Method and device for producing a perovskite-containing layer on a semiconductor substrate

Abstract

The invention relates to a method for producing a perovskite-containing layer on a semiconductor substrate, comprising the method steps A: providing a semiconductor substrate; B: applying a solution to the semiconductor substrate; and C: annealing the semiconductor substrate, wherein the perovskite-containing layer is formed by means of multiple precursors and the solution has at least a portion of the precursors. It is essential that, in method step B, the solution is applied to the semiconductor substrate by means of a rotary printing method using at least one rotating printing cylinder.

Description

[0001] title

[0002] Method and apparatus for producing a perovskite-containing layer

[0003] on a semiconductor substrate

[0004] Description

[0005] The invention relates to a method for producing a perovskite-containing layer on a semiconductor substrate according to claim 1, a device for producing a perovskite-containing layer on a semiconductor substrate according to claim 14, and the use of a device with at least one rotating pressure cylinder for forming a perovskite-containing layer on a semiconductor substrate according to claim 17.

[0006] Semiconductor structures containing a perovskite layer have been researched for several years. The use of perovskite layers offers great potential, particularly for the production of photovoltaic solar cells, especially multi-junction solar cells, and in particular tandem solar cells based on a silicon substrate.

[0007] To create a perovskite-containing layer (hereinafter also referred to as perovskite layer) on a semiconductor substrate, a solution is applied to the prepared semiconductor substrate and then heated in a annealing step. The solution contains precursors for the formation of the perovskite layer. Two different methods for creating the perovskite-containing layer have been investigated so far:

[0008] A) In a wet chemical process, the solvent, which contains all the essential precursors for generating the perovskite-containing layer, is applied to the semiconductor substrate by means of spin coating.

[0009] B) In a hybrid process, a portion of the precursors, in particular inorganic components for forming the perovskite-containing layer, is first vapor-deposited, followed by the application of a solution liquid by centrifugal coating, wherein the solution liquid contains further precursors, in particular organic components for forming the perovskite layer.

[0010] 34769-P-WO Di / co 28.11.2025 These two approaches are described in Schulze et al., Perovskite hybrid evaporation / spincoating method: From band gap tuning to thin film deposition on textures, Thin Solid Films Volume 704, 30 June 2020, 137970, https: / / doi.Org / 10.1016 / j.tsf.2020.137970, in particular Figure 1 and the accompanying description.

[0011] The methods investigated so far for producing a perovskite-containing layer have the disadvantage that no upscaling and, in particular, no significant increase in processing speed for industrial application, especially in an inline process, is possible.

[0012] The present invention therefore aims to provide a method for producing a perovskite-containing layer on a semiconductor substrate which avoids or at least reduces the aforementioned disadvantages.

[0013] This problem is solved by a method according to claim 1, by a device according to claim 14, and by a use according to claim 17. Advantageous embodiments are found in the dependent claims.

[0014] The method according to the invention is preferably designed to be carried out using the device according to the invention, in particular a preferred embodiment thereof. The device according to the invention is preferably designed to carry out the method according to the invention, in particular a preferred embodiment thereof.

[0015] The inventive method for producing a perovskite-containing layer on a semiconductor substrate comprises the following process steps:

[0016] In process step A, a semiconductor substrate is provided. In process step B, a solvent is applied to the semiconductor substrate. In process step C, the semiconductor substrate is annealed.

[0017] 34769-P-WO Di / co 28.11.2025 It is essential that in process step B the solvent is applied to the semiconductor substrate by means of a rotary printing process using at least one rotating printing cylinder.

[0018] Investigations by the applicant show that the methods used to date, in particular centrifugal coating, are cost-intensive. The use of a rotary printing process for applying the solvent in process step B enables a uniform, homogeneous application of the solvent with high throughput, especially in an inline process, and is also more cost-effective compared to centrifugal coating.

[0019] A key difference between spin coating and rotary printing is that in spin coating the substrate rotates, whereas in rotary printing at least one rotating printing cylinder is used to apply the solvent fluid either indirectly (for example, via other rotating cylinders) or directly (directly) to the semiconductor substrate. The solvent fluid is preferably applied to a surface of the printing cylinder and transferred from this surface directly (direct printing) or indirectly (indirect printing) via one or more transfer cylinders used in the printing process to the surface of the semiconductor substrate.

[0020] Investigations by the applicant show that the methods examined so far have particular disadvantages when using textured semiconductor substrates: The previously known methods lead to uneven deposition on textured semiconductor substrates and / or are not cost-effectively scalable in terms of throughput for textured surfaces due to high effort and throughput. The purely wet-chemical method known from the prior art has significant disadvantages with textured semiconductor substrates, particularly due to uneven deposition, and essentially only works with sufficient quality, especially with sufficient homogeneity, on planar or sub-pm textured surfaces. The spin coating method is cost-intensive and therefore not suitable for industrial production.The established method using purely vapor-deposited perovskite layers enables the uniform application of perovskite layers to planar and textured surfaces.

[0021] 34769-P-WO Di / co 28.11.2025 Semiconductor material, but has significant disadvantages in process control, especially the evaporation of organic precursors of the perovskite material, and is also limited in throughput and cost-intensive.

[0022] In an advantageous embodiment of the process, the surface of the semiconductor substrate is pretreated before the application of the solvent in process step B in order to modify the surface properties, in particular by means of plasma treatment, adhesion promoters or the application of particles to the surface of the semiconductor substrate.

[0023] The pretreatment thus serves to optimize the process and can serve one or more of the further goals described below.

[0024] One goal of pretreatment can be to selectively modify the surface energy of the substrate surface. The advantage of this is improved wetting of the surface with the solution applied in process step B, resulting in a more uniform and homogeneous application of the liquid.

[0025] Preferably, the surface is pretreated with a cold atmosphere plasma using ionized nitrogen.

[0026] Another goal of pretreatment, independent of or combinable with the above, can be to improve the nucleation and subsequent crystallization of the perovskite-containing layer. This can be achieved, for example, by applying particles, particularly seed crystals, to the surface of the semiconductor substrate. The advantage is the targeted control of crystal growth, which increases the crystal quality and homogeneity of the final layer.

