Tin-based perovskite field effect transistor memory and method for manufacturing the same

Abstract

To provide a tin-based perovskite field effect transistor memory and a method for manufacturing the same.SOLUTION: The present invention provides a perovskite containing one or more elements selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA), a compound represented by the structural formula 1, one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and tin (Sn). The thin-film transistor memory of the present invention can be used as a p-type transistor and memory element, exhibits uniform and stable memory element operation, and is lead-free, making it easy to industrialize as an environmentally friendly material, and can subsequently be used as an element for in-memory processing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a tin-based perovskite field effect transistor memory and a method for manufacturing the same, and more particularly to a tin-based perovskite thin film that is used as a semiconductor active layer of a memory device by adding an organic cation having two ammonium groups that induce hollowness to the thin film. The present invention also relates to a thin film transistor memory made using this active layer and a method for manufacturing the same. [Background technology]

[0002] Industrial developments such as machine learning and artificial intelligence (AI) are demanding semiconductors with the ability to calculate and process ever-increasing amounts of data at high speeds. The Von Neumann architecture, the basic structure of a typical computer, separates the processing unit, which calculates and processes information, from the memory unit. However, when processing large amounts of data, the amount of data that can travel between the processing unit and the memory unit is limited, resulting in latency and requiring significant power consumption. In particular, for increasingly important AI information processing, the latency of accessing data from the memory unit is a major bottleneck in performance.

[0003] Various ideas have been proposed to reduce this latency and excessive power consumption. The most prominent of these are near-memory computing and in-memory computing. Near-memory computing refers to a circuit configuration method in which the processing unit and memory unit are placed very close to each other, and the calculation method performed through this. Generally, both units are placed on a single chip, or the two units are stacked vertically to minimize the round-trip distance of data, thereby minimizing latency and power consumption. Vertical stacking technology is currently being actively researched and applied to memory semiconductor devices such as HBM and HMC, and an M3D process has also been proposed to enable denser integration of memory units and processing units.

[0004] Another approach, in-memory computing, is a computational memory unit designed to perform specific computational tasks within the memory itself. This eliminates the need for data transfer between two distinct units and the need to access and reread memory content stored in the memory unit, significantly reducing latency and power consumption. Attempts to achieve in-memory computing using DRAM, SRAM, and flash memory, which are already widely used and researched in industry, have shown limitations in scaling down due to their large surface area and the need for large capacitors. Therefore, active research is underway to achieve in-memory computing using new types of memory devices, such as resistive random access memory (RRAM) and phase-change random access memory (PRAM), rather than conventional MOSFET-based memory. Furthermore, single-transistor memory is also being actively researched to utilize the high-integration technology of conventional transistor processes, and recent research has even been reported on devices in which a single transistor functions as a memory. Typically, two-dimensional transition metal dichalcogenide compounds with adjustable electrostatic properties are used as semiconductor active layers, which can be used as both memory and transistor elements, and research has been reported on transistor-type elements that can be highly integrated, as well as PIM (Processing in Memory) semiconductors based on these. However, such two-dimensional transition metal dichalcogenide compounds have limitations in that uniformity decreases during large-area production and process costs are high.

[0005] Halide perovskites are commonly referred to as materials with the ABX3 chemical formula and a unique crystal structure. Here, A is a monovalent organic or inorganic cation, B is a divalent inorganic cation, and X is a halogen anion. Inorganic or mixed organic and inorganic halide perovskites have been primarily used as light absorbers in solar cells due to their high absorbance and excellent photoelectric properties. Furthermore, they can be used with a wide variety of organic and inorganic cations and anions, even multiple cations and anions at once. This allows for easy tuning of optical and electrical properties by varying the combination of various components, making them suitable for a variety of electronic and photoelectric materials. Furthermore, their easy thin-film and device fabrication, such as simple solution processing and thermal evaporation, has attracted industrial and academic attention in various fields. Based on these advantages, active research has recently been conducted into their use as semiconductor layers in thin-film transistors (TFTs) and memory semiconductors. Research into perovskite-based memory semiconductors has focused primarily on resistive memory that utilizes anion vacancies, but these have relatively unstable data storage and slow operating speeds compared to resistive memory based on other semiconducting materials, including oxide semiconductors, and these issues need to be overcome.

[0006] Furthermore, resistive memory devices that offer relatively stable and excellent performance have generally relied on toxic lead-based perovskite materials. Therefore, for commercialization, it is crucial to develop lead-free halide perovskite materials with superior performance and stability. Lead-free perovskites are also being extensively studied, and tin, a member of the same group as lead, is harmless to humans and the environment. Its size is similar to that of lead, making it a candidate for the perovskite B cation. Furthermore, tin-based halide perovskites are gaining attention as next-generation p-type semiconductors that can be used as the channel layer of p-type transistors due to their excellent electrical properties, such as low effective hole mass and high hole mobility. Furthermore, like lead-based perovskites, they can be applied with a variety of cation and anion materials, allowing for easy adjustment of electrical properties by varying their combination. Memory properties can also be achieved by adjusting the type and amount of additives. Furthermore, thin film fabrication and device fabrication can be performed on desired areas of a wafer using simple processes, such as thermal evaporation. Therefore, based on these advantages, tin-based halide perovskites can also be utilized as the semiconductor active layer of memory semiconductors for in-memory computing.

[0007] As mentioned above, tin-based perovskite has excellent electrical properties among lead-free perovskite materials. However, unlike lead, tin is easily converted into Sn by moisture and oxygen in the air. 2+ From Sn 4+ Sn vacancies are easily oxidized, which induces the formation of tin vacancies in tin-based halide perovskite. Sn vacancies, which are also created during the thin film formation process, create shallow traps near the valence band maximum (VBM) of tin-based halide perovskite, increasing the number of holes. However, if there are too many, the hole concentration becomes too high and electrons cannot be switched on and off, which induces lattice instability, resulting in the loss of excellent electrical properties of tin-based perovskite.

[0008] Therefore, in order to use such tin-based perovskite thin films as stable semiconductor active layers in transistors, memory devices, solar cells, LEDs, light-emitting devices, light-receiving devices, etc., a technology to suppress and control the formation of tin vacancies and the oxidation of tin is required. Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a thin film transistor memory having memory properties capable of stably storing information by forming a tin-based halide perovskite thin film having a hollow structure by adding diammonium organic cations, and a method for manufacturing the same.

[0010] Another object of the present invention is to provide a thin film transistor memory that does not contain lead, but instead contains a semiconductor layer that contains tin ions, which are an environmentally friendly material, as cations, and is therefore easy to industrialize. [Means for solving the problem]

[0011] According to one aspect of the present invention, there is provided a perovskite containing one or more elements selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA), a compound represented by the following structural formula 1, one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and tin (Sn). [Structural formula 1] [ka] During the ceremony, R 1 is a hydrogen atom, a methyl group, or an ethyl group, R 2 is a hydrogen atom, a methyl group, or an ethyl group, n is an integer of 1 to 3.

[0012] In addition, the compound represented by Structural Formula 1 may include at least one selected from the group consisting of EDA (ethane-1,2-diammonium), P2DA (propane-1,2-diammonium), P3DA (propane-1,3-diammonium), piperazine-1,4-diium iodide, piperazine-1,4-diium chloride, and piperazine-1,4-diium bromide.

