Method for preparing a pocket of encapsulated material containing a core surrounded by encapsulation.

Abstract

The present invention relates to a method for preparing pockets containing encapsulated material. The pockets are formed by first forming one or more bases B of a barrier material on a substrate, followed by applying a core material on at least a part of the bases B and forming a lid L on the bases B provided with the core material. The core material comprises at least one photoemissive particle or compound, such as a quantum dot. The present invention also relates to a pocket or pockets containing encapsulated material obtained by such a method, a device comprising the encapsulation material of at least one pocket, and a process for transferring the encapsulated material of such pockets from one substrate to another.

Description

[Technical Field]

[0001] Field of the present invention The present invention relates to a method for preparing at least one, preferably more than one, pocket containing an encapsulated material. Such a pocket comprises a core material (encapsulated material) surrounded by an encapsulation body containing a barrier material. The present invention also relates to one or more pockets containing the encapsulated material obtained by such a method. [Background technology]

[0002] Background technology Many materials, particularly nanomaterials, are highly sensitive and need to be protected from their surroundings to avoid decomposition. Semiconductor nanocrystals or quantum dots (QDs) are especially susceptible to chemical decomposition when exposed to oxygen or water vapor. Chemical decomposition of quantum dots inevitably leads to a decrease in their radiative efficiency and should therefore be avoided.

[0003] Quantum dots, characterized by their spectrally narrow and tunable photoluminescence, are of particular interest as photoluminescent color converters for applications such as displays, lighting, and projection. However, the sensitivity of quantum dots is one of the main, significant, and long-standing drawbacks of using quantum dots in most applications. This problem is even more pronounced in lighting and display applications, where the emitted color and intensity must remain constant throughout continuous operation for thousands of hours. Quantum dots can be implemented as so-called remote phosphors, which allows them to be sufficiently isolated from the main blue LED, or they can be precisely placed directly on the blue LED chip (on-chip approach). The on-chip approach implicitly involves localized heating of the quantum dots (around 100°C), which would further accelerate the decomposition of the quantum dots.

[0004] For example, the precise mechanism of quantum dot decomposition by oxygen and / or water vapor remains unclear, and significant global research efforts are being made to create more resistant quantum dots. Nevertheless, it is established that gas diffusion barriers must be implemented in some form in quantum dot-based devices for the development of large-scale and reliable quantum dots.

[0005] To protect quantum dots from oxygen and water vapor, they are typically encapsulated. Currently, there are two main strategies for encapsulating such materials: the thin-film encapsulation (TFE) approach and the bead approach. In both cases, quantum dots are typically embedded in a polymer resin. The resin is poured and cured as a thin film (TFE) or as micro-sized particles (beads). Barrier properties are implemented by applying multiple alternating layers of inorganic materials (e.g., SiO2, TiO2, or Al2O3) and organic (polymer) materials on the film or beads. This multilayer barrier approach is designed to bypass the unavoidable presence of defects in the inorganic layer by creating meandering pathways for gas diffusion. However, multilayer applications typically require various continuous deposition techniques, among others, atomic layer deposition (ALD), chemical vapor deposition (CVD), and vacuum deposition methods such as sputtering. As a result, multilayer applications result in complex and expensive manufacturing processes. Furthermore, materials encapsulated using the TFE approach may suffer from a so-called edge ingress effect on their sides. In the bead approach, quantum dots are isotropically protected by multilayer barriers, but the physical deposition of inorganic barrier layers around the microparticles remains technically challenging. Moreover, the beads need to be mixed again with another resin to enable further processing.

[0006] Therefore, it is clear that there is a need to provide nanomaterials that are adequately protected from decomposition by oxygen and water vapor. In particular, there is a need to provide quantum dots that are adequately protected from decomposition by oxygen and water vapor.

[0007] For example, since nanomaterials such as quantum dots are highly sensitive materials, it is clear that any processing of such nanomaterials must take into account their highly sensitive nature. Such processing of nanomaterials would, in practice, not involve any treatments that implicitly involve the use of high temperatures. Furthermore, the processing of nanomaterials is preferably suitable for large-scale manufacturing. [Overview of the Initiative]

[0008] Summary of the present invention The object of the present invention is to provide a method for preparing pockets containing encapsulated material that avoid the drawbacks of the prior art. This method is particularly suitable for preparing pockets containing quantum dots as the encapsulated material.

[0009] Another object of the present invention is to provide a method for preparing a pocket containing encapsulated material, wherein the encapsulated material is not subjected to edge ingress.

[0010] A further object of the present invention is to provide a method for preparing pockets containing encapsulated material that do not require the continuous formation of multilayer encapsulated bodies using various techniques.

[0011] A further object of the present invention is to provide a method for preparing an array of pockets containing encapsulated material, which allows for the combination of different types of pockets, for example, pockets containing different encapsulated materials, in a single array.

[0012] A further object of the present invention is to provide a method for preparing pockets containing encapsulated materials, which makes it possible to obtain a high versatility of shapes in two or three dimensions.

[0013] Another object of the present invention is to provide a method that enables the preparation of large-scale as well as miniaturized production of pockets of encapsulated materials.

[0014] A further object of the present invention is to provide pockets of encapsulated materials and an array of pockets of encapsulated materials.

[0015] Furthermore, an object of the present invention is to provide pockets containing encapsulated materials including quantum dots and an array of pockets containing encapsulated materials including quantum dots.

[0016] A further object of the present invention is to provide a device including pockets of encapsulated materials, for example, containing quantum dots.

[0017] Yet another object of the present invention is to provide a process for transferring pockets of encapsulated materials, particularly a process for transferring pockets containing quantum dots.

