Method for preparing color conversion composition including organometallic halide compound, color conversion composition prepared thereby, and application thereof

Abstract

The present invention relates to a method for preparing a color conversion composition including an organometallic halide compound, a color conversion composition prepared thereby, and application thereof. The color conversion composition including an organometallic halide compound is prepared by forming an organometallic halide compound having a chemical formula of A2MX4, and by mixing the organometallic halide compound with an anhydrous alcohol-based solvent, so that the anhydrous alcohol-based solvent causes partial softening and temporary swelling of the organometallic halide compound, thereby increasing viscosity of the composition. Therefore, the color conversion composition having an appropriate viscosity without adding a separate binder or thickener may be provided, and may be actively applied to a scintillator film, a color conversion film, a color conversion pattern, or a color conversion layer of a white light-emitting diode.

Description

Method for preparing a color-changing composition comprising an organometal halide compound, a color-changing composition prepared thereby, and an application thereof

[0001] The present invention relates to a color-changing material, and more specifically, to a method for preparing a color-changing composition comprising an organometal halide compound, a color-changing composition prepared thereby, and applications thereof.

[0002] The development of new materials combining high efficiency and stability is emerging as a critical challenge in the field of light-emitting materials. In particular, Micro Light Emitting Diode (μ-LED) technology is attracting attention as a next-generation display technology based on its advantages, such as high efficiency, long lifespan, and low power consumption. However, the commercialization and mass application of μ-LEDs still face several challenges. Specifically, realizing a high-quality color conversion layer for light-emitting diodes is one of the core technical challenges, as the efficient and uniform production of color conversion materials is critical.

[0003] Perovskite materials are receiving significant attention as color-changing materials due to their excellent luminescence properties and variable bandgaps. Despite the outstanding optical performance of commonly used lead-based perovskite materials, the toxicity of lead and the production and disposal of electronic products containing it cause serious environmental and health problems. To address this, lead-free metal halide materials, in which lead is replaced with other low-toxicity elements to prevent the generation of harmful combustion byproducts during combustion, have recently been gaining attention.

[0004] Specifically, materials containing metals such as copper, silver, or bismuth are not only more environmentally friendly than lead (Pb) but can also maintain high luminous efficiency, making them suitable for use in various applications including color conversion layers. These lead-free metal halide materials generally require binders such as resins or polydimethylsiloxane (PDMS) to maintain consistent optical properties and ensure uniform film formation.

[0005] However, the difference in refractive index between the binder and the active material can lead to optical loss. Furthermore, as the amount of binder increases, the color conversion layer and scintillator film become unnecessarily thick, which can delay the device's response time and reduce energy efficiency. Additionally, chemical interactions between the binder and the active material can cause long-term stability issues, posing a serious obstacle to the development of high-performance light-emitting materials; therefore, a new approach is required to overcome these challenges.

[0006] To solve the aforementioned problems, the present invention aims to provide a method for manufacturing a color-changing composition comprising an organometal halide compound, which allows the organometal halide compound to be effectively applied as a color-changing material without involving a binder, a color-changing composition manufactured thereby, and an application thereof.

[0007] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below.

[0008] To achieve the above objective, one aspect of the present invention provides a method for preparing a color-changing composition comprising the steps of: mixing an organic halide compound having the chemical formula AX and a metal halide compound having the chemical formula MX2 to form an organic metal halide compound having the chemical formula A2MX4; and mixing an anhydrous alcohol-based solvent with the organic metal halide compound to form a color-changing composition, wherein A is an organic onium cation, M is a metal cation, and X is a halogen anion.

[0009] The above organic onium cation may include an organic phosphonium ion or an organic ammonium ion.

[0010] The above organic phosphonium ion may include cyclopropyltriphenylphosphonium ions.

[0011] The above organic ammonium ion may include tetrapropylammonium ions.

[0012] The above metal cation may be a manganese (Mn) cation.

[0013] The above anhydrous alcohol-based solvent may include one or more selected from anhydrous ethanol, anhydrous methanol, anhydrous isopropanol, and anhydrous butanol.

[0014] 0.1 to 5.0 ml of the anhydrous alcohol-based solvent can be mixed with 1 g of the above organometallic halide compound.

[0015] Another aspect of the present invention provides a color-changing composition comprising an anhydrous alcohol-based solvent and an organometal halide compound particle having the chemical formula A2MX4, the surface of which is softened and temporarily swollen by said anhydrous alcohol-based solvent, wherein A is an organoonium cation, M is a metal cation, and X is a halogen anion.

[0016] The above organometal halide compound may include (CPTP)2MnBr4 or (TPA)2MnBr4.

[0017] For every 1 g of the above organometallic halide compound, 0.1 to 5.0 ml of the above anhydrous alcohol-based solvent may be mixed.

[0018] The above composition may not include a binder or a thickener.

[0019] The above composition may have clay-like properties.

[0020] When the above composition is dried, the anhydrous alcohol-based solvent evaporates, and the shape is maintained while it can solidify.

[0021] Another aspect of the present invention provides a color-changing composition comprising particles of an organometal halide compound having the chemical formula A2MX4 but not a binder, wherein A is an organoonium cation, M is a metal cation, and X is a halogen anion, and a scintillator film is provided.

[0022] Another aspect of the present invention provides a color-changing composition comprising particles of an organometal halide compound having the chemical formula A2MX4 but not a binder, wherein A is an organoonium cation, M is a metal cation, and X is a halogen anion, and a color-changing film or color-changing pattern is provided.

[0023] Another aspect of the present invention provides a white light-emitting diode comprising: a blue or ultraviolet LED; and a color conversion layer disposed on the LED and comprising a green light-emitting organic metal halide compound particle having the chemical formula A2MX4 and a red phosphor, but not comprising a binder, wherein A is an organic onium cation, M is a metal cation, and X is a halogen anion.

[0024] The method for preparing a color-changing composition equipped with an organometal halide compound of the present invention allows for the easy preparation of a color-changing composition having appropriate viscosity without the need for separate heat treatment or the addition of a binder or thickener, through plasticity resulting from the interaction between the organometal halide compound and an anhydrous alcohol-based solvent.

[0025] In addition, the color-changing composition equipped with the organometal halide compound of the present invention can be applied in various fields such as luminescent clay, luminescent ink, scintillator film, color-changing film, color-changing pattern, or color-changing layer of a white light-emitting diode by controlling the concentration of the composition by adjusting the mixing amount of an anhydrous alcohol-based solvent.

[0026] In addition, the color-changing composition equipped with the organometal halide compound of the present invention can simplify the production process by eliminating the need for binders or thickeners, and can stably manufacture a color-changing film.

[0027] In addition, the color-changing composition equipped with the organometal halide compound of the present invention can form a thin and uniform color-changing film and optimize the film thickness, thereby improving the luminous efficiency and stability of the light-emitting diode to which it is applied. That is, the color-changing composition equipped with the organometal halide compound of the present invention can be successfully applied as a color-changing layer of a blue light-emitting diode-based white light-emitting diode, and thus has potential for use in various technical fields including not only micro LEDs but also other displays, lighting, and scintillators.

[0028] As such, the color-changing composition equipped with the organometal halide compound of the present invention can effectively prevent the problem of performance degradation caused by the use of binders or thickeners during the manufacture of conventional color-changing layers and scintillators.

[0029] The technical effects of the present invention are not limited to those mentioned above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description below.

[0030] FIG. 1 is a flowchart for explaining a method for preparing a color-changing composition equipped with an organometal halide compound of the present invention.

[0031] Figure 2 is an image showing the mechanochemical synthesis process for preparing polycrystalline (CPTP)2MnBr4 in Example 1 of the preparation of organometallic halide compounds of the present invention.

[0032] Figure 3 is an image showing the synthesis process of a single crystal (CPTP)2MnBr4 through antisolvent vapor-assisted crystallization in Example 2 of the preparation of organometallic halide compounds of the present invention.

[0033] Figure 4 is the crystal structure of (CPTP)2MnBr4, an organometallic halide compound according to one embodiment of the present invention.

[0034] FIG. 5 shows CPTP constituting an organometal halide compound according to one embodiment of the present invention. + It is the molecular structure of a cation.

[0035] FIG. 6 shows [MnBr4] constituting an organometal halide compound according to one embodiment of the present invention. 2- It is the molecular structure of a tetrahedron.

[0036] Figure 7 is a crystal structure obtained from data obtained by performing single-crystal X-ray diffraction (SC-XRD) on (CPTP)2MnBr4 of Preparation Example 2 of the organometallic halide compound of the present invention.

[0037] Figure 8 is a graph showing the diffraction profile obtained after performing full-pattern Rietveld refinement on the polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention.

[0038] Figure 9 is a graph comparing the powder X-ray diffraction (PXRD) patterns of the polycrystalline (CPTP)2MnBr4 of the organometallic halide compound preparation example 1 of the present invention and the single-crystal (CPTP)2MnBr4 of the organometallic halide compound preparation example 2.

[0039] FIG. 10 is a full-range X-ray photoelectron spectroscopy (XPS) spectrum of various elements constituting the polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention.

[0040] Figure 11 is a mapping image of the single crystal (CPTP)2MnBr4 of the organometallic halide compound preparation example 2 of the present invention analyzed by scanning electron microscopy-energy dispersive spectrometry (SEM-EDS).

[0041] FIG. 12 is a graph comparing the photoluminescence (PL) and photoluminescence excitation (PLE) spectra of polycrystalline (CPTP) 2MnBr4 of the organometal halide compound preparation example 1 of the present invention and single-crystal (CPTP) 2MnBr4 of the organometal halide compound preparation example 2.

[0042] FIG. 13 is a graph comparing the luminescence decay curves of polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention and single-crystal (CPTP) 2MnBr4 of the organometallic halide compound preparation example 2.

[0043] FIG. 14 is an image showing the photoluminescence quantum yield (PLQY) results of the organometal halide compound of the present invention, FIG. 14a is the single crystal (CPTP)2MnBr4 of the organometal halide compound preparation example 2, and FIG. 14b is the polycrystalline (CPTP)2MnBr4 of the organometal halide compound preparation example 1.

[0044] FIG. 15 shows the [MnBr4] of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 of the organometallic halide compound of the present invention and the single crystal (CPTP)2MnBr4 of Preparation Example 2. 2- This is an image showing the tetrahedron and the Mn-Mn distance.

[0045] Figure 16 is a graph showing the correlation between PLQY and the shortest Mn-Mn distances in the polycrystalline (CPTP) 2MnBr4 of Preparation Example 1 of the organometallic halide compound of the present invention and the single crystal (CPTP) 2MnBr4 of Preparation Example 2.

[0046] Fig. 17 is d 5 It is a Tanabe-Sugano diagram.

[0047] Figure 18 is a UV-vis absorption spectroscopy (UV-Vis) absorption spectrum showing multiple electronic transitions of polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention.

[0048] FIG. 19 is a graph showing the luminescence mechanism of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 and the single-crystal (CPTP)2MnBr4 of Preparation Example 2 of the color-changing composition of the present invention.

[0049] Figure 20 is a graph showing the band structure of polycrystalline (CPTP)2MnBr4 of Preparation Example 1 of the color-changing composition of the present invention and single-crystalline (CPTP)2MnBr4 of Preparation Example 2.

[0050] Figure 21 shows the valence band maximum (VBM) of the density of states analysis of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 and the single-crystal (CPTP)2MnBr4 of Preparation Example 2 of the organometallic halide compound of the present invention.

[0051] FIG. 22 is the conduction band minimum (CBM) of the density of states analysis of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 and the single-crystal (CPTP)2MnBr4 of Preparation Example 2 of the organometallic halide compound of the present invention.

[0052] Figure 23 is the temperature-dependent PL spectrum of polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention.

[0053] FIG. 24 is a graph showing (a) light transmittance (PL) and (b) X-ray diffraction analysis (XRD) performed on the polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention in the pristine state and after 2,500 hours of air exposure.

[0054] FIG. 25 is a graph showing (a) PL spectrum and (b) XRD pattern, as a result of the stability analysis of polycrystalline (CPTP)2MnBr4 of the organometallic halide compound of the present invention Preparation Example 1 under various environmental conditions (exposure to ultraviolet rays (UV, 254 nm) for 12 hours, heat treatment at 150°C, X-ray irradiation, and storage at 100% relative humidity).

[0055] Figure 26 is a graph showing the photoluminescence quantum yield (PLQY) after 2,500 hours of polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention.

[0056] Figure 27 is a graph showing the photoluminescence quantum yield (PLQY) according to the excitation wavelength of polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention.

[0057] FIG. 28 is a graph showing the XRD pattern of the polycrystalline (CPTP)2MnBr4 of the preparation example 1 of the organometallic halide compound of the present invention and the (CPTP)2MnBr4 after the polycrystalline (CPTP)2MnBr4 was immersed in a vial containing ethanol, removed, and dried.

[0058] Figure 29 is the PL spectrum of the polycrystalline (CPTP)2MnBr4 of the preparation example 1 of the organometallic halide compound of the present invention, and the (CPTP)2MnBr4 after the polycrystalline (CPTP)2MnBr4 was immersed in a vial containing ethanol, removed, and dried.