[0027] Preferably, AlOx particles dissolved in ethanol (AIO) are used. X ) applied using a wet chemical process to ensure a uniform particle distribution on the

[0028] 34769-P-WO Di / co 28.11.2025 Surface to be achieved.

[0029] Preferred methods for carrying out this pretreatment include, for example, plasma treatment, corona treatment, the application of an adhesion promoter, or the targeted application of particles.

[0030] This surface treatment precedes the actual printing process and can take place at different times depending on the design of the overall process.

[0031] If the process is carried out as a purely wet chemical process in which all precursors are contained in the solvent, this surface treatment preferably takes place before process step B.

[0032] If the process is carried out as a hybrid process, in which a portion of the perovskite precursors is first vapor-deposited, the surface treatment of the substrate surface can advantageously take place before and / or after this vapor deposition step.

[0033] A surface treatment prior to the vapor deposition step aims to modify the growth, porosity, and morphology of the perovskite precursors to be deposited. This improves the interaction with the subsequent pressure and annealing steps and can also optimize nucleation and crystallization.

[0034] Preferably, AlOx particles dissolved in ethanol (AIO) are used. X ) applied using a wet chemical process to achieve a uniform particle distribution on the surface.

[0035] 34769-P-WO Tue / co 28.11.2025 A surface treatment after the vapor deposition step serves to optimize the process by specifically adjusting the surface energy of the already coated surface. This improves the wetting with the solvent applied in the subsequent printing step and also improves the final crystallization of the perovskite-containing layer.

[0036] Preferably, the surface is pretreated after the vapor deposition step with a cold atmosphere plasma using ionized nitrogen in a protective gas atmosphere (N2).

[0037] It is therefore advantageous that the pretreatment takes place between process steps A and B, in particular that the precursors are divided into a first and a second subset and that the first subset of the precursors is provided with the semiconductor substrate in process step A and the solvent in process step B comprises the second subset of the precursors.

[0038] Possible methods for surface pretreatment include, in particular, plasma treatment, corona treatment, the application of an adhesion promoter, or the application of particles such as seed crystals.

[0039] The method according to the invention is characterized by the fact that it can be used cost-effectively and scalably even on textured semiconductor substrates. Particularly for the production of photovoltaic solar cells, it is advantageous to texture at least one surface, preferably the surface facing the incident radiation. This allows for multiple reflections and / or, by oblique incidence, the lengthening of the beam path in the substrate, resulting in higher absorption and thus higher efficiency. The method according to the invention is particularly advantageous in the following applications:

[0040] 34769-P-WO Di / co 28.11.2025 the use of textured semiconductor substrates a cost-effective, high-throughput process.

[0041] In an advantageous embodiment, a semiconductor substrate with a textured surface is provided in process step A. In this advantageous embodiment, the semiconductor substrate has a textured surface onto which the solvent is applied in process step B. To achieve high efficiencies, particularly in the formation of solar cells, it is advantageous for the textured surface of the semiconductor substrate to have pyramidal structures, wherein the pyramids preferably have a mean base length of 0.5 pm to 10 pm, more preferably 0.5 pm to 5 pm, and more preferably 1 pm to 5 pm.

[0042] Investigations by the applicant show that a pressure cylinder with a flexible, in particular compressible, outer surface is preferably used to apply the solution liquid to the substrate. This compensates for unevenness and textures of the semiconductor substrate and enables a uniform distribution of the solution liquid.

[0043] Preferably, at least the outer surface of the printing cylinder has a Shore hardness (Shore A) in the range of 40 to 90.

[0044] Preferably, a printing cylinder is used whose outer surface has one or more of the layers from the group consisting of rubber layer, photopolymer layer, chromium layer, copper layer, nickel layer, preferably with a layer thickness in the range of 0.1 mm to 20 mm.

[0045] In particular, the use of a cylinder with a rubber outer surface for applying the solvent to the semiconductor substrate is advantageous, preferably with a layer thickness in the range of 0.1 mm to 20 mm.

[0046] Investigations by the applicant show that carrying out the process according to the invention under ambient atmosphere, particularly in an atmosphere containing oxygen, is fundamentally possible. However, to form a perovskite-containing layer that is homogeneous and has a predeterminable thickness, it is advantageous to conduct chemical reactions of the substances in the solvent liquid with gases from the ambient atmosphere.

[0047] 34769-P-WO Di / co 28.11.2025 to avoid or at least reduce the aforementioned reactions. Investigations by the applicant show that a particularly good quality of the perovskite-containing layer is achieved when a protective gas, in particular an inert gas, is supplied to the pressure cylinder in order to avoid or reduce the aforementioned reactions. It is therefore advantageous to carry out the process according to the invention in a protective gas atmosphere, in particular an inert gas atmosphere.

[0048] The protective gas preferably has a lower oxygen content than the ambient atmosphere, in particular essentially no oxygen, preferably no oxygen at all. In particular, an inert gas is preferably used as the protective gas, preferably one or more of the following gases: nitrogen, argon.

[0049] It is therefore advantageous to create a protective gas atmosphere at least for those areas of the cylinder's outer surface that are covered with the solvent. When using several rotating cylinders, it is advantageous to create a protective gas atmosphere, in particular a protective gas purge, at least for those outer surfaces of the cylinders that are covered with the solvent.

[0050] The process is therefore advantageously designed such that in process step B a protective gas environment is generated at least for the surface of the pressure cylinder wetted with solvent, in particular a protective gas purge, and in particular that several rotating cylinders are used for applying the solvent and a protective gas environment is generated at least for the surfaces of the cylinders wetted with solvent, in particular a protective gas purge, wherein the protective gas is preferably an inert gas.

[0051] In an advantageous embodiment, the process is designed as a wet chemical process: In process step B, a solution liquid containing the precursors of the perovskite material, in particular all precursors necessary for the formation of the perovskite material, is applied to the semiconductor substrate. This eliminates the need to apply precursors before process step B, resulting in lower costs.

