Color conversion film with ALD sealed edges

Abstract

The present invention relates to an edge-sealed color conversion film. The color conversion film emits light in the visible region when excited with blue light. The edge seals comprise an inorganic material, have a thickness of 1-500 nm with a standard deviation of less than 10%, and are disposed on all edges of the native color conversion film, thereby completely and defect-free covering the edges. The present invention also provides a method for producing such edge-sealed color conversion films using ALD techniques.

Description

[Technical Field]

[0001] The present invention relates to the field of color conversion films suitable for use in display backlight components and light emitting devices. Specifically, the present invention provides edge-sealed color conversion films, thereby improving the stability of such films. Furthermore, the present invention relates to a novel manufacturing process for obtaining edge-sealed color conversion films. [Background technology]

[0002] Color conversion films are well known and widely used in industry, such as in LCD backlights. These films contain green and / or red color conversion materials that emit green and red light, respectively, when excited with blue light. These films are manufactured using roll-to-roll coating equipment, resulting in rolls of color conversion film. Finally, rectangular sheets roughly equivalent to the size of the corresponding LCD display are cut by die cutting or laser cutting. The cut edges of the resulting rectangular color conversion film leave the color conversion material within the QD film exposed to air. The cut edges of such color conversion films often contain defects such as fine cracks and other irregularities.

[0003] Color conversion films are known to be sensitive to air and humidity. Therefore, the main surfaces of such films are usually covered with a protective layer. In this regard, Nehm et al. discuss ultrathin AlOx films deposited by ALD (ACS Appl. Mater. Interfaces 2015, 7, 22121-22127). The authors observed that these AlOx films are unstable and rapidly lose their protective properties when directly exposed to ambient relative humidity. To overcome this drawback, an additional coating, preferably an adhered PET film, allows for reliable WVTR (water vapor transmission rate) of 2 × 10 at 38 °C and 90% RH. -5 g(H2O)m -2 d -1While this method is suitable for the major surfaces of a film, it is clear that it is not effective for the edges of such a film.

[0004] Edge ingress is a well-known problem in the industry and has been discussed by Nelson et al. (TechConnect Breif 2015, ISBN978-1-4987-4727-1, pp. 282-285). Briefly, color conversion materials (especially quantum dots and perovskite crystals) degrade at the edges of such films due to moisture and / or oxygen diffusing into the film from the edges. This results in so-called edge ingress, which refers to the distance from the edge toward the center of the film at which the green and / or red color conversion materials degrade and either cease to emit light or their emission is significantly reduced. While Nelson et al. recognize the edge ingress problem, they offer no suggestions for solving it.

[0005] Kim et al. disclose a light guide plate and a display device including the same (US2020 / 0209463). The application shows an encapsulated light conversion film. The encapsulation disclosed in this application is of non-uniform thickness and does not allow adequate control of edge penetration. Furthermore, Skipor et al. disclose a light-emitting polymer film, a display including the same, and a method for manufacturing the same (US9470399). The sides are protected by a barrier layer. It is proposed that such a barrier be formed using transfer molding. Furthermore, Luechinger et al. disclose a freestanding film and a light-emitting device (EP3936585). This application does not mention edge sealing. Furthermore, Chu discloses a display device with edge sealing by thermal curing using laser technology (US2020 / 0251529). Furthermore, Lee et al. disclose a light guide panel including a passivation layer on the edge of the wavelength conversion layer, and proposes using CVD for its formation (US2019 / 0154901). Finally, Fang et al. discuss encapsulation of quantum dots, describing the use of a sol-gel method combined with an ALD process to form a multilayer coating of SiO2 and Al2O3 on the quantum dots (Adv. Optical Mater., 2020, 8, 1902118). Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to overcome one or more of the shortcomings of the prior art. In particular, the present invention addresses the need for a color conversion film with improved stability across its entire surface. This is achieved by avoiding, or at least reducing, edge intrusion of the color conversion film. [Means for solving the problem]

[0007] Specifically, the object is achieved by providing an edge-sealed color conversion film as defined in claim 1 and by providing a manufacturing method as defined in claim 9. Further aspects of the invention are disclosed in the present specification and the independent claims, and preferred embodiments are disclosed in the specification and the dependent claims.

[0008] The present invention will be described in more detail below. It should be understood that the various embodiments, preferences, and ranges provided / disclosed herein can be arbitrarily combined. Furthermore, depending on the specific embodiment, the selected definitions, embodiments, or ranges may not apply.

[0009] Unless otherwise noted, the following definition applies herein.

[0010] As used in the context of the present invention, the words "a," "an," "the," and similar words should be understood to include both the singular and the plural, unless otherwise stated in this disclosure or clearly contradicted by context. The term "containing" encompasses all of "comprising," "essentially consisting of," and "consisting of." Percentages are given by weight unless otherwise stated herein or clearly contradicted by context. "Independently" means that one substituent / ion can be selected from one of the specified substituents / ions, or may be a combination of one or more of the above.

[0011] A "film" is a thin structure made up of one or more layers (a "laminate") and having two major surfaces separated by an edge. Upper film region: The upper film region refers to the top surface of the color conversion film. Lower film region: The lower film region refers to the surface of the color conversion film that is opposite and below the upper film region. The upper and lower film regions are also collectively referred to as "major surface regions." Edge region: The first, second, third, and fourth edge regions refer to the regions at each of the four edges of a rectangular color conversion sheet. For a disk-shaped film, one edge separates the upper and lower film regions.

[0012] The term "color conversion material" is known in the art and in the context of the present invention relates to a material which emits light in the visible range when excited with blue light. In the context of the present invention, the color conversion material preferably emits red or green light. The color conversion material may be organic (polymers or small organic molecules) or inorganic. Inorganic color conversion materials are preferably selected from the list consisting of luminescent crystals, quantum dots, perovskite crystals or micron-sized phosphors, most preferably perovskite crystals and quantum dots.

[0013] The term "luminescent crystal" (LC) is known in the art and, in the context of the present invention, refers to crystals of 2 to 100 nm made of semiconductor materials. This term includes quantum dots, typically in the 2 to 10 nm range, and nanocrystals, typically in the 10 to 100 nm range. LCs, as the term suggests, emit light. In the context of the present invention, the term luminescent crystal includes both monocrystalline and polycrystalline particles. In the latter case, a particle may consist of multiple crystalline regions (grains) connected by boundaries between crystalline or amorphous phases. Luminescent crystals are semiconductor materials that exhibit a direct bandgap (typically 1.1 to 3.8 eV, more commonly 1.4 to 3.5 eV, and even more commonly 1.7 to 3.2 eV). When irradiated with electromagnetic waves above the bandgap, electrons in the valence band are excited to the conduction band, leaving holes in the valence band. The generated excitons (electron-electron-hole pairs) then undergo radiative recombination in the form of photoluminescence (PL), which exhibits a maximum intensity centered around the LC bandgap value and a photoluminescence quantum yield of at least 1%. When in contact with an external electron and electron-hole source, LCs can exhibit electroluminescence.

[0014] The term "quantum dot" (QD) is well-known and specifically refers to semiconductor nanocrystals, typically with diameters between 2 and 10 nm. In this range, the physical radius of the QD is smaller than the bulk exciton Bohr radius, and quantum confinement effects become dominant. As a result, the electronic states of the QD, and therefore the bandgap, are a function of the QD's composition and physical size. This means that the absorption / emission color is related to the QD's size. The optical quality of a QD sample is directly related to its uniformity (more monodisperse QDs have a smaller full width at half maximum (FWHM) of emission). When QDs reach sizes larger than the Bohr radius, quantum confinement effects are inhibited, and the sample may cease to emit light because the nonradiative process of exciton recombination becomes dominant. QDs are therefore a specific subgroup of nanocrystals, specifically defined by their size and size distribution. Typical QD compositions contain cadmium or indium, e.g., in the form of cadmium selenide (CdSe) or indium phosphide (InP).

[0015] The term "core-shell quantum dots" is known and particularly relates to quantum dots that typically include an indium- or cadmium-containing core, typically a CdSe or InP core with an additional shell that generally includes zinc sulfide (ZnS), zinc selenide (ZnSe), cadmium sulfide (CdS), or a combination thereof. Core-shell quantum dots may include multiple shells or shell gradients.

