Photon up-conversion film, method for producing photon up-conversion film, photon up-conversion body, laminate, and energy conversion device

Abstract

Provided are a photon up-conversion film, a photon up-conversion body, a laminate, and an energy conversion device which are capable of highly efficient up-conversion, and methods for producing the same. A photon up-conversion film according to an embodiment of the present invention is provided with a color-developing section that contains at least a sensitizing component capable of absorbing light in a first wavelength range [lambda] 1 and a light-emitting component capable of emitting light in a second wavelength range [lambda] 2 having a shorter wavelength than the first wavelength range [lambda] 1. The relaxation time of the photon up-conversion film as measured by a spin-echo method using a time-domain nuclear magnetic resonance method (pulsed NMR) at 298 K is less than 210 ms.

Description

Technical Field

[0001] This invention relates to a photon upconversion film, a method for manufacturing a photon upconversion film, a photon upconverter, a laminate, and an energy conversion device. Background Technology

[0002] Photon upconversion (hereinafter sometimes simply referred to as "upconversion"), which converts low-energy light into high-energy light, holds promise for applications in various fields such as solar cells or solar power generation, photocatalysts, bioimaging, and optical devices. As an example of upconversion luminescence in organic materials, a technique utilizing triplet-triplet annihilation (TTA) caused by collisions between molecules in the triplet state is known. Regarding TTA-UC upconversion, a solution system in which donor and acceptor compounds are dissolved in a solvent allows for efficient energy transfer through the diffusion of donor and acceptor molecules. However, solution systems suffer from limitations in their practical applicability.

[0003] Based on the above, research and development of upconversion luminescence in the solid state is underway. However, since molecular diffusion is almost non-existent in the solid state, there is a problem of inefficient utilization of TTA. For example, although a resin membrane incorporating donor and acceptor compounds has been studied, its upconversion luminescence efficiency is insufficient.

[0004] Previous technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 5491408 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] The present invention was made to solve the aforementioned prior problems, and its main objective is to provide a photon upconversion film, a photon upconverter, a laminate, and an energy conversion device capable of high-efficiency upconversion, as well as a method for manufacturing the same.

[0009] Furthermore, the main objective of this invention is to provide a photon upconversion film, a photon upconverter, a laminate, and an energy conversion device that have high transmittance and high efficiency through optimization of the medium, as well as a method for manufacturing the same.

[0010] [Technical means to solve the problem]

[0011] [1] In one embodiment of the present invention, the photonic upconversion film includes a color-developing section. The color-developing section includes at least a sensitizing component and a luminescent component. The sensitizing component is capable of absorbing light within a first wavelength range λ1. The luminescent component is capable of emitting light within a second wavelength range λ2, which has a wavelength shorter than the first wavelength range λ1. Regarding the photonic upconversion film, the relaxation time measured by spin echo method using pulsed nuclear magnetic resonance (NMR) at 298K is less than 210 ms.

[0012] [2] As described in [1] above, the photon upconversion film may further include a matrix. The chromogenic portion is dispersed in the matrix in the form of a dispersed phase.

[0013] [3] As described in [2] above, the photon upconversion film may contain a resin.

[0014] [4] The photon upconversion film described in [3] above, wherein the resin may comprise polyethylene oxide and / or polyvinyl alcohol resin.

[0015] [5] The photon upconversion film described in any of [1] to [4] above, wherein the colorimetric part may contain a solvent with a boiling point of 80°C or higher.

[0016] [6] The photon upconversion film described in any of [1] to [5] above, wherein the colorimetric part may contain a solvent with a viscosity of 0.6 mPa·s or more at 23°C.

[0017] [7] The photon upconversion film described in any of [1] to [6] above, wherein the color rendering part may contain a monomolecular liquid crystal compound.

[0018] [8] The photon upconversion film as described in any one of [3] to [7] above, wherein 1 g of the above-described resin may contain 7.00 × 10⁻⁶ of the above-described sensitizing component. -9 mol~5.00×10 -6 mol, and the above-mentioned luminescent component 5.00 × 10 -6 mol~7.00×10 -5 mol.

[0019] [9] Another aspect of the present invention is a method for manufacturing a photon upconversion film as described in any one of [1] to [8] above, comprising the following steps: preparing an emulsion from a medium in which the above-mentioned sensitizing component and the above-mentioned luminescent component are dispersed and / or dissolved, and an aqueous solution containing a water-soluble resin; coating the emulsion onto a substrate to form a coating film; and drying the coating film.

[0020]

[10] Another embodiment of the present invention comprises a laminate having a photon upconversion film as described in any one of [1] to [8] above.

[0021]

[11] A further embodiment of the present invention provides an energy conversion device comprising a photon upconversion membrane as described in any one of [1] to [8] above.

[0022]

[12] In another further embodiment of the present invention, the photon upconverter includes a color-developing section. The color-developing section includes at least a sensitizing component and a luminescent component. The sensitizing component is capable of absorbing light within a first wavelength range λ1. The luminescent component is capable of emitting light within a second wavelength range λ2, which has a wavelength shorter than the first wavelength range λ1. Regarding this photon upconversion film, the relaxation time measured by spin echo method using time-domain nuclear magnetic resonance (pulse NMR) at 298K is less than 210 ms.

[0023] [The effects of the invention]

[0024] According to embodiments of the present invention, a photon upconversion film, a photon upconverter, a laminate, and an energy conversion device capable of high-efficiency upconversion, as well as a method for manufacturing the same, can be realized. Furthermore, a photon upconversion film, a photon upconverter, a laminate, and an energy conversion device, as well as a method for manufacturing the same, can be realized by optimizing the medium to achieve high transmittance and high-efficiency upconversion. Attached Figure Description

[0025] Figure 1 This is a conceptual diagram of energy levels that illustrates the mechanism of upconversion. Detailed Implementation

[0026] The following describes embodiments of the present invention, but the present invention is not limited to these embodiments.

[0027] A. Mechanism of photon upconversion

[0028] Reference Figure 1 The mechanism of photon upconversion is explained. First, the sensitized component (donor) absorbs incident light and, through self-excited singlet state S... D An excited triplet state T is generated by an intersystem crossing. D Next, a triplet-triplet energy transfer (TTET) occurs from the donor to the luminescent component (acceptor), generating the excited triplet T of the acceptor. A Next, through the excited triplet state T A The acceptors approach each other within a range where diffusion, collision, or energy transfer can occur, resulting in triplet-triplet annihilation (TTA). This results in the production of the higher excited singlet energy state S of the acceptor. A The higher excited singlet energy state S AIt emits upconversion light (light with energy greater than that of the excitation light).

[0029] B. Overall Structure of the Photon Upconversion Coating

[0030] The photonic upconversion film (hereinafter, sometimes referred to as an upconversion film) of an embodiment of the present invention includes a color-developing section. This color-developing section comprises at least a sensitizing component (donor) and a luminescent component (acceptor). The sensitizing component is capable of absorbing light within a first wavelength range λ1. The luminescent component is capable of emitting light within a second wavelength range λ2, which has a wavelength shorter than the first wavelength range λ1. Typically, the sensitizing component and the luminescent component are located close to each other to enable energy transfer.