[0018] According to a first aspect of the present invention, there is provided a method for preparing at least one pocket, preferably a plurality of pockets, containing an encapsulated material. At least one such pocket of encapsulated material comprises a core material surrounded, preferably completely surrounded, by an encapsulant comprising a barrier material. The method according to the present invention comprises a. hereinafter, a1. applying a barrier material b containing a resin, for example, a layer of barrier material b, onto a substrate; a2. locally curing the barrier material b to form one or more bases B of the cured barrier material b, each base B being spatially distinct from another base B, and each base B being an area A of the substrateB Cover; a3. Remove the uncured barrier material b; The step of forming one or more barrier material bases B on a substrate, b. Below, b1. Applying a core material c comprising a resin and at least one photoemissive particle or photoemissive compound, for example, a layer of core material c (containing the resin and at least one photoemissive particle or photoemissive compound), onto the substrate obtained from step a; b2. Locally harden the core material c, forming one or more core deposits of the hardened core material c, each core deposit of the hardened core material c accumulating on top of the base B, and none of the hardened core material c spread beyond area AB; b3. Remove the uncured core material c; The step of forming a core material c on the upper part of at least a portion of the base B, c. Below, c1. Applying a barrier material l containing resin, for example, a layer of barrier material l, onto the substrate obtained from step b; c2. Locally harden the barrier material l and form a lid L of the hardened barrier material l on top of each base B fitted with the core material c, each lid L being spatially separated from another lid L, and each base B fitted with the core material c and the lid L formed on top of the base B form a pocket, thereby completely encapsulating the core material c provided on the base B of the pocket. c3. Remove the uncured barrier material l. The steps include: forming one or more base portions B on a substrate equipped with a core material, and forming one or more lid portions L of a barrier material on the substrate; Includes.

[0019] The combination of all core materials c accumulated on the base B is referred to as core C. Core C can be formed by applying core materials c, curing core materials c, and removing uncured core materials c, i.e., by performing steps b1 to b3 once. Alternatively, core C can be formed by performing steps b1 to b3 more than once, thereby applying either the same core material c or different core materials c in various iterations of steps b1 to b3.

[0020] In the specific method, the first core material c1 is formed on the base B by applying the first core material c1, curing the first core material c1, and removing the uncured first core material c1, i.e., by performing steps b1 to b3. Subsequently, the second core material c2 is formed on the base B by applying the second core material c2, curing the second core material c2, and removing the uncured second core material c2, i.e., by performing steps b1 to b3 twice. In this case, the barrier material is applied on the base B in contact with the deposit of the first core material c1 between forming the second core material and forming the second core material.

[0021] It is clear that core C may include more than two different types of core materials, for example, a first core material c1, a second core material c2, and any further core material cn.

[0022] The application of barrier material b (step a1), core material c (step b1), and / or barrier material l may be carried out by any technique known in the art. Preferred techniques for applying barrier material b, core material c, and / or barrier material l include techniques for applying extrusion, doctor blade method, jet method, and roll-to-roll method.

[0023] The curing of barrier material b (step a2), core material c (step b2), and / or barrier material l (step c2) may include any type of curing known in the art. Preferably, the curing of barrier material b, core material c, and / or barrier material l includes photocuring. Photocuring involves hardening a material induced by exposure to a light source, typically a UV or visible light source.

[0024] Preferably, the application and local curing of barrier material b, the application and local curing of core material c, and / or the application and local curing of barrier material l include photolithography or digital optical modulation using a physical mask. Examples of photolithography using digital optical modulation include digital photoprocessing (DLP), laser-based stereolithography (SLA), liquid crystal display (LCD) masking, light crystal display (LCD) projection, and multiphoton lithography (e.g., two-photon lithography (TPL)).

[0025] Barrier material b, core material c, and / or barrier material l include resins, and more preferably photocurable resins. Resins are typically solid or viscous substances that can be converted into polymers. Often, resins are mixtures of organic compounds. Photocurable resins are resins that harden / solidify when exposed to light.

[0026] Preferred (photocurable) resins include photopolymers containing thiol-ene, acrylate, epoxy, urethane, or vinyl-based resins or mixtures thereof.

[0027] The barrier material b, core material c, and / or barrier material l may further contain at least one photoinitiator and / or at least one filler and / or at least one dye.

[0028] Preferred photoinitiators include 2,2-dimethoxy-2-phenylacetophenone (DMPA), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), or photoinitiators or photoinitiator blends from the Irgacure® or Darocur® product lines.

[0029] Possible fillers include inorganic fillers, 1D fillers, 2D fillers, or combinations thereof. Inorganic fillers include, for example, oxide particles such as SiO2, TiO2, or Al2O3 particles. 1D fillers include, for example, cellulose-based materials such as cellulose nanofibrils. 2D fillers include, for example, nanoclays such as montmorillonite nanoclay.

[0030] Preferred dyes include organic dyes that undergo photocatalytic biodegradation, such as Reactive Orange 16 or Orange Orasol G.

[0031] Preferably, both barrier material b and barrier material l have water vapor and oxygen barrier properties.

[0032] Barrier material b and barrier material l include, for example, a photocurable resin, at least one photoinitiator, and at least one 1D filler such as cellulose nanofibrils and / or at least one 2D filler such as nanoclay.

[0033] Barrier material b and barrier material l may contain the same material or different materials.

[0034] In a preferred embodiment, barrier material b and barrier material l of the encapsulated material pocket comprise the same material. Such an embodiment allows for the formation of a pocket of encapsulated material, where the core material is surrounded by an encapsulation layer comprising one material.