[0052] 34769-P-WO Tue / co 28.11.2025 In an alternative advantageous embodiment, the process is designed as a hybrid process. In this advantageous embodiment, the precursors are divided into a first and a second subset, and the first subset of the precursors is provided with the semiconductor substrate in process step A, while the solution liquid in process step B comprises the second subset of the precursors.

[0053] It is particularly advantageous that the precursors provided in process step A are deposited onto the semiconductor substrate by vapor deposition, especially that inorganic precursors are deposited onto the semiconductor substrate by vapor deposition in process step A, in particular one or more precursors from the list of lead halides, tin halides, and cesium halides. This results in the advantage of a particularly homogeneous and conformal perovskite-containing layer.

[0054] The vapor deposition is preferably carried out by means of co-evaporation, in particular as described in https: / / doi.org / 10.1021 / acsaem.3c00698, https: / / doi.org / 10.1002 / pip.3770.

[0055] When the process is designed as a hybrid process, it is advantageous to achieve particularly homogeneous layers if the solvent contains one or more organic precursors, in particular if all organic precursors are provided in process step B by means of the solvent.

[0056] The method according to the invention can be designed as a direct printing method using exactly one rotating printing cylinder.

[0057] In an advantageous embodiment, the printing process is designed as an indirect printing process. Advantageously, in the process according to the invention, one or more further rotating cylinders are used to supply the solvent to the printing cylinder. In particular, the use of a cylinder designed as an anilox roller and / or as a dipping roller for supplying the solvent to the printing cylinder is advantageous for achieving a homogeneous layer.

[0058] 34769-P-WO Di / co 28.11.2025The inventive method can be designed as a flexographic printing process or as a gravure printing process.

[0059] The printing cylinder is preferably designed as a form cylinder, especially when the process is designed as a flexographic printing process.

[0060] In this advantageous embodiment of the printing process as an indirect printing process using several cylinders, it is correspondingly advantageous, as described above, to supply protective gas, in particular inert gas, to several, in particular to all, cylinders used for the printing process, so that a protective gas environment is preferably created on the outer surfaces of the cylinders, at least in the partial areas which are covered with solvent.

[0061] In an advantageous embodiment of the process, the solvent is therefore applied in process step B by means of a rotary printing process, in particular the flexographic printing process, wherein the printing process is designed as a direct printing process and preferably a cylinder with a material that is flexible at least on its outer surface, in particular rubber, is used as the printing cylinder, in particular a printing form cylinder, or the printing process is designed as an indirect printing process, in particular indirect gravure printing, using at least one additional rotating transfer cylinder and the transfer cylinder has a flexible material, in particular rubber, at least on its outer surface.

[0062] It is within the scope of the invention that in process step A a semiconductor substrate is provided which is coated with one or more layers and / or has further structures, in particular contact structures, especially metallic structures. It is also within the scope of the invention to form further layers and / or structures, in particular contact structures, after the perovskite layer has been produced.

[0063] The process according to the invention is particularly suitable for the formation of semiconductors based on a silicon substrate. It is therefore advantageous that in process step A a

[0064] 34769-P-WO Di / co 28.11.2025 Silicon substrate is provided as a semiconductor substrate, in particular a silicon substrate coated with one or more layers.

[0065] The method according to the invention is suitable for producing a perovskite-containing layer on a flexible or preferably on a rigid semiconductor substrate.

[0066] The method according to the invention is preferably used for the production of photovoltaic solar cells. In particular, the method according to the invention is preferably designed for the production of a photovoltaic solar cell. The production of multi-junction solar cells, which have several sub-cells, is particularly promising for increasing the overall efficiency, wherein one or more of the sub-cells are formed using the perovskite-containing layer. The production of a tandem solar cell is particularly advantageous in this respect. Investigations show that the production of a multi-junction solar cell, which has a silicon-based sub-junction and a sub-junction based on a perovskite-containing layer, and especially a tandem solar cell produced in this way, exhibits an advantageous ratio of efficiency to production costs.

[0067] Advantageously, in process step A, a silicon substrate is provided as a semiconductor substrate for forming a solar cell. It is within the scope of the invention that the silicon substrate is coated with one or more layers and / or has one or more structures for forming the solar cell. Advantageously, the semiconductor substrate is designed as a silicon substrate coated with one or more layers.

[0068] Typical silicon substrates for use in tandem or multiple solar cells can have, among others, TOPCon, PERC or SHJ architectures.

[0069] The aforementioned problem is further solved by a device for producing a perovskite-containing layer on a semiconductor substrate according to claim 11.

[0070] The device according to the invention for producing a perovskite-containing layer on a semiconductor substrate comprises a conveying device for the semiconductor substrate, at least one

[0071] 34769-P-WO Di / co 28.11.2025 Printing cylinder and a feed unit for supplying solvent to the printing cylinder.

[0072] The conveying device, pressure cylinder, and feed unit are designed and arranged to work together in order to apply the solution fluid to the semiconductor substrate, preferably over a surface. The solution fluid is applied to the semiconductor substrate by means of the pressure cylinder.

[0073] It is essential that the device has at least one protective gas unit for forming a protective gas environment, wherein the protective gas unit is designed to interact with the pressure cylinder in order to form a protective gas environment at least on the surface of the pressure cylinder covered with solvent, in particular that the protective gas unit is designed as an inert gas unit.

[0074] The device according to the invention thus enables the cost-effective production of the perovskite-containing layer on the semiconductor substrate with a higher throughput compared to previously known methods. At the same time, a high quality of the perovskite-containing layer, in particular a homogeneous formation due to the supply of protective gas to the pressure cylinder, can be achieved.

[0075] In an advantageous embodiment, the protective gas unit has a protective gas container in which at least the pressure cylinder is arranged; in particular, it is advantageous that the protective gas container is designed as the housing of the device.

[0076] In this advantageous design, protective gas, preferably inert gas, can be supplied to the protective gas container, thereby creating a protective gas atmosphere on the outer surface of the pressure cylinder in a structurally simple manner.