[0013] The perovskite may have a hollow structure within the lattice.

[0014] The perovskite may further include a compound represented by the following structural formula 2: [Structural formula 2] [ka] During the ceremony, R 3 is a hydrogen atom, a methyl group, or an ethyl group, R 4 is a hydrogen atom, a methyl group, or an ethyl group, R 5 represents a hydrogen atom, a methyl group, an ethyl group, a C6 to C10 aryl group, or a C6 to C14 aryl group fused to the benzene ring, p is an integer from 0 to 3, q is an integer of 1 to 3.

[0015] The perovskite may contain 0.1 to 100 mol of one or more compounds selected from the group consisting of the compounds represented by the structural formula 1 and the compounds represented by the structural formula 2, based on 100 mol of tin.

[0016] Furthermore, the perovskite can have a 2D / 3D (quasi 2D) structure.

[0017] In addition, the compound represented by the structural formula 2 can be located on the surface of the perovskite crystal.

[0018] In addition, the perovskite includes crystal grains and grain boundaries formed between adjacent crystal grains, and one or more fluorine metal compounds selected from the group consisting of SnF2 and SbF3 may be located at the crystal grain boundaries.

[0019] The perovskite may also be for use in one or more semiconductor layers selected from the group consisting of memory elements, transistors, solar cells, light-emitting diodes, photodiodes, and photosensors.

[0020] The semiconductor layer may have a thickness of 1 to 100 nm.

[0021] According to another aspect of the present invention, there is provided a transistor memory including a gate electrode, an insulating layer 100 located on the gate electrode, a semiconductor layer 300 located on the insulating layer and including a perovskite, and a source electrode 400 and a drain electrode 500 located spaced apart from each other on the semiconductor layer.

[0022] The perovskite may contain one or more elements selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA), a compound represented by the following structural formula 1, one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and tin (Sn). [Structural formula 1] [ka] During the ceremony, R 1 is a hydrogen atom, a methyl group, or an ethyl group, R 2 is a hydrogen atom, a methyl group, or an ethyl group, n is an integer of 1 to 3.

[0023] According to another aspect of the present invention, there is provided a method for producing perovskite, comprising the steps of: (a) preparing a precursor solution containing one or more selected from the group consisting of a cesium (Cs) precursor, a methylammonium (MA) precursor, and a formamidinium (FA) precursor, a tin precursor, a compound represented by the following structural formula 1', and a solvent; (b) coating a substrate with the precursor solution to form a coating layer; and (c) heat-treating the coating layer to produce perovskite. [Structural formula 1'] [ka] During the ceremony, R 1 is a hydrogen atom, a methyl group, or an ethyl group, R 2 is a hydrogen atom, a methyl group, or an ethyl group, X is F, Cl, Br or I; n is an integer of 1 to 3.

[0024] The perovskite may contain at least one element selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA), a compound represented by the following structural formula 1, at least one element selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and tin (Sn). [Structural formula 1] [ka] During the ceremony, R 1 is a hydrogen atom, a methyl group, or an ethyl group, R 2 is a hydrogen atom, a methyl group, or an ethyl group, n is an integer of 1 to 3.

[0025] In addition, the compound represented by structural formula 1' may include one or more selected from the group consisting of EDAI2 (ethane-1,2-diammonium diiodide), EDABr2 (ethane-1,2-diammonium dibromide), P2DAI2 (propane-1,2-diammonium diiodide), P2DABr2 (propane-1,2-diammonium dibromide), P3DAI2 (propane-1,3-diammonium diiodide), and P3DABr2 (propane-1,3-diammonium).

[0026] The precursor solution may further include a compound represented by structural formula 2'. [Structural formula 2'] [ka] During the ceremony, R 3 is a hydrogen atom, a methyl group, or an ethyl group, R 4 is a hydrogen atom, a methyl group, or an ethyl group, R 5 represents a hydrogen atom, a methyl group, an ethyl group, a C6 to C10 aryl group, or a C6 to C14 aryl group fused to the benzene ring, Y is F, Cl, Br or I; p is an integer from 0 to 3, q is an integer of 1 to 3.

[0027] In addition, the compound represented by the structural formula 2' may include at least one selected from the group consisting of PEAI (phenylethylammonium iodide), BAI (n-butylammonium iodide), and NMAI (1-naphthylmethylammonium iodide).

[0028] The coating in step (b) may be performed by one or more methods selected from the group consisting of spin coating, bar coating, slot coating, inkjet, spray coating, dispensing, thermal evaporation, chemical vapor deposition (CVD), atomic layer deposition (ALD), sputtering, flexography, screen coating, dip-coating, gravure, and combinations thereof.

[0029] The heat treatment in step (c) can be carried out at room temperature to 200°C.

[0030] According to another aspect of the present invention, there is provided a method for manufacturing a transistor memory, comprising the steps of: (1) providing a gate electrode / insulating layer stack including a gate electrode and an insulating layer located on the gate electrode; (2) forming a semiconductor layer including the perovskite of claim 1 on the insulating layer; and (3) forming source and drain electrodes on the semiconductor layer. [Effects of the Invention]

[0031] The thin film transistor memory of the present invention can be used as a p-type transistor and memory device, and can subsequently be used as a device for in-memory processing.

[0032] Furthermore, by using tin-based halide perovskite instead of lead-based for the thin film, it is easy to industrialize it as an environmentally friendly material.

[0033] In addition, the thin film transistor memory of the present invention induces the formation of a hollow structure by adding an additive containing a diammonium halide compound, which induces the formation of deep traps in the channel, thereby providing a high-performance memory device that exhibits long information retention time and strong endurance at a low driving voltage.

[0034] In addition, by widening the bandgap and lowering the VBM level, it is possible to suppress tin oxidation and vacancy formation, control the hole concentration, and act as a crystallization retarder during the thin film formation process, thereby improving crystallinity and blurring the grain boundaries, thereby providing a transistor memory with stability, reproducibility, and uniformity.

[0035] In addition, the present invention can provide a stable and reproducible transistor memory by adding an additive containing an ammonium iodide compound to suppress tin oxidation and vacancy formation and control the hole concentration.

[0036] In addition, the present invention provides a transistor memory having stability, reproducibility, and uniformity by adding an additive containing a metal fluoride compound to suppress tin oxidation and vacancy formation, control the concentration of holes, and act as a crystal nucleus to form a uniform, highly crystalline thin film. [Brief explanation of the drawings]

[0037] These drawings are to be referred to when describing exemplary embodiments of the present invention, and therefore the technical idea of ​​the present invention should not be interpreted as being limited to the attached drawings. [Figure 1] 1 is a schematic diagram of a thin film transistor memory according to one embodiment of the present invention; [Figure 2] 1 is a flowchart illustrating a manufacturing process of a thin film transistor memory according to an embodiment of the present invention. [Figure 3]FIG. 1 is a diagram showing the results of XRD analysis of Examples 1-1, 1-2, and 1-3 and Comparative Example 1. [Figure 4] [Fig. 4a] A diagram showing the results of absorbance analysis of Examples 1-1, 1-2, and 1-3, and Comparative Example 1. [Fig. 4b] A diagram showing the results of extrapolation to a Tauc plot for deriving the optical bandgap of Examples 1-1, 1-2, and 1-3, and Comparative Example 1. [Figure 5] FIG. 1 is a diagram showing output curves of element example 1-1 and element comparative example 1. [Figure 6] FIG. 10 is a diagram showing transfer curves of Element Example 1-1 and Element Comparative Example 1 when VDS is set to −5 V. [Figure 7] FIG. 10 is a diagram showing transition curves of element examples 1-1 to 1-3 and element comparative example 1 when VDS is set to −0.5 V. [Figure 8] FIG. 10 is a diagram showing the results of measuring the retention time of stored information for element example 1-1. [Figure 9] FIG. 1 is a graph showing the results of measuring the cycling endurance of element example 1-1. [Figure 10] 1 is a diagram showing the basic structure of perovskite. DETAILED DESCRIPTION OF THE INVENTION

[0038] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily understand the present invention.