[0016] The term "perovskite crystal" is known and includes in particular crystalline compounds of perovskite structure. Such perovskite structures are known per se and have the general formula M 1 M 2 X3 cubic, pseudocubic, tetragonal, or orthorhombic crystals, where M 1 is a cation with a coordination number of 12 (cuboctahedron), M 2 is a cation with a coordination number of six (octahedral), and X is an anion located at a cubic, pseudocubic, tetragonal, or orthorhombic position in the lattice. In these structures, selected cations or anions can be substituted (up to 30 atomic %) with other ions, either stochastically or systematically, to obtain doped or non-stoichiometric perovskites while maintaining the original crystal structure. Preferably, the luminescent perovskite crystals are approximately isotropic (e.g., spherical or cubic). Particles are considered approximately isotropic when the aspect ratio (longest:shortest direction) in all three orthogonal dimensions is between 1 and 2. Thus, LC aggregates preferably contain 50-100% (n / n), preferably 66-100% (n / n), and more preferably 75-100% (n / n). The production of such luminescent perovskite crystals is known, for example, from WO2018 / 028869, which is incorporated by reference.

[0017] The term "micron-sized phosphor" is well known, and in particular K2SiF6:Mn 4+ (KSF).

[0018] The term "polymer" is well known and includes organic and inorganic synthetic materials composed of repeating units ("monomers"). The term polymer includes homopolymers and copolymers. It also includes crosslinked and non-crosslinked polymers. In some contexts, the term polymer also includes its monomers and oligomers. By way of example, polymers include acrylate polymers, carbonate polymers, sulfone polymers, epoxy polymers, vinyl polymers, urethane polymers, imide polymers, ester polymers, furan polymers, melamine polymers, styrene polymers, norbornene polymers, silazane polymers, silicone polymers, and cyclic olefin copolymers. Polymers may also include other materials, such as polymerization initiators, stabilizers, and fillers, as is commonly used in the art.

[0019] The term "color conversion film" is well known in the art. Color conversion films have wide applications in commercial products such as displays. According to the present invention, such films contain red and / or green color conversion materials. According to the present invention, such films partially or completely convert blue light to red and / or green light. Typically, blue light is partially converted to produce light emission in the blue, green, and / or red spectrum. By adjusting the intensity of the blue light and the concentration, film thickness, and amount of the green and / or red light-emitting material, the emitted color can be tailored according to customer needs. Such color conversion films can be described as laminate structures and identified by their individual layers, such as a "light-emitting polymer layer," a "red-light-emitting polymer layer," a "green-light-emitting polymer layer," a "first set of coating layers," a "second set of coating layers," an "inorganic encapsulation layer," and optionally a "non-light-emitting polymer layer." Furthermore, such color conversion films can be identified by their individual surface regions, such as a "top film region," a "bottom film region," a "first end region," a "second end region," a "third end region," a "fourth end region," and so forth. The color conversion film typically has a thickness, including all individual layers, of 10 to 500 micrometers, preferably 20 to 250 micrometers, and most preferably 30 to 200 micrometers. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 shows a perspective view of a rectangular native color conversion film of the present invention before edge treatment. [Figure 2] FIG. 1 shows a plan view of a rectangular color conversion film of the present invention after edge treatment. [Figure 3a] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 3b] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 3c] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 3d] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 4] 1 shows the manufacturing configuration of the film of the present invention. [Figure 5] 1A and 1B are a plan view and a side view cut along a horizontal dotted line of a rectangular color conversion film after the edges and main surfaces have been subjected to the treatment of the present invention. [Figure 6b] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 6c] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 6d] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 6e] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 6f] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 6g] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 6h] FIG. 1 shows a side view of the color conversion film of the present invention. [Figure 7] 1 shows the manufacturing configuration of the film of the present invention. [Figure 8] 1 illustrates an alternative manufacturing configuration for the film of the present invention. [Figure 9] 1 shows a color conversion film of the present invention with additional layers. DETAILED DESCRIPTION OF THE INVENTION

[0021] The invention will be better understood with reference to the drawings, in which the following list of references applies: 010 Color conversion film 010' Native color conversion film, i.e. no edge sealing layer 011 First end area 013 Second end area 012 Third end area 014 Fourth end area 020 Color conversion film laminate 021 Upper film area 022 Lower Film Area 030 Edge sealing layer (sealing layer on all edges of native film 010') 030' Surface sealing layer (sealing layer covering both main surfaces of native film 010') 040 Free volume accessible to ALD process gases (e.g., gaseous metal-organic reactants and purge gases) 050 ALD chamber 070 Additional layer 080 Color conversion material that converts blue light to light with longer wavelengths 090 Light-emitting polymer layer 100 Green color conversion material 110 Green light-emitting polymer layer 200 Red color conversion material 210 Red light-emitting polymer layer 121 First set of coating layers 122 Second set of coating layers

[0022] 1 shows a perspective view of a rectangular native color conversion film of the present invention before edge treatment. The main surface areas are designated 022 and 021, and the edges are designated 011...014.

[0023] FIG. 2 shows a plan view of a rectangular color conversion film 010 after edge treatment of the present invention. The encapsulation layer 30 (not to scale) and the native film 010′ (color conversion material not shown) are labeled. The enlarged portion on the top right shows complete, defect-free edge coverage. The inorganic encapsulation layer uniformly covers the cracks in film 010′, thereby preventing oxygen and / or H2O from diffusing into the color conversion film. For comparison, the enlarged portion on the bottom right shows an incomplete, defective edge coverage: inorganic encapsulation layer, when deposited by a directional deposition method (e.g., CVD, PVD). Due to shadow effects, the cracks in film 010′ are not uniformly covered.

[0024] FIG. 3 shows various color conversion films of the present invention in side view, thereby illustrating potential stack configurations. 3a: Side view of the film of Figure 2. Such films are typically further processed on both major surfaces 021, 022, such as by being coated with coating layers 120, 121, to obtain a laminated film structure, for example as shown in Figure 3b. 3b: The film of FIG. 2 with an additional conventional coating layer (eg, a barrier film) on a major surface. 3c: The film of Figure 3b with two different types of color converter materials in one layer, see Example 3. 3d: The film of Figure 2 with two different types of color converter materials in two separate layers, see Example 1.

[0025] FIG. 4 shows a manufacturing configuration for the inventive film 010. A stack 020 of color conversion films, consisting of multiple individual native films 010', is placed in an ALD chamber 040. The stack 020 is adapted to seal the edges of as many of the color conversion films as possible in one ALD batch, and incidentally to prevent ALD process gases from contacting the main surfaces (except the top surface of the stack 020). This configuration allows for all edges to be sealed, with no or limited sealing of the main surfaces, as shown on the right. This results in multiple edge-sealed color conversion films 010 of the inventive invention.

[0026] FIG. 5 shows a plan view and a side view cut along a horizontal dotted line of a rectangular color conversion film 010 after its edges and major surfaces have been subjected to the treatment of the present invention. The encapsulation layer 30 (not to scale) and the native film 010' are labeled. As shown, the thickness of the encapsulation layer on the edges and major surfaces can differ. In the embodiment shown, the edge encapsulation is thinner than the major surface encapsulation.

[0027] FIG. 6 is a side view of various color conversion films of the present invention, showing potential laminate structures sealed on all edges and both major surfaces with sealing layer 30 of the present invention (also not to scale). 6b: Simple film coated on edges and main faces. 6c: The film of FIG. 6b, but with an additional pair of conventional coating layers 122, 121. 6d: The film of FIG. 6c, but with two different color conversion materials 100, 200. 6e: The film of FIG. 6d, but with only one set of conventional coating layers. 6f: The film of FIG. 6d, but with the red and green light-emitting layers separated into individual layers 110 and 210. 6g: The film of FIG. 6f, but with only one set of conventional coating layers 121. 6h: The film of FIG. 6b, but with the red and green light-emitting layers separated into individual layers 110 and 210.

[0028] FIG. 7 shows a manufacturing configuration for a film 010 of the present invention, as shown in FIG. 6, with sealing layers on all edges and both major surfaces. A modified stack 020' of color conversion films, consisting of multiple individual native films 010', is placed in an ALD chamber. The stack 020' allows ALD process gases to contact the major surfaces and edges. This configuration allows all edges 030 to be sealed and the major surfaces 030' to be sealed, as shown on the right, resulting in multiple edge-sealed and surface-sealed color conversion films 010 of the present invention.

[0029] Figure 8 shows an alternative manufacturing configuration for the inventive film compared to Figure 7. The edge sealing film is subjected to an additional ALD step.

[0030] FIG. 9 shows a film 10 of the present invention with an additional layer 070, such as layer 070 without edge seals 030.