[0031] Regarding such photon upconversion films, if the relaxation time measured by spin echo method using time-domain nuclear magnetic resonance (TD-NMR, pulsed NMR) at 298 K (24.85 °C) is less than 210 ms, the absolute quantum yield of the upconversion film can be improved. Therefore, upconversion films capable of high-efficiency upconversion can be realized. Furthermore, upconversion films with improved transmittance and high efficiency can be fabricated by optimizing the medium.

[0032] In one embodiment, the photonic upconversion film further comprises a matrix. The chromogenic component is dispersed in the matrix as a dispersed phase. Typically, the photonic upconversion film has an island structure.

[0033] The domain size of the colorimetric region is, for example, 0.05 μm to 10 μm, preferably 0.1 μm to 10 μm, more preferably 0.1 μm to 5.0 μm, and even more preferably 1.0 μm to 5.0 μm. The domain size of the colorimetric region is determined, for example, by observing the cross-section using a scanning electron microscope (SEM) or by observing the surface using an optical microscope. If the domain size of the colorimetric region is within such a range, the luminous efficiency of the upconversion film can be stably improved.

[0034] The content ratio of the colorimetric component in the upconversion film is, for example, 1.0 vol% to 60 vol%, preferably 5.0 vol% to 50 vol%. The content ratio of the colorimetric component is determined, for example, from a cross-sectional SEM image by any appropriate image processing. If the content ratio of the colorimetric component is within such a range, the luminous efficiency of the upconversion film can be further and more stably improved.

[0035] The thickness of the upconversion film is, for example, 5 μm to 200 μm, preferably 10 μm to 150 μm, and more preferably 15 μm to 100 μm. If the thickness of the upconversion film is within such a range, the colorimetric portion can be well dispersed throughout the thickness direction of the film, and the desired upconversion can be stably achieved.

[0036] C. Detailed information on photonic upconversion films

[0037] As described above, regarding the photonic upconversion film, the relaxation time (mean relaxation time) measured by TD-NMR at 298K (24.85°C) is less than 210 ms, preferably less than 150 ms, more preferably less than 90 ms, and even more preferably less than 80 ms. As a method for measuring the relaxation time (mean relaxation time), spin echo method is used, for example. The lower limit of the relaxation time (mean relaxation time) measured by TD-NMR at 298K is typically 20 μs, and typically 6 μs. Furthermore, details of the method for measuring the relaxation time (mean relaxation time) will be described in the examples described later.

[0038] If the relaxation time obtained by TD-NMR at 298 K falls within this range, it is speculated that the chromogenic portion contained in the upconversion film exists in a form capable of efficient energy transfer at 298 K. Furthermore, it is speculated that a highly efficient upconversion luminescent material can be obtained by reducing energy loss caused by non-radiative deactivation in the chromogenic portion. Therefore, molecular diffusion between the sensitizing and luminescent components can occur in the chromogenic portion, enabling efficient energy transfer and reception.

[0039] In one embodiment, the colorimetric section includes a medium capable of dissolving and / or dispersing the sensitizing and luminescent components. Therefore, molecular diffusion of the sensitizing and luminescent components can be readily achieved in the colorimetric section, further improving the luminescence efficiency of the upconversion film.

[0040] D. The medium for the color development section

[0041] Examples of media include, for example, monomolecular liquid crystal compounds and / or solvents. Media can be used alone or in combination.

[0042] If the colorimetric part contains a single-molecule liquid crystal compound, the absolute quantum yield of the upconversion film can be further improved.

[0043] Monomolecular liquid crystal compounds can exhibit liquid crystal properties or crystallinity at 298 K (24.85 °C). These compounds can be nematic, smectic, or cholesteric. Nematic liquid crystal compounds are preferred.

[0044] Monomolecular liquid crystal compounds that exhibit liquid crystal properties at 298K (hereinafter, sometimes referred to as room temperature liquid crystal compounds) are typically able to dissolve both the sensitizing and luminescent components.

[0045] Examples of room-temperature liquid crystal compounds include: cyanobiphenyl derivatives, cyanophenylcyclohexane esters, alkoxyphenyl diphenylacetylene derivatives, and Schiff bases. Room-temperature liquid crystal compounds can be used alone or in combination.

[0046] Among room-temperature liquid crystal compounds, the following are preferred examples: cyanobiphenyl compounds, cyanophenylcyclohexane esters, and alkoxyphenyldiphenylacetylene compounds.

[0047] Examples of cyanobiphenyls include: 4-cyano-4'-pentylbiphenyl, 4-cyano-4'-hexylbiphenyl, 4-cyano-4'-heptylbiphenyl, 4-cyano-4'-n-octylbiphenyl, and other 4-cyano-4'-alkylbiphenyls.

[0048] Examples of cyanophenylcyclohexane esters include 4-cyano-4'-pentylphenylcyclohexane ester, 4-cyano-4'-butylphenylcyclohexane ester, 4-cyano-4'-propylphenylcyclohexane ester, and other 4-cyano-4'-alkylphenylcyclohexane esters.

[0049] Examples of alkoxyphenyl diphenylacetylenes include: 4-ethoxy-4'-butylphenyl diphenylacetylene, 4-methoxy-4'-ethylphenyl diphenylacetylene, 4-butoxy-4'-propylphenyl diphenylacetylene, and other 4-alkoxy-4'-alkylphenyl diphenylacetylenes.

[0050] Monomolecular liquid crystal compounds that exhibit crystallinity at 298 K (hereinafter sometimes referred to as high-temperature liquid crystal compounds) can either solidify or disperse the sensitizing and luminescent components at 298 K (24.85 °C).

[0051] Examples of high-temperature liquid crystal compounds include: cyanophenylcyclohexane derivatives, cyanophenyl esters, alkoxyphenyl esters, alkoxyphenylcyclohexane esters, and alkoxycyanobiphenyl derivatives. High-temperature liquid crystal compounds can be used alone or in combination.

[0052] Among high-temperature liquid crystal compounds, the following are preferred examples: cyanophenylcyclohexane derivatives, cyanophenyl esters, alkoxyphenyl esters, alkoxyphenylcyclohexane esters, and alkoxycyanobiphenyl derivatives.

[0053] Examples of cyanophenylcyclohexanes include 4-cyano-4'-pentylphenylcyclohexane, 4-cyano-4'-propylphenylcyclohexane, and other 4-cyano-4'-alkylphenylcyclohexanes.

[0054] Examples of cyanophenyl esters include 4-cyano-4'-nonylphenyl ester, 4-cyano-4'-ethylphenyl ester, 4-cyano-4'-butylphenyl ester, and other 4-cyano-4'-alkylphenyl esters.

[0055] Examples of alkoxyphenyl esters include 4-pentyl-4'-hexyloxyphenyl ester, 4-pentyl-4'-methoxyphenyl ester, 4-ethyl-4'-hexyloxyphenyl ester, and other 4-alkyl-4'-alkoxyphenyl esters.