[0059] FIG. 30 (a) is an image of a sample of the polycrystalline (CPTP)2MnBr4 of the preparation example 1 of the organometallic halide compound of the present invention stored in ethanol for more than one month, FIG. 30 (b) is a graph comparing the PL spectra of (CPTP)2MnBr4 before and after storage in ethanol, and FIG. 30 (c) is a graph showing the XRD patterns of the dried (CPTP)2MnBr4 and the original (CPTP)2MnBr4 after storage in ethanol.

[0060] FIG. 31 is an image showing the form of the composition prepared in Preparation Examples 1 to 3 of the color-changing composition of the present invention.

[0061] FIG. 32 is an image comparing the PL measurement results of the compositions prepared in Preparation Examples 1 to 1 of the color-changing compositions of the present invention, measured under daylight, 365 nm, and 254 nm light.

[0062] FIG. 33 is a schematic diagram showing the recrystallization mechanism of (CPTP)2MnBr4 at various ethanol concentrations of the color-changing composition of the present invention.

[0063] FIG. 34 is an SEM image of the compositions prepared in Preparation Examples 1 to 4 of the color-changing composition of the present invention, (a) Color-changing composition Preparation Example 1, (b) Color-changing composition Preparation Example 2, (c) Color-changing composition Preparation Example 3, and (d) Color-changing composition Preparation Example 4.

[0064] FIG. 35 is (a) a schematic diagram and (b) an image of the actual application of the color-changing composition of the present invention as luminescent clay.

[0065] FIG. 36 is (a) a schematic diagram and (b) an actual application image of the color-changing composition of the present invention applied to direct ink writing.

[0066] FIG. 37 is (a) a schematic diagram and (b) an actual applied image of the color conversion composition of the present invention applied to pattern printing.

[0067] FIG. 38 is (a) a schematic diagram and (b) an actual application image of the color conversion composition of the present invention applied to ink printing.

[0068] FIG. 39 shows the polycrystalline (CPTP)2MnBr4 prepared in Preparation Example 1 of the color conversion composition of the present invention and K2SiF6:Mn 4+ and, (CPTP)2MnBr4 and K2SiF6:Mn of the color conversion layer of White Light Emitting Diode Preparation Example 4 of the present invention 4+ This is an image showing the emission colors at various excitation sources (under UV, under 450nm).

[0069] FIG. 40 shows the (CPTP)2MnBr4 and K2SiF6:Mn of the color conversion layer of white light-emitting diode preparation examples 1 to 6 of the present invention. 4+ This is the PL spectrum at various weight ratios.

[0070] FIG. 41 shows the (CPTP)2MnBr4 and K2SiF6:Mn of the color conversion layer of white light-emitting diode preparation examples 1 to 6 of the present invention. 4+ These are the CIE 1931 color coordinates at various weight ratios.

[0071] FIG. 42 is an image of the color-converted white powder clay prepared in Preparation Examples 2-1 to 2-3 of the color-converting composition of the present invention, exposed to daylight and an excitation ray of 365 nm.

[0072] FIG. 43 is a schematic image of a white light-emitting diode manufactured using only the white light-emitting powder-based PDMS mixture (white powder PDMS mixture + blue LED) of the white light-emitting diode manufacturing example 3-1 of the present invention and the white powder clay containing the white light-emitting powder (white powder clay + blue LED) of the white light-emitting diode manufacturing example 1-4 of the present invention.

[0073] FIG. 44 is an image comparing white light-emitting diode chips prepared in white light-emitting diode preparation examples 3-1 to 3-3 of the present invention.

[0074] FIG. 45 is the EL spectrum of white light-emitting diode preparation example 3-1 (PDMS + blue LED) of the present invention and white light-emitting diode preparation example 1-1 (clay + blue LED) of the present invention.

[0075] FIG. 46 is an actual image of the white light-emitting diode manufacturing example 3-1 (PDMS + blue LED) of the present invention and the white light-emitting diode manufacturing example 1-1 (clay + blue LED) of the present invention.

[0076] FIG. 47 is a graph showing the CIE 1931 color coordinates of the white light-emitting diode manufacturing example 3-1 (PDMS + blue LED) of the present invention and the white light-emitting diode manufacturing example 1-1 (clay + blue LED) of the present invention.

[0077] FIG. 48 is a graph and image comparing the EL intensity at various currents of the light-emitting diode of Example 1-1 of the white light-emitting diode of the present invention.

[0078] FIG. 49 is a schematic diagram illustrating a PDMS-based scintillator film and a clay-based scintillator film fabrication method according to one embodiment of the present invention.

[0079] FIG. 50 is a graph comparing the RL intensity of the PDMS-based scintillator film preparation example 1 and the clay-based scintillator film preparation example 1 of the present invention.

[0080] Figure 51 is a graph showing the linear response of the films of PDMS-based scintillator film preparation Example 1 and clay-based scintillator film preparation Example 1.

[0081] FIG. 52 is a schematic diagram of an indirect X-ray imaging system according to one embodiment of the present invention.

[0082] FIG. 53 is a graph comparing the spectral sensitivity of (CPTP)2MnBr4 and a CMOS photodiode provided in the color-changing composition of the present invention.

[0083] FIG. 54 is an X-ray image of a ballpoint pen using the scintillator film preparation example 1 (clay-based film) and the scintillator film preparation example 2 (PDMS mixed film) of the present invention.

[0084] (a) The clay-based film of Scintillator Film Preparation Example 1 and the Gd2O2S:Tb of Scintillator Film Comparison Example 1 used in the MTF analysis of FIG. 55. 3+ (b) an image of the diagonal corner of the film, (b) a graph comparing the modulation transfer function (MTF) between the films of the scintillator film Preparation Example 1, Preparation Example 2, and Comparative Example 1, (c) the clay-based film of the scintillator film Preparation Example 1 and the Gd2O2S:Tb film of the scintillator film Comparative Example 1. 3+ This is a graph comparing the average brightness of X-ray images obtained from film.

[0085] FIG. 56 is a graph comparing the X-ray absorption spectra of the films of the scintillator film preparation example 1 and comparative example 1 of the present invention.

[0086] FIG. 57 is an image of the composition of the color conversion composition of Example 7 of the present invention applied to a screen printer.

[0087] Fig. 58 is a 5x5 circular pattern design applied to the screen printer of Fig. 57.

[0088] FIG. 59 is an image of a color conversion layer having a 5x5 pattern formed based on the pattern presented in FIG. 58.

[0089] FIG. 60 is an SEM image of a plan view of a screen printing pattern to which the composition of Example 7 of the color conversion composition of the present invention is applied.

[0090] FIG. 61 is an SEM image of a side view of a screen printing pattern to which the composition of Example 7 of the color conversion composition of the present invention is applied.

[0091] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0092] While the present invention allows for various modifications and variations, specific embodiments are illustrated in the drawings and will be described in detail below. However, it is not intended to limit the invention to the particular forms disclosed, but rather the invention includes all modifications, equivalents, and substitutions consistent with the spirit of the invention as defined by the claims.

[0093] When an element such as a layer, region, or substrate is referred to as existing "on" another component, it can be understood that this exists directly on the other element, or that an intermediate element may exist between them.

[0094] Although terms such as first, second, etc., may be used to describe various elements, components, regions, layers, and / or regions, it will be understood that these elements, components, regions, layers, and / or regions should not be limited by these terms.

[0095] Throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0096]

[0097] Method for preparing a color-changing composition equipped with an organometal halide compound

[0098] One aspect of the present invention may provide a method for preparing a color-changing composition. Specifically, a method for preparing a color-changing composition comprising an organometal halide compound may be provided.

[0099] FIG. 1 is a flowchart for explaining a method for preparing a color-changing composition equipped with an organometal halide compound of the present invention.

[0100] Referring to FIG. 1, first, an organic halide compound having the chemical formula AX and a metal halide compound having the chemical formula MX2 can be mixed to form an organic metal halide compound having the chemical formula A2MX4 (S100).

[0101] The above A may be an organic cation comprising at least one element selected from C, H, O, P, and N. Specifically, the above A may be an organic onium cation. The above organic onium cation may be an onium cation to which an organic group is bonded. The above organic onium cation may refer to an ion that carries a positive charge when a mononuclear parent hydride of an element from Group 15 (nitrogen group, pnictogen), Group 16 (oxygen group, chalcogen), or Group 17 (halogen group) of the periodic table is protonated, or when an organic substituent derived therefrom is bonded thereto. For example, the above organic onium cation may be an ammonium (RNR4) containing nitrogen (N). + ) ions, phosphonium (RPH4) containing phosphorus (P) + ) ions, oxygen-containing oxonium (ROH3 + ) ions, or sulfonium containing sulfur (RSH3 +) may include ions. In this case, R may be, independently of each other, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C2-C30 heteroaryl group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C3-C30 cycloalkenyl group, a substituted or unsubstituted C3-C30 cycloalkynyl group, a substituted or unsubstituted C3-C30 heterocycloalkyl group, a substituted or unsubstituted C3-C30 heterocycloalkenyl group, a substituted or unsubstituted C3-C30 heterocycloalkynyl group, a substituted or unsubstituted C7-C30 aralkyl group, or a substituted or unsubstituted C3-C30 heteroaralkyl group.

[0102] Specifically, the above A may be an organic phosphonium ion or an organic ammonium ion.

[0103] The above organic phosphonium ion may refer to a chemical species in which four organic groups (carbon-based functional groups) are bonded to a central phosphorus (P) atom, and the phosphorus (P) atom carries a positive charge. Specifically, the above organic phosphonium ion may be a cation having the structure of Chemical Formula 1 below.

[0104]

[0105] In the above chemical formula 1, R 1 to R 3 are each independently a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C2-C30 heteroaryl group, and R 4is a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, an amino group, a substituted or unsubstituted C1-C20 alkylamino group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C3-C30 cycloalkenyl group, a substituted or unsubstituted C3-C30 cycloalkynyl group, a substituted or unsubstituted C3-C30 heterocycloalkyl group, a substituted or unsubstituted C3-C30 heterocycloalkenyl group, a substituted or unsubstituted C3-C30 heterocycloalkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C2-C30 heteroaryl group, a substituted or unsubstituted C7-C30 aralkyl group, a substituted or unsubstituted C3-C30 hetero It may be an aralkyl group, a substituted or unsubstituted C6-C30 aryl amino group, a substituted or unsubstituted C2-C30 heteroaryl amino group, a substituted or unsubstituted C6-C30 aryloxy group, a substituted or unsubstituted C2-C30 heteroaryloxy group, or a substituent having the structure of Chemical Formula 2 below.

[0106]

[0107] In the above Chemical Formula 2, L is a single bond, a substituted or unsubstituted C1-C20 alkylene group, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C2-C30 heteroarylene group, and R 11 It may be a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, an amino group, a substituted or unsubstituted C1-C20 alkylamino group, or a substituted or unsubstituted C1-C20 alkoxy group. The asterisk (*) above may indicate a connection position.

[0108] In one embodiment, R of Formula 1 1 to R 3 Each can independently be a substituted or unsubstituted C6-C30 aryl group. R of Chemical Formula 1 above1 to R 3 Each is independently one of a phenyl group, a naphthyl group, and anthracenyl group, and each of the phenyl group, naphthyl group, and anthracenyl group may be independently unsubstituted or substituted with at least one functional group selected from a C1-C20 alkyl group, a C2-C20 alkenyl group, and a C2-C20 alkynyl group.

[0109] Specifically, for example, the organic phosphonium ion is the cyclopropyltriphenylphosphonium ion ([P(C6H5)3(C3H5)] + , CPTP + ), tetraalkylphosphonium ion ([PR4] + (R is an alkyl group having 1 to 30 carbon atoms)), tetraarylphosphonium ion ([PAr4] + (Ar is an aryl group having 6 to 30 carbon atoms)), or, an alkyl-aryl mixed phosphonium ion ([P(C6H5)3R] + It may include ). Specifically, the organic phosphonium ion may include cyclopropyltriphenylphosphonium ions.

[0110] The above organic ammonium ion may refer to a chemical species in which one or more organic groups (carbon-based functional groups such as alkyl or aryl) are bonded to a central nitrogen (N) atom, and this nitrogen atom carries a positive charge. Depending on the number of bonded organic groups, the above organic ammonium ion may include a primary ammonium ion, a secondary ammonium ion, a tertiary ammonium ion, or a quaternary ammonium ion. For example, the above quaternary ammonium ion may have four organic groups bonded to the nitrogen (N) atom. The above quaternary ammonium ion may include a tetramethylammonium ion or a tetrapropylammonium ion. Specifically, the above organic ammonium ion may include a tetrapropylammonium ion.

[0111] The above M may be a metal cation. Specifically, the above M may be a non-lead metal cation excluding lead (Pb). More specifically, the above M may be a cation of one or more metals selected from copper (Cu), zinc (Zn), cadmium (Cd), antimony (Sb), tin (Sn), iron (Fe), and manganese (Mn). Preferably, the above M may be a manganese (Mn) cation.

[0112] The above X may be a halogen anion. Specifically, the above X may be an anion of one or more elements selected from fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). More specifically, the above X may be a bromine (Br) anion.

[0113] The organic halide compound having the chemical formula AX and the metal halide compound having the chemical formula MX2 can be mixed in a molar ratio of 2:1, which is a stoichiometric equivalent ratio. By mixing the organic halide compound having the chemical formula AX and the metal halide compound having the chemical formula MX2 in a molar ratio of 2:1, an organic metal halide compound having the chemical group of A2MX4 can be effectively formed.