[0039] However, the following description does not limit the present invention to specific embodiments, and when describing the present invention, if it is determined that a specific description of related known technology may obscure the gist of the present invention, the detailed description will be omitted.

[0040] The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprise" or "have" and the like are intended to specify the presence of features, numbers, steps, operations, components, or combinations thereof described in the specification, and should be understood not to preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, or combinations thereof.

[0041] Furthermore, terms including ordinal numbers, such as "first" and "second," may be used below to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another. For example, a first component can be named a second component, and similarly, a second component can be named a first component, without departing from the scope of the present invention.

[0042] Furthermore, when a component is said to be "formed" or "laminated" on another component, it should be understood that the component may be formed or laminated in direct contact with the entire surface or one side of the surface of the other component, or that there may be another component interposed therebetween.

[0043] The semiconductor layer including the Sn-based perovskite of the present invention, the thin film transistor memory including the same, and the method for fabricating the same using spin coating will be described in detail below, but these are presented as examples and are not intended to limit the present invention, which is defined only by the scope of the claims below.

[0044] The present invention provides a perovskite containing one or more elements selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA), a compound represented by the following structural formula 1, one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and tin (Sn). [Structural formula 1] [ka] During the ceremony, R 1 is a hydrogen atom, a methyl group, or an ethyl group, R 2 is a hydrogen atom, a methyl group, or an ethyl group, n is an integer of 1 to 3.

[0045] In addition, the compound represented by Structural Formula 1 may include at least one selected from the group consisting of EDA (ethane-1,2-diammonium), P2DA (propane-1,2-diammonium), P3DA (propane-1,3-diammonium), piperazine-1,4-diium iodide, piperazine-1,4-diium chloride, and piperazine-1,4-diium bromide.

[0046] In addition, the compound represented by Formula 1 can form a hollow structure in the lattice to induce memory characteristics, and can also lower the VBM (Valence Band Maximum) level and inhibit oxidation, thereby enhancing stability.

[0047] The perovskite complex may contain 0.05 to 20 mol, preferably 0.1 to 10 mol, and more preferably 0.1 to 5 mol of the compound represented by structural formula 1 based on 100 mol of tin in the tin-based perovskite.

[0048] If the perovskite complex contains less than 0.05 mol of the compound represented by Structural Formula 1 based on 100 mol of tin in the tin-based perovskite, the hollow structure is not sufficiently formed, and memory characteristics are not exhibited, which is undesirable. On the other hand, if the perovskite complex contains more than 20 mol, the hollow structure is no longer formed and the compounds are present on the surface or grain boundary of the lattice, or the lattice is destabilized, which may cause problems such as degraded electrical characteristics of the device.

[0049] Furthermore, the fluorine metal compound suppresses the oxidation of tin and the generation of vacancy defects, controls the hole concentration, and provides uniform crystal nuclei, thereby enabling the generation of stable, uniform, and highly crystalline thin film crystals.

[0050] The fluorine metal compound can be contained in an amount of 0.01 to 50 mol, preferably 1 to 20 mol.

[0051] When the tin-based perovskite contains less than 0.01 mol of the fluorine metal compound based on 100 mol of tin, the oxidation inhibition and hole concentration reduction effects are negligible, and the off current is high, which is undesirable as it may not have memory properties. On the other hand, when the fluorine metal compound is contained in an amount exceeding 50 mol, it is undesirable as it may cause a problem of phase separation due to clumping of the fluorine metal compound.

[0052] Moreover, the perovskite can have a hollow structure within the lattice.

[0053] The perovskite may further include a compound represented by the following structural formula 2: [Structural formula 2] [ka] During the ceremony, R 3 is a hydrogen atom, a methyl group, or an ethyl group, R 4 is a hydrogen atom, a methyl group, or an ethyl group, R5 represents a hydrogen atom, a methyl group, an ethyl group, a C6 to C10 aryl group, or a C6 to C14 aryl group fused to the benzene ring, p is an integer from 0 to 3, q is an integer of 1 to 3.

[0054] The perovskite may contain 0.1 to 100 mol, preferably 0.1 to 50 mol, and more preferably 0.1 to 30 mol of one or more compounds selected from the group consisting of the compounds represented by Structural Formula 1 and the compounds represented by Structural Formula 2, based on 100 mol of tin.

[0055] Furthermore, the perovskite can have a 2D / 3D (quasi 2D) structure.

[0056] The 2D / 3D (quasi 2D) structure is an intermediate structure between 2D and 3D perovskite, and refers to a plate-like crystal structure with a thickness limited by the additive represented by structural formula 2. This structure is A'2A n-1 B n X 3n+1 where A' can include one or more elements selected from the group including compounds represented by structural formula 2, A can include one or more elements selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA), B is tin (Sn), and X can include one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). In addition, in this chemical formula, if n = 1, it corresponds to a 2D structure, and if n = ∞, it corresponds to a 3D structure. If it has a specific natural number between them, it is called a 2D / 3D (quasi 2D) structure.

[0057] In addition, the compound represented by the structural formula 2 may be located on the surface of the perovskite crystal.

[0058] In addition, the compound represented by Structural Formula 2 can suppress tin oxidation and vacancy defect generation and control hole concentration by inducing a 2D / 3D mixed perovskite structure by introducing PEA, BA, or NMA into the lattice.

[0059] In addition, the perovskite includes crystal grains and grain boundaries formed between adjacent crystal grains, and one or more fluorine metal compounds selected from the group consisting of SnF2 and SbF3 may be located at the crystal grain boundaries.

[0060] In addition, the fluorine metal compound suppresses oxidation of tin and generation of vacancy defects, controls the hole concentration, and provides uniform crystal nuclei, thereby enabling the production of stable, uniform, and highly crystalline thin film crystals.

[0061] The compounds represented by the structural formulas 1 and 2 and the fluorine metal compounds are either EDAI2, EDABr2, P2DAI2, P2DABr2, P3DAI2, or P3DABr2, or PEAI:EDAI2:SnF2, BAI:EDAI2:SnF2, NMAI:EDAI2:SnF2, PEAI:EDABr2:SnF2, BAI:EDABr2:SnF2, or NMAI:EDABr2:SnF2 , PEAI:P2DAI2:SnF2, BAI:P2DAI2:SnF2, NMAI:P2DAI2:SnF2, PEAI:P2DABr2:SnF2, BAI:P2DABr2:SnF2, NMA I:P2DABr2:SnF2, PEAI:P3DAI2:SnF2, BAI:P3DAI2:SnF2, NMAI:P3DAI2:SnF2, PEAI:P3DABr2:SnF2, BAI:P3 DABr2:SnF2, NMAI:P3DABr2:SnF2, PEAI:EDAI2:SbF3, BAI:EDAI2:SbF3, NMAI:EDAI2:SbF3, PEAI:EDABr2:S bF3, BAI:EDABr2:SbF3, NMAI:EDABr2:SbF3, PEAI:P2DAI2:SbF3, BAI:P2DAI2:SbF3, NMAI:P2DAI2:SbF3, PE It may contain one or more species selected from the group consisting of AI:P2DABr2:SbF3, BAI:P2DABr2:SbF3, NMAI:P2DABr2:SbF3, PEAI:P3DAI2:SbF3, BAI:P3DAI2:SbF3, NMAI:P3DAI2:SbF3, PEAI:P3DABr2:SbF3, BAI:P3DABr2:SbF3, NMAI:P3DABr2:SbF3.