[0031] In a first aspect, the present invention relates to a color conversion film 010 that emits light in the visible range, preferably red and / or green, when excited with blue light. Such a film comprises a native film (010', without edge sealing) having two major surfaces (021, 022) and at least one edge 011...014, and comprises a color conversion material 80, 100, 200. Such a film further comprises an inorganic sealing layer 030 in the entire edge region, which is an atomically deposited layer that completely covers all edges with a highly uniform thickness. This aspect of the invention is described in more detail below.

[0032] (End sealing layer 030) In the context of the present invention, the encapsulation layer 030 has the following characteristics: The edge encapsulation layer 030 completely covers the edges of the film 010' without defects or pinholes. "Complete and defect-free" coverage can be estimated by the stability of the color conversion film after accelerated aging tests. The term "complete and defect-free coverage" was chosen to distinguish it from incomplete and defect-free coverage obtained by directional deposition techniques (e.g., CVD, PVD), which cannot guarantee "complete and defect-free coverage" of the surface due to shadowing effects. The edge encapsulation layer 030 has a thickness of 1 to 500 nm, preferably 3 to 200 nm, and most preferably 10 to 100 nm. In an embodiment, the thickness is 2 to 90 nm. In a further embodiment, the thickness is 5 to 50 nm. These thicknesses are characterized by a highly uniform thickness across the coated substrate, characterized by a standard deviation of thickness variation across the substrate of less than 10%, preferably less than 3%, and most preferably less than 1%. The thickness of the inorganic encapsulation layer can be determined by observing, preferably, microtome-prepared samples with a transmission electron microscope (TEM). Without being bound by theory, the thickness and its standard deviation are believed to be characteristic of the ALD fabrication steps described herein.

[0033] The edge sealing layer 030 comprises an inorganic material, and in particular consists of an inorganic material. The term "inorganic material" is known in the art. In view of the ALD manufacturing method described below, suitable inorganic materials are selected from the group consisting of metal oxides or metal nitrides. More preferably, silicon oxide, aluminum oxide, zirconium oxide, hafnium oxide, titanium oxide (e.g., SiO x x = 1.9 to 2.1, AlO x x = 1.4 to 1.6, TiO x ;x=1.9~2.1, ZrO x x = 1.9 to 2.1, HfO x; x = 1.9-2.1). They may be made of a single inorganic material or two or more inorganic materials (e.g., multiple layers of different inorganic layers with different chemical compositions). ALD fabrication results in very pure inorganic layers, although residual organic material from the precursor materials may be present. Thus, references to inorganic material layers refer to purities greater than 95 wt%, typically greater than 99 wt%, e.g., greater than 99.5 wt%. The composition of the inorganic sealing layer can be determined by X-ray photoelectron spectroscopy (XPS) or TEM equipped with EDX spectroscopy (EDX analysis of a cross section of the inorganic sealing layer).

[0034] When applying ALD fabrication to the film edges 011,...,014, some inorganic material may be deposited on the major surfaces 021,022, resulting in additional coatings on portions of the major surfaces. Such partial coatings on the major surfaces do not adversely affect the film properties and are encompassed by the present invention. This partial coating is not shown in the schematic diagrams discussed herein.

[0035] In one embodiment, the inorganic sealing layer consists of alternating layers of two different metal oxides, preferably the number of distinct metal oxide layers is greater than two, preferably greater than three, and most preferably greater than five.

[0036] In a further embodiment, the inorganic sealing layer is comprised of alternating layers of the following combinations of different metal oxides: AlOx / TiOx AlOx / SiOx AlOx / ZrOx AlOx / HfOx TiOx / SiOx Here, the first oxide layer preferably has a thickness of 3 to 100 nm (preferably 10 to 50 nm), and the second oxide layer preferably has a thickness of 2 to 50 nm (preferably 5 to 20 nm).

[0037] In a further embodiment, the inorganic sealing layer is AlO x / MO xHere, M=Si, Zr, Ti, Hf, the thickness of the aluminum oxide layer is preferably 3 to 100 nm (preferably 10 to 50 nm), and the thickness of the MOx layer is preferably 2 to 50 nm (preferably 5 to 20 nm).

[0038] Preferably, the inorganic sealing layer is deposited on the edges and, optionally, on the main surfaces of the film by atomic layer deposition (ALD). ALD is a coating technique known per se, but has not yet been applied in the context described herein. Accordingly, the present invention also provides a color conversion film 010 that emits light in the visible range, preferably red and / or green, when excited with blue light. Such a film comprises a native film (010', without edge sealing) having two main surfaces 021, 022 and at least one edge 011...014, and comprises a color conversion material 80, 100, 200. Such a film further comprises an inorganic sealing layer 030 on the entire edge region, which is an ALD-deposited inorganic layer covering the entire edge region.

[0039] (Surface sealing layer 030') In the context of the present invention, in addition to the edge sealing layer 030 covering all edges, there may be one or two sealing layers 030' covering one or both of the main surfaces. Such a surface sealing layer 030', if present, has the following properties: They completely cover one or both major surfaces of the film 010' without defects or pinholes. They have a thickness of 1 to 500 nm, preferably 3 to 200 nm, most preferably 10 to 100 nm. These are characterized by a very uniform thickness across the coated substrate, with a standard deviation of thickness variation across the substrate of less than 10%, preferably less than 3%, and most preferably less than 1%. · They contain inorganic materials and are especially composed of inorganic materials.

[0040] The same considerations as those for the edge sealing layer 030 apply to the above-mentioned properties of the surface sealing layer 030', particularly the definition of the inorganic material, the defect-free coverage, the layer structure, the thickness, and the standard deviation thereof.

[0041] In embodiments, the average thickness of the surface seal 030' is less than the average thickness of the edge seal 030, for example, at least two times less, and preferably at least five times less.

[0042] (Color conversion material) The term color conversion material has already been defined.

[0043] In one embodiment of the present invention, the red conversion material emits red light (630 nm±30 nm) in response to excitation with shorter wavelength light and is preferably selected from core-shell quantum dots or perovskite crystals. The core-shell quantum dots are preferably selected from core-shell quantum dots made of indium or cadmium, most preferably indium.

[0044] The green conversion material emits green light (centered at 500-550 nm, particularly about 525-535 nm) in response to excitation by shorter wavelength light, and is preferably selected from core-shell quantum dots or perovskite crystals, preferably perovskite crystals.

[0045] Perovskite crystals have the chemical formula (I): [M 1 A 1 ] a M 2 b X c (I) wherein A 1 represents one or more organic cations, particularly formamidinium (FA). M 1 represents one or more alkali metals, especially Cs. M 2 is M 1 represents one or more metals other than Pb, in particular Pb. X is one or more anions selected from the group consisting of halides, pseudohalides and sulfides, and in particular represents Br. a represents 1 to 4. b represents 1 to 2. c represents 3 to 9. where M 1 , A 1 , or M 1 and A 1 , or either

[0046] In a further advantageous embodiment of the invention, the green emitting crystal has the formula (I'): FAPbBr3(I') This is a green-emitting perovskite crystal.

[0047] In particular, formulas (I) and (I') represent perovskite luminescent crystals that, upon absorbing blue light, emit light at wavelengths in the green light spectrum centered between 500 nm and 550 nm, particularly about 525-535 nm.

[0048] (Light-emitting polymer layer 090) The light-emitting polymer layer 090 comprises a color conversion material 080 (preferably red and / or green) dispersed within the polymer. Suitable color conversion materials 080 are defined above. Suitable polymers may be selected from the group consisting of acrylates, methacrylates, epoxies, silazanes, urethanes, preferably acrylates and methacrylates. In embodiments, such polymers are crosslinked. In embodiments, combinations / blends of two or more polymers are used. Suitably, the light-emitting polymer layer has a thickness of 10 to 200 micrometers, preferably 20 to 100 micrometers.

[0049] (Green light-emitting polymer layer 110) The green light-emitting polymer layer includes a polymer and a green conversion material 100 dispersed within the polymer. Suitable green conversion materials 100 can be selected from the group consisting of perovskite crystals and indium-containing core-shell quantum dots, preferably perovskite crystals. Suitable polymers can be selected from the group consisting of acrylates, methacrylates, epoxies, silazanes, and urethanes, preferably acrylates and methacrylates. In embodiments, such polymers are crosslinked. In embodiments, combinations / blends of two or more polymers are used. Suitably, the green light-emitting polymer layer has a thickness of 10 to 200 micrometers, preferably 20 to 100 micrometers.