[0114] Specifically, the organometal halide compound may have a polycrystalline or single crystal structure. This may vary depending on the type of solvent used in the step of forming the organometal halide compound by mixing the organohalide compound having the chemical formula AX and the metal halide compound having the chemical formula MX2, the manufacturing process conditions, or the mixing method (such as stirring or grinding).

[0115] When mixing the organic halide compound having the chemical formula AX and the metal halide compound having the chemical formula MX2 in the above S100, a mixing solvent may be added. The mixing solvent may be an organic solvent. In one embodiment, the mixing solvent may include an anhydrous alcohol-based solvent. In another embodiment, the mixing solvent may include dimethylformamide (N,N-Dimethylformamide, DMF) and dichloromethane (DCM).

[0116] Specifically, in one embodiment, an organic halide compound having the chemical formula AX and a metal halide compound having the chemical formula MX2 can be mixed to form an organic metal halide compound having a polycrystalline structure. For example, an organic metal halide compound having a polycrystalline structure can be formed by performing mechanochemical synthesis by adding an anhydrous alcohol-based solvent to a mixture of the organic halide compound having the chemical formula AX and the metal halide compound having the chemical formula MX2, and grinding and mixing them by a method such as hand grinding.

[0117] In another embodiment, an organometallic halide compound having a single-crystal structure can be formed by mixing an organic halide compound having the chemical formula AX and a metal halide compound having the chemical formula MX2. For example, an organometallic halide compound having a single-crystal structure can be formed using an antisolvent vapor-assisted crystallization method. Specifically, dimethylformamide (DMF) can be added to a mixture of the organic halide compound having the chemical formula AX and the metal halide compound having the chemical formula MX2 to completely dissolve the mixture in the dimethylformamide, and then the mixture can be gradually mixed with dichloromethane (DCM) to form the organometallic halide compound having a single-crystal structure. Specifically, this can be done by referring to the following manufacturing example.

[0118]

[0119] Referring again to FIG. 1, a color-changing composition can be formed by mixing an anhydrous alcohol-based solvent with the organometallic halide compound (S200).

[0120] The above anhydrous alcohol-based solvent may include one or more selected from anhydrous ethanol, anhydrous methanol, anhydrous isopropanol, and anhydrous butanol. Specifically, the above anhydrous alcohol-based solvent may include anhydrous ethanol.

[0121] When the anhydrous alcohol-based solvent is mixed with the organometal halide compound, the anhydrous alcohol-based solvent can locally (partially) soften the particle surface of the organometal halide compound. Accordingly, the adhesion between the particles of the organometal halide compound increases, thereby forming a color-changing composition having a viscous state similar to clay. Specifically, the interaction between the anhydrous alcohol-based solvent and the organometal halide compound may result in the anhydrous alcohol-based solvent not completely dissolving the entire organometal halide compound particle, but rather inducing localized partial dissolution and swelling limited to the organic layer on the particle surface of the organometal halide compound. As a result, the intrinsic internal crystal structure of the organometal halide compound may be maintained, and the formed color-changing composition may temporarily transition to a clay-like physical state.

[0122] That is, the surface-limited softening phenomenon of the organometal halide compound by the anhydrous alcohol-based solvent can provide plasticity to the color-changing composition without damaging the crystallinity of the organometal halide compound. As previously explained, this behavior may be attributed to semi-solidification caused by physical interactions between the anhydrous alcohol-based solvent and the organometal halide compound particles and particle aggregation, rather than traditional recrystallization in which complete dissolution by the solvent leads to recrystallization.

[0123] 0.1 to 5.0 ml of the anhydrous alcohol-based solvent can be mixed with 1 g of the organometal halide compound. Specifically, 0.2 to 4.0 ml, more specifically 0.3 to 3.0 ml, and preferably 0.4 to 2.8 ml of the anhydrous alcohol-based solvent can be mixed with 1 g of the organometal halide compound. When the organometal halide compound and the anhydrous alcohol-based solvent are mixed within the above-described range, a color-changing composition having a viscosity suitable for application in a patterning process for forming a color-changing layer of a luminescent clay, luminescent ink, scintillator film, color-changing film, color-changing pattern, or white light-emitting diode can be formed.

[0124] As described above, the method for preparing a color-changing composition of the present invention can easily prepare a color-changing composition having a viscosity suitable for a solution process by using the anhydrous alcohol solvent, which is a polar organic solvent with a relatively low dielectric constant, to locally soften the surface of the organometal halide compound without ionizing it and thereby swelling the organometal halide compound.

[0125]

[0126] Color-changing composition equipped with an organometal halide compound

[0127] Another aspect of the present invention may provide a color-changing composition. The color-changing composition may be prepared by a method for preparing a color-changing composition comprising the organometal halide compound described above.

[0128] The color-changing composition may be provided with an organometal halide compound. Specifically, the color-changing composition may include an anhydrous alcohol-based solvent and an organometal halide compound particle having the chemical formula A2MX4, the surface of which is softened and temporarily swollen by the anhydrous alcohol-based solvent. In this case, A may be an organoonium cation, M may be a metal cation, and X may be a halogen anion. To avoid duplication, the description of A, M, and X may be based on the previously described content.

[0129] Specifically, the organometal halide compound particles may have the chemical formula A2MnX4, more specifically, A2MnBr4. Preferably, the organometal halide compound may include (CPTP)2MnBr4 or (TPA)2MnBr4.

[0130] The color-changing composition may be semi-solidified due to the interaction between the organometal halide compound particles and the anhydrous alcohol-based solvent and the aggregation of the particles. Specifically, as previously described, this can be seen as a result of the anhydrous alcohol-based solvent locally softening the surface of the organometal halide compound particles, thereby inducing localized partial dissolution and swelling limited to the organic layer on the surface of the organometal halide compound particles. Accordingly, the color-changing composition may have a clay-like consistency.

[0131] The color-changing composition may not include a binder or a thickener. Specifically, the color-changing composition may not require a separate thickener or binder as it possesses plasticity without damaging the crystallinity of the organometal halide compound. Accordingly, the problems associated with the addition of conventional thickeners or binders can be effectively resolved.

[0132] 0.1 to 5.0 ml of the anhydrous alcohol-based solvent may be mixed with 1 g of the organometal halide compound. Specifically, 0.2 to 4.0 ml, more specifically 0.3 to 3.0 ml, and preferably 0.4 to 2.8 ml of the anhydrous alcohol-based solvent may be mixed with 1 g of the organometal halide compound. The color-changing composition of the present invention may vary in form or viscosity depending on the amount of the anhydrous alcohol-based solvent added to the organometal halide compound, that is, the concentration of the anhydrous alcohol-based solvent within the composition.

[0133] When the color-changing composition is dried, the anhydrous alcohol-based solvent evaporates, and the composition can solidify while maintaining its shape. Accordingly, the color-changing composition can easily form a film or pattern of a desired shape by utilizing its inherent plasticity, and since the shape formed through the drying process described above can be maintained, it can be actively utilized in fields such as screen printing processes or color-changing films.

[0134]

[0135] Application of color-changing compositions

[0136] Another aspect of the present invention may provide an application of a color-changing composition comprising an organometal halide compound. The color-changing composition comprising the organometal halide compound may be prepared by the method for preparing the color-changing composition described above.

[0137] Specifically, a color-changing composition comprising the anhydrous alcohol-based solvent and an organometallic halide compound particle having the chemical formula A2MX4, the surface of which is softened and temporarily swollen by the anhydrous alcohol-based solvent, wherein A is an organoonium cation, M is a metal cation, and X is a halogen anion, may have a clay-like appearance. Accordingly, the color-changing composition may be applied as a luminescent clay or a luminescent ink.

[0138] The above-mentioned luminescent clay may refer to clay that absorbs and stores light and then gradually emits light in the dark. The above-mentioned luminescent ink may refer to a special ink that emits light only when illuminated with specific light (such as ultraviolet or infrared light) or that absorbs light and emits light in the dark. The above-mentioned luminescent ink may primarily possess fluorescence or phosphorescence properties.

[0139] The color-changing composition can function as a light source for the luminescent clay or luminescent ink by exhibiting luminescence within a specific color range. The color-changing composition has superior plasticity (or processability or dispersibility) compared to conventional inorganic phosphors, which can improve physical stability and luminescence uniformity when applied as luminescent clay or luminescent ink. In one embodiment, when the color-changing composition includes manganese (Mn) to form a complex, it can exhibit phosphorescent properties, thereby enhancing the afterglow effect.

[0140] When the above composition is dried, the anhydrous alcohol-based solvent evaporates, allowing the composition to solidify while maintaining its shape. Accordingly, the color-changing composition can be applied as a scintillator film, a color-changing film, a color-changing pattern, or a color-changing layer of a white light-emitting diode. That is, by adjusting the concentration of the anhydrous alcohol-based solvent within the color-changing composition, the composition can be made to have a shape or viscosity suitable for the application field, and a uniform film or pattern can be formed through the evaporation of the anhydrous alcohol-based solvent.

[0141] Specifically, the present invention may provide a scintillator film comprising a color-changing composition that includes particles of an organometal halide compound having the chemical formula A2MX4 but does not include a binder, wherein A is an organoonium cation, M is a metal cation, and X is a halogen anion. The scintillator film is also called a scintillator film and generally refers to a film made of a material that emits scintillation in the form of visible light or ultraviolet light when ionizing radiation, such as X-rays, gamma rays, or beta rays, is incident. The light emitted from the scintillator film can be detected by a photodetector and used to measure the presence or energy of radiation.

[0142] When the above color-changing composition is applied to the scintillator film, specifically, when the organometal halide compound provided in the color-changing composition is (CPTP)2MnBr4, the scintillator material provided in the scintillator absorbs high-energy radiation and emits UV or blue light, and the color-changing composition can absorb the UV or blue light and re-emit it as visible light in the green-orange range characteristic of manganese(II) complexes. Accordingly, the scintillator film containing the above color-changing composition can improve light transmission efficiency by reducing light loss within the film through the color-changing composition, and can easily realize a specific luminescent color suitable for a specific application. In addition, the above color-changing composition can be processed even at low temperatures, thereby simplifying the manufacturing process of the scintillator film.

[0143] Specifically, the present invention provides a color-changing film or color-changing pattern comprising an organometal halide compound particle having the chemical formula A2MX4, but not including a binder, wherein A is an organoonium cation, M is a metal cation, and X is a halogen anion. When the color-changing composition is applied to the color-changing film or color-changing pattern, a thin and uniform film can be formed through the excellent plasticity of the color-changing composition. Accordingly, the color-changing film or color-changing pattern can increase uniformity and thereby improve the distribution of light.

[0144] Specifically, the present invention may provide a white light-emitting diode comprising: a blue or ultraviolet LED; and a color conversion layer disposed on the LED, comprising a green light-emitting organic metal halide compound particle having the chemical formula A2MX4 and a red phosphor, but not including a binder. In this case, A may be an organic onium cation, M may be a metal cation, and X may be a halogen anion. The color conversion layer of the white light-emitting diode (WLED) may not directly emit white light from a single chip, but may realize white light through various principles. Accordingly, the color conversion layer provided in the white light-emitting diode may be the most important part, as it performs the role of generating white light by converting the wavelength of light emitted from the LED chip.

[0145] When the above color-converting composition is applied to the color-converting layer of the white light-emitting diode, the color-converting composition can perform a role similar to that of a phosphor or quantum dot in a conventional color-converting layer, thereby converting the wavelength of light emitted from the LED chip to ultimately realize white light. Accordingly, the white light-emitting diode of the present invention may include the color-converting composition described above and a red phosphor as a color-converting layer.

[0146] Specifically, when the organometal halide compound provided in the color-changing composition is (CPTP)2MnBr4, the (CPTP)2MnBr4 can emit light in a green to orange spectral range, specifically in a green range. That is, the color-changing composition may include green-emitting organometal halide compound particles. If the white light-emitting diode is provided with a blue or ultraviolet LED and a color-changing layer is provided that includes the green-emitting organometal halide particles and the red phosphor but does not include a binder, white light can be realized as the green-emitting organometal halide particles absorb the light from the blue or ultraviolet LED and emit green light.

[0147] As described above, when the color-changing composition of the present invention is provided in the color-changing layer of the white light-emitting diode, it may not contain a binder, so the green light-emitting organic metal halide particles can re-emit light with higher quantum efficiency. Specifically, this can be understood by referring to the following experimental examples and drawings.

[0148] Hereinafter, preferred manufacturing examples and experimental examples are presented to aid in understanding the present invention. However, the following manufacturing examples and experimental examples are intended only to aid in understanding the present invention, and the present invention is not limited by the following manufacturing examples and experimental examples.

[0149] <Preparation of Materials>

[0150] In the following preparation and experimental examples, manganese bromide (MnBr2, 98%), N,N-dimethylformamide (DMF, >=99.8%), and dichloromethane (DCM, >=99.8%) were purchased from Sigma-Aldrich. Cyclopropyltriphenylphosphonium bromide ((CPTP)Br), C 21 H 20PBr (98%) was purchased from Alfa Aesar. Anhydrous ethanol was purchased from Daejeong. All reagents were used without purification.