[0035] Core material c comprises a resin and at least one photoemission particle or photoemission compound, for example, at least one photoluminescent particle or at least one photoluminescent compound. Preferably, the core comprises a plurality of photoemission particles or photoemission compounds. Barrier material b and barrier material l preferably do not contain any photoemission particles or compounds.

[0036] Examples of photoemission particles or photoemission compounds include semiconductor nanocrystals such as quantum dots, organic dyes, inorganic phosphors, metal clusters, carbon dots, doped nanocrystals such as lanthanide-doped nanocrystals, or combinations thereof.

[0037] Particularly desirable photoluminescent particles include quantum dots.

[0038] The core material c includes, for example, a photocurable resin, at least one photoinitiator, and quantum dots.

[0039] According to the present invention, the encapsulated material pockets are preferably formed on a substrate. The substrate may include a flexible substrate or a rigid substrate. Preferred substrates include a Si wafer, a glass substrate, a metal substrate, or a polymer substrate.

[0040] If multiple bases B are applied to the substrate in step a, the different bases B applied to the substrate may have the same size and / or the same shape and / or the same area A B It may cover the substrate. Alternatively, a different type of base may be placed on the substrate, for example, having a first size and / or a first shape and / or a first area A of the substrate. B1 A first type of base B1 which may cover, having a second size and / or a second shape and / or a second area A of the substrate B1 A second type of base B2 which may cover the substrate, and optionally further areas A having a larger size and / or a larger shape. BfA further type of base Bf may be applied, which may cover the base.

[0041] In step b, the core material is applied to at least a portion of the base B. Preferably, the core material is applied to the entire base B. Alternatively, the core material is provided to only a portion of the base B.

[0042] A first core material c, for example, a layer of core material c, is applied to the substrate obtained from step a, i.e., to a substrate equipped with one or more bases B. Subsequently, this core material is locally cured to form one or more core deposits of cured core material c. The uncured core material is then removed.

[0043] The core deposit of hardened core material accumulated on base B is in area A B In other words, it does not spread beyond the area of ​​the substrate covered by the substrate.

[0044] Preferably, the top surface of base B is not completely covered with core material c. Most preferably, the outer circumference of the top surface of base B is not covered with core material. In other cases, the top surface of the core material accumulated on base B is completely covered with core material. In such cases, the core material is in area A B Area A is equal to c Cover.

[0045] In step c, one or more lid portions L of the barrier material are formed on top of at least a part of the base B. The first barrier material l, for example, a layer of the barrier material l, is applied onto a substrate provided with one or more bases B and provided with a core material, that is, onto the substrate obtained from step b. Subsequently, the barrier material l is locally cured to form a lid portion L of the cured barrier material on top of each base provided with the core material c. Then, the uncured barrier material l is removed. Each base B provided with the core material c and the lid portion B formed on top of this base B form a pocket. Thus, such a pocket contains the barrier material b of the base B and the barrier material of the lid portion L and completely encapsulates the core material c provided on top of the base B of this pocket.

[0046] For each pocket, the lid portion L covers the upper part of the core material and the outer edge of the core material accumulated on the base B of this pocket. Thus, the core material accumulated on the base B is completely encapsulated by the combination of the barrier material of the base B and the barrier material of the lid portion L. As a result, the core material and especially the optoelectron-emitting particle(s) or compound(s) present in the core material are completely encapsulated by the barrier material. The core material and especially the optoelectron-emitting particle(s) or compound(s) are not covered by edge ingress.

[0047] The lid deposit of the cured barrier material l or the lid portion L of the pocket may extend beyond area A B , that is, beyond the area of the substrate covered by the base B. Thus, the area A of the substrate covered by the lid portion L L may be larger than area A B .

[0048] In another aspect, area A L is equal to area A B (and does not extend beyond area A B ).

[0049] The base B may be formed by applying and curing one layer of substrate, or by repeatedly applying layers of barrier material and curing such barrier material. In such cases, step a of the above method for preparing a pocket of encapsulated material comprises, for example, n iterative steps of steps a1' to a3', where n is at least 2, and a1' to a3' comprises the following steps: For each iteration step i where a1'.i takes the range from 1 to n, barrier material b i Apply the layer of barrier material b to the substrate or to the substrate equipped with barrier material obtained from the iterative step prior to step a, thereby for each iterative step where i is greater than 1, the barrier material b i This includes the same or different barrier material used in the preceding iteration step of step a; For each iteration step i where a2'.i takes the range from 1 to n, barrier material b i The hardened barrier material b is localized and cured. i Forming one or more base deposits, a cured barrier material b i Each base deposit is in contact with the substrate or with a deposit of cured barrier material obtained in an iterative step prior to step a, forming one or more base Bs after iterative step n, each base B being spatially distinct from another base B, and each base B substrate having area A B Cover; a3'. For each iteration step i where i ranges from 1 to n, the uncured barrier material b i To remove it.

[0050] The number of iteration steps n is, in principle, not limited. The number of iteration steps n can be, for example, 2, 3, 4, 5, or 6.

[0051] It is clear that base B may include one base deposit or multiple base deposits of the hardened barrier material, for example, multiple deposits accumulated in contact with and / or on top of each other.

[0052] By repeating step a as described above, many types of base B and / or combinations of many types of base B can be obtained. For example, it is possible to provide multiple base B on a substrate, where the base B may contain the same barrier material, or where the base B or some of the base B may contain different barrier materials. For example, it is possible to provide a first type of base B containing a first barrier material, a second type of base B containing a second barrier material, and one or more further types of bases optionally containing further barrier materials. Furthermore, it is also possible to provide base B or multiple base B, where each base B contains one type of barrier material or various types of barrier materials. Base B may include, for example, a first layer containing a first barrier material, a second layer containing a second barrier material, and one or more further layers optionally containing further barrier materials. In addition, base B may include deposits of hardened barrier material in contact with each other. Such deposits may contain the same barrier material or different barrier materials. The base may include, for example, a deposit of a hardened first barrier material, a deposit of a hardened second barrier material, and optionally a deposit of a further hardened barrier material, together forming a single base B.