[0056] Examples of alkoxyphenylcyclohexane esters include 4-methoxy-4'-pentylphenylcyclohexane ester, 4-ethoxy-4'-butylphenylcyclohexane ester, and 4-ethoxy-4'-propylphenylcyclohexane ester.

[0057] Examples of alkoxycyanobiphenyls include: 4-cyano-4'-pentoxybiphenyl, 4-cyano-4'-butoxybiphenyl, 4-cyano-4'-ethoxybiphenyl, etc.

[0058] The solvent is typically liquid at 298 K (24.85 °C). Alternatively, the solvent may be solid at 298 K (24.85 °C), provided it is a material with a melting point that becomes liquid at the temperature in question during the fabrication of the upconversion film or upconversion body, or a material whose melting point can be lowered by mixing with an organic solvent. The solvent is typically capable of dissolving both the sensitizing and luminescent components.

[0059] The viscosity of the solvent at 23°C is, for example, 0.6 mPa·s or higher, preferably 4.0 mPa or higher. The viscosity of the solvent can be measured using any suitable viscosity / viscoelasticity measuring device (e.g., a rheometer, trade name "RS-600", manufactured by HAAKE Corporation), as the solution viscosity (mPa·s) of the coating liquid at a shear rate of 800 rpm under conditions of 23°C.

[0060] The boiling point of the solvent is, for example, 60°C or higher, preferably 80°C or higher, more preferably 150°C or higher, and even more preferably 200°C or higher. The upper limit of the boiling point of the solvent is typically 300°C, and typically 400°C. Furthermore, when multiple solvents are used as a medium, the boiling point of the mixed solvent is defined as the temperature at which a 95% weight reduction occurs when the mixed solvent is heated in TG / DTA (Thermogravimetry / Differential Thermal Analysis) at a rate of 10°C / min from 30°C to 400°C.

[0061] When the viscosity and / or boiling point of the solvent contained in the colorimetric part are within such a range, the solvent is not easily volatilized during the process, which can suppress energy loss caused by non-radiative deactivation. Therefore, the absolute quantum yield of the upconversion film can be further improved.

[0062] Examples of solvents include organic solvents, and more specifically, phthalates, glycerol, triglyceride compounds, and ionic liquids. Solvents can be used alone or in combination. Phthalate esters and triglyceride compounds are preferred examples of solvents.

[0063] Examples of phthalate esters include dimethyl phthalate, dibutyl phthalate, and dioctyl phthalate.

[0064] Examples of triglyceride compounds include: tridecanoic acid glyceride (1,2,3-tridecanoylglycerol), triacetic acid glyceride (glycerol triacetate), tricaprylic acid glyceride (tricaprylic glycerol triacetate), and trihexanoic acid glyceride (trihexanoic glycerol triacetate).

[0065] In such a medium, room-temperature liquid crystal compounds are preferred. When the medium contains a room-temperature liquid crystal compound, the luminous efficiency of the upconversion film can be further improved.

[0066] The medium may contain additives. Examples of additives include fatty acid oils such as MCT (Medium Chain Triglyceride) oil; and saturated hydrocarbons such as hexadecane and liquid paraffin. Unlike solvents, additives are defined as materials with low pigment solubility. Low pigment solubility means that when the pigment is added to the additive and mixed at room temperature and pressure (23°C, 0.1 MPa), the pigment concentration is, for example, below 0.1 mM. By including additives in the medium, the viscosity, refractive index, or phase transition temperature of the medium can be appropriately adjusted.

[0067] E. Matrix

[0068] Materials that can be used as a matrix include, for example, resin and glass.

[0069] In one embodiment, the matrix comprises a resin. The resin is typically a water-soluble resin.

[0070] As a water-soluble resin, any suitable water-soluble resin can be used, as long as it forms a matrix. Specific examples of water-soluble resins include: polystyrene sulfonates, polyethylene oxide, polyethyleneimine, polyvinyl alcohol-based resins, and cellulose-based resins. For example, sodium polystyrene sulfonate can be used as a polystyrene sulfonate. For example, polyethyleneimine hydrochloride can be used as a polyethyleneimine. For example, polyvinyl alcohol, amine-modified polyvinyl alcohol, and carboxylic acid-modified polyvinyl alcohol can be used as polyvinyl alcohol. For example, hydroxyethyl cellulose can be used as a cellulose-based resin.

[0071] Among such water-soluble resins, preferred examples include: polyethylene oxide and polyvinyl alcohol resins, with polyvinyl alcohol resins being more preferred examples.

[0072] When the resin constituting the matrix contains polyethylene oxide and / or polyvinyl alcohol-based resins, the luminous efficiency of the upconversion membrane can be stably improved.

[0073] The distance Ra between the resin constituting the matrix and the Hansen solubility parameter (HSP) of the sensitizing and luminescent components is, for example, 10 (MPa). 1 / 2 The above, for example, is 11 (MPa). 1 / 2 The preferred value is 12 MPa. 1 / 2 The above is preferred, with 15 MPa being more ideal. 1 / 2 The above is further optimized to 18 (MPa). 1 / 2 That's all. On the other hand, the distance Ra between the resin constituting the matrix and the HSP of the sensitizing component and the luminescent component is, for example, 25 (MPa). 1 / 2 Preferably, it is 23 MPa. 1 / 2 The preferred value is 21 MPa. 1 / 2 The following applies. A HSP distance Ra within this range indicates that the resin constituting the matrix has a low affinity for both the sensitizing and luminescent components. As a result, the migration of the sensitizing and luminescent components into the matrix is ​​significantly suppressed, allowing them to exist stably in the chromogenic region.

[0074] HSP divides the Hildebrand solubility parameter into three components: dispersion force (δD), permanent dipole intermolecular force (δP), and hydrogen bonding force (δH), represented by vectors plotted in three-dimensional space. Parameters with similar vectors can be judged to have higher solubility. That is, the similarity of solubility can be determined based on their HSP distance Ra. The definition and calculation of HSP are described in Charles M. Hansen's *Hansen Solubility Parameters: A Users Handbook* (CRC Press, 2007). For HSP values, there are known values ​​for various resins and solvents, which can be used directly, or values ​​calculated using computer software, namely HSPiP (Hansen Solubility Parameters in Practice). Furthermore, HSPiP also has a database of resins and solvents.

[0075] Resin (HSP value: δD) R δP R δH R ) with sensitizing or luminescent components (HSP value: δD) C δP C δH C The HSP distance Ra of ) can be calculated using equation (1).

[0076] Ra={4×(δD R -δD C ) 2 +(δP R -δPC ) 2 +(δH R -δH C ) 2} 1 / 2 ···(1)

[0077] In equation (1), δD R δP represents the dispersion force of the resin. R δH represents the permanent dipole intermolecular force of the resin. R δD represents the hydrogen bonding force of the resin. C δP represents the dispersion force of the sensitizing or luminescent component. C δH represents the permanent dipole intermolecular force of the sensitizing or luminescent component. C This indicates the hydrogen bonding force of the sensitizing or luminescent component.