[0151] <Preparation Example 1 of Organometal Halide Compounds: Synthesis of Polycrystalline (CPTP)2MnBr4>

[0152] Figure 2 is an image showing the mechanochemical synthesis process for preparing polycrystalline (CPTP)2MnBr4 in Example 1 of the preparation of organometallic halide compounds of the present invention.

[0153] As shown in FIG. 2, (CPTP)2MnBr4 of the polycrystalline phase (where CPTP + (cyclopropyltriphenylphosphonium, C 21 H 20 To synthesize the cation, the precursors (CPTP)Br and MnBr2 were weighed in a molar ratio of 2:1, and 2 mmol of (CPTP)Br and 1 mmol of MnBr2 were placed in an agate mortar. Anhydrous ethanol (abs EtOH) was added as a mixed solvent, and the two precursors were wet-grinded for 5 minutes using an agate mortar by hand-grinding. During the grinding of the precursors, the material turned into a pale green powder, thereby obtaining polycrystalline (CPTP)2MnBr4.

[0154] <Preparation Example 2 of Organometal Halide Compounds: Synthesis of Single Crystal (CPTP)2MnBr4>

[0155] Figure 3 is an image showing the synthesis process of a single crystal (CPTP)2MnBr4 through antisolvent vapor-assisted crystallization in Example 2 of the preparation of organometallic halide compounds of the present invention.

[0156] As shown in Fig. 3, an antisolvent vapor-assisted crystallization method was used to synthesize single-crystal (CPTP)2MnBr4. First, 2 mmol of (CPTP)Br and 1 mmol of MnBr2 were weighed, and the CPTPBr and MnBr2 were placed in a small vial at a molar ratio of 2:1. 1 ml of dimethylformamide (DMF) was added to the vial and mixed by stirring at 70°C for 10 minutes. Once the precursor was completely dissolved, the vial was sealed with Parafilm and a small hole was punched. This vial was placed into a larger vial containing 8 ml of the antisolvent dichloromethane (DCM). After 1 day, a green (CPTP)2MnBr4 single crystal was precipitated.

[0157] <Preparation Example 1 of Color-Changing Composition>

[0158] A color-changing composition was prepared by adding 0.5 ml / g of anhydrous ethanol to the organometal halide compound prepared in Example 1 of the above organometal halide compound preparation and mixing.

[0159] <Preparation Example 2 of Color-Changing Composition>

[0160] A color-changing composition was prepared by performing the same procedure as in Example 1 of the preparation of the color-changing composition, except that 1.0 ml / g of anhydrous ethanol was added.

[0161] <Preparation Example 3 of Color-Changing Composition>

[0162] A color-changing composition was prepared by performing the same procedure as in Example 1 of the preparation of the color-changing composition, except that 1.5 ml / g of anhydrous ethanol was added.

[0163] <Preparation Example 4 of Color-Changing Composition>

[0164] A color-changing composition was prepared by performing the same procedure as in Example 1 of the preparation of the color-changing composition, except that 2.0 ml / g of anhydrous ethanol was added.

[0165] <Preparation Example 5 of Color-Changing Composition>

[0166] A color-changing composition was prepared by performing the same procedure as in Example 1 of the preparation of the color-changing composition, except that 2.5 ml / g of anhydrous ethanol was added.

[0167] The amount of anhydrous ethanol added to the organometal halide compound (CPTP)2MnBr4 in the above color-changing composition preparation examples 1 to 5 is summarized as shown in Table 1 below.

[0168] Classification Amount of Anhydrous Ethanol Added Color-Changing Composition Preparation Example 1 0.5 ml / g Color-Changing Composition Preparation Example 2 1.0 ml / g Color-Changing Composition Preparation Example 3 1.5 ml / g Color-Changing Composition Preparation Example 4 2.0 ml / g Color-Changing Composition Preparation Example 5 2.5 ml / g

[0169] Structure and Chemical Measurement Methods

[0170] The synthesized (CPTP)2MnBr4 was analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer mapping (EDS), and X-ray photoelectron spectroscopy (XPS).

[0171] XRD was performed using a Rigaku miniflex600 diffractometer to analyze Cu K-α in the range of 5 to 60° at 0.01° intervals.

[0172] Single crystal structure determination was performed at the Korea Basic Science Institute (KBSI) West Seoul Center. Pink crystals were collected in paraton oil and mounted on a Bruker SMART CCD diffractometer equipped with graphite monochromatic light and a Mo Kα (λ=0.71073 Å) radiation source under a cold nitrogen (223 K) flow. Data acquisition and integration were performed using the SMART and Saint Plus software packages. Semi-empirical absorption correction based on equivalent reflections was applied using SADABS. The structure was determined using F via SHELXTL. 2 It was interpreted using the direct and refined method based on the full-matrix least-squares method.

[0173] Polycrystalline structure information was derived through Rietveld refinement using SmartLab Studio II software.

[0174] SEM images of single-crystal grains were taken using the S-4800 Hitachi instrument at the Standard Measurement and Characterization Laboratory of Hanyang University.

[0175] XPS measurements were taken using the Thermofisher Nexsa and Al K-α light source at the Research Facility Center of the University of Seoul.

[0176] Optical Measurement

[0177] Photoluminescence properties were measured over a wavelength range from 200 nm to 700 nm using a Hitachi F-7000 fluorescence spectrophotometer. 0.2 g of the sample was accurately weighed for each measurement. Absorbance measurements were performed using a Cary 5000 UV-Vis-NIR spectrophotometer. Photoluminescence quantum yield (PLQY) and time-correlated single-photon counting (TCSPC) data were obtained using a FluoroMax Horiba instrument.

[0178] <Calculation Details>

[0179] Density functional theory (DFT) calculations were performed using the Vienna Ab initio Simulation Package (VASP), the projector augmented-wave (PAW) technique, and the generalized gradient approximation (GGA) technique formulated by Perdew-Burke-Ernzerhof (PBE). During the structural optimization process, a plane-wave basis set with a cutoff energy of 520 eV was used to minimize Pulley stress. Structural optimization was continued until Hellmann-Feynman forces were less than 0.01 eV / Å, and electronic energy convergence was 1 × 10⁻⁶ -5It was set to eV. Considering the large unit cell size, a 1×1×1 k-point mesh was used for Brillouin zone sampling. The DFT-1 / 2 method was applied to the Br element to correct the bandgap. In this case, the power index was 50, the strip value was 0.50 e, and the scan cutoff radius was 7.5 bohr. These parameters were selected based on internal testing and were confirmed to be in good agreement with the experimental data.

[0180] <X선 영상(X-ray imaging)>

[0181] The X-ray imaging system was developed based on previous research. A wafer-sized CMOS flat-panel image sensor was designed and developed using a 0.35 mm CMOS image sensor (CIS) process along with stitching technology for medical X-ray applications. A 3-transistor (3T) active pixel structure using buried photodiodes was applied to the pixels to reduce dark current. The CMOS detector is a 1200-pixel × 1200-pixel array measuring 100 mm × 100 mm, providing an effective detection area of ​​120 mm × 120 mm. The readout circuit has 6 banks consisting of 200 readout channels and horizontal row drivers (HRD). A thermal parallel readout architecture was used to achieve high speed and reduce random noise. A 14.3-bit extended-counting analog-to-digital converter (ADC) was used to improve grayscale resolution while reducing area. Each of the proposed detectors uses an analog binning function and has a full resolution mode of 30fps and a 2×2 binning mode of 60fps.

[0182] FIG. 4 is a crystal structure of (CPTP)2MnBr4, an organometal halide compound according to one embodiment of the present invention, and FIG. 5 is a CPTP constituting an organometal halide compound according to one embodiment of the present invention. + It is the molecular structure of a cation, and FIG. 6 is [MnBr4] constituting an organometal halide compound according to one embodiment of the present invention 2- It is the molecular structure of a tetrahedron.

[0183] Referring to Fig. 4, Mn 2+ The ion consists of 4 Br - [MnBr4] is coordinately bonded to the ion in a tetrahedral form. 2- A complex can be formed. That is, the above four Br - The ion is the above Mn 2+ It can form a tetrahedral structure centered around an ion.

[0184] Referring to FIG. 5 and FIG. 6 together, the [MnBr4] 2- The complex is large CPTP + It can be separated into an 0D structure by a monovalent cation. Specifically, the [MnBr4] 2- The complex is the above CPTP + A zero-dimensional structure can be formed by maintaining independent molecular or ionic units that are not connected to each other, as they exist separately by a single cation. That is, the above CPTP + The cation is the negatively charged [MnBr4] 2- It can serve the role of physically separating complexes by intervening between them, preventing them from directly interacting with each other. In addition, the aforementioned CPTP + Cation and the above [MnBr4] 2- Van der Waals interactions between the complexes are the [MnBr4] 2- It can help maintain spatial separation between the tetrahedrons of the complex.

[0185] Figure 7 shows the crystal structure obtained from data obtained by performing single-crystal X-ray diffraction (SC-XRD) on (CPTP)2MnBr4 of Preparation Example 2 of the organometallic halide compound of the present invention. The single-crystal X-ray diffraction (SC-XRD) can determine the atomic arrangement within the crystal and provide accurate data regarding lattice parameters and symmetry. This is summarized in Table 2 below. The structural parameters of the (CPTP)2MnBr4 single crystal in Table 2 below were obtained from single-crystal X-ray diffraction (SC-XRD) data at 223K through structural analysis, and the numbers in parentheses are the estimated standard deviation of the last significant figure.

[0186] Parameter valuea(Å)14.8216(6)b(Å)16.2641(7)c(Å)17.0891(9)α(°)90.000β(°)90.000γ(°)90.000ν(Å 3 )4119.5(3)

[0187] In addition, the detailed parameters of the (CPTP)2MnBr4 single crystal obtained through the structural solution from the above single-crystal X-ray diffraction (SC-XRD) data are summarized in Table 3 below (Correction method = Reported T Limits): T min =0.634, T max =0.746).

[0188] Parameter value(value)AbsCorrMULTI-SCAData completeness1.81 / 1.00R(reflections)0.0337(8176)wR 2 (reflections)0.0596(10212)S1.018Theta(max)28.297Wavelength0.71073Bond precisionC-C = 0.0071 ATemperature223 K

[0189] Referring to Figure 7, Table 2, and Table 3 together, it can be confirmed that the (CPTP)2MnBr4 crystal belongs to the P212121 space group, which exhibits an orthorhombic structure with lattice parameters a = 14.82 Å, b = 16.26 Å, c = 17.08 Å, and α = β = γ = 90°. Next, the identity of the material was confirmed based on the crystal structure using powder X-ray diffraction (PXRD) and Rietveld refining.

[0190] FIG. 8 is a graph showing the diffraction profile obtained after performing full-pattern Rietveld refinement on the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 of the organometal halide compound of the present invention. In FIG. 8, dots represent observed, green represents calculated, and deep green represents difference. The Rietveld refinement was performed to refine the structural parameters of the polycrystalline (CPTP)2MnBr4 using X-ray diffraction data at room temperature. This is summarized in Table 4 below. In Table 4 below, the number in parentheses is the estimated standard deviation of the last significant figure.

[0191] Parameter values ​​(value) a(Å)14.821(0) b(Å)16.263(1) c(Å)17.088(1) α(°)90.000 β(°)90.000 γ(°)90.000 V(Å 3 )4119.498(1)Rwp0.0929χ 2 11.795

[0192] Figure 9 is a graph comparing the powder X-ray diffraction (PXRD) patterns of the polycrystalline (CPTP)2MnBr4 of the organometallic halide compound preparation example 1 of the present invention and the single-crystal (CPTP)2MnBr4 of the organometallic halide compound preparation example 2.

[0193] Referring to Figures 8 and 9, it can be confirmed that the Rietveld refining results are in perfect agreement with the expected structural model of the powder X-ray diffraction (PXRD) pattern. This shows that the successful XRD patterns of the polycrystalline and single-crystal forms differ in peak intensity but are consistent in peak position, indicating that both phases share the same crystal structure. Additionally, looking at the XRD pattern of the single-crystal (CPTP)2MnBr4 powder in Figure 9, it can be seen that it grows preferentially along the (142) plane.

[0194] FIG. 10 is a full-range X-ray photoelectron spectroscopy (XPS) spectrum of various elements constituting the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 of the organometallic halide compound of the present invention. The elemental composition of (CPTP)2MnBr4 was investigated through the above X-ray photoelectron spectroscopy (XPS).

[0195] In Figure 10, XPS analysis revealed peaks corresponding to C, P, Mn, and Br. Specifically, peaks corresponding to C 1s (281–295 eV), Mn 2p (634–647 eV), P 2p (128–137 eV), and Br 3d (64–72 eV) were observed. Among these, the C 1s peak exhibited the highest intensity, which corresponds to CPTP. + It can be seen as originating from the three benzene rings of the cation.

[0196] Figure 11 is a mapping image obtained by analyzing the single crystal (CPTP)2MnBr4 of Preparation Example 2 of the organometallic halide compound of the present invention using scanning electron microscopy-energy dispersive spectrometry (SEM-EDS). Through this, the morphology and elemental composition of the synthesized material can be confirmed.

[0197] In Fig. 11, all constituent elements of the single crystal (CPTP) 2MnBr4 of the above-mentioned organometal halide compound preparation example 2 can be identified, and through this, it can be seen that the composition of the organometal halide compound was appropriately synthesized.