[0053] The core material accumulated on top of one or more base portions B and / or lid portions L may also be formed by multiple repetitions of the application of the core material and barrier material, and the curing of such core material and barrier material, respectively.

[0054] In a case where the core material accumulated on the base B is formed by multiple repetitions of the application and curing of the core material, step b of the above method for preparing a pocket of encapsulated material comprises, for example, m iterations of steps b1' to b3', where m is at least 2, and b1' to b3' comprises the following steps: For each iteration step i where b1'.i takes the range from 1 to m, the core material c i Apply the layer of the core material c to the substrate obtained from step a or from a subsequent iteration step in step b, thereby for each iteration step where i is greater than 1 i This includes the same or different core material used in the iterative step preceding step b; For each iteration step i where b2'.i takes the range from 1 to m, the core material c i The hardened core material c is localized and hardened. i Forming one or more core deposits, a cured core material c i Each core deposit is in contact with the base B, or with a deposit of the cured core material obtained in an iterative step prior to step b, and all of the core deposits of the cured core material are in area A B It does not spread beyond a certain point; For each iteration step i where b3'.i takes the range from 1 to m, the uncured core material c i To remove it.

[0055] The number of iteration steps m is, in principle, not limited. The number of iteration steps m can be, for example, 2, 3, 4, 5, or 6.

[0056] It is clear that the core material accumulated on base B may include one core deposit or multiple base deposits of hardened core material, for example, accumulated in contact with and / or on top of each other.

[0057] By repeating step b as described above, a high degree of flexibility can be obtained for the accumulation of core materials and / or combinations of core materials. For example, it is possible to apply the same core material to all bases B, or to apply different core materials to different bases B. For example, it is possible to apply a first type of core material to a specific base B, a second type of core material to another base B, and optionally further types of core materials to further bases B. In a preferred method, a first type of core material containing a first type of quantum dot, e.g., green quantum dots, is applied to a specific base B, and a second type of core material containing a second type of quantum dot, e.g., red quantum dots, is applied to another base B.

[0058] Furthermore, the base B may be equipped with one type of core material or various types of core materials. The base B may include, for example, a first layer containing a first core material, a second layer containing a second core material, and one or more further layers optionally containing further core materials. In a preferred method, a first type of core material containing a first type of quantum dot, e.g., green quantum dots, and a second type of core material containing a second type of quantum dot, e.g., red quantum dots, are applied to the base B.

[0059] In addition, the base B may be provided with deposits of core materials that are cured in contact with each other. Such deposits may contain the same core material or different core materials. The base may be provided with, for example, a cured deposit of a first core material, a cured deposit of a second core material, and optionally a deposit of further cured core materials. In a preferred method, the base B is provided with a cured deposit of a first type of core material containing a first type of quantum dot, e.g., green quantum dots, and a cured deposit of a second type of core material containing a second type of quantum dot, e.g., red quantum dots.

[0060] In cases where one or more lid portions L are formed by repeatedly applying and curing a barrier material, step c of the above method for preparing a pocket of encapsulated material comprises, for example, p iterative steps of steps c1' to c3', where p is at least 2, and c1' to c3' comprises the following steps: For each iteration step i where c1'.i takes the range from 1 to p, the barrier material l i Apply the layer of the barrier material l on the substrate obtained from step b or on the substrate obtained from a subsequent iteration step c, thereby for each iteration step where i is greater than 1. i This includes the same or different barrier material used in the iterative step prior to step c; For each iteration step i where c2.i takes the range from 1 to m, the barrier material l i The barrier material l is locally cured to form a lid L for each base B equipped with the core material after the iterative step p. i To form one or more lid deposits, each lid L is spatially separated from another lid L, thereby forming a pocket between each base B equipped with core material c and the lid L provided on this base B, so that all core material provided on this base B is completely encapsulated by the combination of the base B and lid L in the pocket; For each iteration step i where c3.i takes the range from 1 to p, the uncured barrier material l i To remove it.

[0061] The number of iteration steps p is, in principle, not limited. The number of iteration steps p may be, for example, 2, 3, 4, 5, or 6.

[0062] It is clear that the lid L may include one lid deposit of the hardened barrier material l or multiple lid deposits of the hardened barrier material l, for example, so as to be accumulated in contact with each other and / or on top of each other.

[0063] The lid deposit of the cured barrier material may be in contact with the core material applied in step b, and / or (for iteration steps where i is greater than 1) with the barrier material obtained in the subsequent iteration step c. The lid deposit of the cured barrier material may also be in contact with the substrate (partially or entirely).

[0064] As mentioned above, for each pocket, the lid L covers the top of the core material and the outer edge of the core material accumulated on the base B of that pocket, so that the core material accumulated on the base B is completely encapsulated by the combination of the barrier material of the base B and the barrier material of the lid L.

[0065] By repeating step c as described above, many types of lids L and / or combinations of many types of lids L can be obtained. For example, it is possible to provide multiple lids L, where the lids L may contain the same barrier material, or where some of the lids L may contain different barrier materials. For example, it is possible to provide a first type of lid L containing a first barrier material, a second type of lid L containing a second barrier material, and one or more further types of lids L optionally containing further barrier materials. Furthermore, it is also possible to provide lids L or multiple lids L, where each lid L contains one type of barrier material or different types of barrier materials. A lid L may, for example, include a first layer containing a first barrier material, a second layer containing a second barrier material, and one or more further layers optionally containing further barrier materials. In addition, a lid L may include a deposit of barrier material hardened in contact with each other. Such a deposit may contain the same barrier material or different barrier materials. The lid L may include, for example, a deposit of a hardened first barrier material, a deposit of a hardened second barrier material, and optionally a deposit of a further hardened barrier material, together forming a single lid L.