[0062] In addition, the tin-based perovskite may include at least one selected from the group consisting of formamidinium tin triiodide (FASnI3), cesium tin triiodide (CsSnI3), methylammonium tin triiodide (MASnI3), phenylethylammonium formamidinium tin triiodide (PEAFASnI3), and cesium formamidinium tin triiodide (CsFASnI3).

[0063] The perovskite is also intended for use in one or more semiconductor layers selected from the group consisting of memory elements, transistors, solar cells, light-emitting diodes, photodiodes, and photosensors, and is particularly preferably intended for use as an active layer of a memory element.

[0064] The thickness of the semiconductor layer may be 1 to 100 nm, preferably 3 to 50 nm. If the thickness of the semiconductor layer is less than 1 nm, it is difficult to apply the semiconductor layer to the entire surface of the substrate, which is undesirable. If the thickness of the semiconductor layer is more than 100 nm, it is undesirable because it retains an excess charge and exhibits unstable memory characteristics. By forming the memory device in such a very thin structure, it can be realized in flexible applications.

[0065] FIG. 1 is a schematic diagram of a thin film transistor memory according to one embodiment of the present invention, and FIG. 2 is a flowchart showing a manufacturing process of the thin film transistor memory according to the present invention.

[0066] Referring to FIG. 1, the present invention provides a transistor memory including a gate electrode 100, an insulating layer 200 located on the gate electrode, a semiconductor layer 300 including a perovskite located on the insulating layer, and a source electrode 400 and a drain electrode 500 located spaced apart from each other on the semiconductor layer.

[0067] The perovskite may contain at least one element selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA), a compound represented by the following structural formula 1, at least one element selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and tin (Sn). [Structural formula 1] [ka] During the ceremony, R 1 is a hydrogen atom, a methyl group, or an ethyl group, R 2 is a hydrogen atom, a methyl group, or an ethyl group, n is an integer of 1 to 3.

[0068] The thin film transistor memory of the present invention may further include a substrate or a substrate including the gate electrode, if necessary. While the thin film transistor memory 10 has been described as having a bottom gate top contact (BGTC) structure, it is not limited thereto and may also be applied to a top gate bottom contact (TGBC) structure, etc., without being limited thereto. A bottom-type thin film transistor memory includes the steps of providing a substrate, forming a gate electrode on the substrate, forming an insulating layer on the gate electrode, forming a semiconductor layer on the insulating layer, and forming a source electrode and a drain electrode spaced apart from each other on the organic semiconductor layer.

[0069] The substrate may include, but is not limited to, an n-type or p-type doped silicon wafer, a glass substrate, a plastic film containing at least one selected from the group consisting of polyacrylate, polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, and polyethersulfone, a glass substrate coated with indium tin oxide, or a plastic film.

[0070] In addition, the gate electrode 100 may be made of any of gold (Au), silver (Ag), aluminum (Al), aluminum alloy (Al-alloy), molybdenum (Mo), molybdenum alloy (Mo-alloy), n-doped silicon (n-doped Si), p-doped silicon (p-doped Si), silver nanowire, gallium indium eutectic, platinum (Pt), nickel (Ni), titanium (Ti), tungsten (W), chromium (Cr), magnesium (Mg), calcium (Ca), ytterbium (Yb), gold oxide, platinum oxide, silver oxide, palladium oxide, iron oxide, graphene, carbon nanotube (CNT), indium tin oxide (InT). The gate electrode may be formed using at least one selected from the group consisting of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). The gate electrode may be formed using at least one selected from the group consisting of thermal evaporation, sputtering, and spin coating.

[0071] Also, a gate insulating layer 200 may be formed over the entire surface of the gate electrode 100. The gate insulating layer 200 may be formed as a single layer or a multilayer of an inorganic insulating film or an organic insulating film, or as an organic-inorganic hybrid film. The inorganic insulating film may include at least one selected from the group consisting of silicon oxide, silicon nitride, hafnium oxide (HfO2), alumina (Al2O3), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), BST (Barium Strontium Titanate), PZT (Pb(Zr,Ti)O3), glass, quartz, silicon carbide, magnesium oxide, and germanium. The organic insulating film may include at least one selected from the group consisting of polymethylmethacrylate (PMMA), polystyrene (PS), phenolic polymers, acrylic polymers, imide polymers such as polyimide, aryl ether polymers, amide polymers, fluorine polymers, p-xylene polymers, vinyl alcohol polymers, and parylene.

[0072] Also, the semiconductor layer 300 may be formed on the entire surface of the insulating layer 200. The semiconductor layer 300 may include FASnI3 (formamidinium tin triiodide), CsSnI3 (cesium tin triiodide), MASnI3 (methylammonium tin triiodide), or a mixture of FASnI3 and a cation such as PEAFASnI3, CsFASnI3, or PEACsFASnI3. The semiconductor layer 300 may be formed on the insulating layer 200 by one or more methods selected from the group consisting of a solution process (spin coating, bar coating, slot coating, inkjet, spray coating, dispensing, etc.), thermal evaporation and mixing process (two-step process: vacuum evaporation after solution process or solution process after vacuum evaporation), chemical vapor deposition (CVD), atomic layer deposition (ALD), sputtering, flexography, screen, dip-coating, and gravure methods, preferably spin coating, bar coating, or thermal evaporation, more preferably a spin coating process.

[0073] When the substrate is included, the temperature of the substrate may be from room temperature to 300° C. in the thermal evaporation process.

[0074] After the semiconductor layer 300 is formed, heat treatment or optical exposure may be further performed to improve device performance such as semiconductor crystallinity and stability.

[0075] In addition, the source electrode 400 and the drain electrode 500 may be formed as a single layer containing at least one selected from the group consisting of Au, Ag, Pt, Al, W, Mg, Ca, Yb, Mo, or alloys thereof, Cs-ITO, gold oxide, platinum oxide, silver oxide, palladium oxide, iron oxide, and indium tin oxide (ITO).

[0076] In addition, when the substrate is included, it may be formed as a multi-layer structure by further including an adhesive metal layer such as Ti, Cr, Ni, etc. to improve adhesion to the substrate. Also, it may be fabricated as a device that is more elastic and flexible than conventional metals by using conductive polymers such as graphene, carbon nanotubes (CNT), PEDOT:PSS, silver nanowires, etc.