[0050] (Red light-emitting polymer layer 210) The red light-emitting polymer layer includes a polymer and a red light conversion material 200 dispersed within the polymer. Suitable red light conversion materials 200 include red perovskite crystals or indium-containing core-shell quantum dots, preferably indium-containing core-shell quantum dots. Suitable polymers may be selected from the group consisting of acrylates, methacrylates, epoxies, silazanes, and urethanes, preferably acrylates and methacrylates. In embodiments, the polymer is crosslinked. In embodiments, a combination / blend of two or more polymers is used. In embodiments, the polymer includes a monofunctional polycyclic acrylate or methacrylate and a multifunctional acrylate or methacrylate. Suitably, the red light-emitting polymer layer has a thickness of 100 to 200 micrometers, preferably 20 to 100 micrometers.

[0051] (First and second set of coating layers 121, 122) Adjacent to the light-emitting polymer layer, there may be cover layers 121, 122. The first and second sets of cover layers may each independently comprise a single layer or multiple layers, and such layers may be inorganic or polymeric and non-emissive (meaning they do not emit light when excited with blue light). The cover layers have different functions: Barrier films / layers Intermediate film / layer Adhesive film / layer Light management films / layers Non-luminescent polymer films / layers It is possible to select from.

[0052] Barrier film / layer: In the context of the present invention, a barrier film exhibits low permeability to oxygen and / or moisture. Such a barrier film has an oxygen transmission rate (OTR) of 10 cm 3 / m 2 Less than 1cm, preferably 3 / m 2 Less than 1 day, most preferably 0.1 cm 3 / m 2 The OTR is based on ISO 15105 and is measured at a temperature of 23°C / 90% RH, atmospheric pressure, and / or a water vapor transmission rate (WVTR) of 10 g / m². 2 Less than 1g / m per day, preferably 2 Less than 0.1g / m 2 The WVTR can be determined in less than 1 day. The WVTR can be determined according to ISO15106-3:2003 at a temperature of 40°C / 90%RH. Inorganic barrier films comprise or consist of a continuous layer of an inorganic material. Typically, the thickness of such a layer is between 1 nm and 10 micrometers, preferably between 10 nm and 1 micrometer. Suitable inorganic materials include SiO x (x=1.7~2.3), AlO x (x=1.3~1.7), and Si x N y (x=3 and y=3.5-4.5). Polymeric barrier films are composed of polymers or polymer blends and typically have a thickness of 5-200 micrometers, preferably 10-100 micrometers, and most preferably 20-50 micrometers. Inorganic and polymeric barrier films are commercially available and may be supported by an additional polymer substrate.

[0053] Intermediate Film / Layer: An intermediate film can be implemented in the color conversion film to further increase the stability of the color conversion material (usually perovskite crystals), to separate certain layers to avoid contact between such certain layers, or to facilitate the production of the color conversion film, for example, to reduce production costs. The intermediate layer comprises or consists of a polymer. Suitable polymers are selected from the list of acrylate or methacrylate polymers, epoxy polymers, silazane polymers, cyclic olefin copolymers, polyesters, preferably acrylate polymers or methacrylate polymers. In embodiments, such polymers are crosslinked. The intermediate layer has a thickness of 5 to 100 micrometers, preferably 10 to 80 micrometers, and most preferably 20 to 60 micrometers.

[0054] Adhesive Films / Layers: Such layers are known in the art and can be included in color conversion films to improve compatibility between layers, improve adhesion between layers, or facilitate manufacturing. Typically, such layers are used on barrier films to improve adhesion between adjacent polymer layers, such as interlayers or light-emitting polymer layers. Such layers typically have a thickness of 0.1 to 20 micrometers, preferably 0.5 to 10 micrometers, and most preferably 1 to 5 micrometers. In embodiments, such layers consist of a polymer or polymer blend. Typical polymers are selected from the list of acrylate or methacrylate polymers, epoxy polymers, and urethane polymers.

[0055] Light Management Films / Layers: Light management films / layers are sometimes used in color conversion films, for example, to increase the light output of the color conversion film or to reflect specific portions of light. Light management films include prism sheets, brightness enhancement films, microlens array (MLA) films (such as those supplied by Brightview Technologies), and blue-light-pass filter films (also called dichroic mirror films, which transmit blue light and reflect green and red light; such films are supplied by 3M and have been used in the Apple® iPad Pro XDR® since 2021). MLA films are typically 10 to 50 micrometers thick. Dichroic mirror films are typically 20 to 100 micrometers thick.

[0056] (film geometry) In one embodiment, the color conversion film has a rectangular shape. The length and width of this film are similar to those of a typical LCD display, ranging from the size of a cell phone to that of a TV. This includes aspect ratios of 4:3, 3:2, 16:9, or 3:1, and diagonal lengths ranging from 5 cm to 250 cm. As is customary in the art, rectangular films may deviate slightly from a strict geometric definition. For example, the edges may be rounded or notched to accommodate the film's intended use or facilitate device manufacture. In an embodiment, the color conversion film has a rectangular shape with rounded corners. Such rounded edges typically have a radius of less than 5 mm. In an embodiment, the edges of a rectangular color conversion film may have one or more small geometric features that protrude slightly from the edge (such edge features, also known as "notches," are implemented on the edges to properly secure the color conversion film within the display backlight and prevent unwanted repositioning). The edge sealing method of the present invention is applicable to such rounded edges as well as edges with additional geometric features. This is believed to be a further advantage of the inventive method described below. In an embodiment, the color conversion film is disc-shaped and therefore has only one edge 011 separating the major surfaces 021 and 022. It has been found that the inventive method for edge sealing is also applicable to such non-conventional shapes.

[0057] (Film structure) Within the scope of the present invention, various laminate structures (film structures) can be implemented, which have in common the feature that at least the light-emitting polymer layers 090, 110, 210 are encapsulated on all edges with inorganic encapsulation layers 030.

[0058] In Figures 1 and 2, the color conversion film 010 has an inorganic sealing layer 030 in all four edge regions 011...014, whereby the inorganic sealing layer completely covers all four edge regions and the standard deviation of the thickness including all four edges is less than 10%, preferably less than 3%, and most preferably less than 1%.

[0059] In FIGS. 3a-3d, the color conversion film 010 comprises an inorganic sealing layer 030 that covers all edges (“edge sealing”). In this embodiment, the film is free or substantially free of an inorganic coating on its main surfaces. This is achieved by the methods described below, which provide a stack 20 in which direct contact of films 010′ is provided, or in which films 010′ are separated by an auxiliary separating film. However, those skilled in the art will be aware that in fabrication by ALD deposition, some inorganic coating may occur on the main surfaces due to the diffusion effects of the ALD process gases. However, such a diffusion process does not result in complete coverage of the main surfaces. Considering this situation, the expression “free or substantially free of coating” is chosen. Such an embodiment can be obtained by performing an ALD process according to FIG. 4.

[0060] 6b-6g, the color conversion film 010 includes an inorganic sealing layer 030' ("surface sealing") covering both major surfaces, in addition to an inorganic sealing layer 030 ("edge sealing") covering all edges. In embodiments, the average thickness of the surface sealing 030' is smaller (at least two times smaller, preferably five times smaller) than the average thickness of the edge sealing 030. Such embodiments can be obtained by performing an ALD process according to FIG. 8.

[0061] In an embodiment, the surface seal 030' and the edge seal 030 have substantially the same thickness, differing by less than 10%, preferably less than 3%, and most preferably less than 1%. In this embodiment, the film thickness may range from 1 to 500 nm, preferably 10 to 100 nm. Such an embodiment can be obtained by performing an ALD process according to FIG. 7.

[0062] Preferably, both the native color conversion film 010' and the color conversion film of the present invention are free-standing films. When the film of the present invention is incorporated into a display device, its properties are improved.

[0063] 9, it is within the scope of the present invention that the color conversion film 010 of the present invention (including the edge sealing layer 030 and optional surface sealing layer 030') may include one or more layers (additional layer 70) on the top and / or bottom. Such additional layers do not include the inorganic sealing layer in the edge region. If such additional layers are present, they may be: Glass substrates, Barrier films / layers Intermediate film / layer Adhesive film / layer Light management films / layers Non-luminescent polymer films / layers This embodiment showing the additional layer 070 can be obtained when the finishing step (d) is an additional lamination process.

[0064] Advantageous Embodiments In line with this disclosure, the following inventive film 010 is considered particularly advantageous.

[0065] In one embodiment, the color conversion film contains only one type of color conversion material 080, either red conversion material 200 or green conversion material 100, preferably green conversion material 100. (See e.g., Figures 3a, 3b, 6b, 6c, and 9.)

[0066] In a further embodiment, the color conversion film includes a green conversion material and a red conversion material (see, for example, Figures 3c and 6d).