[0066] It is clear that a method for preparing one or more pockets of encapsulated material according to the present invention may include a number of iterative steps a1' to a3' for forming one or more bases B and / or a number of iterative steps b1' to b3' for forming a core material on top of the bases B and / or one or more iterative steps c1' to c3' for forming one or more lids L of barrier material on a substrate equipped with one or more bases B. Similarly, a method for preparing one or more pockets of encapsulated material according to the present invention may include a number of iterative steps a1' to a3' for forming one or more bases B and / or a number of iterative steps b1' to b3' for forming a core material on top of the bases B and / or one or more iterative steps c1' to c3' for forming one or more lids L of barrier material on a substrate equipped with one or more bases B.

[0067] In a specific method according to the present invention, the substrate is provided with a release layer, for example, a thermal release layer, and at least one pocket of the encapsulated material is applied to the substrate provided with the release layer such that at least one pocket of the encapsulated material is in contact with the release layer. Alternatively, the method includes applying a release layer, for example, a thermal release layer, before applying at least one pocket of the encapsulated material, and in particular before forming one or more bases B on the substrate.

[0068] The presence of a release layer may facilitate the release of pockets containing encapsulated material. In cases where the release layer includes a thermal release layer, pockets containing encapsulated material may be released from the substrate by the application of heat, for example, by the application of localized heat.

[0069] A method according to the present invention may include one or more additional steps. The method may include, for example, an additional step of applying one or more first intermediate layers to the top of a base B between steps a and b of the method according to the present invention. Alternatively or in addition, the method may include an additional step of applying a second intermediate layer to a core material c between steps b and c of the method according to the present invention.

[0070] The first and / or second intermediate layer may act, for example, as a gas diffusion barrier layer.

[0071] The first and / or second intermediate layer may be applied by techniques applying immersion, extrusion, doctor blade, jet, and roll-to-roll methods, or by any technique known in the art, such as atomic layer deposition. Preferred techniques for applying the first and / or second intermediate layer include atomic layer deposition.

[0072] The first and / or second intermediate layer includes an oxide layer such as SiO2, TiO2, or Al2O3.

[0073] The method according to the present invention is particularly suitable for producing arrays of pockets containing encapsulated materials, in particular arrays of pockets containing encapsulated photoemission particles or photoemission compounds such as quantum dots. The method according to the present invention has the advantage of making it possible to prepare any type of array of pockets, whether identical or different pockets. The method makes it possible to select the number of pockets and the position of the pockets (one or more). Furthermore, the method according to the present invention makes it possible to select one or more pockets for individual pickups and / or transfers, as further described in this application.

[0074] According to a second aspect of the present invention, a pocket of encapsulated material or a plurality of pockets of encapsulated material is provided. The plurality of pockets of encapsulated material are arranged, for example, to form an array of pockets of encapsulated material.

[0075] A pocket of encapsulated material or an array of pockets of encapsulated material is preferably obtained by the above method for preparing pockets of encapsulated material.

[0076] The core material of the pocket in the encapsulated material includes, for example, quantum dots.

[0077] It is clear that multiple pockets or arrays of pockets may contain identical or different pockets. An array of pockets may contain pockets having different types of core materials, for example, different types of quantum dots.

[0078] A third aspect of the present invention is provided, which includes a device comprising one pocket of encapsulated material or multiple pockets of encapsulated material, for example, an array of pockets containing encapsulated material.

[0079] Preferred devices include one pocket of encapsulated material containing quantum dots or multiple pockets of encapsulated material containing quantum dots, for example, an array of pockets containing encapsulated material containing quantum dots.

[0080] Examples of such devices include devices in which pockets of encapsulated material, such as pockets containing quantum dots, are illuminated by a primary light source, such as a blue LED, to create a customized emission spectrum. Examples of customized emission spectra, though not limited to these, include, but are not limited to, white light with high color rendering, separate thin lines of blue, green, and red light, or a single thin line. Such light sources, though not limited to these, may be used for indoor lighting, display, or projection applications.

[0081] A fourth aspect of the present invention is provided, which is a process for transferring pockets or arrays of pockets of encapsulated material from one substrate to another. The method comprises the following steps: - To provide a structure comprising a first substrate equipped with pockets of encapsulated material obtained by the method defined above; - Transferring the encapsulated material pockets to a second substrate.

[0082] In a preferred embodiment, a structure comprising a first substrate having pockets of encapsulated material includes a release layer, for example, a thermal release layer between the first substrate and the pockets of encapsulated material.

[0083] In a preferred method, a structure comprising a first substrate having pockets of encapsulated material is brought into contact with a second substrate to transfer the pockets of encapsulated material from the first substrate to the second substrate. Subsequently, the pockets of encapsulated material are released from the first substrate and transferred to the second substrate. Optionally, an adhesion-promoting layer is used to adhere the pockets of encapsulated material to the second substrate.

[0084] Alternative methods for transferring encapsulated material pockets from a first substrate to a second substrate include laser-induced forward transfer.

[0085] To form a light source, this transition may lead to the direct accumulation of pockets or multiple pockets on an LED chip that provides primary light, such as a blue LED strip; the accumulation of pockets or multiple pockets on a light guide illuminated by the primary light source; or the accumulation of pockets or multiple pockets on any structure that links primary light into the pockets or multiple pockets.