[0077] According to another aspect of the present invention, there is provided a method for producing perovskite, comprising the steps of: (a) producing a precursor solution containing one or more selected from the group consisting of a cesium (Cs) precursor, a methylammonium (MA) precursor, and a formamidinium (FA) precursor, a tin precursor, a compound represented by the following structural formula 1', and a solvent; (b) coating a substrate with the precursor solution to form a coating layer; and (c) heat-treating the coating layer to produce perovskite. [Structural formula 1'] [ka] During the ceremony, R 1 is a hydrogen atom, a methyl group, or an ethyl group, R 2 is a hydrogen atom, a methyl group, or an ethyl group, X is F, Cl, Br or I; n is an integer of 1 to 3.

[0078] The perovskite may contain at least one element selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA), a compound represented by the following structural formula 1, at least one element selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), and tin (Sn). [Structural formula 1] [ka] During the ceremony, R 1 is a hydrogen atom, a methyl group, or an ethyl group, R 2 is a hydrogen atom, a methyl group, or an ethyl group, n is an integer of 1 to 3.

[0079] In addition, the compound represented by structural formula 1' may include one or more selected from the group consisting of EDAI2 (ethane-1,2-diammonium diiodide), EDABr2 (ethane-1,2-diammonium dibromide), P2DAI2 (propane-1,2-diammonium diiodide), P2DABr2 (propane-1,2-diammonium dibromide), P3DAI2 (propane-1,3-diammonium diiodide), and P3DABr2 (propane-1,3-diammonium).

[0080] In addition, the compound represented by the structural formula 1' can form a hollow structure in the lattice to induce memory characteristics, and can also lower the VBM (Valence Band Maximum) level and inhibit oxidation, thereby enhancing stability.

[0081] The precursor solution may further include a compound represented by structural formula 2'. [Structural formula 2'] [ka] During the ceremony, R 3 is a hydrogen atom, a methyl group, or an ethyl group, R 4 is a hydrogen atom, a methyl group, or an ethyl group, R 5 represents a hydrogen atom, a methyl group, an ethyl group, a C6 to C10 aryl group, or a C6 to C14 aryl group fused to the benzene ring, Y is F, CI, Br or I; p is an integer from 0 to 3, q is an integer of 1 to 3.

[0082] In addition, the compound represented by the structural formula 2' may include at least one selected from the group consisting of PEAI (phenylethylammonium iodide), BAI (n-butylammonium iodide), and NMAI (1-naphthylmethylammonium iodide).

[0083] In addition, the compound represented by Structural Formula 2' can suppress the oxidation of tin and the generation of vacancy defects and control the hole concentration by inducing a 2D / 3D mixed perovskite structure through the introduction of PEA, BA, or NMA into the lattice.

[0084] When the present invention contains the compound represented by Structural Formula 1, the compound represented by Structural Formula 2, and a fluorine metal compound, it is possible to suppress oxidation and vacancy defect generation, control hole concentration, improve stability, improve crystallinity, and impart memory properties to form an optimal memory semiconductor thin film, and it can be said that the compound represented by Structural Formula 1 and the fluorine metal compound play particularly important roles.

[0085] Ammonium iodide-based additives, diammonium halide-based additives, and metal fluoride-based additives all suppress tin oxidation and vacancy defect generation and control hole concentration during thin film fabrication by spin coating. Furthermore, diammonium halide-based additives form localized hollow structures in the thin film, inducing deep traps and imparting memory properties to the thin film crystals. Metal fluoride-based additives provide uniform crystal nuclei, thereby inducing the formation of stable, uniform, and highly crystalline thin film crystals.

[0086] The perovskite may contain 0.1 to 100 mol, preferably 0.1 to 50 mol, and more preferably 0.1 to 30 mol of one or more compounds selected from the group consisting of the compounds represented by Structural Formula 1 and the compounds represented by Structural Formula 2, based on 100 mol of tin.

[0087] The perovskite complex may contain 0.05 to 20 mol, preferably 0.1 to 10 mol, and more preferably 0.1 to 5 mol of the compound represented by structural formula 1 based on 100 mol of tin in the tin-based perovskite.

[0088] When the perovskite complex contains less than 0.05 mol of the compound represented by Structural Formula 1 based on 100 mol of tin in the tin-based perovskite, the hollow structure is not sufficiently formed, and memory characteristics are not exhibited, which is not preferred. On the other hand, when the perovskite complex contains more than 20 mol, the hollow structure is no longer formed, and the compound is present on the surface or grain boundary of the lattice, or the lattice is destabilized, which may result in problems such as deteriorated electrical characteristics of the device, which is not preferred.

[0089] The fluorine metal compound can be contained in an amount of 0.01 to 50 mol, preferably 1 to 20 mol.

[0090] If the tin-based perovskite contains less than 0.01 mol of the fluorine metal compound based on 100 mol of tin, the oxidation inhibition and hole concentration reduction effects are negligible, and the off current is high, which may result in no memory properties, which is undesirable. If the fluorine metal compound is contained in excess of 50 mol, there is a possibility that a problem of phase separation may occur due to the clumping of the fluorine metal compound, which is undesirable.

[0091] Step (b) may be performed by at least one method selected from the group consisting of a solution process (spin coating, bar coating, slot coating, inkjet, spray coating, dispensing, etc.), a thermal evaporation and mixing process (two-step process: vacuum deposition after a solution process or a solution process after vacuum deposition), chemical vapor deposition (CVD), atomic layer deposition (ALD), sputtering, flexography, screen coating, dip coating, and gravure methods, preferably a spin coating method.

[0092] The heat treatment in step (c) can be performed at room temperature to 200°C, preferably 40 to 180°C, and more preferably 80 to 150°C. If the heat treatment is performed below room temperature, the thermal energy required for the reaction between the perovskite precursor applied by solution processing and the additives and for the crystallization of the thin film may be insufficient, resulting in unstable crystal formation and oxidation due to residual solvents and anti-solvents. If the heat treatment is performed above 200°C, the excessive thermal energy can undesirably cause damage to the crystal structure, such as the generation of defects. The heat treatment can also refer to annealing, which refers to the supply of thermal energy to an object by maintaining the object at a constant temperature.

[0093] 2 is a flowchart illustrating a method for manufacturing a semiconductor layer according to one embodiment of the present invention. Referring to FIG. 2, the present invention provides a method for manufacturing a transistor memory, including: (1) preparing a gate electrode / insulating layer stack including a gate electrode and an insulating layer located on the gate electrode; (2) forming a semiconductor layer including the perovskite on the insulating layer; and (3) forming a source electrode and a drain electrode on the semiconductor layer.

[0094] When the present invention contains a compound represented by Structural Formula 1, a compound represented by Structural Formula 2, and a fluorine metal compound, it is possible to suppress oxidation and vacancy defect generation, control hole concentration, improve stability, improve crystallinity, and impart memory properties to form an optimal memory semiconductor thin film, and it can be said that the compound represented by Structural Formula 1 and the fluorine metal compound play particularly important roles.

[0095] Ammonium iodide-based additives, diammonium halide-based additives, and metal fluoride-based additives all inhibit tin oxidation and vacancy defect generation and control hole concentration during thin film fabrication by spin coating. Furthermore, diammonium halide-based additives form localized hollow structures in the thin film, inducing deep traps and imparting memory properties to the thin film crystals. Metal fluoride-based additives provide uniform crystal nuclei, thereby inducing the formation of stable, uniform, and highly crystalline thin film crystals.