[0067] In a further embodiment, the color conversion film comprises a green conversion material selected from the list consisting of perovskite crystals, indium-containing core-shell quantum dots, or cadmium-containing core-shell quantum dots, preferably perovskite crystals.

[0068] In a further embodiment, the color conversion film comprises a red color conversion material selected from the list consisting of perovskite crystals, indium-containing core-shell quantum dots, or cadmium-containing core-shell quantum dots, preferably indium-containing or perovskite crystal-containing core-shell quantum dots, most preferably indium-containing core-shell quantum dots.

[0069] In a further embodiment, the color conversion film comprises a green color conversion material selected from perovskite crystals and a red color conversion material selected from core-shell quantum dots comprising indium.

[0070] In further embodiments, the green and red conversion materials are present in different polymer layers, with the green conversion material being in a green light-emitting polymer layer and the red conversion material being in one or more red light-emitting polymer layers (see, e.g., Figures 6f and 3d).

[0071] In a further embodiment, the color conversion film comprises a first set of coating layers and a second set of coating layers, whereby the color conversion material is disposed between these two sets of conversion layers (see, for example, Figures 3b, 3c, and 3d).

[0072] In a further embodiment, the color conversion film comprises a first set of coating layers and a second set of coating layers, whereby the color conversion material is disposed between these two sets of conversion layers, and whereby each of the two sets of coating layers comprises at least one barrier film, preferably at least one inorganic barrier film.

[0073] In a further embodiment, the color conversion film 010 includes the edge seals 030 and the surface seals 030' but does not include any additional layers 070, 121, 122. (See, e.g., Figures 6b and 6g.)

[0074] In a further embodiment, the color conversion film 010 comprises an edge seal 030, a surface seal 030' and a set of cover layers 121 or 122 (see, for example, FIG. 6e). Preferably, the set of cover layers 121 or 122 comprises or consists of a polymer film, most preferably a PET film.

[0075] In further embodiments, the color conversion film includes one or more intermediate layers or one or more adhesive layers between the one or more light emitting polymer layers and the one or more sets of cover layers.

[0076] In a further embodiment, the color conversion film includes a green light-emitting polymer layer and a red light-emitting polymer layer separated by one or more inorganic barrier films.

[0077] In a further embodiment, the color conversion film comprises a green light emitting polymer layer and a red light emitting polymer layer separated by a polymer film, preferably a PET film.

[0078] In a further embodiment, the color conversion filter comprises a dichroic mirror film (blue light pass filter film) in one of the first or second set of coating layers 121, 122.

[0079] In a further embodiment, the color conversion film comprises a microlens array film (MLA) in one of the first or second set of cover layers 121, 122.

[0080] In a further embodiment, the color conversion film comprises a dichroic mirror film (blue light pass filter film) in the covering layer 121 and a microlens array film (MLA) in the covering layer 122 .

[0081] In a further embodiment, the film of the present invention is composed of the following layer sequence: barrier film / green light-emitting polymer layer / barrier film.

[0082] In a further embodiment, the film of the present invention is composed of the following layer sequence: barrier film / interlayer / green light-emitting polymer layer / interlayer / barrier film.

[0083] In a further embodiment, the film of the present invention is composed of the following layer sequence: barrier film / light-emitting polymer layer comprising red and green conversion materials / barrier film.

[0084] In a further embodiment, the film of the present invention is composed of the following layer sequence: barrier film / green light-emitting polymer layer / red light-emitting polymer layer / barrier film.

[0085] In a further embodiment, the film of the present invention is comprised of the following layer sequence: PET coating layer / green light-emitting polymer layer / PET coating layer.

[0086] In a further embodiment, the film of the present invention is composed of the following layer sequence: PET coating layer / light-emitting polymer layer comprising red and green conversion materials / PET coating layer.

[0087] In a further embodiment, the film of the present invention is constructed with the following layer sequence: PET coating layer / green light-emitting polymer layer / red light-emitting polymer layer / PET coating layer.

[0088] In a further embodiment, the film of the present invention is composed of the following layer sequence: barrier film / interlayer / green light-emitting polymer layer / red light-emitting polymer layer / barrier film.

[0089] In a further embodiment, the film of the present invention is constructed with the following layer sequence: interlayer / green light-emitting polymer layer / red light-emitting polymer layer.

[0090] In a further embodiment, the film of the present invention is comprised of the following layer sequence: interlayer / green light-emitting polymer layer / red light-emitting polymer layer / interlayer.

[0091] In a further embodiment, the film of the present invention is comprised of the following layer sequence: green light-emitting polymer layer comprising perovskite crystals / red light-emitting polymer layer comprising core-shell quantum dots comprising indium.

[0092] In a further embodiment, the film of the present invention is composed of the following layer sequence: an interlayer comprising an acrylate or methacrylate polymer / a green light-emitting polymer layer comprising perovskite crystals / a red light-emitting polymer layer comprising core-shell quantum dots comprising indium.

[0093] In a further embodiment, the film of the present invention is comprised of the following layer sequence: barrier film / light-emitting polymer layer comprising green core-shell quantum dots comprising indium and red core-shell quantum dots comprising indium / barrier film.

[0094] In a further embodiment, the film of the present invention is comprised of the following layer sequence: PET film / light-emitting polymer layer comprising green core-shell quantum dots comprising indium and red core-shell quantum dots comprising indium / PET film.

[0095] (Industrial Applicability) The color conversion film of the present invention can be assembled to obtain a backlight component for a display. Thus, the present invention also provides a display backlight component comprising the color conversion film described herein.

[0096] The color conversion film of the present invention can be assembled to obtain a light emitting device such as a liquid crystal display. Thus, the present invention also provides a light emitting device, preferably a liquid crystal display, comprising the color conversion film described herein.

[0097] (Manufacturing method of color conversion film) In a second aspect, the present invention describes a method for manufacturing a color conversion film as described herein. Generally speaking, the method comprises applying atomic layer deposition (ALD) in multiple ALD cycles to a plurality of stacked color conversion films 020 in an ALD batch reactor 050. Such an ALD process results in an inorganic encapsulation layer 030 on all edge regions and, optionally, additionally, on the upper and lower film regions 030'. The present invention therefore relates to a method for manufacturing a color conversion film according to the preceding claims. This includes the steps of: (a) providing a plurality of native color conversion films (010') and assembling them into a stack (020), (b) subjecting the stack of step (a) to a first ALD process to obtain a stack of sealed color conversion films (010), (c) optionally repeating steps (a) and (b) to obtain a multi-sealed color conversion film, and (d) optionally subjecting the sealed or multi-sealed color conversion film to a finishing process, as will be explained in more detail below.

[0098] We have found that atomic layer deposition (ALD) is highly advantageous for effectively sealing all four edges 011...014 of a color conversion film (rectangular in shape) with a highly uniform inorganic layer of thickness that is free of pinholes and other defects across the entire surface of the four edge regions and completely covers cracks (even internal cracks). In comparison, conventional chemical vapor deposition and physical vapor deposition methods are disadvantageous because they exhibit directional deposition of inorganic materials. Conventional methods are prone to the shadowing effect, which means that, for example, cracks or other defects in the edge regions of the color conversion film are not covered with a uniform inorganic layer (see Figure 2), allowing oxygen and / or HO to diffuse into the color conversion film, resulting in edge penetration. It is not possible to deposit the inorganic layer with a uniform thickness on all four edge regions of the color conversion film in a single processing step. On the other hand, ALD allows for a uniform thickness of the inorganic layer on all four edge regions in a single ALD process, and the cracks / defects are completely covered by such a uniform inorganic layer because ALD is less prone to shadowing effects. That ALD can achieve such good results is surprising given the teachings of Nehm et al., cited above.

[0099] Furthermore, we found that a cost-effective ALD batch process can efficiently deposit uniform inorganic layers simultaneously on all four edge regions with multiple color conversion films. This batch process can also optionally deposit such uniform inorganic layers on the top and bottom film regions (see Figures 5–7b), which can make the color conversion films more stable to oxygen and / or moisture or eliminate the need for expensive barrier films (typically inorganic layers on a PET substrate) when fabricating native color conversion films.

[0100] In view of the above, methods A, B, and C disclosed below are particularly suitable for obtaining a film 010 of the present invention comprising a sealing layer 030 that provides complete and defect-free coverage on the edges and an optional additional sealing layer 030' that provides complete and defect-free coverage on the main surfaces.