[0077] Advantageously, the protective gas container has a feed opening for supplying the semiconductor substrate into the protective gas container and, more preferably, an additional outlet opening for supplying the semiconductor substrate out of the protective gas container. In particular, the conveying device is preferably designed to feed the semiconductor substrate through the feed opening into

[0078] 34769-P-WO Di / co 28.11.2025 to introduce the protective gas container and preferably discharge it through the outlet opening. In an advantageous embodiment, the conveying device penetrates the inlet opening, and preferably also the outlet opening.In an alternative advantageous embodiment, the conveying device has an interruption in the area of ​​the feed opening and, more preferably, in the area of ​​the discharge opening, and is designed to transfer the semiconductor substrate through the feed opening from a part of the conveying device located outside the protective gas container, which is arranged in the transport direction upstream of the protective gas container, to a part located inside the protective gas container through the feed opening, and preferably from the part of the conveying device located inside the protective gas container through the discharge opening to a part of the conveying direction located outside the protective gas container, which is downstream of the protective gas container in the transport direction.

[0079] In particular, it is advantageous to design the transport device as a linear transport device, especially as a conveyor belt, which has at least a first, a second and a third part, wherein the first part is arranged in the transport direction in front of the protective gas container, the second part inside the protective gas container and the third part in the transport direction after the protective gas container.

[0080] To prevent or at least reduce the escape of protective gas from the protective gas container and the ingress of ambient gas, especially oxygen, into the protective gas container, it is advantageous to arrange a gas curtain device at the inlet opening and preferably at the outlet opening to form a gas curtain or gas wall. In an advantageous embodiment, the gas curtain device has a nozzle to form a wall-like gas flow at the opening, preferably using protective gas, especially an inert gas.

[0081] It is within the scope of the invention to design the device according to the invention for the direct printing process, in particular with exactly one printing cylinder. Likewise, it is within the scope of the invention to design the device according to the invention for an indirect printing process, wherein the device comprises further rotating cylinders, in particular transfer cylinders, for supplying the solvent to the printing cylinder.

[0082] 34769-P-WO Di / co 28.11.2025The rotating cylinder(s) of the device are preferably driven by one or more electric motors of the device.

[0083] In an advantageous embodiment, the protective gas unit has at least one protective gas supply nozzle to purge at least the surface of the printing cylinder wetted by the solvent with protective gas, in particular inert gas. In an advantageous embodiment of the device, in which the device has, in addition to the printing cylinder, further rotating cylinders, in particular transfer cylinders and / or anilox rollers, the protective gas unit has several protective gas supply nozzles to purge at least the surface of the printing cylinder and the further cylinders wetted by the solvent with protective gas, in particular inert gas.

[0084] The supply of protective gas, in particular inert gas, prevents or reduces, as previously described, at least a reaction of the solvent liquids with gases of the ambient atmosphere, especially with oxygen and humidity.

[0085] The device can be configured for direct or indirect printing. In particular, the device can be configured for flexographic or gravure printing. Specifically, the device can include, as previously described, additional rotating cylinders such as transfer cylinders, anilox rollers, and / or immersion rollers.

[0086] The supply of the solvent to the printing cylinder can be carried out in a manner known per se from printing processes. Advantageously, the solvent is transferred by an anilox roller, particularly preferably by a line-like application in the axial direction of the printing cylinder, in order to achieve a homogeneous layer of solvent on the outer surface of the printing cylinder in the axial and preferably in the radial direction due to the rotation of the printing cylinder during the continuous supply of solvent.

[0087] In particular, it is advantageous to feed the solvent onto the printing cylinder using a chambered doctor blade, preferably via an anilox roller. The device according to the invention has

[0088] 34769-P-WO Di / co 28.11.2025, thus preferably at least one chambered doctor blade for supplying the solvent to the printing cylinder, in particular for uniform application to the outer surface of the printing cylinder.

[0089] A chamber doctor blade has the advantage that inert gas can be supplied to the chamber for purging, so that a reaction with gases of the ambient atmosphere, especially oxygen and humidity, is avoided or at least reduced at this point as well.

[0090] Advantageously, the gas supply unit of the device is therefore designed to additionally supply inert gas to the chamber of the chamber doctor blade.

[0091] The aforementioned problem is further solved by a use according to claim 17, wherein a device with at least one rotating pressure cylinder is used for forming a perovskite-containing layer on a semiconductor substrate, preferably for the production of a multi-junction solar cell, in particular a tandem solar cell. Preferably, the use is carried out by performing a method according to the invention, in particular a preferred embodiment thereof. More preferably, a device according to the invention, in particular an advantageous embodiment thereof, is used.

[0092] It is within the scope of the invention that a multiple, in particular a sequential, printing process takes place: In an advantageous embodiment of the method, the precursors are applied in process step B by means of several printing cylinders, preferably arranged one behind the other in the transport direction of the semiconductor substrate. Accordingly, the device according to the invention advantageously has several printing cylinders, which are preferably arranged one behind the other and / or next to each other, preferably one behind the other, in the transport direction of the semiconductor substrate.

[0093] The inventive method and the inventive device enable the use of precursors known per se for forming the perovskite layer, in particular the precursors known from single-stage wet chemical processes and the precursors known from hybrid processes.

[0094] 34769-P-WO Di / co 28.11.2025 In an advantageous embodiment of the inventive process as a hybrid process, a semiconductor substrate with deposited layers having a layer thickness in the range of 100 nm to 2 pm, in particular 300 nm to 1 pm, preferably 400 nm to 700 nm, is provided in process step A. Preferably, at least one Pbh layer and one Csl layer or one Pbl2 and one CsBr layer are deposited to provide the semiconductor substrate in process step A.

[0095] The tempering in process step C is preferably carried out at a temperature in the range of 80°C to 200°C, preferably for a duration in the range of 1 minute to 60 minutes, preferably at a temperature of 150°C for 25 minutes.