[0078] F. Sensitizing components and luminescent components

[0079] F-1. Sensitizing ingredient

[0080] As described in section A, the sensitizing component absorbs light (incident light), undergoes an intersystem crossing from a self-excited singlet state to an excited triplet state, and then undergoes a triplet-triplet energy transfer to the luminescent component. Examples of sensitizing components include compounds with porphyrin, phthalocyanine, or fullerene structures. Such compounds may contain metal atoms within their molecules. Examples of metal atoms include: Pt, Pd, Zn, Ru, Re, Ir, Os, Cu, Ni, Co, Cd, Au, Ag, Sn, Sb, Pb, P, and As. Pt, Pd, and Os are preferred. Furthermore, specific examples of compounds that can function as sensitizing components are described later in section F-3.

[0081] The sensitizing component can be quantum dots. Quantum dots can be made of any suitable material. Preferably, quantum dots may contain inorganic materials, more preferably inorganic conductor materials or inorganic semiconductor materials. Examples of semiconductor materials include, for example, semiconductors of groups II-VI, III-V, IV-VI, and IV. Specific examples include: Si, Ge, Sn, Se, Te, B, C (including diamond), P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdS eZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si3N4, Ge3N4, Al2O3, (Al, Ga, In)2(S, Se, Te)3, Al2CO, and their combinations (complexes).

[0082] The preferred sensitizing component is 7.00 × 10⁻¹⁰ relative to 1 g of matrix. -9 mol~5.00×10 -6 mol, more preferably 1.00 × 10 -8 mol~3.00×10 -6 mol, more preferably 4.50 × 10 -8 mol~2.00×10 -6 The mol ratio is included in the upconversion membrane.

[0083] If the content of the sensitizing component is within this range, triplet excitons can be sufficiently generated, which can improve the efficiency of achieving triplet-triplet annihilation.

[0084] F-2. Luminescent component

[0085] According to the mechanism described in section A, the luminescent component, being a self-sensitizing component, receives a triplet-triplet energy transfer, generating an excited triplet state. Furthermore, the luminescent molecules in the excited triplet state approach each other at a distance sufficient for diffusion, collision, or energy transfer, resulting in triplet-triplet annihilation and the generation of a higher-energy excited singlet state. Various compounds with fused aromatic rings are known as luminescent components. Specific examples include compounds with naphthalene, anthracene, pyrene, perylene, tetraphenyl, Bodipyrromethene, and diketopyrrolopyrrole structures. Further specific examples of compounds that can function as luminescent components are described later in section F-3.

[0086] The luminescent component is preferably 5.00 × 10⁻¹⁰ relative to 1 g of matrix. -6 mol~7.00×10 -5 mol, more preferably 6.00 × 10 mol. -6 mol~6.00×10 -5 mol, more preferably 7.00 × 10 -6 mol~5.00×10 -5 The mol ratio is included in the upconversion membrane.

[0087] If the content of the luminescent component is within such a range, the triplet excitons received by the self-sensitized pigment can diffuse sufficiently between the molecules of the luminescent component.

[0088] The molar ratio of the sensitizing component to the luminescent component (sensitizing component: luminescent component) is, for example, 1:10 to 1:7000, preferably 1:25 to 1:3000, more preferably 1:30 to 1:200, and even more preferably 1:35 to 1:100. When the ratio is within this range, the triplet excitons generated by the sensitizing component move efficiently to the luminescent pigment, minimizing deactivation between luminescent pigments and effectively achieving triplet-triplet annihilation.

[0089] F-3. Combination of sensitizing and luminescent components

[0090] The preferred combination of sensitizing and luminescent components corresponding to the wavelengths of the incident and upconversion light is shown below.

[0091] The sensitizing component that absorbs light in the wavelength range λ1 of 510nm to 550nm is the following compound, and the luminescent component that emits light in the wavelength range λ2 of 400nm to 500nm is the following compound. This combination can upconvert green light into blue light.

[0092] <Sensitizing ingredients>

[0093] [Chemical Formula 1]

[0094]

[0095] <Luminous Components>

[0096] [Chemical Formula 2]

[0097]

[0098] [Chemical Formula 3]

[0099]

[0100] The sensitizing component that absorbs light in the wavelength range λ1 of 610nm to 650nm is the following compound, and the emitting component that emits light in the wavelength range λ2 of 500nm to 600nm is the following compound. This combination can upconvert red light into yellow-green light.

[0101] <Sensitizing ingredients>

[0102] [Chemical Formula 4]

[0103]

[0104] <Luminous Components>

[0105] [Chemical Formula 5]

[0106]

[0107] The sensitizing component that absorbs light in the wavelength range λ1 of 700nm to 810nm is the following compound, and the emitting component that emits light in the wavelength range λ2 of 500nm to 700nm is the following compound. This combination can upconvert near-infrared light into visible light (red to green light).

[0108] <Sensitizing ingredients>

[0109] [Chemical Formula 6]

[0110]

[0111] <Luminous Components>

[0112] [Chemical Formula 7]

[0113]

[0114] [Chemical Formula 8]

[0115]

[0116] The sensitizing component that absorbs light in the wavelength range λ1 of 700nm to 730nm is the following compound, and the emitting component that emits light in the wavelength range λ2 of 400nm to 500nm is the following compound. This combination can upconvert near-infrared light into visible light (blue light).

[0117] <Sensitizing ingredients>

[0118] [Chemical Formula 9]

[0119]

[0120] <Luminous Components>

[0121] [Chemical Formula 10]

[0122]

[0123] The sensitizing component that absorbs light in the wavelength range λ1 (410 nm to 500 nm) is the following compound, and the luminescent component that emits light in the wavelength range λ2 (300 nm to 400 nm) is the following compound. This combination can upconvert blue light into ultraviolet light.

[0124] <Sensitizing ingredients>

[0125] [Chemical Formula 11-1]

[0126]

[0127] [Chemical Formula 11-2]

[0128]

[0129] <Luminous Components>

[0130] [Chemical Formula 12-1]

[0131]

[0132] [Chemical Formula 12-2]

[0133]

[0134] [Chemical Formula 12-3]

[0135]

[0136] The sensitizing component that absorbs light in the wavelength range λ1 near 630nm to 640nm (e.g., 635nm) is quantum dots (CdSe, CdSe / ZnS), and the luminescent component that emits light in the wavelength range λ2 near 440nm to 460nm (e.g., 450nm) is the following compound. This combination can upconvert near-infrared light into visible light (blue light).

[0137] <Luminous Components>

[0138] [Chemical Formula 13]

[0139]

[0140] The sensitizing component that absorbs light in the wavelength range λ1 near 970nm to 990nm (e.g., 980nm) is quantum dots (PbSe, PbS / CdS), and the luminescent component that emits light in the wavelength range λ2 near 550nm to 570nm (e.g., 560nm) is the following compound. This combination can upconvert near-infrared light into visible light (green light).