[0096] Sn-based halide perovskites are very unstable to oxygen and moisture in the atmosphere. This is partly because the material itself has a strong ionic character, but the main reason is that tin is easily oxidized when it comes into contact with moisture and oxygen. Very slight oxidation and Sn 2+ The formation of vacancies induces hole self-doping, which results in excellent p-type properties. However, excessive oxidized tin in the perovskite and the combined excess Sn 2+ Vacancy formation leads to the destabilization of the crystal structure and the deterioration of its excellent electrical properties, resulting in the collapse of the crystal structure. Therefore, the Sn-based perovskite thin film of the present invention contains various additives to adjust p-doping and suppress oxidation and vacancy formation.

[0097] In the case of the compound represented by the structural formula 1 of the present invention, it is an additive that induces a hollow structure in the thin film that causes the semiconductor layer to have memory properties. In the case of EDAI2, EDA 2+ and two I's - ionized into EDA 2+ is included in the A cation site, and I - Also X - This can be included in the site. 2+ In the case of , unlike the general A cation, it is a divalent cation, so in order to balance the charge, the existing A cation, FA + Or B cation Sn 2+ may be included in an additional small amount.

[0098] In addition, in the case of FAI, it is completely ionized in the solvent and becomes FA + (CH(NH2)2 + ) and I - In the case of SnI2, it is completely ionized in the solvent and becomes Sn 2+ and I - In the solution, it exists in the form of FA in the ABX3 type perovskite lattice. + is a monovalent cation A + , Sn 2+ is a divalent cation B 2+ , and I - is a monovalent anion, X - Referring to Figure 10, B 2+ and X - constitutes an octahedral structure, which are repeatedly connected via corner sharing, and A + The cations are sandwiched together to ultimately form the perovskite lattice structure.

[0099] Possible A cations include FA + Even excluding Cs + , M.A. + (Methylammonium, CH3NH3 +In this case, CsI and MAI can be used instead of FAI in the first step of preparing the first mixed solution. Of course, the A cation can be included not only as a single substance, but also as one of the three substances listed above, or as two or three substances mixed in different ratios. Alternatively, the sum of the mole numbers of these can be the same as the mole number of Sn in the precursor. 2+ The amount is 1:1 ratio, x - The ratio of PEAI and EDAI to PEA is 1:3. + and I - and EDA 2+ and I - is completely ionized.

[0100] Furthermore, the fluorine metal compound of the present invention can inhibit oxidation. SnF2 is the most commonly known and used additive. Without the fluorine metal compound, tin-based halide perovskite exhibits properties closer to a conductor than a semiconductor and is very unstable, as self-p-doping and oxidation inhibition are not regulated unless another oxidation inhibitor is added.

[0101] The additive may further include a compound represented by Formula 2, and the compound represented by Formula 2 may include an ammonium iodide-based compound.

[0102] The compound represented by structural formula 2 of the present invention can form a special structure that is somewhat resistant to tin oxidation, and therefore can form a stable tin-based halide perovskite thin film.

[0103] Furthermore, the compound represented by structural formula 2, which is a large organic cation, cannot be introduced into the ABX3 lattice due to its size. However, since it is a monovalent cation with an ammonium group, it can bind to the A cation site. In this case, the perovskite lattice no longer grows in that direction, and the cations of the compound represented by structural formula 2 attach to the surface of the lattice, filling the A cation site and completing the crystal growth.

[0104] Therefore, when a perovskite crystalline thin film is formed containing a compound represented by structural formula 2, continuous bulk 3D crystals are not formed in all three-dimensional directions, but rather, grains and crystals are formed on one side in the form of an aggregate of flakes with various thicknesses whose growth is restricted, which is called a 2D / 3D (2D-3D) structure.

[0105] Due to its large size and hydrophobic nature, the compound represented by Structural Formula 2 can prevent moisture and oxygen from penetrating into the perovskite lattice, preventing oxidation and forming a relatively stable thin film. The following examples and drawings include results when the compound represented by Structural Formula 2 is included to demonstrate stable memory device operation.

[0106] Then, the prepared precursor solution was mixed with HfO2 / p ++ After dropping it onto a Si substrate, it is applied to the substrate by spin coating. The substrate with the film applied is then heated to complete the perovskite thin film crystal. After that, gold is deposited by thermal evaporation to form separated source / drain electrodes, and finally, a BGTC structure perovskite memory is fabricated as shown in Figure 1.

[0107] [Example] The present invention will be described below by way of preferred embodiments, which are merely illustrative and are not intended to limit the scope of the present invention.

[0108] Fabrication of semiconductor layers containing perovskite complexes Example 1: EDAI 2 +SnF 2 + Use of PEAI additives Example 1-1: 1 mol of EDAI 2 : 10 mol SnF 2 : 20 mol of PEAI FIG. 2 is a flowchart illustrating a method for manufacturing a semiconductor layer according to an embodiment of the present invention. Referring to FIG. 2, a precursor solution of a perovskite complex is prepared, and then the precursor solution is mixed with hafnium oxide / silicon (HfO2 / Si ++ ) and a tin-based perovskite semiconductor thin film was formed by spin coating.

[0109] Specifically, FAI (Formamidinium Iodide, CH(NH2)2I) and SnI2 (Tin iodide) were mixed in a co-solvent of N,N-dimethylformamide (DMF) and dimethylsulfoxide (DMSO) (DMF:DMSO = 4:1 (vol:vol)) to concentrations of 0.18 M and 0.2 M, respectively, to prepare a first mixed solution.

[0110] Here, in the case of FAI, it is completely ionized in the solvent and becomes FA + (CH(NH2)2 + ) and I - In the case of SnI2, it is completely ionized in the solvent and becomes Sn 2+ and I - In the solution, it exists in the form of FA in the ABX3 type perovskite lattice. + is a monovalent cation A + , Sn 2+ is a divalent cation B 2+ , and I - is a monovalent anion, X - Referring to Figure 10, B 2+ and X - constitutes an octahedral structure, which are repeatedly connected via corner sharing, and A + The cations are sandwiched together to ultimately form the perovskite lattice structure.

[0111] Possible A cations include FA + Even excluding Cs + , M.A. + (Methylammonium, CH3NH3 + In this case, CsI and MAI can be used instead of FAI in the first step of preparing the first mixed solution. Of course, the A cation can be included not only as a single substance, but also as a mixture of the three listed substances, or as a mixture of two or three substances in different ratios. Alternatively, the sum of the mole numbers of these substances can be the sum of the moles of Sn in the precursor. 2+ The amount is 1:1 ratio, x - The amount of 1:3 should be used.

[0112] A second mixed solution was prepared by adding EDAI2, SnF2, and PEAI to the prepared perovskite precursor solution so that the molar ratio of tin:EDAI2:tin fluoride (SnF2):PEAI was 100 mol:1 mol:10 mol:20 mol, based on 100 mol of tin.

[0113] The second mixed solution was heated at a temperature of about 60° C. for 2 to 3 hours to prepare a precursor solution.

[0114] The precursor solution is HfO2 / Si ++ The solution was dropped onto a substrate and spin-coated at 5 krpm (revolutions per minute) for 60 seconds, followed by heat treatment at 100°C for 10 minutes to produce a semiconductor layer containing a perovskite complex containing 1 mol of EDAI2, 10 mol of SnF2, and 20 mol of PEAI based on 100 mol of tin-based perovskite.