[0096] The annealing process can be carried out in one or more stages. A single-stage process involves both solvent removal and crystallization of the perovskite-containing layer in a single step. In a multi-stage process, the solvent system is driven off in a first, separate step at temperatures preferably below 80°C, but preferably between 25°C and 80°C. Crystallization of the perovskite-containing layer then occurs in a subsequent second step, where the semiconductor substrate is preferably subjected to a higher temperature in the subsequent step than in the first.

[0097] The annealing of perovskite layers is a process that promotes the formation and stabilization of the perovskite structure. After the application of the solvent, a drying step is preferably carried out in which the layer is dried at room temperature or slightly elevated temperatures to remove solvents and concentrate the precursors. This drying step is preferably assisted by gas quenching with nitrogen or argon. Subsequently, the coated layer is heated, preferably to a temperature in the range of 80°C to 200°C, to promote the crystallization of the perovskite structure. During this heating process, the molecules arrange themselves into the desired crystal structure, which is advantageous for the optoelectronic properties of the layer.

[0098] 34769-P-WO Tue / co 28.11.2025 To avoid undesirable chemical reactions with the environment, annealing is preferably carried out in a controlled atmosphere, preferably consisting of inert gases such as nitrogen or argon. This controlled environment minimizes oxidation and other reactive processes that could impair the quality of the perovskite layer. In an advantageous alternative embodiment, annealing is carried out in a vacuum, which allows for even greater purity and control over the process, especially when sensitive materials are used.

[0099] Furthermore, a controlled temperature gradient can be applied to specifically optimize the properties of the layer. This helps to improve the morphology and optoelectronic properties of the perovskite structure. After annealing, the layer is often slowly cooled to avoid stress and ensure the stability of the crystal structure. These various annealing processes are crucial for the quality of the perovskite layers and have a direct impact on the performance of perovskite solar cells.

[0100] The annealing of the semiconductor substrate is preferably carried out by one of the following process steps.

[0101] passive drying through evaporation (to the surrounding atmosphere),

[0102] Gas quenching,

[0103] Thermal drying / crystallization (convection, IR radiation, laser, intense pulsed light),

[0104] Vacuum-assisted drying / crystallization,

[0105] Drying / crystallization in a protective atmosphere,

[0106] Drying / crystallization by antisolvent crystallization

[0107] as well as combinations of the aforementioned process steps in a single or multi-stage embodiment for the conversion of the chemical precursors into a perovskite-containing layer.

[0108] The perovskite-containing layer produced by the process according to the invention preferably has a substantially 3D ABX3 structure, wherein A is a cation, B is a smaller cation, and X is an anion, typically a halogen. Preferred materials for A are: methylammonium (CH3NH3) + ), Ethylammonium (C2H5NH3 + ), Formamidinium (NH2CH3 + ), Ceasium

[0109] 34769-P-WO Tue / co 28.11.2025(Cs + ) and / or rubidium (Rb + Preferred materials for B are: lead (Pb) 2+), tin (Sn 2+ ), Germanium (Ge 2+ ) and / or cadmium (Cd 2+ ); Preferred materials for X are: iodide (I"), bromide (Br"), chloride (CI") and pseudohalides such as cyanate (OCN") and / or thiocyanate (SCN").

[0110] In an alternative preferred embodiment of the process, the perovskite layer is formed with 2D and quasi-2D perovskites such as Ruddlesden-Popper phases (RP) and Dion-Jacobson phases (DJ), which are described by the structural formula (A')m(A) n -iB n X3n+i can be described. Here, A' represents monovalent cations in the RP phase (with m=2) or divalent cations in the DJ phase (with m=1). n represents the number of inorganic layers. Preferred materials are the typically sterically demanding A cations, in particular one or more of the amidine cations, especially guanidinium (GA). + ), alkylammonium cations such as butylammonium (BA +), arylammonium cations such as phenylethyl ammonium (PEA) + ) and / or divalent Dion-Jacobson space cations, in particular 1,4-butanediamonium (BDA) 2+ ), 4-(Ammoniummethyl)piperidinium (4AMP 2+ ).

[0111] In an alternative preferred embodiment of the process, the perovskite layer is composed of double (or multiple) perovskites with the general structure A?B + B 3+ X6 formed, with preferred for position B cations such as silver (Ag) + , Ag 3+ ), copper (Cu + ), sodium (Na + ) Bismuth (Bi 3+ ), Antimony (Sb 3+ ), Lanthanides (ln 3+ ) and iron (Fe 3+ ) can be used.

[0112] Chemical precursors are the starting materials necessary for the formation of a perovskite-containing layer. These starting materials are essentially divided into organic and inorganic precursors, which can be further subdivided into additional classes of substances.

[0113] The organic precursors preferably comprise precursors from the classes of alkyl ammonium salts and halides, in particular one or more of the substances methylammonium iodide (MAI), ethylammonium iodide (EAI), propylammonium iodide (PAI), butylammonium iodide (BAI), formamidinium iodide (FAI), and their bromide / chloride variants, in particular methylammonium bromide (MABr), methylammonium chloride (MACI), ethylammonium bromide (EABr), ethylammonium chloride (EACI), formamidinium bromides (FABr), formamidinium chloride (FACI), propylammonium bromide (PABr), propylammonium chloride (PACI), butylammonium bromide (BABr), and butylammonium chloride.

[0114] 34769-P-WO Di / co 28.11.2025(BACI); the arylammonium salts and halides, in particular phenylammonium iodide (PAI), phenylammonium bromide (PABr), phenylammonium chloride (PACI) and aliphatic ammonium salts and halides, in particular butylammonium iodide (BAI), butylammonium bromide (BABr) and / or butylammonium chloride (BACI).