[0141] <Luminous Components>

[0142] [Chemical Formula 14]

[0143]

[0144] G. Surfactants

[0145] The photon upconversion film may further contain a surfactant. When the photon upconversion film contains a surfactant, the dispersibility of the chromogenic portion in the matrix can be improved. Examples of surfactants include cationic surfactants such as cetyltrimethylammonium bromide (CTAB), anionic surfactants, and nonionic surfactants, with CTAB being a preferred example.

[0146] The ratio of surfactant added relative to 100 parts by mass of medium is, for example, 0 to 200 parts by mass, preferably 1 to 50 parts by mass.

[0147] H. Manufacturing method of photonic upconversion film

[0148] In one embodiment, the method for manufacturing a photonic upconversion film includes the following steps: preparing an emulsion from an aqueous solution containing a water-soluble resin, and a solution or dispersion of a sensitizing component and a luminescent component (hereinafter, sometimes collectively referred to as "pigment solution, etc."); coating the emulsion onto a substrate to form a coating film; and drying the coating film. Each step will be described in detail below.

[0149] <Preparation of Emulsions>

[0150] In the preparation of the emulsion, firstly, a pigment solution, etc., is prepared according to the required upconversion membrane.

[0151] When manufacturing an upconversion membrane (UC membrane) using a medium that is fluid at 298K (24.85°C), an organic solvent is added to the medium described in section C above (specifically, a room-temperature liquid crystal compound and / or solvent) as needed, followed by the addition of the sensitizing component and the luminescent component described in section F above, and then the mixture is stirred.

[0152] Adding an organic solvent to the medium can improve the solubility of the sensitizing and luminescent components. Especially when the fluid medium is a room-temperature liquid crystal compound, it is preferable to add an organic solvent to the room-temperature liquid crystal compound.

[0153] As organic solvents, volatile solvents can be used, for example. Specific examples of such solvents include: ethers such as tetrahydrofuran; halogenated hydrocarbons such as chloroform and dichloromethane; and toluene. Organic solvents can be used alone or in combination. Among such organic solvents, ethers are preferred, and tetrahydrofuran is more preferred.

[0154] The ratio of organic solvent added relative to 100 parts by mass of the fluid medium is, for example, 0 to 200 parts by mass, preferably 80 to 120 parts by mass.

[0155] Alternatively, the above-mentioned additives can be added to the medium. The additives can be added to the medium together with the organic solvent, or they can be added to the medium alone. When additives are added to the medium, the viscosity, refractive index, and / or phase transition temperature of the medium can be appropriately adjusted.

[0156] The additive ratio is, for example, 0 to 200 parts by mass relative to 100 parts by mass of the medium, preferably 5 to 100 parts by mass.

[0157] In addition, various liquid crystal compounds, organic solvents, and other additives can be mixed in any ratio.

[0158] In addition, when using a high-temperature liquid crystal compound to manufacture an upconversion film (a UC film containing a high-temperature liquid crystal compound), after heating the high-temperature liquid crystal compound described in item C above to make it into a liquid crystal state, the organic solvent described above is added as needed, and the sensitizing component and luminescent component described in item F above are added, and the mixture is stirred.

[0159] The heating temperature of high-temperature liquid crystal compounds can be arbitrarily and appropriately adjusted according to the specific high-temperature liquid crystal compound. For example, the heating temperature of a high-temperature liquid crystal compound is the phase transition temperature T between crystallization and liquid crystal. K-N The above, and the phase transition temperature T between the liquid crystal and the isotropic liquid. N-I the following.

[0160] By adding an organic solvent to a high-temperature liquid crystal compound in a liquid crystal state, the solubility of the sensitizing and luminescent components can be improved. The ratio of the organic solvent added relative to 100 parts by mass of the high-temperature liquid crystal compound is, for example, 0 to 200 parts by mass, preferably 80 to 120 parts by mass.

[0161] These methods enable the preparation of pigment solutions and similar materials suitable for manufacturing UC membranes with relaxation times less than 210 ms. Pigment solutions and similar materials are typically media in which sensitizing and luminescent components are dissolved and / or dispersed.

[0162] The concentration of the sensitizing component in these pigment solutions can be, for example, 0.001 mM to 1 mM, and the concentration of the luminescent component can be, for example, 1 mM to 50 mM.

[0163] In addition, prepare an aqueous solution of the water-soluble resin described in section E above. The concentration of the aqueous solution may be, for example, 3% to 20% by weight, and for example, 5% to 10% by weight.

[0164] Next, the aqueous solution of the water-soluble resin is mixed with a pigment solution, etc., such that the amounts of the sensitizing component and the luminescent component relative to the water-soluble resin (matrix) are within the desired range described in section F above. More specifically, the aqueous solution of the water-soluble resin and the pigment solution, etc., are mixed and emulsified using a homogenizer. At this time, the aforementioned surfactant is added as needed. Thus, droplets of the pigment solution, etc., are suitably dispersed in the aqueous solution of the water-soluble resin, and an emulsion can be prepared. The obtained emulsion can also be defoamed as needed. In addition, volatile components (e.g., organic solvents) contained in the obtained emulsion can be removed by vacuum distillation. This can increase the concentration of the sensitizing component and the luminescent component in the emulsion. The volume fraction of the emulsion particles is, for example, 5% to 60%. The average particle size of the emulsion particles is, for example, 0.1 μm to 10 μm. If the volume fraction and / or average particle size of the emulsion particles are within such a range, a colorimetric portion having the desired size can be formed in the form of a dispersed phase in the upconversion membrane.

[0165] <Coating Formation and Drying>

[0166] Next, the emulsion obtained above is coated onto a substrate to form a coating film. Typical substrates include resin sheets or glass. Any suitable resin can be used as the resin constituting the resin sheet. Specific examples include: polyimide resins, cellulose resins such as triacetyl cellulose (TAC), polyester resins such as polyethylene terephthalate (PET), polyvinyl alcohol resins, polycarbonate resins, polyamide resins, polyethersulfone resins, polysulfone resins, polystyrene resins, polynorbornene resins, polyolefin resins, (meth)acrylic resins, acetate resins, and other transparent resins. Additionally, thermosetting or UV-curing resins such as (meth)acrylic resins, urethane resins, (meth)acrylate urethane resins, epoxy resins, and silicone resins can also be included. Furthermore, glassy polymers such as siloxane polymers can also be included.

[0167] Any suitable coating method can be used. Specific examples include: roller coating, spin coating, wire rod coating, dip coating, die coating, curtain coating, spray coating, and blade coating (such as corner wheel coating). Alternatively, a cylindrical film-forming machine can be used to form the coating. In this case, the film-forming roller (drying roller) of the cylindrical film-forming machine functions as a substrate. The film-forming roller (drying roller) is made of metals such as nickel, chromium, copper, iron, or stainless steel. The temperature of the emulsion during coating can be, for example, 10°C to 60°C. The thickness of the coated film can be adjusted so that the thickness of the obtained upconversion film is within the desired range (e.g., 5 μm to 200 μm) described in section B above. The thickness of the coated film can be, for example, 100 μm to 1000 μm.