[0101] Method A, see FIG. 4: In one embodiment, prior to the ALD process, the color conversion film does not yet include an inorganic encapsulation layer (i.e., a native color conversion film 010') in all four edge regions and in the top and bottom film regions, which are in physical contact with either another color conversion film (see FIG. 4) or a separate film (not shown). This method results in a color conversion film in which, after the ALD process, all four edge regions are covered with an inorganic encapsulation layer 030, but the top and bottom films are uncovered or substantially uncovered. As noted above, diffusion effects may result in partial coverage of surface regions adjacent to the edges. Such side effects are not shown in the figures and do not adversely affect film properties.

[0102] A separation film (not shown) can be used to prevent direct contact between different color conversion films or to minimize diffusion of ALD precursors to the interface between the two color conversion films, thereby minimizing deposition of inorganic layers on the upper and lower film regions. Suitable separation films are polymeric or metallic films. Preferably, they are soft polymeric films, such as elastomeric polymeric films (e.g., PDMS) or other soft polymeric films (e.g., PTFE).

[0103] Method B, see Figure 5: In a further embodiment, the color conversion film before the ALD process does not yet include an inorganic encapsulation layer on all four edge regions and on the top and bottom film regions, which are separated by air gaps, thereby resulting in a color conversion film 010 after step b of the ALD process in which all edge regions and both the top and bottom film regions are covered with an inorganic encapsulation layer 030, 030'.

[0104] Method C, see FIG. 8: The color conversion film of Method A is subjected to an additional ALD step. In this further step, films 010 are separated in the laminate 020 by voids permeable to ALD process gases 040. This method provides a film 010 of the present invention comprising edge sealing layers 030 on all edges and surface sealing layers 030' on both major surfaces, where thickness 030 > thickness 030'.

[0105] Atomic Layer Deposition (ALD): A key feature of the present invention is the implementation of ALD to produce layer 030 (step b) and optional layer 030' in step (b) or step (c). Atomic layer deposition (ALD) is a well-known manufacturing method. It must be distinguished from chemical vapor deposition (CVD). (ALD) is a thin film deposition technique based on the sequential use of gas-phase chemical processes. In the context of the present invention, an ALD reaction uses two gas-phase chemical precursors (also called "reactants"). These precursors react with the material surface, one at a time, in a sequential and self-limiting manner. Thin films are slowly deposited by repeated exposure to the separate precursors. Thus, in ALD, a film is grown on a substrate by exposing the substrate surface to alternating gas species (i.e., ALD precursors or ALD reactants, respectively). In contrast to chemical vapor deposition (CVD), multiple precursors are never simultaneously present in the reactor but are inserted as a series of sequential, non-overlapping pulses. In each of these pulses, precursor molecules react with the surface in a self-limiting manner. The reaction terminates when all reactive sites on the surface are consumed. Therefore, the maximum amount of material deposited on a surface after a single exposure to all precursors (a so-called ALD cycle) is determined by the nature of the precursor-surface interactions. By varying the number of cycles, it is possible to grow materials uniformly and with high precision on arbitrarily complex and large substrates. The ALD fabrication process thus produces very thin, conformal films with atomic-level control of film thickness and composition. To determine the thickness of the deposited ALD layer for a specific number of cycles, the ALD layer can be deposited on a silicon substrate and the layer thickness determined by X-ray reflectivity and ellipsometry.

[0106] In a further embodiment, the ALD process is carried out at temperatures between 50 and 170° C., preferably between 60 and 140° C., and most preferably between 70 and 120° C. Such reaction conditions are believed to be advantageous for compatibility with the polymeric materials present within the film 010′.

[0107] In a further embodiment, the ALD process is carried out at less than 10 mbar, preferably less than 1 mbar, and most preferably less than 0.1 mbar, these conditions ensuring a self-limiting reaction between the reactants and the surface.

[0108] The ALD process includes at least one ALD cycle, typically two or more ALD cycles, where one ALD cycle includes the following steps: b1. Introduction of the first reactant into the ALD reaction chamber. In this step, the first reactant is adsorbed onto the edges 011...014 and, optionally, onto the major surfaces 021, 022. b2. Optionally, purge the reaction chamber with a purge gas. This step removes any unadsorbed first reactant. b3. A second reactant is introduced into the ALD reaction chamber, where it reacts with the first reactant adsorbed on the substrate. Optionally, purge the reaction chamber with a purge gas. This step removes unreacted second reactant.

[0109] In one embodiment, 1 to 100 cycles, preferably 5 to 20 cycles, are carried out in step b.

[0110] In one embodiment, the first reactant for the ALD process is a metal-containing compound having a molecular weight of less than 500 g / mol, preferably less than 300 g / mol. In a further embodiment, the first reactant for the ALD process is selected from the list of metal chlorides, metal alkoxides, metal alkyls, and metal alkylates. In a further embodiment, the first reactant for the ALD process is a metal alkyl, metal alkoxyl, or metal chloride compound containing silicon, aluminum, titanium, zirconium, or hafnium, preferably consisting of aluminum. In a further embodiment, the first reactant for the ALD process is selected from the list of AlCl, TiCl, ZrCl, SiCl, Al-isopropoxide, Ti-isopropoxide, Al(CH), Ti(CH), Si(CH), preferably Al(CH), Ti(CH), and Si(CH). Such starting materials are commercially available and can be used as purchased.

[0111] In one embodiment, the second reactant is selected from the group consisting of H2O or ozone.

[0112] In a further embodiment, the purging gas is nitrogen or CO2, preferably nitrogen. [Example]

[0113] Comparative Example 1 (unsealed film with red and green emitting layers): A color conversion film consisting of a green light-emitting polymer layer having perovskite crystals and a red light-emitting polymer layer having indium-containing core-shell quantum dots is prepared as follows: The color conversion film does not include a sealing layer in the edge region.

[0114] Preparation of Comparative Example 1: Formulation of Green Coating Formulation: Green perovskite luminescent crystals with the composition formamidinium lead tribromide (FAPbBr3) were synthesized in toluene as follows: Formamidinium lead tribromide (FAPbBr3) was synthesized by grinding PbBr2 and FABr: 16 mmol of PbBr2 (5.87 g, 98% ABCR, Karlsruhe, DE) and 16 mmol of FABr (2.00 g, Greatcell Solar Materials, Queanbeyan, AU) with yttrium-stabilized zirconia beads (5 mm diameter) for 6 hours to obtain pure cubic FAPbBr3, which was confirmed by XRD. Orange FAPbBr3 powder was added to oleylamine (80-90, Acros Organics, Geel (BE)) (weight ratio FAPbBr3:oleylamine = 100:15) and toluene (>99.5%, Puriss, Sigma-Aldrich). The final concentration of FAPbBr3 was 1 wt%. The mixture was then milled and dispersed using 200 μm diameter yttrium-stabilized zirconia beads at ambient conditions (unless otherwise specified, atmospheric conditions for all experiments were 35 °C, 1 atm, in air) for 1 h, resulting in a green-emitting ink. 0.1 g of green ink was mixed in a Speedmixer with a UV-curable monomer / crosslinker mixture (0.7 g of FA-513AS, Hitachi Chemical, Japan / 0.3 g of Miramer M240, Miwon, Korea) containing 1 wt % of the photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TCI Europe, The Netherlands) and 2 wt % polymeric scattering particles (organopolysiloxane, Shin-Etsu Chemical, KMP-590). The toluene was then evaporated under vacuum (<0.01 mbar) at room temperature.

[0115] Formation of green light-emitting polymer layer: The obtained green coating formulation was coated on a 25 micron barrier film (supplier: I-components, Korea; film configuration: PET substrate / SiOx layer / adhesive layer) with a layer thickness of 50 microns on the adhesive layer side, and then laminated with a 100 micron PET film. The laminated structure was then UV-cured for 60 seconds (UVAcube 100 equipped with a mercury lamp and quartz filter, Hoenle, Germany). The initial performance of the as-obtained film was Green emission wavelength of 526 nm with a FWHM of 22 nm showed.

[0116] Formation of the red coating formulation: 0.1 g of red-emitting crystals, which were isotropic core-shell QDs with an InP core and a ZnS shell (1 wt % suspension in toluene), were mixed in a Speedmixer with a UV-curable monomer / crosslinker mixture (0.5 g FA-DCPA, Hitachi Chemical, Japan / 0.5 g Miramer M2372, Miwon, Korea) containing 1 wt % of the photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TCI Europe, The Netherlands) and 2 wt % of polymeric scattering particles (organopolysiloxane, Shin-Etsu Chemical, KMP-590). The toluene was then evaporated under vacuum (<0.01 mbar) at room temperature.