[0115] The inorganic precursors preferably comprise the metal halides. From this class of substances, one or more of the following are preferably used: lead(II) iodide (Pbl2), lead(II) bromide (PbBr2), lead(II) chloride (PbCl2), tin(II) iodide (SnI2), tin(II) bromide (SnBr2), tin(II) chloride (PbCl2), germanium(II) iodide (Geh), germanium(II) bromide (GeBr2), germanium(II) chloride (GeCl2), cesium iodide (CsI), cesium bromide (CsBr), cesium chloride (CsCl), rubidium iodides (RuI), rubidium bromide (RuBr) and / or rubidium chloride (RuCl). Preferably, the inorganic precursors comprise alkali metal halides, in particular one or more of the substances sodium iodide (Nal) and potassium iodide (Kl) and / or alkaline earth metal halides, in particular magnesium iodide (Mgl2).

[0116] It is within the scope of the invention that these materials are used in different processes for producing the perovskite-containing layer, preferably using wet-chemical and / or hybrid processes to generate the desired layer. The solution concentration of the perovskite precursors in the solution liquid of process step B is preferably in the range of 0.1 M to 2 M, particularly in the range of 0.5 M to 1.5 M, and preferably at 1.0 M.

[0117] A polar solvent is preferably used as the solvent for the solution liquid.

[0118] In a preferred embodiment of the process according to the invention as a purely wet-chemical process, all perovskite precursors, in particular all substances and / or precursor substances for the formation of the perovskite-containing layer, are preferably dissolved in the solution liquid, and dimethylformamide (DMF), dimethyl sulfoxide (DMSO), γ-butyrolactone (GBL), N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMA), and / or acetonitrile (ACN) are preferably used for this purpose. In a preferred embodiment of the process according to the invention as a hybrid process, preferably only the alkylammonium salts and halides are dissolved, and 2-methoxyethanol, ethanol, 1-propanol, or isopropanol is preferably used as the solvent system.

[0119] 34769-P-WO Di / co 28.11.2025 and / or n-butanol is used.

[0120] Preferably, both solutions (wet chemical and hybrid) have additional additives in the solvent which preferably have a positive effect on the printability (rheology) and thus the homogeneity of the print result and / or improve the crystallization and thus the absorber quality.

[0121] Further advantageous features and designs are explained below with reference to exemplary embodiments and the figures. These show:

[0122] Figure 1 shows a first embodiment of a device according to the invention in perspective view,

[0123] Figure 2 shows the first embodiment in sectional view, with the section plane perpendicular to an axis of rotation of the printing cylinder;

[0124] Figure 3 shows a second embodiment of a device according to the invention in perspective view;

[0125] Figure 4 shows the second embodiment in sectional view, with the section plane perpendicular to an axis of rotation of the printing cylinder and

[0126] Figure 5 shows a modification of the first embodiment with a protective gas unit designed as a housing.

[0127] All figures are schematic representations, not to scale. Identical reference symbols within the figures denote identical or equivalent elements.

[0128] The first embodiment of a device according to the invention for producing a perovskite-containing layer on a semiconductor substrate, shown in Figure 1, comprises a conveyor device 1 designed as a conveyor belt, a pressure cylinder 2, and a feed unit 3, in this case designed as a slot nozzle, for supplying solvent from a

[0129] 34769-P-WO Di / co 28.11.2025 Solution liquid container 4 for the pressure cylinder 2. The illustrated embodiment of a device according to the invention serves to carry out a first embodiment of a method according to the invention. A single-stage, wet-chemical process is described as an embodiment.

[0130] A semiconductor substrate 5, designed as a coated silicon wafer, is arranged on the conveying device 1 and is moved linearly in the direction indicated by an arrow by means of the conveying device 1. The pressure cylinder 2 rotates about an axis of rotation, which is identical to the cylinder axis of the pressure cylinder 2, in the direction of rotation indicated by a curved arrow.

[0131] Using the device shown, a tandem solar cell is formed based on a silicon bottom-tom solar cell (lower sub-cell) and a perovskite top solar cell (upper sub-cell).

[0132] The semiconductor substrate 5 provided in process step A is configured as a silicon heterojunction solar cell (SHJ) with several additional layers. The substrate is a p-doped crystalline silicon wafer (c-Si) with a thickness of approximately 150 to 180 pm, in this case 170 pm. A thin layer of intrinsic amorphous silicon (ia-Si), acting as a buffer, prevents the recombination-active c-Si surface from coming into direct contact with the doped layers and has a thickness of approximately 5 to 10 nanometers, in this case 7 nanometers. An n-doped amorphous silicon layer (na-Si), acting as an emitter layer, typically has a thickness of 10 nm to 20 nm, in this case 15 nm. A transparent conductive oxide layer (TCO), in this case made of indium tin oxide (ITO), provides light transmission and a conductive surface.The TCO layer facing the perovskite cell, also called recombination TCO, typically has a thickness of 10 nm to 30 nm, in this case 20 nm.

[0133] In process step B, the feed unit 3 applies solvent from the solvent container 4 evenly distributed along the axial direction of the printing cylinder onto the cylinder. A [feature / component] is located on the leading edge of the feed unit 3 (in the direction of rotation).

[0134] 34769-P-WO Di / co 28.11.2025Squeegee arranged to ensure a uniform application of the solvent fluid to the outer surface of the printing cylinder 2.

[0135] The printing cylinder 2 is designed for a flexographic printing process and has a rubber surface with a thickness of 5 mm. The printing cylinder 2 has a diameter of 10 cm to 60 cm, in this case 30 cm.

[0136] A gas supply unit 6 of the device is arranged directly downstream of the feed unit 3 in the direction of rotation of the pressure cylinder. The gas supply unit 6 is designed as a slot nozzle and is fluidly connected to an inert gas tank 7 containing nitrogen gas. By means of the gas supply unit 6, the outer surface of the pressure cylinder 2 is purged with inert gas in the direction of rotation immediately downstream of the feed unit 3 up to the surface of the semiconductor substrate 5, so that a reaction with gases from the ambient atmosphere, in particular oxygen, is avoided or at least reduced.

[0137] As a result of the printing process, a printing layer 8 is created on the semiconductor substrate 5.