[0168] Next, the coating is dried. Drying is carried out using any suitable apparatus (e.g., an oven). The drying temperature can be, for example, 60°C to 90°C, and the drying time can be, for example, 20 minutes to 60 minutes. Through drying, a dried coating film with substantially the same thickness as the obtained upconversion film can be obtained. The dried coating film can typically be allowed to cool naturally to room temperature (23°C).

[0169] Upconversion membranes are prepared using the methods described above. The upconversion membrane can be peeled off from the substrate, or it can be used as a laminate with the substrate without peeling it off.

[0170] I. Applications of photon upconversion films

[0171] The upconversion membranes described in items A through H above can be used in any suitable industrial products. Examples of industrial products include laminates and energy conversion devices. Therefore, one embodiment of the present invention also includes laminates and energy conversion devices using such upconversion membranes.

[0172] The laminate includes the upconversion membrane described in items A to H above, and any suitable membrane (layer) laminated on the upconversion membrane.

[0173] The energy conversion device shall at least have the upconversion membrane described in items A to H above, and may also have any suitable configuration in addition to the upconversion membrane.

[0174] I-1. Laminated Structure

[0175] Alternatively, a first protective layer and a second protective layer can be disposed on the light incident surface and light exit surface of the upconversion film, respectively, in the laminate. The first and second protective layers can also be omitted depending on the purpose. Furthermore, any suitable optical component can be disposed between the upconversion film and the first protective layer, and / or between the upconversion film and the second protective layer, as long as the effects of the present invention are achieved.

[0176] In one embodiment, the laminate has at least one configuration in which the first protective layer to the second protective layer are integrated. Here, "integrated from the first protective layer to the second protective layer" means that the components constituting the laminate from the first protective layer to the second protective layer are integrally connected. Integration can be achieved, for example, by bonding adjacent components together via adhesive layers such as adhesive layers or bonding agents. Alternatively, layers with different functions, such as outer coatings, can be directly applied to the photonic upconversion film. Preferably, integration is achieved via adhesive layers from the first protective layer, the upconversion film, the second protective layer, up to any protective layer.

[0177] The outer coating can be made of any suitable material. Examples of materials that can be used for the outer coating include acrylic resins and epoxy resins.

[0178] In another embodiment, the laminate has a configuration where the first protective layer and the second protective layer are not integrated. Here, "the first protective layer and the second protective layer are not integrated" means that at least one component comprising the laminate from the first protective layer to the second protective layer is simply stacked on one or two adjacent components. For example, the laminate in this embodiment may have a configuration where the first protective layer, the upconversion film, and the second protective layer are arranged sequentially without an adhesive layer. Alternatively, for example, the laminate in this embodiment may have a configuration where the first protective layer to the upconversion film is integrated via an adhesive layer, and the second protective layer is disposed on the light-emitting side of the integrated laminate without an adhesive layer. Alternatively, for example, the laminate in this embodiment may have a configuration where the upconversion film to the second protective layer is integrated via an adhesive layer, and the first protective layer is disposed on the light-incident side of the integrated laminate without an adhesive layer.

[0179] I-2. Protective layer

[0180] The first and second protective layers are each formed from any suitable membrane that can be used as an upconversion membrane. Specific examples of materials that form the main component of the membrane include: cellulose resins such as triacetyl cellulose (TAC), or transparent resins such as polyester, polyvinyl alcohol, polycarbonate, polyamide, polyimide, polyethersulfone, polysulfone, polystyrene, polynorbornene, polyolefin, (meth)acrylic acid, and acetate. Additionally, examples include: thermosetting or UV-curing resins such as (meth)acrylic acid, urethane, (meth)acrylate urethane, epoxy, and silicone, as well as inorganic materials such as glass or silica. Furthermore, examples include, for instance, vitreous polymers such as siloxane polymers. Additionally, the polymer membrane described in Japanese Patent Application Publication No. 2001-343529 (WO01 / 37007) can also be used. As the material for this membrane, for example, a resin composition containing a thermoplastic resin having substituted or unsubstituted imine groups in the side chains, and a thermoplastic resin having substituted or unsubstituted phenyl and nitrile groups in the side chains can be used. Examples include resin compositions containing an alternating copolymer of isobutylene and N-methylcis-imide and an acrylonitrile-styrene copolymer. The polymer membrane can be, for example, an extruded product of the above resin composition.

[0181] J. Photon upconverter

[0182] The upconversion membrane is described in detail in sections A through H above. However, there are no restrictions on the shape of the membrane, as long as it can perform upconversion in the solid state.

[0183] Photon upconverters exist in a solid state at room temperature (23°C) and atmospheric pressure (0.1 MPa). Examples of possible shapes for photon upconverters include crystals, powders, and gels.

[0184] Regarding photon upconverters, except in solution conditions, they will be described in the same way as upconversion films. Therefore, the description of photon upconverters is omitted.

[0185] Example

[0186] The present invention will now be specifically described through examples, but the present invention is not limited to these examples. Furthermore, unless otherwise specified, "parts" and "%" in the examples are based on weight.

[0187] <Example 1>

[0188] 1. Preparation of DMP solutions containing sensitizing and luminescent components.

[0189] Inside a glove box, octaethylporphyrin platinum (PtOEP: hereinafter chemical formula) as the sensitizing component and 9,10-diphenylanthracene (DPA: hereinafter chemical formula) as the luminescent component were dissolved in dimethyl phthalate (DMP) to prepare DMP solutions of the sensitizing and luminescent components. The concentration of the sensitizing component in the solution was 2.39 × 10⁻⁶. -7 M, the concentration of the luminescent component is 4.78 × 10⁻⁶. -5 M. That is, the molar ratio of sensitizing component to luminescent component is 1:200. The prepared solution is sealed in vials for storage before the emulsification process.

[0190] <Sensitizing ingredients>

[0191] [Chemical Formula 15]

[0192]

[0193] <Luminous Components>

[0194] [Chemical Formula 16]

[0195]

[0196] 2. Emulsion Preparation

[0197] Add 0.4 ml of the solution obtained above to 5 g of a 9% (w / w) aqueous solution of polyvinyl alcohol (PVA). While injecting the solution through a 0.75 mm inner diameter tube, stir using a homogenizer (17500 rpm) until a complete emulsion is formed. Purge the resulting emulsion with argon gas for approximately 2 minutes, and then stir using a THINKY mixer at mixing mode (2000 rpm) for 5 minutes, followed by degassing mode (2200 rpm) for 5 minutes. This method prepares the emulsion. Furthermore, the PVA used has a degree of polymerization of 1700 and a saponification degree of 99%.

[0198] 3. Formation of the upconversion membrane

[0199] Using a coating apparatus, the emulsion obtained above was coated onto a polyimide film (substrate) to a thickness of 700 μm. The coating / polyimide film laminate was dried in a constant temperature bath at 80°C for 30 minutes. After drying, the laminate was allowed to cool naturally to room temperature (23°C). Finally, the dried coating was peeled off from the polyimide film to obtain an upconversion film (63 μm thick). Furthermore, subsequent processes following the emulsion preparation were carried out in air in a light-protected environment (light only in a light-protected chamber).