[0198] FIG. 12 is a graph comparing the photoluminescence (PL) and photoluminescence excitation (PLE) spectra of polycrystalline (CPTP) 2MnBr4 of the organometal halide compound preparation example 1 of the present invention and single-crystal (CPTP) 2MnBr4 of the organometal halide compound preparation example 2.

[0199] Referring to Fig. 12, both forms are λ em = 517 nm, λ ex = 468 nm, and PL emission was observed at a full width at half maximum (FWHM) of 46 nm. In the PLE spectrum, Mn 2+ Three bands corresponding to transitions in the 4F, 4P, and 4D energy states were observed. In particular, the similarity between the PL and PLE spectra of the two forms suggests that they share the same crystal phase.

[0200] Figure 13 is a graph comparing the luminescence decay curves of polycrystalline (CPTP)2MnBr4 of the organometallic halide compound preparation example 1 of the present invention and single-crystalline (CPTP)2MnBr4 of the organometallic halide compound preparation example 2. This is the result of performing time-correlated single-photon counting (TCSPC) measurements to investigate the emission mechanism in more detail.

[0201] Referring to Fig. 13, it can be seen that in both forms, the luminescence decay is well fitted to a single exponential function. This indicates that the emission is solely Mn 2+ 4 T1→ 6 This may imply that it arises from A1 transitions. Additionally, it can be observed that the single crystal exhibits a longer lifetime (328 µs) compared to the polycrystalline form (307 µs). This may imply fewer structural defects and, consequently, fewer nonradiative recombination pathways.

[0202] FIG. 14 is an image showing the photoluminescence quantum yield (PLQY) results of the organometal halide compound of the present invention, FIG. 14a is the single crystal (CPTP)2MnBr4 of the organometal halide compound preparation example 2, and FIG. 14b is the polycrystalline (CPTP)2MnBr4 of the organometal halide compound preparation example 1.

[0203] As shown in FIGS. 14a and 14b, the photoluminescence quantum yield (PLQY) values ​​are 83.42% for single crystal and 62.80% for polycrystalline, which can be confirmed to be consistent with the results of FIG. 13 described above.

[0204] Conventional Cs2Ag 1-x K x In 0.875 Bi 0.125 C l6 Lead-free double perovskites such as [the example] generally achieve a maximum PLQY of about 15.96% under optimized conditions, but often face problems related to phase stability and a relatively broad emission spectrum.

[0205] In contrast, (CPTP)2MnBr4, an organometallic halide compound included in the color-changing composition of the present invention, exhibits a significantly high PLQY of 83.42% in a single-crystal state and a sharp emission peak (FWHM: 46 nm) at 517 nm, which can be seen as providing advantages in applications requiring color purity.

[0206] In addition, Mn in OD hybrid organic-inorganic manganese bromide 2+ The distance between ions can be seen as playing an important role in PLQY crystallization. Mn 2+ The proximity of ions can lead to concentration quenching, which can reduce luminescence efficiency through energy transfer. In other words, high PLQY is Mn 2+ It is believed to have been achieved by maintaining the optimal distance between ions, and in (CPTP)2MnBr4, large CPTP + The cation [MnBr4] 2- It can be seen as ensuring an appropriate spacing between the tetrahedrons.

[0207] FIG. 15 shows the [MnBr4] of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 of the organometallic halide compound of the present invention and the single crystal (CPTP)2MnBr4 of Preparation Example 2. 2- Figure 16 is an image showing the tetrahedral and Mn-Mn distances, and is a graph showing the correlation between PLQY and the shortest Mn-Mn distances in the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 of the organometallic halide compound of the present invention and the single-crystal (CPTP)2MnBr4 of Preparation Example 2.

[0208] Referring to Figures 15 and 16, the closest Mn-Mn distance in (CPTP)2MnBr4 was measured to be 9.21 Å, which is consistent with the results of the study on Mn-Mn distance and PLQY in Figures S6 and S7.

[0209] Generally, Mn2+ The ion has five non-covalent three-dimensional electrons, which result in 16 LS term symbols due to electron-electron repulsion. These may include a spin sextet 6S, spin quartets 4P, 4D, 4F, and several spin doublets. The various energy states are influenced by Coulomb interactions and can be described using racah parameters B and C. These parameters can be calculated as shown in Equations (1) and (2) below.

[0210] … … Equation (1)

[0211] … … Equation (2)

[0212] F in the above equations (1) and (2). k (k = 0, 2, 4) can be used to quantify electron-electron repulsion within an atom. These values ​​were obtained through quantum mechanical calculations that account for the spatial distribution and interactions of electrons. Specifically, d 5 Mn with electron configuration 2+ In the case of, F 2 is approximately 12,000 cm -1 , F 4 is approximately 7,500 cm -1 This is the case. Using these values, the Racah parameter can be calculated as shown in the following equations (3) and (4).

[0213] … … Equation (3)

[0214] … … Equation (4)

[0215] Mn coordinated in a tetrahedral structure 2+In the case of ions, due to Coulomb repulsion 6 A 1→ 4 G and 6 A 1→ 4 D metastasis occurs. 6 A1 and 4 G, 6 A1 and 4 The energy difference between D can be expressed by the Racah parameters 10 B + 5 C and 7 B, respectively. Additionally, since the d orbitals of the central Mn overlap with four ligands, they are repelled, resulting in three t 2g orbitals and 2 e g It splits into orbitals. Therefore, the original degenerate d orbital of Mn, which forms a tetrahedron with Br, is a high-energy t 2g Orbitals and low-energy e g It splits into orbitals. This phenomenon is known as crystal field splitting, and the degree of splitting is determined by the crystal field strength (Δ). Considering these three independent variables (B, C, Δ), the positions of free ion energy levels can be determined using the Tanabe-Sugano diagram. This diagram is based on the energy levels (E / B) and crystal field strength (Δ / B) of metal ions.

[0216] Fig. 17 is d 5 It is a Tanabe-Sugano diagram.

[0217] As shown in FIG. 17, the above d 5 Referring to the Tanabe-Sugano diagram, Mn with a weak crystal field strength 2+ In the case of ions, electronic transitions 4 At T1 6 It can be confirmed that it occurs as A1, and thus it may exhibit green luminescence in tetrahedral coordination.

[0218] Figure 18 is a UV-vis absorption spectroscopy (UV-Vis) spectrum showing multiple electronic transitions of the polycrystalline (CPTP)2MnBr4 of the organometallic halide compound preparation example 1 of the present invention. Through this, the energy states of the polycrystalline (CPTP)2MnBr4 of the organometallic halide compound preparation example 1 were investigated.

[0219] In the absorption spectrum of Fig. 18, several distinct peaks corresponding to various electronic transitions can be identified. These peaks were located at 284, 326, 363, 379, 456, 471, and 487 nm. The corresponding electronic transitions are, respectively 6 A 1→ 4 T1(F), 6 A 1→ 4 T1(P), 6 A1 → 4 E(D), 6 A 1→ 4 T2(D), 6 A 1→ 4 A1(G) and 4 E(G), 6 A 1→ 4 T2(G), 6 A 1→ 4 It is T1(G).

[0220] FIG. 19 is a graph showing the luminescence mechanism of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 and the single crystal (CPTP)2MnBr4 of Preparation Example 2 of the organometal halide compound of the present invention, and FIG. 20 is a graph showing the band structure of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 and the single crystal (CPTP)2MnBr4 of Preparation Example 2 of the organometal halide compound of the present invention.

[0221] The comprehensive luminescence mechanism can be confirmed through Fig. 19. To investigate the photophysical properties of (CPTP)2MnBr4, the band structure and density of states (DOS) were theoretically calculated as shown in Fig. 20. The calculated band gap is 2.56 eV, which is in good agreement with the emission wavelength.

[0222] FIG. 21 is the valence band maximum (VBM) of the density of states analysis of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 and the single crystal (CPTP)2MnBr4 of Preparation Example 2 of the organometal halide compound of the present invention, and FIG. 22 is the conduction band minimum (CBM) of the density of states analysis of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 and the single crystal (CPTP)2MnBr4 of Preparation Example 2 of the organometal halide compound of the present invention.

[0223] As shown in FIGS. 21 and 22, the above-described density of states (DOS) analysis results indicate that the valence band maximum (VBM) and conduction band minimum (CBM) states are formed by Mn 3d and Br 3p orbitals. Mn 2+ Wow Br - Electronic transitions contributing to luminescence through charge density evenly distributed across ions [MnBr4] 2- It can be confirmed that this occurs within the complex. Thermal and chemical stability are important characteristics of luminescent materials, and a rise in temperature in luminescent materials can lead to a decrease in luminescence efficiency due to electron-phonon coupling.

[0224] Figure 23 is the temperature-dependent PL spectrum of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1 of the organometallic halide compound of the present invention. To evaluate the thermal stability of (CPTP)2MnBr4, thermal quenching (TQ) was measured up to 150°C.

[0225] Referring to Fig. 23, it can be seen that this material exhibited excellent thermal stability and maintained a light transmittance (PL) of over 90% at room temperature.

[0226] Meanwhile, when halide-based compositions are exposed to environmental conditions, they may decompose in humid environments, leading to a degradation of their optical properties. Therefore, air stability can be an important indicator for halide-based luminescent materials.

[0227] Next, the room temperature stability of (CPTP)2MnBr4 was evaluated by exposing it to air for 2,500 hours.

[0228] FIG. 24 is a graph showing (a) light transmittance (PL) and (b) X-ray diffraction analysis (XRD) performed on the polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention in the pristine state and after 2,500 hours of air exposure.

[0229] Referring to Fig. 24, a comparison of PL and XRD before and after 2,500 hours of exposure to air showed that (CPTP)2MnBr4 has an emission wavelength (λ em It was confirmed that it maintained the luminescence intensity (= 517 nm) and exhibited the same XRD pattern. This confirms the excellent chemical stability of (CPTP)2MnBr4. Furthermore, these results indicate that (CPTP)2MnBr4 is superior to Cs2Ag, which exhibits phase instability and environmental degradation under similar conditions. 1-x K x In 0.875 Bi 0.125 C l6 This suggests that it is significantly more stable compared to lead-free double perovskites such as [the example].

[0230] FIG. 25 is a graph showing (a) the PL spectrum and (b) the XRD pattern, representing the results of the stability analysis of the polycrystalline (CPTP)2MnBr4 of the organometallic halide compound of the present invention, Preparation Example 1, under various environmental conditions (exposure to ultraviolet rays (UV, 254 nm) for 12 hours, heat treatment at 150°C, X-ray irradiation, and storage at 100% relative humidity). To further evaluate the stability under actual environmental conditions, stress tests were conducted under the various environmental conditions described above.

[0231] Referring to FIG. 25, no significant change in PL or XRD characteristics was observed under these conditions. This confirms the robustness and stability of the organometal halide compound provided in the color-changing composition of the present invention.

[0232] Next, the photoluminescence quantum yield (PLQY) of (CPTP)2MnBr4 was measured under various conditions.

[0233] Figure 26 is a graph showing the photoluminescence quantum yield (PLQY) after 2,500 hours of polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention.

[0234] As shown in Fig. 26, the PLQY after storage at room temperature for 2,500 hours was 63.98%, which is similar to the initial value of 62.8%, confirming the excellent long-term stability of the polycrystalline (CPTP)2MnBr4 of the color-changing composition of Example 1 of the present invention.

[0235] Figure 27 is a graph showing the photoluminescence quantum yield (PLQY) according to the excitation wavelength of polycrystalline (CPTP) 2MnBr4 of the organometallic halide compound preparation example 1 of the present invention.

[0236] As shown in Fig. 27, PLQY measurement results across various excitation wavelengths showed consistent performance. This may support the high performance and versatility of the polycrystalline (CPTP)2MnBr4 of Preparation Example 1, an organometal halide compound incorporated in the color conversion composition of the present invention, in optoelectronic applications.

[0237] Next, after analyzing the structural and optical properties of the organometallic halide compound (CPTP)2MnBr4, additional experiments were conducted to evaluate reactivity with ethanol and investigate phase stability. These results suggest that although (CPTP)2MnBr4 dissolved in anhydrous ethanol during the process of forming the color-changing composition, it recrystallized without the formation of impurities, thereby maintaining its crystalline phase and optical properties even after recrystallization.

[0238] FIG. 28 is a graph showing the XRD pattern of the polycrystalline (CPTP)2MnBr4 of the preparation example 1 of the organometallic halide compound of the present invention and the (CPTP)2MnBr4 after the polycrystalline (CPTP)2MnBr4 was immersed in a vial containing ethanol, removed, and dried.

[0239] Referring to Fig. 28, it can be confirmed that the XRD patterns of the polycrystalline (CPTP)2MnBr4 powder of Preparation Example 1 of organometallic halide compounds before and after treatment with ethanol match. That is, although the viscosity changes due to changes in plasticity depending on the amount of ethanol added, as shown in the XRD pattern results, it can be seen that the intrinsic crystal structure is maintained regardless of the amount of ethanol added. This suggests that the polycrystalline (CPTP)2MnBr4 can undergo dissolution and recrystallization while maintaining its intrinsic structural integrity even when reacting with anhydrous ethanol. Through this, it can be seen that the material can recover its original crystal structure without decomposition through recrystallization rather than through intrinsic stability.

[0240] Next, the photoluminescence properties of the above (CPTP)2MnBr4 were evaluated to determine whether the reaction with ethanol affects optical performance.