[0115] Example 1-2: 2 mol of EDAI 2 : 10 mol SnF 2 : 20 mol of PEAI A semiconductor layer containing a perovskite complex was produced in the same manner as in Example 1-1, except that when producing the second mixed solution, EDAI2, tin fluoride (SnF2), and PEAI were added to the first mixed solution so that the molar ratio of tin:EDAI2:tin fluoride (SnF2):PEAI was 100 mol:2 mol:10 mol:20 mol based on 100 mol of tin in the finally produced perovskite complex.

[0116] Examples 1-3: 4 mol of EDAI 2 : 10 mol SnF 2 : 20 mol of PEAI A semiconductor layer containing a perovskite complex was produced in the same manner as in Example 1-1, except that when producing the second mixed solution, EDAI2, tin fluoride (SnF2), and PEAI were added to the first mixed solution so that the molar ratio of tin:EDAI2:tin fluoride (SnF2):PEAI was 100 mol:4 mol:10 mol:20 mol based on 100 mol of tin in the finally produced perovskite complex.

[0117] Comparative Example 1: 10 mol of SnF 2 : 20 mol of PEAI (without using the compound represented by structural formula 1) A semiconductor layer containing a perovskite complex was produced in the same manner as in Example 1-1, except that EDAI2 (a compound represented by structural formula 1) was not added when the second mixed solution was produced.

[0118] Table 1 below shows the molar ratio of each additive relative to 100 mol of tin in Examples 1-1 to 1-3 and Comparative Example 1. [Table 1]

[0119] Thin-film transistor manufacturing Element Examples 1-1 to 1-3 FIG. 1 is a schematic diagram of a thin film transistor according to one embodiment of the present invention, and FIG. 2 is a flowchart showing a method for manufacturing a semiconductor layer according to one embodiment of the present invention.

[0120] Transistors of element examples 1-1 to 1-3 were manufactured according to Figures 1 and 2. First, the precursor solutions manufactured in Examples 1-1 to 1-3 were mixed with HfO2 / Si ++ The solution was dropped onto the HfO2 substrate and spin-coated at 5 krpm (revolutions per minute) for 60 seconds, followed by heat treatment at 100°C for 10 minutes to produce a semiconductor layer containing a perovskite complex.

[0121] Au electrodes were thermally evaporated on the semiconductor layer to form source and drain electrodes, thereby fabricating a thin film transistor (BGTC structure perovskite memory).

[0122] Comparative element example 1 A thin film transistor was manufactured in the same manner as in Device Example 1-1, except that the precursor solution manufactured in Comparative Example 1 was used.

[0123] Table 2 below summarizes the semiconductor layers used in element examples 1-1 to 1-3. [Table 2]

[0124] [Test example] Test Example 1: Analysis of changes in crystal lattice and optical properties due to the addition of fluorine metal compounds and confirmation of the formation of hollow structures FIG. 3 shows the XRD analysis results of Examples 1-1, 1-2, and 1-3 and Comparative Example 1, FIG. 4a shows the absorbance analysis results of Examples 1-1, 1-2, and 1-3 and Comparative Example 1, and FIG. 4b shows the results of extrapolation to a Tauc plot for deriving the optical bandgap of Examples 1-1, 1-2, and 1-3 and Comparative Example 1.

[0125] 3, it can be seen that the peaks in Example 1-1 shift to a smaller θ overall compared to Comparative Example 1, in which no EDAI2 was added to the Sn-based perovskite, and that this shift is even more pronounced in Examples 1-2 and 1-3, in which a larger amount of the compound represented by Structural Formula 1 was added. The shift of the peak to a smaller θ generally indicates an increase in the lattice constant, which explains the creation of a hollow structure within the lattice.

[0126] For details, see EDAI2 EDA 2+ is a general cation that can be included in B, C, and D in structural formula 1, Cs + , F.A. + , M.A. + etc., and therefore when introduced into the lattice, the lattice constant increases and the peak shifts to a smaller θ.

[0127] Furthermore, when compared with Comparative Example 1, the peaks in Examples 1-1, 1-2, and 1-3 are larger, confirming that the crystallinity is excellent when EDAI2 is added. Specifically, EDA having two ammonium groups 2+ actively interacts with the perovskite constituent ions, causing the crystals to grow more slowly and improving the quality of the thin film, thereby allowing it to exhibit stable electrical properties.

[0128] Referring to Figure 4, by adding more EDAI2 to the tin-based perovskite, the optical band gap, E g The reason for this increase in the optical bandgap is the increase in the FA in the bulk lattice. + and Sn 2+ EDA website 2+ Instead, Sn occupies the CB (Conduction Band) and VB (Valence Band) 2+This is because the number of VBs decreased and the thickness of the VB and CB became thinner, which confirmed the formation of a hollow structure.

[0129] Test Example 2: Added EDAI 2 Confirmation of transistor characteristics by mole ratio 5 shows the output curves of the device example 1-1 and the device comparative example 1, and FIG. 6 shows the transfer curves of the device example 1-1 and the device comparative example 1 when Vds is set to −5 V. In detail, FIG. 5 shows the voltage V between the gate electrode and the source electrode. GS The current I flowing through the active layer in response to the application of drain voltage when DS 6 shows the current I that flows through the active layer in response to the application of the gate voltage. DS (In this case, the voltage between the source and drain electrodes is -5V (V DS =-5V).

[0130] 5 and 6, it was confirmed that the perovskite transistor manufactured according to the present invention exhibits the characteristics of a typical P-type transistor.

[0131] Also, referring to Figure 5, in the linear region, V DS With the increase of I DS This shows that the linear increase of all V GS The same results were obtained, and it was confirmed that good contact was made between the semiconductor layer and the source and drain electrodes.

[0132] Furthermore, referring to FIG. 6, the current flashing ratio (I on / off )10 6 Although the above-mentioned excellent characteristics are exhibited, the on-current is slightly lowered due to the hole generation suppression effect of the compound represented by structural formula 1, and as a result, the hole mobility μ FET is 7.49cm 2 / V·s to 5.79 cm 2 / V·s. It was also confirmed that the hysteresis phenomenon of the transition curve was greatly expanded when the compound represented by structural formula 1 was added.

[0133] Test Example 3: Added EDAI 2 Confirmation of memory characteristics by molar ratio Figure 7 shows the V DS 8 shows transfer curves of Device Examples 1-1 to 1-3 and Device Comparative Example 1 when Vcc was set to −0.5V. FIG. 8 shows the results of measuring the retention time of stored information for Device Example 1-1. FIG. 9 shows the results of measuring the cycling endurance for Device Example 1-1.

[0134] Referring to FIG. 7, in the case of Comparative Example 1 of the device to which the compound EDAI2 represented by Structural Formula 1 was not added, V DS Similarly to when a voltage of -5V was applied, a small hysteresis phenomenon was observed, but it was confirmed that a very large hysteresis phenomenon was observed in Examples 1-1 to 1-3 in which the compound represented by Structural Formula 1 was added. In particular, when the additive was added, it was introduced into the bulk lattice in place of existing cations, forming a hollow structure, which resulted in the generation of deep traps in the channel portion of the semiconductor layer, causing the above-mentioned hysteresis phenomenon and resulting in the characteristics of a memory device.