[0200] <Example 2>

[0201] The DMP solution of the sensitizing and luminescent components was replaced with a crystalline solution of the sensitizing and luminescent components prepared as follows, and the upconversion membrane was obtained in the same manner as in Example 1.

[0202] At room temperature (23°C), 100 parts by mass of tetrahydrofuran (THF) were added to 100 parts by mass of 5CB (4-cyano-4'-pentylbiphenyl), and the mixture was stirred and mixed to prepare a liquid crystal solvent. Then, PtOEP, as the sensitizing component, and DPA, as the luminescent component, were dissolved in the liquid crystal solvent to prepare a liquid crystal solution containing both the sensitizing and luminescent components.

[0203] <Example 3>

[0204] The upconversion membrane was obtained in the same manner as in Example 2, except that 5CB was replaced with 7CB (4-cyano-4'-heptylbiphenyl).

[0205] <Example 4>

[0206] The DMP solution of the sensitizing and luminescent components was replaced with a crystalline solution of the sensitizing and luminescent components prepared as follows, and the upconversion membrane was obtained in the same manner as in Example 1.

[0207] 100 parts by mass of 5OCB (4-cyano-4'-pentoxybiphenyl) were heated to 60°C in a hot water bath to induce a liquid crystal state. 100 parts by mass of tetrahydrofuran were then added, and the mixture was stirred and mixed to prepare a liquid crystal solvent. Next, PtOEP (as a sensitizing component) and DPA (as a luminescent component) were dissolved in the liquid crystal solvent to prepare a liquid crystal solution containing both the sensitizing and luminescent components.

[0208] <Example 5>

[0209] The PVA aqueous solution was replaced with a polyethylene oxide (PEO) aqueous solution (molecular weight 200,000) (9% by mass), and the upconversion membrane was obtained in the same manner as in Example 2.

[0210] <Example 6>

[0211] The sensitizing component was changed to meso-tetraphenyl-tetraanthroporphyrin palladium (PdTPTAP: hereinafter the chemical formula), and the luminescent component was changed to rubrene (hereinafter the chemical formula). Otherwise, the upconversion membrane was obtained in the same manner as in Example 2. The concentration of PdTPTAP in the solution was set to 0.554 mM, and the concentration of rubrene was set to 20 mM. That is, the molar ratio of sensitizing component to luminescent component was set to 1:36.

[0212] <Sensitizing ingredients>

[0213] [Chemical Formula 17]

[0214]

[0215] <Luminous Components>

[0216] [Chemical Formula 18]

[0217]

[0218] <Example 7>

[0219] At room temperature (23°C), PtOEP as a sensitizing component, DPA as a luminescent component, 100 parts by weight of tetrahydrofuran (THF), and 5 parts by weight of MCT oil were added to 100 parts by weight of 5CB (4-cyano-4'-pentylbiphenyl) and stirred to prepare a liquid crystal solvent. The liquid crystal solution was then added to 1 mL of a 1% by weight CTAB aqueous solution (surfactant aqueous solution) and stirred using an ultrasonic homogenizer to prepare an emulsion solution. 1.8 mL of the solution obtained above was added to 5 g of a 9% by weight polyvinyl alcohol (PVA) aqueous solution. The subsequent steps were the same as in Example 1 to obtain the upconversion membrane.

[0220] <Example 8>

[0221] The upconversion membrane was obtained in the same manner as in Example 7, except that 5CB was replaced with PCH5CN (4-cyano-4'-pentylphenylcyclohexane).

[0222] <Example 9>

[0223] The upconversion membrane was obtained in the same manner as in Example 7, except that 5CB was replaced with 5OCB (4-cyano-4'-pentoxybiphenyl).

[0224] <Example 10>

[0225] The upconversion membrane was obtained in the same manner as in Example 7, except that 5 parts by mass of MCT oil were replaced with 5 parts by mass of hexadecane.

[0226] <Example 11>

[0227] The upconversion membrane was obtained in the same manner as in Example 7, except that 5 parts by weight of MCT oil were replaced with 5 parts by weight of liquid paraffin.

[0228] <Example 12>

[0229] The sensitizing component was changed to meso-tetraphenyl-tetraanthraphenoporphyrin palladium (PdTPTAP: the above chemical formula), and the luminescent component was changed to rubrene (the above chemical formula). Otherwise, the upconversion membrane was obtained in the same manner as in Example 7. The concentrations were the same as in Example 6.

[0230] <Example 13>

[0231] The upconversion film was obtained in the same manner as in Example 2, except that 5CB was replaced with ZLI1052 (a mixed liquid crystal of PE105 (4-pentylphenyl 4-methoxybenzoate) and PE605 (4-pentylphenyl 4-hexyloxybenzoate)).

[0232] <Example 14>

[0233] The upconversion film was obtained in the same manner as in Example 2, except that 5CB was replaced with ZLI1132 (a mixed liquid crystal of PCH-3CN (4-cyano-4'-propylphenylcyclohexane), PCH-5CN (4-cyano-4'-pentylphenylcyclohexane), PCH-7CN (4-cyano-4'-phenylcyclohexane), and BCH-5CN (4-cyano-4'-pentylbiphenylcyclohexane).

[0234] <Example 15>

[0235] The 5CB was replaced with ZLI1083 (a mixed liquid crystal of PCH-3CN (4-cyano-4'-propylphenylcyclohexane), PCH-5CN (4-cyano-4'-pentylphenylcyclohexane), and PCH-7CN (4-cyano-4'-phenylcyclohexane), and the upconversion film was otherwise obtained in the same manner as in Example 2.

[0236] <Example 16>

[0237] The upconversion film was otherwise obtained in the same manner as in Example 2, except that 5CB was replaced with E7 (a mixed liquid crystal of 5CB (4-cyano-4'-pentylbiphenyl), 7CB (4-cyano-4'-heptylbiphenyl), 8OCB (4-cyano-4'-n-octyloxybiphenyl), and 5CT (4-cyano-4'-pentyl-p-terphenyl).

[0238] <Example 17>

[0239] The upconversion film was obtained in the same manner as in Example 2, except that 5CB was replaced with E8 (a mixed liquid crystal of 5CB (4-cyano-4'-pentylbiphenyl), 7CB (4-cyano-4'-heptylbiphenyl), 5OCB (4-cyano-4'-pentoxybiphenyl), 8OCB (4-cyano-4'-n-octyloxybiphenyl), and 5CT (4-cyano-4'-pentyl-p-terphenyl).

[0240] <Example 18>

[0241] The DMP was replaced with glyceryl tridecanoate, and the upconversion membrane was obtained in the same manner as in Example 1.