[0241] Figure 29 is the PL spectrum of the polycrystalline (CPTP)2MnBr4 of the preparation example 1 of the organometallic halide compound of the present invention, and the (CPTP)2MnBr4 after the polycrystalline (CPTP)2MnBr4 was immersed in a vial containing ethanol, removed, and dried.

[0242] As shown in FIG. 29, the luminescence characteristics of the polycrystalline (CPTP)2MnBr4 powder of Preparation Example 1 of organometallic halide compounds before and after treatment with ethanol were maintained without a significant decrease in intensity or changes in excitation and emission wavelengths. This confirms that the electronic state responsible for luminescence in the color-changing composition of the present invention is not affected by ethanol. Furthermore, this can further support the structural integrity and phase stability of the material under solvent interaction.

[0243] Next, the stability of the above (CPTP)2MnBr4 in ethanol was evaluated. For this purpose, samples stored in ethanol for more than one month were dried and then analyzed.

[0244] FIG. 30 (a) is an image of a sample of the polycrystalline (CPTP)2MnBr4 of the preparation example 1 of the organometallic halide compound of the present invention stored in ethanol for more than one month, FIG. 30 (b) is a graph comparing the PL spectra of (CPTP)2MnBr4 before and after storage in ethanol, and FIG. 30 (c) is a graph showing the XRD patterns of (CPTP)2MnBr4 dried after storage in ethanol and the original (pristine) (CPTP)2MnBr4.

[0245] As shown in FIG. 30, when comparing the PL and XRD results between the dried sample and the untreated sample, no significant differences were found in intensity, luminescence profile, or crystal structure. This confirms that ethanol does not cause photoluminescence quenching of the (CPTP)2MnBr4, an organometal halide compound, or deterioration of the photophysical properties of the material, which further supports the potential for various applications of the color-changing composition of the present invention.

[0246] As previously described, the (CPTP)2MnBr4, an organometal halide compound included in the color-changing composition of the present invention, possesses the ability to dissolve and recrystallize without generating impurities, thereby maintaining structural integrity and optical properties even during solvent treatment. Due to these characteristics, the color-changing composition of the present invention containing the (CPTP)2MnBr4 may be particularly suitable for applications where performance maintenance is critical during solvent-based manufacturing processes, such as thin film color-changing layers for optoelectronic devices. In other words, unlike other metal halide perovskites that often degrade upon exposure to solvents, the (CPTP)2MnBr4 has impurity-free recrystallization properties, which can reduce the need for complex encapsulation techniques and thus simplify the manufacturing process. These characteristics may be particularly useful for practical applications where stability under various environmental conditions is critical.

[0247] More specifically, compared to other metal halide perovskites that generally exhibit instability in solvent environments such as ethanol, the (CPTP)2MnBr4 can demonstrate excellent resilience. While many perovskites show significant degradation upon exposure to ethanol, (CPTP)2MnBr4, one of the organometal halide compounds applied to the color-changing composition of the present invention, can be utilized as a more durable material for optoelectronic devices due to its ability to recover its crystal structure after recrystallization. This resilience to solvent exposure not only extends the lifespan of the material but also opens up new possibilities for designing more flexible and solvent-resistant devices.

[0248] Next, based on the recovery power of (CPTP)2MnBr4 observed in a solvent environment, a series of experiments were conducted to further investigate the effect of solvent concentration on physical properties. As a result, it was confirmed that changes in the concentration of ethanol added to the color-changing composition of the present invention directly affect the morphology of the organometal halide compound material.

[0249] FIG. 31 is an image showing the form of the composition prepared in Preparation Examples 1 to 3 of the color-changing composition of the present invention, and FIG. 32 is an image comparing the PL measurement results of the composition prepared in Preparation Examples 1 to 3 of the color-changing composition of the present invention measured at sunlight (daylight), 365 nm, and 254 nm light.

[0250] Referring to Figures 31 and 32, it can be seen that as the concentration of ethanol added to the color-changing composition decreases, the composition exhibits clay-like viscosity and particle aggregation. However, as the concentration of ethanol added to the color-changing composition increases, it appears more fluid, similar to ink. These results indicate how significantly the concentration of the solvent in the color-changing composition can influence the interaction of organometal halide compound particles and the resulting aggregation behavior.

[0251] FIG. 33 is a schematic diagram showing the recrystallization mechanism of (CPTP)2MnBr4 at various ethanol concentrations of the color-changing composition of the present invention.

[0252] As shown in Fig. 33, adding a small amount of ethanol (less EtOH) can cause the solution to rapidly reach a saturation state, which can lead to rapid nucleation. When a high solute concentration is present in a small amount of solvent, a supersaturated state is created, which can result in the formation of numerous small nuclei. However, because the amount of solvent is small, the mobility of solute molecules is limited, which restricts nucleation growth and can lead to the formation of many small and incompletely formed crystal grains. Additionally, the limited solvent supply hinders efficient mass transfer, which can result in non-uniform crystal growth.

[0253] Conversely, if the amount of ethanol increases (more EtOH), the solute concentration decreases, and it may take longer for the solution to reach saturation. This slow nucleation process can result in the formation of fewer nuclei. However, as the amount of solvent increases, the mobility of solute molecules improves, allowing nuclei to grow into larger and clearer crystals. In other words, an abundant solvent promotes mass transfer, which can produce crystals that grow more uniformly and homogeneously.

[0254] Supersaturation acts as the driving force behind nucleation and can play a significant role in this process. High supersaturation accelerates nucleation, generating many small nuclei, whereas low supersaturation slows it down, allowing for the growth of larger and better-formed crystals. Classical nucleation theory (CNT) emphasizes that the nucleation rate and the size of critical nuclei are determined by the level of supersaturation. Therefore, solvent concentration can effectively control supersaturation, thereby directly influencing nucleation and growth kinetics. These differences in crystal size and uniformity caused by supersaturation kinetics demonstrate that the amount of solvent plays a crucial role in regulating the nucleation and crystal growth processes.

[0255] These results may indicate that (CPTP)2MnBr4, an organometal halide compound included in the color-changing composition of the present invention, is highly sensitive to the amount of solvent used during the recrystallization process, which affects both the morphology and the overall crystallization kinetics.

[0256] In summary, when the amount of solvent is small, nucleation predominates, resulting in smaller and more irregular crystals, whereas when the amount of solvent is large, growth predominates, resulting in larger and more uniform crystals. Understanding this solvent-controlled recrystallization mechanism is important for optimizing the synthesis conditions of the color-changing composition of the present invention and can be particularly useful for tailoring properties to specific applications, such as ink-based painting or luminescent clay.

[0257] FIG. 34 is an SEM image of the compositions prepared in Preparation Examples 1 to 4 of the color-changing composition of the present invention, (a) Color-changing composition Preparation Example 1, (b) Color-changing composition Preparation Example 2, (c) Color-changing composition Preparation Example 3, and (d) Color-changing composition Preparation Example 4.

[0258] As with the mechanism described above, Figure 34 shows that as the concentration of ethanol in the color-changing composition increases, the particle size increases and the uniformity improves. This confirms that the amount of ethanol in the color-changing composition has a significant effect on the crystallization of the organometallic halide compound (CPTP)2MnBr4. These results not only highlight the importance of the amount of solvent in controlling nucleation and growth but also suggest new possibilities for practical applications.

[0259] FIG. 35 is (a) a schematic diagram and (b) an image of the actual application of the color-changing composition of the present invention as luminescent clay.

[0260] As shown in FIG. 35, the color-changing composition of the present invention forms clay-like aggregates when ethanol is added at a low concentration during preparation, so it can be utilized as luminescent clay. Specifically, when a small amount of ethanol is added during the preparation of the color-changing composition of the present invention, the organometal halide compound particles partially dissolve and recrystallize, causing them to aggregate and form plastic-like viscosity. Subsequently, when the ethanol evaporates, the material maintains its shape and hardens.

[0261] As shown in Fig. 35, about 1 cm 3 A luminescent clay cube was produced, and a lion approximately 5 cm in size was produced using a cookie cutter, allowing the aforementioned characteristics of the color-changing composition of the present invention to be confirmed.

[0262] FIG. 36 is (a) a schematic diagram and (b) an actual application image of the color-changing composition of the present invention applied to direct ink writing.

[0263] As shown in FIG. 36(a), due to the viscosity and plasticity of the composition when ethanol is present in the color-changing composition of the present invention, the color-changing composition can also be used for direct ink writing. For the direct ink writing process, in Preparation Example 1 of the color-changing composition, (CPTP)2MnBr4 is mixed with ethanol and about 0.5 mL g -1 A composition prepared in the form of a homogeneous ink by mixing in the ratio was placed into a 3 mL syringe without a needle. By pressing the syringe plunger to manually apply a constant flow rate and pressure, the material could be printed in a specific shape or thickness. As shown in Fig. 36 (b), the initials "HY" of Hanyang University were printed in a size of approximately 2 to 3 cm. That is, the color-changing composition of the present invention is applied as a luminescent ink, and by applying continuous pressure thereto, the color-changing composition can be printed in a specific shape or thickness.

[0264] FIG. 37 is (a) a schematic diagram and (b) an actual applied image of the color conversion composition of the present invention applied to pattern printing.

[0265] As shown in FIG. 37 (a), when preparing the color-changing composition of the present invention, if the amount of ethanol is increased to make the material more fluid, pattern printing can be obtained using various pattern masks.

[0266] Referring to Fig. 37 (b), the "funMat" characters engraved on the pattern mask were printed using a doctor blade, resulting in a pattern approximately 3 cm in size.

[0267] FIG. 38 is (a) a schematic diagram and (b) an actual application image of the color conversion composition of the present invention applied to ink printing.

[0268] When the amount of ethanol was significantly increased to apply the color-changing composition of the present invention to ink printing, most of the organometal halide compound powder dissolved in anhydrous ethanol, and the remaining material was evenly dispersed in the solvent. When the bright green mixture was applied with a brush, the material recrystallized into a thin film as the ethanol evaporated. Using this, a lion painting artwork approximately 15 cm in size was created, as shown in Fig. 3k(b). After the ethanol had completely evaporated, a visible light image was drawn using luminescent ink under ultraviolet light (under 365 nm).

[0269] These results provide valuable insights into the solvent-controlled recrystallization mechanism of (CPTP)2MnBr4 in the color-changing composition of the present invention and confirm its potential for application in the fields of optoelectronics, printing technology, and luminescent materials. Because its structural and optical properties are stable at various ethanol concentrations and it is highly versatile in diverse applications, the color-changing composition of the present invention can be a promising candidate for future material innovation.

[0270] The present invention enables the formation of a uniform film without the use of a binder by utilizing the solvent-based plasticity of (CPTP)2MnBr4, a novel lead-free metal halide material. This method can optimize the thickness of the material and maximize luminescence efficiency while preventing performance degradation caused by binders.

[0271] Next, the color-changing composition of the present invention was applied to a white light source and a scintillator, and their efficiency was compared.

[0272] <Preparation Example 1-1 of a White Light Emitting Diode Comprising a Color-Converting Layer Equipped with a Color-Converting Composition>

[0273] The WLED is a polycrystalline (CPTP)2MnBr4 prepared in the above color conversion composition preparation example 1, and a blue InGaN chip (λ em=450nm, 3V, SANAN Optoelectronics Co., Ltd.) and the red phosphor K2SiF6:Mn4 + It was fabricated using (CPTP)2MnBr4 and K2SiF6:Mn4 + After measuring the two phosphors in a weight ratio of 1:1, they were ground in an agate mortar for 3 minutes. 0.5 ml / g of ethanol was mixed with the mixed materials. After thoroughly mixing them, the mixture was applied onto the blue InGaN chip (LED chip) to produce a white light-emitting diode equipped with a color conversion layer.

[0274] <Preparation Example 1-2 of a White Light-Emitting Diode Comprising a Color-Converting Layer Equipped with a Color-Converting Composition>

[0275] In the above white light-emitting diode preparation example 1-1, (CPTP)2MnBr4 and K2SiF6:Mn4 + A white light-emitting diode equipped with a color conversion layer was manufactured by performing the same procedure, except that the mixture was measured and mixed in a weight ratio of 2:1.

[0276] <Preparation Example 1-3 of a White Light-Emitting Diode Comprising a Color-Converting Layer Equipped with a Color-Converting Composition>

[0277] In the above white light-emitting diode preparation example 1-1, (CPTP)2MnBr4 and K2SiF6:Mn4 + A white light-emitting diode equipped with a color conversion layer was manufactured by performing the same procedure, except that the mixture was measured and mixed in a weight ratio of 7:3.

[0278] <Preparation Example 1-4 of a White Light-Emitting Diode Comprising a Color-Converting Layer Equipped with a Color-Converting Composition>

[0279] In the above white light-emitting diode preparation example 1-1, (CPTP)2MnBr4 and K2SiF6:Mn4 + A white light-emitting diode equipped with a color conversion layer was manufactured by performing the same procedure, except that the mixture was measured and mixed in a weight ratio of 9:1.

[0280] <Preparation Example 1-5 of a White Light Emitting Diode Comprising a Color-Converting Layer Equipped with a Color-Converting Composition>

[0281] In the above white light-emitting diode preparation example 1-1, (CPTP)2MnBr4 and K2SiF6:Mn4 + A white light-emitting diode equipped with a color conversion layer was manufactured by performing the same procedure, except that the mixture was measured and mixed in a weight ratio of 18:1.