[0086] A further method for transferring encapsulated material pockets from a first substrate to a second substrate includes microtransfer printing, which uses an elastomer stamp to transfer the encapsulated material pockets from the first substrate to the second substrate. [Brief explanation of the drawing]

[0087] Simple description of the drawing The present invention will be discussed in more detail below with reference to the accompanying drawings: [Figure 1] Figure 1 shows a method for preparing a pocket for encapsulated material according to the present invention; [Figure 2]Figure 2 shows a pocket containing encapsulated material according to the present invention; [Figure 3] Figures 3, 4, and 5 show various embodiments of a pocket containing encapsulated material, where the base B of the pocket, the core material, and / or lid L each contain deposits of various cured barrier materials b, various cured core materials c, and various cured barrier materials l, respectively; [Figure 4] Figures 3, 4, and 5 show various embodiments of a pocket containing encapsulated material, where the base B of the pocket, the core material, and / or lid L each contain deposits of various cured barrier materials b, various cured core materials c, and various cured barrier materials l, respectively; [Figure 5] Figures 3, 4, and 5 show various embodiments of a pocket containing encapsulated material, where the base B of the pocket, the core material, and / or lid L each contain deposits of various cured barrier materials b, various cured core materials c, and various cured barrier materials l, respectively; [Figure 6] Figure 6 illustrates the transition of the encapsulated material pocket from the first substrate to the second substrate.

[0088] Description of the manner The present invention is described in relation to specific embodiments and with reference to certain drawings, but is not limited thereto and is limited only by the claims. The drawings are schematic and non-limiting. The sizes of some elements in the drawings may be exaggerated for illustrative purposes and not drawn to scale. Dimensions and relative dimensions do not correspond to actual reductions in the implementation of the invention.

[0089] When referring to the endpoints of a range, the values ​​at the endpoints of the range are included.

[0090] When describing the present invention, terms used shall be interpreted according to the following definitions unless otherwise specified.

[0091] When listing two or more items, the term "and / or" means that any one of the listed items may be taken alone, or any combination of two or more of the listed items may be taken.

[0092] The term quantum dot refers to nanoscale crystals that can emit light of various colors when UV light strikes them. Such nanoscale crystals may have a uniform or substantially uniform composition, for example, a core, or a heterogeneous composition, such as a core / shell quantum dot, which includes a core and a shell surrounding the core. The shell is defined as the material surrounding the core and may include one or more shell layers.

[0093] The core may include, for example, a group III-V material, such as a binary, ternary, or quaternary group III-V material containing Ga and / or In as group III elements and N, P, As and / or Sb as group V elements. Preferred core materials include InP, InAs, InSb, GaP, GaAs, GaSb, In(As,P), In(As,Sb), (In(P,Sb), (In,Ga)P, (In,Ga)As, and (In,Ga)Sb. Furthermore, the core may also include a group II / III material alloyed with a group V pnictide such as (In,Zn)P.

[0094] The shell material includes, for example, group II-VI materials, such as two-component, three-component, or four-component group II-VI materials, which include Zn or Cd as a group II(B) element and O, S, Se and / or Te as group VI(A) elements. Preferred shell materials include ZnSe, ZnS, ZnTe, ZnSSe, ZnCdSe, and ZnSeTe.

[0095] Preferred examples of core / shell quantum dots include InP / ZnSe quantum dots, InP / ZnS quantum dots, InP / ZnSe / ZnS quantum dots, InP / ZnS / ZnSe quantum dots, and InP / XY, which for example allows InP / Cd x Zn 1-x Se or InP / ZnTe x Se 1-x As shown, X contains Cd, and Zn and Y contain S, Se, Te, and combinations thereof.

[0096] Figure 1 illustrates a method for preparing pockets for encapsulated material according to the present invention.

[0097] The first step (i) involves the application and photopatterning of barrier material b. The barrier material comprises a photocurable acrylate resin, for example, optionally containing clay platelets and / or cellulose nanofibrils, and is applied to the substrate 12 by the doctor blade method. Local curing is achieved, for example, by digital phototreatment. In step (ii), the uncured barrier is removed, and spatially distinct bases B are formed on the substrate 12. In the following step (iii), a layer of first type core material c1 is applied and locally cured to form a cured first type core material on top of a portion of the bases B (step (iv)). The first core material c1 comprises, for example, a photocurable thiol-ene resin containing green quantum dots, and is applied, for example, by the doctor blade method. Local curing is achieved, for example, by digital phototreatment, and results in the formation of core C1. In step (v), a layer of the second type of core material c2 is applied and locally cured to form the cured second type of core material c2 on top of another portion of the base B (step (vi)). The second type of core material c2 includes, for example, a photocurable thiol-ene resin containing red quantum dots. Once cured, the core C2 is formed. Subsequently, in step (vii), a barrier material l is applied and locally cured to form a lid L on the base B equipped with the core material. The barrier material l forming the lid L includes, for example, the same material as the barrier material b forming the base B. The barrier material l includes, for example, a photocurable acrylate resin optionally containing clay plates and / or cellulose nanofibrils, and is applied by a doctor blade method. Local curing is achieved, for example, by digital phototreatment. The curing is carried out in such a manner that a lid L of the cured barrier material is formed on each base B equipped with a core material c (e.g., a first core material c1 or a second core material c2), thereby forming a pocket (step (viii)). In each pocket, the core material is completely encapsulated by the barrier material of the base B and the barrier material of the lid L.