[0117] Formation of the red-light-emitting polymer layer: First, the PET film was peeled off from the green-light-emitting laminate prepared as described above. The resulting red coating formulation was then coated onto the green-light-emitting polymer layer in a layer thickness of 50 microns. This was then laminated with the same type of barrier film used in the green-light-emitting laminate, with the adhesive layer side adjacent to the red-light-emitting polymer layer. The laminate structure was then UV-cured for 60 seconds (UVAcube 100 equipped with a mercury lamp and quartz filter, Hoenle, Germany). The initial performance of the as-obtained film was: It exhibited a green emission wavelength of 630 nm with a FWHM of 45 nm. The resulting film was cut into rectangular pieces of 10 cm x 7 cm and had the following configuration: barrier film (25 microns) - green light emitting layer (50 microns) - red light emitting layer (50 microns) - barrier film (25 microns), with no edge sealing.

[0118] Comparative Example 2 (PLD Edge—Encapsulating Film with Red and Green Light-Emitting Layers): A color conversion film was used as in Comparative Example 1, except that the color conversion film included a sealing layer in the edge region that was coated by PLD (Pulsed Laser Deposition) technology.

[0119] Preparation of Comparative Example 2: Coating of AlOx edge seals by PLD: An 80 nm thick AlOx seal layer was deposited by pulsed laser deposition (PLD) on each edge of the film obtained from Comparative Example 1. Because this method is directional deposition, the rectangular film had to be processed four times (repositioned after each PLD process) to coat each of the four edges with an AlOx seal layer. After PLD processing, the stack was disassembled to obtain a 10 cm x 7 cm inventive film with a dense AlOx seal layer on each of the four edges.

[0120] Test results for Comparative Examples 1 and 2: The stability of the unencapsulated color conversion film of Comparative Example 1 and the PLD-encapsulated color conversion film of Comparative Example 2 was tested for 500 hours in a constant temperature and humidity chamber at 65°C and 95% relative humidity using 10 cm x 7 cm rectangular cut pieces. The average edge penetration at all four edges was measured separately for green and red emission. (Red edge penetration refers to the distance from the film edge toward the film center where red emission is absent or strongly reduced compared to the film center, and green edge penetration refers to the distance from the film edge toward the film center where green emission is absent or strongly reduced compared to the film center.) Additionally, the number of edge penetration spikes (localized points with higher edge penetration than the average edge penetration at all four edges) was determined visually at all four edges. (Edge penetration spikes can be due to cracks at the film edges or localized barrier film delamination.)

[0121] Results after 500 hours at 65°C / 95%RH for pristine film without inorganic edge seal: -Average green edge penetration for all 4 edges: 1.5mm -Average red edge penetration for all 4 edges: 1.0mm - Number of edge penetration spikes for all four edges: Average edge penetration is too large to be determined

[0122] With PLD deposition inorganic edge sealing Results for this film after 500 hours at 65°C / 95%RH: -Average green edge penetration for all 4 edges: <0.1mm -Average red edge penetration for all 4 edges: <0.1mm -Number of edge penetration spikes for all 4 edges: 12

[0123] Conclusions for Comparative Example 1 and Comparative Example 2: These results show that the initial film without inorganic edge sealing exhibited significant edge intrusion for green and red due to the lack of edge sealing. The results show that the PLD-deposited inorganic sealing layer prevented average green and red edge intrusion, but there were still 12 edge intrusion spikes, indicating cracks or defects at the edges. This indicates that the edges are not uniformly covered by the PLD-coated inorganic layer, and therefore, oxygen and / or moisture can penetrate the color conversion film at these defect sites.

[0124] Example 1: (Invention) a green light-emitting polymer layer having perovskite crystals and a red light-emitting polymer layer having core-shell quantum dots containing indium; end area A color conversion film containing an ALD-deposited inorganic sealing layer was prepared as follows.

[0125] Manufacturing: Ten color conversion films (initial films without inorganic edge sealing) from Comparative Example 1 were separated by 200 micron PDMS films to form a pile / stack, which was then compressed with clamps and placed in the reaction chamber of an ALD batch reactor. The entire pile of color conversion films was then coated with a PDMS film of thickness 1000 μm using the ALD process described by Nehm et al. (ACS Appl. Mater. Interfaces 2015, 7, 22121-22127). 20nmAn AlOx inorganic encapsulation layer was deposited. Similar to Nehm et al., the ALD deposition process was performed at 80 °C. The first reactant gas was electronic grade trimethylaluminum, and the second reactant gas was deionized water.

[0126] As a result, the main surface of each color conversion film was free of AlOx encapsulation layer (except for the topmost color conversion film in the pile of color conversion films), but all four edges were coated with a 20 nm AlOx encapsulation layer.

[0127] Test Results, Example 1: This film was subjected to the same deterioration test as in Comparative Examples 1 and 2. With ALD deposited AlOx edge sealing Results for this film after 500 hours at 65°C / 95%RH: -Average green edge penetration for all 4 edges: 0mm -Average red edge penetration for all 4 edges: 0mm -Number of edge penetration spikes for all 4 edges: 0

[0128] Conclusion Example 1: This result indicates that the ALD-deposited AlOx encapsulation layer effectively prevented oxygen and / or moisture diffusion from the edge regions into the color conversion film, indicating that all cracks and other defects were uniformly covered with the AlOx encapsulation layer, preventing edge penetration at these defect sites. This further demonstrates the advantages of ALD-deposited inorganic encapsulation layers over inorganic encapsulation layers deposited by other directional deposition methods, such as PLD.

[0129] Example 2 (Invention, ALD deposition on edge and main surface): a green light-emitting polymer layer having perovskite crystals and a red light-emitting polymer layer having core-shell quantum dots containing indium; Edge region and two major surfaces A color conversion film containing an ALD-deposited inorganic sealing layer was prepared as follows.

[0130] Manufacturing: Step A: A color conversion film was prepared according to Comparative Example 1, in which the two barrier films (containing SiOx as a barrier material) were replaced with two 100 micron PET films with adhesive layers. The resulting film was cut into a 10 cm x 7 cm rectangular piece with the following configuration: PET layer (100 microns) - green light-emitting layer (50 microns) - red light-emitting layer (50 microns) - PET film (100 microns), without edge sealing.

[0131] A 20 nm thick AlOx encapsulation layer was then deposited on the pile / stack of color conversion films according to the procedure in Example 1. Thus, an ALD-coated AlOx encapsulation layer was formed on each of the four edges (Film 2.A).

[0132] Step B: The pile / stack of ALD-treated color conversion films was then ALD-treated again under the same ALD processing conditions as in Example 1, except for the following changes: - The PDMS separation film was removed from the pile / stack. The pile / stack of edge-sealed color conversion films was rotated in the ALD reaction chamber so that one edge of the color conversion film was positioned at the bottom of the reaction chamber, and the color conversion films were positioned vertically. The color conversion films were separated from each other to leave an air gap of approximately 5 mm between each color conversion film, allowing the ALD reactants to diffuse into the air gap and deposit ALD layers on both major surface areas (i.e., the upper and lower film areas).

[0133] The resulting ALD-processed color conversion film contained AlO in all four edge regions and in both the top and bottom film regions. x The sealing layer is shown (Film 2.B).

[0134] Test Results, Example 2: This film was subjected to the same deterioration test as above. All edge areas and top and bottom film areas ALD deposited AlO x For films with a sealing layer, the results after 500 hours at 65°C / 95%RH are: -Average green edge penetration for all 4 edges: 0mm -Average red edge penetration for all 4 edges: 0mm -Number of edge penetration spikes for all 4 edges: 0

[0135] The following color conversion films in this experiment were used to measure the brightness values ​​with a blue backlight using a Konica Minolta spectrometer (CS-2000) before and after the stability test, and the decrease in brightness of the films after leaving them in an environment of 65°C / 95% RH for 500 hours was also compared: -Color conversion film with AlOx encapsulation layer on all edge areas but no AlOx layer on the top and bottom film areas → Brightness reduction: -65% -Color conversion film with AlOx encapsulation layer on all edge areas and upper and lower film areas → Brightness reduction: -8%

[0136] Conclusion Example 2: These results indicate that the AlOx encapsulation layer deposited by ALD effectively prevented oxygen and / or moisture from diffusing into the color conversion film from the edge regions. This indicates that all cracks and other defects were uniformly covered with the AlOx encapsulation layer, preventing edge penetration at these defect sites. Furthermore, these results demonstrate that the ALD batch process procedure used in this experiment can effectively encapsulate not only the film edges but also the top and bottom film regions. This avoids the use of expensive barrier films (including inorganic layers) in the fabrication of native color conversion films.