[0282] <Preparation Example 1-6 of a White Light Emitting Diode Comprising a Color-Converting Layer Equipped with a Color-Converting Composition>

[0283] In the above white light-emitting diode preparation example 1-1, (CPTP)2MnBr4 and K2SiF6:Mn4 + A white light-emitting diode equipped with a color conversion layer was manufactured by performing the same procedure, except that the mixture was measured and mixed in a weight ratio of 36:1.

[0284] (CPTP)2MnBr4 and K2SiF6:Mn4 used in the above white light-emitting diode preparation examples 1-1 to 1-5 + The weight ratios are summarized in Table 5 below.

[0285] Classification (CPTP) 2MnBr 4: K2SiF6:Mn4 + Weight ratio of White Light Emitting Diode Preparation Example 1-11:1 White Light Emitting Diode Preparation Example 1-22:1 White Light Emitting Diode Preparation Example 1-37:3 White Light Emitting Diode Preparation Example 1-49:1 White Light Emitting Diode Preparation Example 1-518:1 White Light Emitting Diode Preparation Example 1-636:1

[0286] The emission spectrum and CIE color coordinates were measured using an integrating sphere spectroradiometer system. Fig. 39 shows the polycrystalline (CPTP)2MnBr4 prepared in Preparation Example 1 of the color conversion composition of the present invention and K2SiF6:Mn 4+ and, This is an image showing the emission colors of the color conversion layer of the white light-emitting diode Manufacturing Example 1-4 of the present invention at various excitation sources (under UV, under 450 nm). The emission colors of these materials can be confirmed in Fig. 39. White light is an image of the white light-emitting diode Manufacturing Example 1-4. As such, when fabricating a WLED (white light-emitting diode), the green emitting material (CPTP)2MnBr4 and the red emitting material K2SiF6:Mn 4+ It may be important to balance the luminescence intensity.

[0287] FIG. 40 shows the (CPTP)2MnBr4 and K2SiF6:Mn of the color conversion layer of white light-emitting diode preparation examples 1-1 to 1-6 of the present invention. 4+ PL spectra at various weight ratios of, and FIG. 41 is the (CPTP)2MnBr4 and K2SiF6:Mn of the color conversion layer of white light-emitting diode Preparation Examples 1-1 to 1-6 of the present invention. 4+ These are the CIE 1931 color coordinates at various weight ratios. That is, as shown in Fig. 40, PL was measured at various weight ratios of the luminescent material, and the luminescent colors were displayed in the CIE 1931 color space as shown in Fig. 41.

[0288] As shown in Fig. 41, CIE(x,y) = (0.2021, 0.7005) are the color coordinates of (CPTP)2MnBr4, and CIE(x,y) = (0.6179, 0.3053) are K2SiF6:Mn 4+ These are the color coordinates. (CPTP)2MnBr4 and K2SiF6:Mn used in the above white light-emitting diode Preparation Examples 1 to 6. 4+The weight ratios were 1:1, 2:1, 7:3, 9:1, 18:1, and 36:1. Referring to FIGS. 40 and 41, it can be confirmed that the CIE 1931 color coordinates change linearly with changes in weight ratio. In addition, the optimal balance of luminescence intensity was achieved in the case of a weight ratio of 9:1, which is the color conversion layer prepared in Example 4 of the white light-emitting diode preparation, and it can be seen that the two luminescent materials contribute to the emission of white light without overwhelming each other.

[0289] This optimal ratio can be attributed to differences in the luminescence characteristics of the materials. (CPTP)2MnBr4, with a wide emission bandwidth (FWHM = 46 nm), requires a higher ratio to compensate for energy distribution over a wider spectral range, whereas K2SiF6:Mn, with a narrow bandwidth (FWHM = 7–10 nm) 4+ It can provide concentrated red luminescence with less material.

[0290]

[0291] Preparation Example 2-1 of a white light-emitting diode comprising a color-converting layer equipped with a color-converting composition

[0292] In the above white light-emitting diode preparation examples 1-4, (CPTP)2MnBr4 and K2SiF6:Mn4 + A white light-emitting diode equipped with a color conversion layer was manufactured by performing the same procedure except that a clay-like material was made by mixing it with anhydrous ethanol (1 ml) in a weight ratio of 9:1 and applying it onto a 445 nm blue LED.

[0293] Preparation Example 2-2 of a white light-emitting diode comprising a color-converting layer equipped with a color-converting composition

[0294] In the above white light-emitting diode preparation example 2-1, (CPTP)2MnBr4 and K2SiF6:Mn4 + A white light-emitting diode equipped with a color-changing layer was prepared by performing the same procedure except that it was mixed with anhydrous ethanol (1.5 ml) in a weight ratio of 9:1.

[0295] Preparation Example 2-3 of a white light-emitting diode comprising a color-converting layer equipped with a color-converting composition

[0296] In the above white light-emitting diode preparation examples 1-4, (CPTP)2MnBr4 and K2SiF6:Mn4 + A white light-emitting diode equipped with a color conversion layer was manufactured by performing the same procedure except that a clay-like material was prepared by mixing it with anhydrous ethanol (2.0 ml) in a weight ratio of 9:1 and applying it onto a 445 nm blue LED.

[0297] FIG. 42 is an image of the color conversion of white powder clay prepared in Preparation Examples 2-1 to 2-3 of the color conversion composition of the present invention by exposing it to daylight and an excitation ray of 365 nm.

[0298] Referring to Fig. 42, when ethanol was evaporated, a solidified color-changing layer was formed within about 10 minutes.

[0299] Preparation Example 3-1 of a white light-emitting diode comprising a color-converting layer equipped with a color-converting composition

[0300] For comparative analysis, WLEDs were fabricated by incorporating the light-emitting material into a silicon elastomer PDMS (Sylgard 184A, Sewang Hitech) matrix. Specifically, the polycrystalline (CPTP)2MnBr4 and K2SiF6:Mn4 prepared in Color Conversion Composition Preparation Example 1 were used. + A white light-emitting powder was prepared by mixing PDMS in a weight ratio of 9:1. To achieve optimal homogeneity, PDMS and the white light-emitting powder were mixed in a weight ratio of 1:1, ground for 3 minutes, and then coated onto a blue LED chip to manufacture a white light-emitting diode.

[0301] Preparation Example 3-2 of a white light-emitting diode comprising a color-converting layer equipped with a color-converting composition

[0302] A white light-emitting diode was manufactured by performing the same procedure as in the above white light-emitting diode manufacturing example 3-1, except that PDMS and white light-emitting powder were mixed in a weight ratio of 2:1.

[0303] Preparation Example 3-3 of a white light-emitting diode comprising a color-converting layer equipped with a color-converting composition

[0304] A white light-emitting diode was manufactured by performing the same procedure as in the above white light-emitting diode manufacturing example 3-1, except that PDMS and white light-emitting powder were mixed in a weight ratio of 3:1.

[0305] FIG. 43 is a schematic image of a white light-emitting diode manufactured using only the white light-emitting powder-based PDMS mixture (white powder PDMS mixture + blue LED) of the white light-emitting diode manufacturing example 3-1 of the present invention and the white powder clay containing the white light-emitting powder (white powder clay + blue LED) of the white light-emitting diode manufacturing example 1-4 of the present invention.

[0306] As shown in FIG. 43, actual white light-emitting diode chips were manufactured using both methods (using only white powder clay, and using a mixture of white powder clay and PDMS) in the above-described white light-emitting diode manufacturing examples 1-4 and white light-emitting diode manufacturing examples 3-1 to 3-3.

[0307] FIG. 44 is an image comparing white light-emitting diode chips prepared in white light-emitting diode preparation examples 3-1 to 3-3 of the present invention.

[0308] As shown in FIG. 44, when the performance of white light-emitting diodes with different PDMS mixing ratios in Preparation Examples 3-1 to 3-3 was compared, significant results were confirmed. Specifically, when the ratio of PDMS to white light-emitting powder was 3:1 (Preparation Example 3-3 of a color conversion layer for WLED) and 2:1 (Preparation Example 3-2 of a color conversion layer for WLED), it was confirmed that blue light leakage was still observed even at a thickness exceeding 2.2 mm. On the other hand, when the ratio of PDMS to white light-emitting powder was 1:1 (Preparation Example 3-1 of a color conversion layer for WLED), stable and uniform white light was generated without blue light leakage at a thickness of approximately 2 mm.

[0309] FIG. 45 is the EL spectrum of white light-emitting diode manufacturing example 3-1 (PDMS + blue LED) of the present invention and white light-emitting diode manufacturing example 1-1 (clay + blue LED) of the present invention, and FIG. 46 is an actual image of white light-emitting diode manufacturing example 3-1 (PDMS + blue LED) of the present invention and white light-emitting diode manufacturing example 1-1 (clay + blue LED) of the present invention.

[0310] As shown in FIGS. 45 and 46, in the above white light-emitting diode preparation example 3-1, it can be seen that a sufficiently thick color conversion layer (2.20 mm) is required for effective white light emission even when PDMS and white light-emitting powder are in a 1:1 ratio.

[0311] However, it can be confirmed that the clay-based white light-emitting diode Preparation Example 1-1 has superior performance compared to the PDMS-based LED of the white light-emitting diode Preparation Example 3-1, enabling efficient color conversion even at a thickness of 1.30 mm. This may imply that a clay-based material with high density and excellent light conversion efficiency enables enhanced white light emission without the blue light interference commonly observed in PDMS-based LEDs.

[0312] FIG. 47 is a graph showing the CIE 1931 color coordinates of the white light-emitting diode manufacturing example 3-1 (PDMS + blue LED) of the present invention and the white light-emitting diode manufacturing example 1-1 (clay + blue LED) of the present invention.

[0313] In Fig. 47, the excellent chromaticity coordinates and correlated color temperature (CCT) of the clay-based system can be observed. Specifically, the above white light-emitting diode Example 3-1, which is a PDMS-based LED at the same thickness (1.30 mm), exhibited CIE(x,y) = (0.2392, 0.2121), corresponding to the blue region of the color space. To realize white light near the Planck locus, the above white light-emitting diode Example 3-1 required a thickness between 1.68 mm and 1.96 mm.

[0314] In contrast, the clay-based white light-emitting diode Example 1-1 reached chromaticity coordinates of CIE(x,y) = (0.2767, 0.3006) at a thickness of 1.30 mm, which closely matched the Planck locus and corresponded to white light emission of 8890 K.

[0315] These results confirm that a clay-based LED composed solely of the color-changing composition of the present invention can achieve efficient white light emission with minimal thickness. Furthermore, it can be seen that a clay-based LED composed solely of the color-changing composition of the present invention is highly advantageous for small, high-performance lighting applications.

[0316] Furthermore, a clay-based LED composed solely of the color-changing composition of the present invention can provide significant practical advantages over existing PDMS or resin-based systems because it does not require heat or UV curing to cure the color-changing layer. Through this, the color-changing layer manufactured using the color-changing composition of the present invention can simplify the manufacturing process while maintaining excellent performance.

[0317] FIG. 48 is a graph and image comparing the EL intensity at various currents of the light-emitting diode of Example 1-1 of the white light-emitting diode of the present invention.

[0318] As shown in FIG. 48, it can be confirmed that the clay-based LED of the white light-emitting diode preparation example 1-1 of the present invention ensures consistent performance under various operating conditions, as the light output increases linearly as the current increases from 50 mA to 200 mA. These results indicate that the clay-based color conversion system using the color conversion composition of the present invention is a very promising candidate in the field of next-generation lighting and display technology, as it not only improves the performance of WLEDs but also simplifies the manufacturing process.

[0319] Next, to further evaluate performance, a film ((CPTP)2MnBr4) containing the color-changing composition of the present invention was compared with a recently developed CsPbBr3NC-based resin film system and a PDMS-based film in terms of long-term stability and luminescence performance. This is shown in Table 6 below. Specifically, Table 6 below is a comparative analysis table of NC-resin composite CCL and (CPTP)2MnBr4 films.

[0320] SamplesPeak positions (nm)FWHMs (nm)Intensity changes (%)PLQY (%)Time (days)Day1Day120Day1Day120Day1Day120Day1Day120Green-CsPbBr3NC-resin CCL52052021.5721.4110091.926856(CPTP)2MnBr4clay film51851846.8046.7910099.556262

[0321] As summarized in Table 6, the (CPTP)2MnBr4 clay film formed from the color-converting composition of the present invention exhibited excellent long-term stability and maintained its luminescence properties even after being stored at room temperature for 120 days, demonstrating superior performance compared to polymer-based systems where binder degradation commonly occurs. These results indicate that this material can be used as a durable and efficient color-converting layer in advanced WLED and scintillator applications. Next, a scintillator film was fabricated using the composition of Preparation Example 1 of the color-converting composition of the present invention without using a binder, and its X-ray imaging performance was compared.

[0322] Example 1 of preparation of a PDMS-based scintillator film equipped with a color-changing composition

[0323] FIG. 49 is a schematic diagram illustrating a PDMS-based scintillator film and a clay-based scintillator film fabrication method according to one embodiment of the present invention.