[0098] Figure 2 illustrates a pocket 20 of an encapsulated material according to the present invention. The pocket 20 comprises an encapsulated body 22 comprising a core material 21 and a barrier material. The core material 21 comprises, for example, a photocurable thiol-ene resin containing quantum dots. The encapsulated body 22 comprises, for example, one or more layers. In the embodiment shown in Figure 2, the encapsulated body 22 comprises a first layer 23 and a second layer 24. The first layer 23 comprises, for example, an oxygen barrier layer containing cellulose nanofibrils, and the second layer 24 comprises, for example, a water vapor barrier layer containing clay plates.

[0099] Figures 3, 4, and 5 illustrate various embodiments of a pocket containing encapsulated material, wherein the base B, core material, and / or lid L each contain one or more deposits of cured barrier material b, one or more deposits of cured core material c, and one or more deposits of cured barrier material l. The base B, core material, and lid L may be accumulated in a single step or by using a number of iterative steps.

[0100] The pocket 30 in Figure 3 is obtained by first forming a base B, by applying barrier material b onto a substrate 31, and by locally curing the barrier material b to form a base deposit 32 of cured barrier material b that is in contact with each other. The various deposits 32 are preferably in contact with each other. The distances created between the various deposits shown in Figure 3 are for illustrative purposes only. In practice, the various deposits are in contact with each other. Once the base B is formed, the material to be encapsulated is applied onto the base B by applying core material c onto the substrate equipped with the base B, and by locally curing the core material to form a base deposit 34 of cured core material. In the next step, a lid L is formed on top of the base B equipped with the core material to form the pocket 30. All the cured core material accumulated on one base B forms the core C. To form the lid L, barrier material l is applied onto the substrate equipped with the base B and core material. Next, the barrier material l is locally cured to form a deposit of cured barrier material l on the upper part of the base B and in contact with the deposit of cured core material l 34, so that the deposit of cured barrier material l l protects the outer edge of the core material accumulated on the base B. Subsequently, the barrier material l is applied, and thus a substrate is obtained. This barrier material l is locally cured to form a deposit of cured barrier material l 38 that covers the deposit of cured core material c 34 and the deposit of cured barrier material l 36. In this way, a lid L that completely encapsulates the core material c is obtained. It is clear that deposits 36 and 38 can also be obtained in a single step.

[0101] The pocket 40 in Figure 4 is obtained by first forming the base B by applying and locally curing the barrier material b in a manner similar to that used in the embodiment shown in Figure 3, thereby forming a deposit 42 of the cured barrier material b on the substrate 41. Subsequently, the encapsulated material is applied to the base B by first applying and locally curing the first core material c1, thereby forming a deposit 44 of the cured first core material c1 on the base B. In the next step, the second core material c2 is applied and locally cured, thereby forming a deposit 45 of the cured second material c2 on the base B. Then, the lid L is formed by accumulating deposits 46 and 48 of the cured barrier material l in a manner similar to that used for deposits 36 and 38 in the embodiment shown in Figure 3. The deposits 44 of the cured first core material c1 and the deposits of the cured second core material c2 accumulated on one base B form the core C. The core C is completely encapsulated by the base B and the lid L, i.e., by deposits 42, 46, and 48.

[0102] The pocket 50 in Figure 5 is obtained by first forming the base B by applying and locally curing a barrier material b in a manner similar to that used in the embodiments shown in Figures 3 and 4, thereby forming a deposit 52 of the cured barrier material b on the substrate 51. Subsequently, the first layer of the encapsulating material is applied to the base B by applying and locally curing a first core material c1, thereby forming a deposit 54 of the cured first core material c1 on the base B. Then, the barrier material l is applied and locally cured, so that a deposit 56 of the cured barrier material l is formed on the upper part of the base B and in contact with the deposit 54 of the cured first core material c1, so that the deposit 56 of the cured barrier material l protects the outer edge of the first core material c1 accumulated on the base B. In the next step, a second layer of the encapsulated material is applied to the deposit 54 by applying the second core material c2 and curing it locally to form a deposit 55 of the cured second core material c2 on top of the deposit 54. Then, the barrier material l is applied and cured locally in the same manner as deposits 36 and 38 in the embodiment shown in Figure 3 and deposits 46 and 48 in the embodiment shown in Figure 4 to form deposits 57 and 58 of the cured barrier material l.

[0103] Figure 6 shows the transfer of encapsulated material pockets 60 from one substrate to another. Figure 6(i) shows the encapsulated material pockets 60 formed on a substrate 61 equipped with a release layer 62, e.g., a thermal release layer. Next, as shown in Figure 6(ii), the substrate 61 equipped with the encapsulated material pockets 60 is turned over and lightly pressed onto a thin layer of uncured resin 64. Subsequently, as shown in Figure 6(iii), the substrate 61 equipped with the encapsulated material pockets 60 is fitted onto the top of an LED array 66, e.g., a blue LED array. Each pocket 60 thereby comes into contact with an LED. Finally, the substrate 61 is removed, for example, by applying heat to remove the thermal release layer 62 (Figure 6(iv)).

[0104] In a preferred method, the LED is illuminated until it is locally heated so that the resin of the thin layer 68 applied on the pockets 60 of the encapsulated material can be cured, thereby ensuring adhesion of the pockets 60 to the LED and / or releasing the pockets 60 from the substrate 61.

