced, and the upper electrode power is 300-800 W, the lower electrode power is 20-100 W, and the process pressure is 1-10 mTorr. Etching is carried out for 1-20 min. The halide perovskite film and the first mask are then removed. The first mask is then unloaded. c. Next, cover the halide perovskite film with a second mask, fix it in position, and place it in the rapid sample inlet of the inductively coupled plasma etching system. Refer to steps a and b to etch the perovskite film, remove the halide perovskite film and the second mask, and then remove the second mask.

2. The method for fabricating halide perovskite array patterns using inductively coupled plasma etching technology as described in claim 1, characterized in that, In step 2), both the first and second mask plates are made of stainless steel sheets.

3. The method for fabricating halide perovskite array patterns using inductively coupled plasma etching technology as described in claim 1, characterized in that, In steps b and c, the gas used for etching the perovskite film includes at least a chlorine-based atmosphere.

4. The method for fabricating halide perovskite array patterns using inductively coupled plasma etching technology as described in claim 3, characterized in that, In steps b and c, the chlorine-based atmosphere is one or a combination of two of Cl2 and BCl3.

5. The method for fabricating halide perovskite array patterns using inductively coupled plasma etching technology as described in claim 4, characterized in that, In steps b and c, the gas also includes one or a combination of two of CHF3 and Ar.

6. The method for fabricating halide perovskite array patterns using inductively coupled plasma etching technology as described in claim 5, characterized in that, In steps b and c, the flow rate of the chlorine atmosphere is 10-40 sccm, the flow rate of CHF3 is 1-5 sccm, the flow rate of Ar is 1-20 sccm, and the other process parameters of the system are: sample stage temperature is 20-30 ℃, and back helium pressure is 5-15 Torr.

7. The method for fabricating halide perovskite array patterns using inductively coupled plasma etching technology as described in claim 6, characterized in that, In step 1), the halide perovskite thin film is prepared by a one-step spin coating method or a two-step spin coating method.

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