[0324] Polycrystalline (CPTP) 2MnBr4 (3g) prepared in Example 1 of the color-changing composition, polydimethylsiloxane (PDMS) (3g), and a curing agent (0.3g) were placed in a vial in a weight ratio of 1:1:0.1 and stirred to be uniformly mixed. After thoroughly stirring the mixed solution, a certain amount of the solution was poured onto a cover glass, and a scintillator thick film was prepared using the spin coating method. This was heat-treated in an 80°C oven for 4 hours. The thickness of the prepared PDMS-based scintillator films was 0.41 mm.

[0325] Example 1 of preparation of a clay-based scintillator film containing a color-changing composition

[0326] Polycrystalline (CPTP)2MnBr4 (3g) and (CPTP)2MnBr4 (3g) prepared in Example 1 of the color-changing composition above were mixed with ethanol (2mL / g) to form a fluid clay, and then, as shown in FIG. 49, the mixture was applied using a doctor blade and dried to produce the film. The thickness of the produced clay-based scintillator film was 0.35mm.

[0327] FIG. 50 is a graph comparing the RL intensity of the PDMS-based scintillator film of Example 1 and the clay-based scintillator film of Example 1 of the present invention, and FIG. 51 is a graph showing the linear response of the PDMS-based scintillator film of Example 1 and the clay-based scintillator film of Example 1. The RL intensity of the two films was compared by varying the X-ray tube currents.

[0328] As can be seen in Fig. 50, the clay-based scintillator film produced 1.25 times brighter light than the PDMS-based scintillator film, despite being thinner. In addition, the RL intensity of both films increased linearly with increasing dose rate. This can also be confirmed in Fig. 51.

[0329] Next, the aforementioned scintillator film was applied to an indirect X-ray imaging system to compare performance.

[0330] FIG. 52 is a schematic diagram of an indirect X-ray imaging system according to one embodiment of the present invention.

[0331] As shown in FIG. 52, an indirect X-ray imaging system may be composed of an imaging target, a scintillator film, and an arrayed CMOS photodiode. X-ray images were acquired using a digital video output interface equipped with a frame grabber.

[0332] FIG. 53 is a graph comparing the spectral sensitivity of CPTP2MnBr4 and a CMOS photodiode provided in the color-changing composition of the present invention.

[0333] As shown in Fig. 53, it can be seen that the radioluminescence (RL) spectrum of the CPTP2MnBr4 matches well with the external quantum efficiency spectrum of the CMOS sensor. This confirms that (CPTP)2MnBr4 is suitable for X-ray imaging.

[0334] Next, static X-ray imaging was performed on both films.

[0335] FIG. 54 is an X-ray image of a ballpoint pen using the scintillator film preparation example 1 (clay-based film) and the scintillator film preparation example 2 (PDMS mixed film) of the present invention. Static X-ray imaging was performed on both films.

[0336] As shown in FIG. 54, the clay-based film of Scintillator Film Preparation Example 1 produces a high-contrast image of the internal structure of a ballpoint pen, whereas the PDMS mixed film of Scintillator Film Preparation Example 2 is blurry and low in brightness.

[0337] Next, the resolution and sensitivity of the clay-based film of Scintillator Film Preparation Example 1 and the PDMS mixed film of Scintillator Film Preparation Example 2 were evaluated through further analysis. For this purpose, commercially available Gd2O2S:Tb 3+ Powder was purchased, mixed with PDMS in a 1:1 ratio, and then spin-coated to produce a film (hereinafter referred to as Scintillator Film Comparative Example 1). The clay-based film of Scintillator Film Preparation Example 1, the PDMS mixed film of Scintillator Film Preparation Example 2, and the Gd2O2S:Tb of Scintillator Film Comparative Example 1. 3+ All films, including the film, were produced with a uniform thickness of 0.35 mm for fair comparison.

[0338] (a) The clay-based film of Scintillator Film Preparation Example 1 and the Gd2O2S:Tb of Scintillator Film Comparison Example 1 used in the MTF analysis of FIG. 55. 3+ (b) an image of the diagonal corner of the film, (b) a graph comparing the modulation transfer function (MTF) between the films of the scintillator film Preparation Example 1, Preparation Example 2, and Comparative Example 1, (c) the clay-based film of the scintillator film Preparation Example 1 and the Gd2O2S:Tb film of the scintillator film Comparative Example 1. 3+ This is a graph comparing the average brightness of X-ray images obtained from film. X-ray imaging was performed using a tube voltage of 90 kV, a tube current of 200 mA, and a source-to-image distance (SID) of 1 m, with an estimated dose rate of 445.08 mGy / s. -1 It was.

[0339] Referring to Fig. 55 (a), it can be seen that both films show similar edge sharpness.

[0340] As shown in FIG. 55(b), the results of the modulation transfer function (MTF) analysis in terms of resolution showed that the (CPTP)2MnBr4 clay film of Scintillator Film Preparation Example 1 and the Gd2O2S:Tb of Comparative Example 1 3+ The film has an MTF value of 0.2 to 1.3 lp / mm -1While it showed the same resolution value, the PDMS mixed film of Scintillator Film Preparation Example 2 showed 0.7 lp mm -1 It exhibited low resolution. Through these results, it can be seen that the (CPTP)2MnBr4 clay film of the scintillator film preparation example 1 provides competitive performance in both sensitivity and resolution compared to commercial scintillators.

[0341] However, it should be noted that directly comparing MTF values ​​with other research results is meaningless because they are influenced by various factors such as source-to-image distance (SID), pixel size and number of imaging sensors, scintillator thickness and quality, and scintillation efficiency.

[0342] Sensitivity was calculated by normalizing the average brightness of the X-ray image in Fig. 55 (c) to the dose rate using the following equation (5).

[0343] Sensitivity = Average brightness (counts) Dose rate (mGy / sec) … … Equation (5)

[0344] As a result of sensitivity calculations, the (CPTP)2MnBr4 clay film of Scintillator Film Preparation Example 1 achieved a sensitivity of 5.30 counts / mGy / sec, which is Gd2O2S:Tb 3+ It corresponded to approximately 86.6% of the scintillator sensitivity (6.12 counts / mGy / sec).

[0345] FIG. 56 is a graph comparing the X-ray absorption spectra of the films of the scintillator film preparation example 1 and comparative example 1 of the present invention.

[0346] Referring to FIG. 56, it is shown that the (CPTP)2MnBr4 prepared in Example 1 of the scintillator film preparation has a relatively low X-ray absorption coefficient compared to commercial scintillators, but it can be seen that this study presents a new binder-free approach for the manufacture of scintillators and WLEDs.

[0347] <Preparation Example 3 of Organometal Halide Compounds: Synthesis of (TPA)2MnBr4>

[0348] An organometallic halide compound composed of (TPA)2MnBr4 (tetrapropylammonium manganese) was prepared by performing the same procedure as in Example 1 of the preparation of organometallic halide compounds above, except that (TPA)Br (where TPA is tetrapropylammonium) was used as the AX material. The formed (TPA)2MnBr4 exhibited uniform luminescence characteristics and was prepared as a green polycrystalline phosphor.

[0349] <Preparation Example 7 of Color-Changing Composition>

[0350] A color-changing composition was prepared in the same manner as in Preparation Example 4 of the above color-changing composition, except that (TPA)2MnBr4 prepared in Preparation Example 3 of the above organometal halide compound was used as the organometal halide compound.

[0351] FIG. 57 is an image of the composition of Preparation Example 7 of the color conversion composition of the present invention applied to a screen printer, FIG. 58 is a design of a 5x5 circular pattern applied to the screen printer of FIG. 57, and FIG. 59 is an image of a color conversion layer having a 5x5 pattern formed based on the pattern presented in FIG. 58. FIG. 57 was performed by screen printing by passing a mixture of (TPA)2MnBr4 and ethanol through a patterned screen using a squeezing technique.

[0352] As shown in FIG. 59, the size of the pattern was set to a diameter of 1 mm and 0.5 mm. Referring to FIG. 57 to FIG. 59, a precise and uniform pattern could be produced by utilizing the appropriate viscosity of the color-changing composition preparation example 7. Through this, it can be confirmed that the composition having (TPA)2MnBr4 prepared in the color-changing composition preparation example 7 of the present invention has wettability and luminescence characteristics suitable for forming such screen printing patterns.

[0353] FIG. 60 is an SEM image of a top view of a screen printing pattern to which the composition of Example 7 of the color-changing composition of the present invention is applied, and FIG. 61 is an SEM image of a side view of a screen printing pattern to which the composition of Example 7 of the color-changing composition of the present invention is applied.

[0354] Referring to FIGS. 60 and FIGS. 61, it can be seen that the color-changing composition having (TPA)2MnBr4 prepared in Example 7 of the color-changing composition of the present invention has wettability and luminescence characteristics suitable for forming a pattern for screen printing. Through this, it can be confirmed that organometallic Mn-based halide compounds such as (TPA)2MnBr4 as well as (CPTP)2MnBr4 of the present invention exhibit the characteristics described above.

[0355] As described above, the present invention confirms that (CPTP)2MnBr4, used as an organometal halide compound, is a promising lead-free metal halide material capable of forming a uniform thin film without a binder due to its unique solvent-based plasticity. Furthermore, the color-changing composition of the present invention, comprising the (CPTP)2MnBr4, can solve common problems occurring in existing systems, such as optical loss, increased layer thickness, and long-term stability issues, by removing the binder. Through the structural and optical analysis described above, high luminescence efficiency was confirmed with a quantum yield of 83.42% in the single-crystal form, and structural and optical properties were maintained even after dissolution and recrystallization. These results demonstrate the versatility of the color-changing composition of the present invention in applications such as luminescent clay, direct ink printing, pattern printing, and ink drawing.

[0356] Furthermore, the color-changing composition of the present invention has demonstrated significant potential to replace existing WLED and scintillator systems that required binders, and binder-free films can improve performance and stability. Such applications in WLEDs demonstrate the potential of lighting technology, while the binder-free approach can indicate potential for next-generation displays, including 5-LEDs, by enabling the development of high-performance, thinner color-changing layers. In addition, binder-free films can be produced through a simple drying process without additional heat treatment or curing, thereby further simplifying the production process.

[0357] The present invention is not limited to the above embodiments and can be manufactured in various different forms, and those skilled in the art will understand that the invention can be implemented in other specific forms without changing the technical concept or essential features of the invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. A step of mixing an organic halide compound having the chemical formula AX and a metal halide compound having the chemical formula MX2 to form an organic metal halide compound having the chemical formula A2MX4; and The method comprises the step of forming a color-changing composition by mixing an anhydrous alcohol-based solvent with the above-mentioned organometallic halide compound; wherein A method for preparing a color-changing composition, wherein A is an organic onium cation, M is a metal cation, and X is a halogen anion.

2. In Paragraph 1, A method for preparing a color-changing composition, wherein the above-mentioned organic onium cation comprises an organic phosphonium ion or an organic ammonium ion.

3. In paragraph 2, the organic phosphonium ion is, A method for preparing a color-changing composition containing cyclopropyltriphenylphosphonium ions.

4. In paragraph 2, the organic ammonium ion is, A method for preparing a color-changing composition containing tetrapropylammonium ions.

5. In Paragraph 1, A method for preparing a color-changing composition, wherein the metal cation is a manganese (Mn) cation.

6. In Paragraph 1, A method for preparing a color-changing composition, wherein the above-mentioned anhydrous alcohol-based solvent comprises one or more selected from anhydrous ethanol, anhydrous methanol, anhydrous isopropanol, and anhydrous butanol.

7. In Paragraph 1, A method for preparing a color-changing composition, wherein 0.1 to 5.0 ml of the anhydrous alcohol-based solvent is mixed with 1 g of the above organometallic halide compound.

8. Anhydrous alcohol-based solvent; and A color-changing composition comprising: organometallic halide compound particles having the chemical formula A2MX4, the surface of which is softened and temporarily swollen by the above-mentioned anhydrous alcohol-based solvent; A color-changing composition in which A is an organic onium cation, M is a metal cation, and X is a halogen anion.

9. In Paragraph 8, The above-mentioned organometallic halide compound is a color-changing composition comprising (CPTP)2MnBr4 or (TPA)2MnBr4.

10. In Paragraph 8, A color-changing composition in which 0.1 to 5.0 ml of the anhydrous alcohol-based solvent is mixed with 1 g of the above organometallic halide compound.

11. In Paragraph 8, The above composition is a color-changing composition that does not contain a binder or a thickener.

12. In Paragraph 8, The above composition is a color-changing composition having clay-like properties.

13. In Paragraph 8, A color-changing composition that maintains its shape and hardens as the anhydrous alcohol-based solvent evaporates when the above composition is dried.

14. A color-changing composition is provided that includes organometallic halide compound particles having the chemical formula A2MX4, but does not include a binder, and A scintillator film in which A is an organic onium cation, M is a metal cation, and X is a halogen anion.

15. A color-changing composition is provided that includes organometal halide compound particles having the chemical formula A2MX4, but does not include a binder, and A color-changing film or color-changing pattern, wherein A is an organic onium cation, M is a metal cation, and X is a halogen anion.

16. Blue or UV LED; and A white light-emitting diode comprising a color conversion layer disposed on the above LED and comprising a green light-emitting organic metal halide compound particle having the chemical formula A2MX4 and a red phosphor, but not comprising a binder; A white light-emitting diode in which A is an organic onium cation, M is a metal cation, and X is a halogen anion.

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