[0135] Referring to FIG. 8, to switch in the program state, V GS Apply a pulse corresponding to =-13V for 2 seconds to switch in the Erase state. GS A pulse corresponding to V = 15 V was applied for 4 seconds. GS =-0.2V and V DS The data was read by applying a voltage corresponding to = -0.2V. As a result, the current values ​​I DS is the difference between on / off is 103 10 or more while maintaining 3 It was confirmed that the information was stably maintained for more than 10 seconds, and that adding the compound represented by structural formula 1 could impart excellent nonvolatile memory properties to the transistor.

[0136] Referring to Figure 9, to switch in the program state, V GS Apply a pulse corresponding to V = -13V for 2 seconds to switch in the Erase state. GS Apply a pulse corresponding to V = 15V for 4 seconds, and GS =-0.2V and V DS As shown in Figure 9, even after about 250 switching cycles, the voltage corresponding to I = -0.2V was applied to read the information. on / off to 10 3 The above-mentioned properties were maintained while exhibiting stable write / erase / read characteristics. In other words, the cycle durability measurement also confirmed that adding the compound represented by structural formula 1 can impart excellent nonvolatile memory characteristics to the transistor.

[0137] The scope of the present invention is indicated by the claims set forth below rather than by the above detailed description, and all changes and modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included within the scope of the present invention.

Claims

1. one or more selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA); A compound represented by the following structural formula 1, one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I); and tin (Sn). [Structural formula 1] 【Chemistry 1】 (In the formula, R １ is a hydrogen atom, a methyl group, or an ethyl group, R ２ is a hydrogen atom, a methyl group, or an ethyl group, n is an integer from 1 to 3.

2. The perovskite according to claim 1, characterized in that the compound represented by structural formula 1 includes one or more selected from the group consisting of EDA (ethane-1,2-diammonium), P2DA (propane-1,2-diammonium), P3DA (propane-1,3-diammonium), piperazine-1,4-diium iodide, piperazine-1,4-diium chloride, and piperazine-1,4-diium bromide.

3. 2. The perovskite of claim 1, characterized in that the perovskite has a hollow structure within the lattice.

4. The perovskite according to claim 1, further comprising a compound represented by the following structural formula 2: [Structural formula 2] 【Chemistry 2】 (In the formula, R ３ is a hydrogen atom, a methyl group, or an ethyl group, R ４ is a hydrogen atom, a methyl group, or an ethyl group, R ５ represents a hydrogen atom, a methyl group, an ethyl group, a C6 to C10 aryl group, or a C6 to C14 aryl group fused to the benzene ring; p is an integer from 0 to 3; q is an integer of 1 to 3.

5. The perovskite according to claim 4, characterized in that it contains 0.1 to 100 mol of one or more compounds selected from the group consisting of compounds represented by structural formula 1 and compounds represented by structural formula 2, based on 100 mol of tin.

6. 5. The perovskite according to claim 4, characterized in that the perovskite has a 2D / 3D (quasi 2D) structure.

7. The perovskite according to claim 4, wherein the compound represented by structural formula 2 is located on the surface of the perovskite crystal.

8. the perovskite includes crystal grains and crystal grain boundaries formed between adjacent crystal grains; The grain boundaries are filled with SnF ２ and SbF ３ 2. The perovskite of claim 1, wherein one or more fluorine-metal compounds selected from the group consisting of:

9. 2. The perovskite of claim 1, wherein the perovskite is for use in one or more semiconductor layers selected from the group consisting of memory elements, transistors, solar cells, light emitting diodes, photodiodes and photosensors.

10. 10. The perovskite according to claim 9, wherein the semiconductor layer has a thickness of 1 to 100 nm.

11. a gate electrode; an insulating layer located on the gate electrode; a semiconductor layer located on the insulating layer and including a perovskite; a source electrode and a drain electrode spaced apart from each other on the semiconductor layer.

12. The perovskite one or more selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA); A compound represented by the following structural formula 1, one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I); 12. The transistor memory of claim 11, further comprising: tin (Sn). [Structural formula 1] 【Transformation 3】 (In the formula, R １ is a hydrogen atom, a methyl group, or an ethyl group, R ２ is a hydrogen atom, a methyl group, or an ethyl group, n is an integer from 1 to 3.

13. (a) preparing a precursor solution containing at least one selected from the group consisting of a cesium (Cs) precursor, a methylammonium (MA) precursor, and a formamidinium (FA) precursor, a tin precursor, a compound represented by the following structural formula 1′, and a solvent; (b) coating the precursor solution onto a substrate to form a coating layer; (c) heat treating the coating layer to produce the perovskite. [Structural formula 1'] 【Chemistry 4】 (In the formula, R １ is a hydrogen atom, a methyl group, or an ethyl group, R ２ is a hydrogen atom, a methyl group, or an ethyl group, X is F, Cl, Br or I; n is an integer from 1 to 3.

14. The perovskite one or more selected from the group consisting of cesium (Cs), methylammonium (MA), and formamidinium (FA); A compound represented by the following structural formula 1, one or more elements selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I); 14. The method for producing perovskite according to claim 13, further comprising: [Structural formula 1] 【Transformation 5】 (In the formula, R １ is a hydrogen atom, a methyl group, or an ethyl group, R ２ is a hydrogen atom, a methyl group, or an ethyl group, n is an integer from 1 to 3.

15. The compound represented by the structural formula 1' is EDAI ２ (ethane-1,2-diammonium diiodide), EDABr ２ (ethane-1,2-diammonium dibromide), P2DAI ２ (propane-1,2-diammonium diiodide), P2DABr ２ (propane-1,2-diammonium dibromide), P3DAI ２ (propane-1,3-diammonium diiodide), and P3DABr ２ (propane-1,3-diammonium) and (propane-1,3-diammonium).

16. The method for producing perovskite according to claim 13, wherein the precursor solution further comprises a compound represented by structural formula 2'. [Structural formula 2'] 【Transformation 6】 (In the formula, R ３ is a hydrogen atom, a methyl group, or an ethyl group, R ４ is a hydrogen atom, a methyl group, or an ethyl group, R ５ represents a hydrogen atom, a methyl group, an ethyl group, a C6 to C10 aryl group, or a C6 to C14 aryl group fused to the benzene ring; Y is F, Cl, Br or I; p is an integer from 0 to 3; q is an integer of 1 to 3.

17. The method for producing a perovskite according to claim 16, characterized in that the compound represented by structural formula 2' includes one or more selected from the group consisting of PEAI (phenylethylammonium iodide), BAI (n-butylammonium iodide), and NMAI (1-naphthylmethylammonium iodide).

18. 14. The method for producing perovskite according to claim 13, wherein the coating in step (b) is carried out by a method comprising one or more selected from the group consisting of spin coating, bar coating, slot coating, inkjet, spray coating, dispensing, thermal evaporation, chemical vapor deposition (CVD), atomic layer deposition (ALD), sputtering, flexography, screen, dip coating, gravure methods, and combinations thereof.

19. The method for producing perovskite according to claim 13, wherein the heat treatment in step (c) is carried out at room temperature to 200°C.

20. (1) providing a gate electrode / insulating layer stack including a gate electrode and an insulating layer overlying the gate electrode; (2) forming a semiconductor layer containing the perovskite according to claim 1 on the insulating layer; (3) forming a source electrode and a drain electrode on the semiconductor layer.

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