Claims

1. A method for preparing at least one pocket containing an encapsulated material, wherein the pocket comprises a core of a core material enclosed by an encapsulated barrier material, and the method is as follows: a. below, a1. Applying barrier material b to the substrate, where barrier material b includes resin; a2. Locally harden the barrier material b to form one or more bases B of the hardened barrier material b, each base B being spatially separated from another base B, and each base B covering an area AB of the substrate; a3. Remove the uncured barrier material b; The step of forming one or more base portions B of barrier material on a substrate, b. below, b1. Applying core material c to the substrate obtained from step a, the core material c comprising a resin and at least one photoemissive particle or photoemissive compound; b2. Locally harden the core material c, forming one or more core deposits of the hardened core material c, each core deposit of the hardened core material c accumulating on top of the base B, and none of the core deposits of the hardened core material c spread beyond area AB. b3. Remove the uncured core material c; The step of forming a core material c on the upper part of at least a portion of the base B, c. below, c1. Apply the barrier material l onto the substrate obtained from step b, the barrier material l comprising a resin; c2. The barrier material l is locally hardened, and a lid L of the hardened barrier material l is formed on top of each base B equipped with the core material c, each lid L is spatially separated from another lid L, and each base B equipped with the core material c and the lid L formed on this base B form a pocket, thereby completely encapsulating the core material c provided on the base B of the pocket. c3. Remove the uncured barrier material l. The steps include: forming one or more base portions B on a substrate equipped with a core material, and forming one or more lid portions L of a barrier material on the substrate; The method, including the method described above.

2. Step a comprises n iterations of steps a1' to a3', where n is at least 2, and a1' to a3' are less than or equal to: a1'. For each iteration step i where i ranges from 1 to n, a layer of barrier material bi is applied to a substrate or a substrate equipped with barrier material obtained from the iteration step prior to step a, so that for each iteration step i greater than 1, the barrier material bi includes the same or different barrier material as the barrier material used in the iteration step prior to step a; a2'. For each iteration step i where i ranges from 1 to n, the barrier material bi is locally cured to form one or more base deposits of the cured barrier material bi, each base deposit of the cured barrier material bi is in contact with the substrate or with a deposit of the cured barrier material obtained in the iteration step prior to step a, and after iteration step n, one or more base B are formed, each base B is spatially separated from another base B, and each base B covers an area AB of the substrate; a3'. For each iteration step i where i ranges from 1 to n, remove the uncured barrier material bi. The method according to claim 1.

3. Step b comprises m iterations of steps b1' to b3', where m is at least 2, and b1' to b3' are less than or equal to: b1'. For each iteration step i where i ranges from 1 to m, a layer of core material ci is applied on the substrate obtained from step a or on the substrate obtained from the iteration step prior to step b, so that for each iteration step i greater than 1, the core material ci includes the same or a different core material as the core material used in the iteration step prior to step b; b2'. For each iteration step i where i ranges from 1 to m, the core material ci is locally cured to form one or more core deposits of the cured core material ci, each core deposit of the cured core material ci is in contact with the base B or with a deposit of the cured core material obtained in the iteration step prior to step b, and none of the core deposits of the cured core material extend beyond area As. b3'. For each iteration step i where i ranges from 1 to m, remove the uncured core material ci. The method according to claim 1 or 2.

4. Step c comprises p iterations of steps c1' to c3', where p is at least 2, and c1' to c3' are less than or equal to: c1'. For each iteration step i where i ranges from 1 to p, a layer of barrier material li is applied to the substrate obtained from step b of the method or from the substrate obtained from the iteration step prior to step c, so that for each iteration step i greater than 1, the barrier material li includes the same or a different barrier material as the barrier material used in the iteration step prior to step c; c2'. For each iteration step i where i ranges from 1 to p, the barrier material li is locally cured, and after iteration step p, one or more lid deposits of the cured barrier material li are formed so as to form lids L on each base B fitted with the core material, each lid L being spatially separated from another lid L, so that each base B fitted with the core material c and the lid L provided on this base B form a pocket, so that all the core material provided on this base B is completely encapsulated by the combination of the base B and lid L in this pocket; c3'. For each iterative step i where i ranges from 1 to p, remove the uncured barrier material li. The method according to any one of claims 1 to 3.

5. The method according to any one of claims 1 to 4, wherein curing the barrier material and / or the core material includes photocuring.

6. The method according to any one of claims 1 to 5, wherein the application and local curing of the barrier material and / or core material includes photolithography using a physical mask or digital light modulation, digital photoprocessing (DLP), laser-based stereolithography (SLA), liquid crystal display (LCD) masking, liquid crystal display (LCD) projection, or multiphoton lithography.

7. The method according to any one of claims 1 to 6, wherein the barrier material and / or core material comprises a photocurable resin.

8. The method according to any one of claims 1 to 7, wherein the barrier material of the base (one or more) B and the barrier material of the lid (one or more) L contain the same material.

9. The method according to any one of claims 1 to 8, wherein at least one photoemission particle or photoemission compound comprises a quantum dot, an organic dye, an inorganic phosphor, a metal cluster, a carbon dot, a doped nanocrystal, or a combination thereof.

10. The method according to any one of claims 1 to 9, wherein the substrate includes a release layer, or the method further includes the step of applying a release layer on the substrate before applying a barrier material to the base B.

11. The method according to any one of claims 1 to 10, further comprising the additional step of applying a first intermediate layer to the top of one or more bases B between step a and step b, and / or applying a second intermediate layer on a core material c between step b and step c.

12. A method according to any one of claims 1 to 11 for preparing an array of pockets containing encapsulated material.

13. A pocket of encapsulated material or an array of pockets of encapsulated material obtained by a method as defined in any one of claims 1 to 12.

14. A device comprising at least one pocket of encapsulated material or an array of pockets of encapsulated material as defined in claim 13.

15. A process for transferring pockets of encapsulated material or arrays of pockets of encapsulated material, the following: - A step of providing a structure comprising a first substrate having pockets of capsule material obtained by a method defined in any one of claims 1 to 12; - A step of transferring the pocket of encapsulated material to a second substrate, The process including the process described above.

16. The process according to claim 15, wherein the structure includes a release layer between the first substrate and the pocket of the encapsulated material.

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