[0138] A further embodiment of the inventive method, designed as a (purely) wet chemical method using the device shown in Figure 1, is described below:

[0139] In this advantageous embodiment as a purely wet chemical process, the liquid container 4 is completely filled with the solvent mixture and the perovskite precursors dissolved therein for the production of a double-cation perovskite absorber (the perovskite layer) by means of a rotary pressure process.

[0140] For the perovskite absorber, a stoichiometric weighing of formamidinium iodide (FAI), cesium iodide (CsI), lead(II) bromide (PbBr), and lead(II) iodide (Pbl2) is carried out to form a double-cation perovskite absorber (the perovskite layer) with the structural formula FAo,75Cso,25Pb(1,8oBro,2o)3. Dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) are added in a 1:4 ratio to obtain a molarity of 1.1 M. The solution is stirred overnight at 60 °C and then transferred to the liquid container.

[0141] 34769-P-WO Di / co 28.11.2025 Using the printing cylinder 2, the printing medium (= dissolved perovskite precursors in solvent) is transferred as a wet film onto the semiconductor substrate 5 to be printed. In a subsequent two-stage annealing step (process step C), the substrate is first heated to a temperature of 30 °C and the solvent mixture of DMSO:DMF is removed using an air-jet with the introduction of nitrogen (gas quenching) to concentrate the precursors. In a final annealing step, crystallization takes place at 100 °C for one hour. During this process, the molecules arrange themselves into the desired crystal structure and a perovskite-containing layer forms on the semiconductor substrate 5.

[0142] In a modification of the first embodiment of the process as a hybrid process, the solution liquid in the solution liquid container contains a one molar (written IM) solution of formamidinium bromide (FABr) to formamidinium iodide (FAI) in a ratio of 65:35. Here, FABr and FAI are dissolved in the following solvent mixture of ethanol (EtOH) and 1-butanol (Bu-tOH) in a ratio of 1:3.

[0143] In this modification, Csl and Pbl 2 are first deposited onto a surface of the semiconductor substrate 5 using a co-evaporation process in a vacuum to deposit a 550 nm thick inorganic scaffold. The evaporation rates of Csl and Pbl 2 are set to 0.1 × / s (achieved at ~400°C) and 1 × / s (achieved at ~280°C), respectively, and measured using quartz crystal sensors.

[0144] Using the device according to the invention (printing cylinder 2), the printing medium (= FABr / FAI solution) is transferred as a wet film onto the semiconductor substrate 5 to be printed, which has the previously deposited inorganic framework of Csl and Pbl2. The solvent mixture of E-tOH and ButOH is then removed passively by evaporation into the ambient atmosphere. In a subsequent annealing step (process step C) in atmosphere, crystallization takes place at 150°C for 25 minutes. During this process, the molecules arrange themselves into the desired crystal structure, and a perovskite-containing layer forms on the semiconductor substrate 5 from the previously provided semiconductor substrate with the inorganic framework of the precursors Csl and Pbl2 and the organic solution of FABr and FAI applied by rotary printing.

[0145] 34769-P-WO Di / co 28.11.2025 Figure 2 shows a sectional view of the embodiment illustrated in Figure 1, with the section plane perpendicular to the axis of rotation of the pressure cylinder 2. Figure 2 shows that the protective gas unit has two inert gas tanks 7 (each for supplying nitrogen as the inert gas) and two gas supply units 6 designed as slot nozzles, wherein a first gas supply unit is arranged for purging the solvent-wetted surface of the pressure cylinder 2 and a second gas supply unit 6 is arranged for purging the generated pressure layer 8. The protective gas unit of the device thus has two gas supply units 6.

[0146] Figure 3 shows a second embodiment of a device according to the invention in a perspective view. The design of the semiconductor substrate, the solvent, and the precursors corresponds to the first embodiment.

[0147] The device according to the second embodiment also has a conveyor device 1 designed as a conveyor belt for conveying a semiconductor substrate 5 along the direction of the arrow.

[0148] The device according to Figure 3 is designed to carry out an indirect printing process. The device comprises a printing cylinder 2 and a transfer cylinder 9. Printing cylinder 2 and transfer cylinder 9 have parallel cylinder axes and rotate in opposite directions about the cylinder axes according to the curved arrows shown in Figure 3.

[0149] The device comprises a feed unit 3, which in this case is designed as a doctor blade unit of the chamber doctor blade for feeding the solvent. The feed unit 3 is connected to a solvent container 4 and to an inert gas tank 7 containing argon gas. The doctor blade unit arranged in the chamber of the feed unit 3 is fluidly connected to the solvent container, and the chamber itself is fluidly connected to the inert gas tank 7.

[0150] By means of the feed unit 3, solvent fluid is supplied uniformly in the axial direction of the transfer cylinder 9, and at the same time the chamber of the feed unit 3 is purged with inert gas to avoid a reaction with gases from the ambient atmosphere.

[0151] 34769-P-WO Di / co 28.11.2025The solvent applied to the outer surface of the transfer cylinder 9 is transferred at the contact point of the cylinders to the outer surface of the printing cylinder 2 and from the outer surface of the printing cylinder 2 to the semiconductor substrate 5.

[0152] In order to prevent a reaction of the solvent liquid with gases from the ambient atmosphere on the outer surfaces of the cylinders, the device has two gas supply units 6, each of which is fluidly connected to an inert gas tank 7 and is arranged and designed to purge the outer surfaces of pressure cylinder 2 and transfer cylinder 9 with inert gas.

[0153] Figure 5 shows a modification of the embodiment shown in Figure 2. In this modification, the protective gas unit is designed as a housing 11 with two gas wall nozzles 10 and openings formed below the gas wall nozzles 10, with the supply opening on the left and the outlet opening on the right in Figure 5. The conveying device 1, designed as a conveyor belt, is divided into three parts: a first part 1a, which is arranged in front of the housing 11 in the conveying direction; a part 11, which is arranged inside the housing 11; and a part 1a, which is arranged behind the housing 11 in the conveying direction. In this embodiment, the conveying device does not penetrate the housing 11; the semiconductor substrate bridges a short free distance in the area of ​​the supply opening and in the area of ​​the outlet opening. Nitrogen is supplied to the gas wall nozzles 10 as an inert gas to prevent ambient air, in particular oxygen, from entering the housing 11.