[0137] Comparative Example 3: (Commercially Available Product) Manufacturing: A color conversion film consisting of red and green indium phosphide quantum dots was obtained by disassembling a commercially available Samsung TV (model: QN85A, manufactured in 2021). The red and green quantum dots in this color conversion film are present in a single light-emitting polymer layer sandwiched between two inorganic barrier films (barrier film configuration: PET substrate / inorganic layer / adhesive layer).

[0138] Stability testing was performed on 10 cm x 7 cm films following the procedure of the previous examples. Results after 500 hours at 65°C / 95%RH for pristine films without inorganic edge seals: -Average green edge penetration for all 4 edges: 1.0mm -Average red edge penetration for all 4 edges: 1.0mm - Number of edge penetration spikes for all four edges: Average edge penetration is too large to be determined

[0139] Example 3: (Commercially available product improved with ALD deposition on edge) Manufacturing: A color conversion film consisting of red and green indium phosphide quantum dots was obtained by disassembling a commercially available Samsung TV (model: QN85A, manufactured in 2021). The red and green quantum dots in this film are present in a single light-emitting polymer layer sandwiched between two inorganic barrier films (barrier film configuration: PET substrate / inorganic layer / adhesive layer).

[0140] A pile / stack of 10 pieces of such film with a size of 10 cm x 7 cm was subjected to ALD treatment using the same procedure as in Example 1.

[0141] Test Results, Example 3: With ALD deposited AlOx edge sealing Results after 500 hours at 65°C / 95%RH for a film of (Invention, Example 3.2): -Average green edge penetration for all 4 edges: 0mm -Average red edge penetration for all 4 edges: 0mm -Number of edge penetration spikes for all 4 edges: 0

[0142] Conclusion Example 3: This result indicates that the Al-deposited AlOx encapsulation layer effectively prevented oxygen and / or moisture diffusion from the edge regions into the color conversion film. This indicates that all cracks and other defects were uniformly covered with the AlOx encapsulation layer, preventing edge penetration at these defect sites. Furthermore, this method of the present invention significantly improved over commercially available films that are considered to be state-of-the-art.

[0143] Summary of working examples: The above examples can be summarized as follows:

[0144] [Table 1]

[0145] The properties of the sealing layer (030) on the edge can be summarized as follows:

[0146] [Table 2]

[0147] For edge penetration, the results obtained after 500 hours at 65°C / 95%RH were as follows:

[0148] [Table 3]

[0149] Thus, ALD edge coating solves the edge penetration problem and also significantly improves commercial products.

[0150] In terms of performance, after 500 hours at 65°C / 95%RH the following results were obtained:

[0151] [Table 4]

[0152] Thus, ALD surface coatings solve the brightness degradation problem and are therefore suitable to replace commercially available barrier films.

Claims

1. A sealed color conversion film (010) comprising a native color conversion film (010') and one or more sealing layers (030), The native color conversion film (010') - has two main faces (021, 022) and at least one edge (011, 012, 013, 014), - a color conversion material (80, 100, 200) that emits light in the visible range when excited by blue light, The sealing layer (030) is - comprises, preferably consists of, inorganic materials, - disposed on all edges of the native color conversion film to provide complete and defect-free coverage of the edges; - has a thickness of between 1 nm and 500 nm, preferably between 2 nm and 90 nm; and - has a standard deviation of thickness of less than 3%, including at all edges; Color conversion film.

2. 10. The color conversion film of claim 1, wherein the encapsulation layer (030) is obtained by an atomic layer deposition process ("ALD process").

3. It is rectangular in shape and has upper and lower surfaces (021, 022) and four ends (011, 012, 013, 014); - aspect ratios of 4:3, 3:2, 16:9 or 3:1, - Diagonal from 5 cm to 250 cm, - a thickness between 10 and 500 micrometers, satisfy one or more of the following characteristics: The color conversion film according to claim 1 or 2.

4. a light-emitting polymer layer comprising a green conversion material (100) and optionally a further light-emitting polymer layer comprising a red conversion material (200), or - a light-emitting polymer layer comprising a green conversion material (100) and a red conversion material (200), and the green conversion material emits green light when excited by blue light; The red conversion material emits red light when excited by blue light. The color conversion film according to any one of claims 1 to 3.

5. - said green converter material (100) is selected from the group of perovskite crystals, - said red conversion material (200) is selected from the group of core-shell quantum dots containing indium; The color conversion film according to claim 4 .

6. The inorganic sealing layer (030) comprises or consists of one or more metal oxides, preferably the inorganic sealing layer (030) comprises or consists of the following layer sequence: AlO ｘ / MO ｘ (wherein M=Si, Zr, Ti, Hf), The color conversion film according to any one of claims 1 to 5.

7. - the color conversion film (010) comprises an inorganic sealing layer (030) covering all edges ("edge sealing"), but the main surface (030') of the color conversion film (010) is free or substantially free of an inorganic coating, or - the color conversion film (010) has, in addition to the inorganic sealing layer (030) ("edge sealing") covering all edges, an inorganic sealing layer (030') ("surface sealing") covering both main surfaces, the thickness of the surface sealing (030') being smaller than the average thickness of the edge sealing (030), and the inorganic material of the surface sealing (030') being the same as or different from the inorganic material of the edge sealing (030), or - the color conversion film (010) has, in addition to the inorganic sealing layer (030) ("edge sealing") covering all edges, an inorganic sealing layer (030') ("surface sealing") covering both main surfaces, the surface sealing (030') and the edge sealing (030) having substantially the same thickness, and preferably the inorganic material of the surface sealing (030') is the same as the inorganic material of the edge sealing (030); The color conversion film according to any one of claims 1 to 6.

8. The inorganic surface sealing layer (030') comprises or consists of one or more metal oxides, preferably the inorganic surface sealing layer (030') comprises or consists of the following layer sequence: AlO ｘ / MO ｘ (wherein M=Si, Zr, Ti, Hf), the color conversion film according to claim 7.

9. a layer sequence of green light-emitting polymer layer containing perevskite crystals / red light-emitting polymer layer containing indium-containing core-shell quantum dots, or - a layer sequence of an intermediate layer comprising an acrylate polymer or a methacrylate polymer / a green light-emitting polymer layer comprising perovskite crystals / a red light-emitting polymer layer comprising core-shell quantum dots comprising indium; The color conversion film according to any one of claims 1 to 8, comprising:

10. A color conversion film according to any one of claims 1 to 9, comprising one or more additional layers 070 at the top and / or bottom, which do not include an inorganic sealing layer (030) in the edge regions.

11. A method for producing the color conversion film according to any one of claims 1 to 10, comprising: (a) providing a plurality of native color conversion films (010') and assembling the plurality of native color conversion films (010') into a stack (020); (b) subjecting the stack of step (a) to a first atomic layer deposition ("ALD") process to obtain an encapsulated stack of color conversion films (010); (c) optionally repeating step (a) and step (b) to obtain a multi-encapsulated color conversion film; (d) optionally subjecting the sealed color conversion film or the multi-sealed color conversion film to a finishing process; A method comprising:

12. In step (a), The laminate (020) comprises native color conversion films (010') that are in direct contact with each other via their respective major surfaces, or native color conversion films (010') that are separated by an auxiliary separating film, This results in a color conversion film with sealed edges. The method of claim 11.

13. In step (a), The stack (020) comprises a plurality of native color conversion films (010'), each separated from the other by an air gap; This results in a color conversion film having edge seals and surface seals, wherein the edge seals and the surface seals comprise the same material and are the same or essentially the same thickness. The method of claim 11.

14. In step (c), a second ALD process is carried out after the initially obtained stack has been reassembled into a modified stack in which each of the initially obtained color conversion films (010) is separated from each other by an air gap; This results in a color conversion film having edge sealing and surface sealing, wherein the edge sealing layer and the surface sealing layer contain the same or different inorganic materials, and the thickness of the surface sealing layer is smaller than the thickness of the edge sealing layer. The method of claim 11.

15. The ALD process is subject to one or more of the following parameters: - the ALD process is carried out at 50°C to 170°C; - the ALD process is carried out at less than 10 mbar; the first reactant for the ALD process is selected from the group consisting of metal chlorides, metal alkoxides, and metal alkylates; The second reactant for the ALD process is H ２ selected from the group consisting of O and ozone; The method according to any one of claims 11 to 14.

16. A color conversion film obtainable by the method according to any one of claims 11 to 15, preferably a color conversion film according to any one of claims 1 to 10.

17. A backlight component for a display, comprising the color conversion film according to any one of claims 1 to 9 and 16.

18. A light-emitting device, preferably a liquid crystal display, comprising the color conversion film according to any one of claims 1 to 9 and claim 16.

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