[0242] <Example 19>

[0243] The liquid crystal solvent was prepared in the same order as in Example 4. Additionally, a glass was placed on a heating plate heated to 80°C, and the liquid crystal solvent was deposited on the glass to allow THF to evaporate. This yielded an upconversion product with a crystalline shape.

[0244] <Comparative Example 1>

[0245] The DMP was replaced with toluene, and otherwise the upconversion film (thickness 60 μm) was obtained in the same manner as in Example 1.

[0246] <Comparative Example 2>

[0247] The crystallization solvent was changed to toluene, and the upconversion membrane was obtained in the same manner as in Example 6.

[0248] <Determination of relaxation time by time-domain nuclear magnetic resonance (TD-NMR)>

[0249] The upconversion membrane or upconversion body obtained in the above embodiments is cut into long strips to prepare samples. The short side of the sample is 1.5 cm and the long side is 7-12 cm. About 2-4 samples are inserted into the sample tube.

[0250] Next, TD-NMR (pulse NMR) was used to measure the sample in the sample tube at 298 K using the spin echo method. Based on the obtained free induction decay curve of spin-spin relaxation of the 1H nucleus, the T2 relaxation time was calculated by nonlinear least squares analysis. The results are shown in Tables 1 to 3.

[0251] Regarding the measurement conditions, the repetition time was 10 seconds, the cumulative number of measurements was 8, and the number of measurement points was 50. Measurements were performed when the signal intensity of the graph at point 1 was standardized to a relative signal intensity between 0.1 and 0.001, and the relaxation time was analyzed.

[0252] Furthermore, using the analytical software "TDNMR-AVersion 6.9Rev2.0" manufactured by BRUKER Corporation, and following the product manual, an exponential function with a Weibull coefficient of 1 was fitted. For some samples where a Weibull coefficient of 1 was not suitable, the optimal value was used within the range of 1 to 2.

[0253] The following describes the measurement conditions.

[0254] Apparatus: Manufactured by Bruker, TD-NMR (theminispecmq20)

[0255] Nucleus type detection: 1 H

[0256] Measurement temperature: 298K

[0257] Measurement method: Spin-echo method

[0258] Analytical method: Nonlinear least squares method

[0259] Scan: 8

[0260] Recycle Delay: 10 seconds

[0261] First 90-180 pulse interval: 0.0082

[0262] Final 90-180 Pulse Separation: Adjusted to the conditions described above.

[0263] Number of data points for fitting: 50

[0264] If more than two components are detected by the obtained relaxation time, the obtained relaxation time is multiplied by the proton ratio, and the average value is calculated based on the relaxation time obtained by summing all components. This average value is taken as the relaxation time.

[0265] Determination of Absolute Quantum Yield

[0266] The absolute quantum yield of upconversion luminescence of the upconversion films or upconverters (hereinafter referred to as samples) obtained in the above examples and comparative examples was measured (100% conversion) using an absolute quantum yield measurement system, Quantaurus-QYPlusC11347-02 (manufactured by Hamamatsu Photonics, detection wavelength: 400-1100 nm).

[0267] In the determination of absolute quantum yield, diode lasers (808 nm, 200 mW, 532 nm, 75 mW, 460 nm, 500 mW, RGB Photonics) were used as the excitation source by adjusting the light intensity through the laser output and the use of an ND (Neutral Density) film. The light intensity was adjusted to achieve 27000 mW / cm² at 808 nm. 2 532nm has a power output of 31000mW / cm². 2 460nm is 31000mW / cm 2 The sample is irradiated with light to perform the measurement.

[0268] The measured absolute quantum yields are shown in Tables 1 to 3.

[0269] <Transmittance Measurement>

[0270] The transmittance of the upconversion films or upconversion bodies obtained in the above examples and comparative examples was measured using a UH4150 UV-Vis-NIR spectrophotometer (manufactured by Hitachi High-Tech Corporation). In the transmittance measurement, the sample was placed directly in front of the integrating sphere, and the total light transmittance was measured at 1 nm intervals within a wavelength range of 400 nm to 800 nm. The average transmittance obtained from 400 nm to 800 nm was then used as the average transmittance.

[0271] The measured average transmittance is shown in Tables 1 to 3.

[0272] [Table 1]

[0273]

[0274] [Table 2]

[0275]

[0276] [Table 3]

[0277]

[0278] [evaluate]

[0279] As can be clearly seen from Tables 1 to 3, a T2 relaxation time of less than 210 ms measured by spin echo method of TD-NMR at 298 K can improve the absolute quantum yield and the upconversion luminescence efficiency.

[0280] [Industry availability]

[0281] The photon upconversion film and photon upconverter of the present invention can be suitably used in solar cells or solar power generation, photocatalysts, bioimaging, optical devices, laminates, energy conversion devices, etc.

Claims

1. A photon upconversion film comprising a color-developing section, said color-developing section comprising at least... Sensitizing components capable of absorbing light within the first wavelength range λ1; and The luminescent component capable of emitting light within a second wavelength range λ2, which is shorter than the first wavelength range λ1. For the photonic upconversion film, the relaxation time measured by the spin echo method using time-domain nuclear magnetic resonance (NTMR) at 298K is less than 210 ms.

2. The photon upconversion film as described in claim 1, comprising a matrix, The colorimetric component is dispersed in the matrix as a dispersed phase.

3. The photon upconversion film as described in claim 2, wherein, The matrix contains resin.

4. The photon upconversion film as described in claim 3, wherein, The resin comprises polyethylene oxide and / or polyvinyl alcohol-based resins.

5. The photon upconversion film as described in claim 1, wherein, The colorimetric part contains a solvent with a boiling point of 80°C or higher.

6. The photon upconversion film as described in claim 1, wherein, The colorimetric part contains a solvent with a viscosity of 0.6 mPa•s or higher at 23°C.

7. The photon upconversion film as described in claim 1, wherein, The color-developing part contains a single-molecule liquid crystal compound.

8. The photon upconversion film as described in claim 3, wherein, Relative to 1g of the resin, it contains 7.00 × 10 -9 mol~5.00×10 -6 The sensitizing component of mol and 5.00 × 10 -6 mol~7.00×10 -5 The luminescent component is mol.

9. A method for manufacturing a photonic upconversion film, which is the method for manufacturing the photonic upconversion film according to any one of claims 1 to 8, comprising the following steps: The process of preparing an emulsion from a medium in which the sensitizing component and the luminescent component are dispersed and / or dissolved, and an aqueous solution containing a water-soluble resin; The process of applying the emulsion to a substrate to form a coating film; and The process of drying the coating film.

10. A laminate comprising the photon upconversion film according to any one of claims 1 to 8.

11. An energy conversion device comprising the photon upconversion membrane according to any one of claims 1 to 8.

12. A photon upconverter comprising a color-developing section, said color-developing section including at least a sensitizing component capable of absorbing light within a first wavelength range λ1; and The luminescent component capable of emitting light within a second wavelength range λ2, which is shorter than the first wavelength range λ1. For the photon upconverter, the relaxation time measured by the spin echo method using time-domain nuclear magnetic resonance (NTMR) at 298K is less than 210 ms.

Images