[0154] Nitrogen is supplied as an inert gas from the inert gas tank 7 to the housing 11, creating an overpressure relative to the environment to provide additional protection against the ingress of ambient air.

[0155] 34769-P-WO Tue / co 28.11.2025 Reference list

[0156] 1, la, lb Conveyor device

[0157] 2 pressure cylinders

[0158] 3 Feed unit

[0159] 4 solution containers

[0160] 5 Semiconductor substrate

[0161] 6 Gas supply unit

[0162] 7 Inert gas tank

[0163] 8 printing layers

[0164] 9 transfer cylinders

[0165] 10 gas wall nozzles

[0166] 11 cases

[0167] 34769-P-WO Tue / co 28.11.2025

Claims

TI Claims 1. Method for producing a perovskite-containing layer on a semiconductor substrate, comprising the process steps A. Providing a semiconductor substrate B. Applying a solvent to the semiconductor substrate, C. Annealing of the semiconductor substrate, wherein the perovskite-containing layer is formed by means of several precursors and the solvent contains at least some of the precursors, characterized by that in process step B the solvent is applied to the semiconductor substrate by means of a rotary printing process using at least one rotating printing cylinder.

2. Method according to claim 1, characterized by that the semiconductor substrate has a textured surface onto which the solvent is applied in process step B, In particular, the textured surface has pyramid structures, wherein the pyramids preferably have a mean base length in the range of 0.5 pm to 10 pm, in particular 0.5 pm to 5 pm, preferably 1 pm to 5 pm.

3. Method according to any of the preceding claims, characterized by that the pressure cylinder has a flexible outer surface, in particular a compressible outer surface, preferably that the outer surface is formed in one or more layers with a Shore hardness in the range of 40 to 90.

4. Method according to any of the preceding claims, characterized by that in process step B at least for the part wetted with solvent 34769-P-WO Di / co 28.11.2025 Surface of the pressure cylinder a protective gas environment is created, in particular a protective gas purge, in particular, that several rotating cylinders are used to apply the solvent liquid and that a protective gas environment is created at least for the surfaces of the cylinders wetted with solvent liquid, in particular a protective gas purge, wherein the protective gas is preferably an inert gas.

5. Method according to any of the preceding claims, characterized by that the solvent contains all precursors, in particular all substances and / or precursor substances for the formation of the perovskite-containing layer.

6. Method according to any one of claims 1 to 4, characterized by that the precursors are divided into a first and a second subset, and the first subset of the precursors is provided with the semiconductor substrate in process step A, and the solution fluid in process step B contains the second subset of the precursors.

7. Method according to claim 6, characterized by that the precursors provided in process step A are applied to the semiconductor substrate by vapor deposition, in particular, that in process step A, inorganic precursors are applied to the semiconductor substrate by evaporation, in particular one or more precursors from the list lead halides, tin halides, cesium halides.

8. Method according to any of the preceding claims, characterized by that the solvent contains one or more organic precursors. 34769-P-WO Di / co 28.11.20259. Method according to one of the preceding claims, characterized by that in process step B, a chambered doctor blade is used to apply the solution to the printing cylinder or another rotating cylinder, in particular an anilox roller, wherein the chambered doctor blade is preferably supplied with protective gas, preferably inert gas.

10. Method according to any of the preceding claims, characterized by that in process step A a silicon substrate is provided as a semiconductor substrate, in particular a silicon substrate coated with one or more layers.

11. Procedure according to any of the preceding claims, characterized by that prior to process step B, a pretreatment of the surface of the semiconductor substrate is carried out to modify the surface properties, in particular the surface energy and / or the morphology.

12. Method according to claim 11, characterized by that the pretreatment includes plasma treatment, corona treatment, the application of an adhesion promoter or the application of particles, especially vaccine crystals.

13. Method according to one of claims 11 to 12, characterized by that the pretreatment takes place between process steps A and B, in particular that according to claim 6 the precursors are divided into a first and a second subset and the first subset of the precursors is provided with the semiconductor substrate in process step A and the solvent in process step 34769-P-WO Di / co 28.11.2025B has the second subset of precursors.

14. Device for producing a perovskite-containing layer on a semiconductor substrate, with a conveying device for the semiconductor substrate, at least one pressure cylinder a feeding unit for supplying solvent to the pressure cylinder, wherein the conveying device, pressure cylinder and feeding unit are designed and arranged to interact in order to apply the solvent to the semiconductor substrate, in particular to apply it over a surface, wherein the solvent is applied to the semiconductor substrate by means of the pressure cylinder, characterized by that the device has at least one protective gas unit for forming a protective gas environment, wherein the protective gas unit is designed to interact with the pressure cylinder in order to form a protective gas environment at least on the surface of the pressure cylinder covered with solvent, in particular that the protective gas unit is designed as an inert gas unit.

15. Device according to claim 14, characterized by that the protective gas unit has a protective gas container in which at least the pressure cylinder is arranged, in particular that the protective gas container is designed as the housing of the device and / or that the protective gas unit has at least one protective gas supply nozzle to purge at least the outer surface of the pressure cylinder wetted by the solvent with protective gas, preferably with inert gas.

16. Device according to claim 14, characterized by that the feed unit has a chambered doctor blade for feeding the solvent, which is preferably attached to the printing cylinder or to a cylinder of the feed unit, in particular a cylinder of the feed unit designed as an anilox roller, 34769-P-WO Tue / co 28.11.2025 is ordered.

17. Use of a device with at least one rotating pressure cylinder for forming a perovskite-containing layer on a semiconductor substrate, preferably for the production of a multi-junction solar cell, in particular a tandem solar cell.

18. Use according to claim 17, wherein a device according to one of claims 11 to 13 is used to form the perovskite-containing layer on the semiconductor substrate, in particular by means of a method according to one of claims 1 to 10. 34769-P-WO Tue / co 28.11.2025

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