Structure, optoelectronic device, and method for manufacturing the structure

Abstract

A structure, an optoelectronic device, and a method for fabricating the structure are disclosed. In an embodiment, a structure includes a first nanoparticle comprising at least one semiconductor material. The first nanoparticle is chromophore in a first wavelength range and emissive in a second wavelength range. The structure further includes a plurality of second nanoparticles. The second nanoparticles are non-chromophore in both the first and second wavelength ranges.

Description

[Technical Field]

[0001] A structure, an optoelectronic device, and a method for fabricating the structure are disclosed. [Background technology]

[0002] Structures with improved performance are desired. Optoelectronic devices with structures with improved performance are desired. Methods for fabricating structures with improved performance are desired. Summary of the Invention

[0003] According to at least one embodiment, a structure is provided, which may include different elements, components or parts with particular properties, particularly different properties.

[0004] According to at least one embodiment, the structure includes first nanoparticles that include or consist of at least one semiconductor material, for example, a material based on a III-V compound semiconductor material or a II-VI compound semiconductor material.

[0005] In particular, the structure comprises exactly one first nanoparticle, or exactly two first nanoparticles, or a plurality of first nanoparticles, for example ten or more first nanoparticles.

[0006] According to at least one embodiment, the first nanoparticles are chromophoric in a first wavelength range and emissive in a second wavelength range. Here and hereinafter, chromophoric means that the first nanoparticles are electronically excitable in a particular wavelength range. In other words, the first nanoparticles are configured or designed to absorb electromagnetic radiation having a wavelength within the first wavelength range, particularly by exciting electrons from a ground state to an excited state. Here and hereinafter, emissive means that the first nanoparticles emit radiation in a particular wavelength range. In other words, the first nanoparticles are configured or designed to emit electromagnetic radiation having a wavelength within the second wavelength range, particularly by returning excited electrons from an excited state to a ground state.

[0007] In particular, the first nanoparticles have wavelength conversion properties. In other words, the first nanoparticles have the ability to absorb electromagnetic radiation in a first wavelength range and emit electromagnetic radiation in a second wavelength range. In further embodiments, the second wavelength range is at least partially different from the first wavelength range. For example, the first nanoparticles are chromophoric in a first wavelength range of 400 nm to 490 nm (inclusive), such as 450 nm. For example, the first nanoparticles are emissive in a second wavelength range of 500 nm to 2000 nm (inclusive), such as 500 nm to 700 nm (inclusive).

[0008] According to at least one embodiment, the structure includes a plurality of second nanoparticles. In other words, the structure includes two or more second nanoparticles, for example, ten or more second nanoparticles. Each second nanoparticle of the plurality of second nanoparticles may be identical, similar, or different from the other second nanoparticles in at least one of size, composition, and shape. In particular, the plurality of second nanoparticles may include different types of second nanoparticles, where the different types of second nanoparticles have, for example, different compositions.

[0009] It should be noted that the number of second nanoparticles in the structure may depend on their size relative to the size of the first nanoparticles. The smaller the second nanoparticles are relative to the first nanoparticles, the more second nanoparticles need to be present in the structure. If the second nanoparticles are the same size as the first nanoparticles or larger than the first nanoparticles, approximately the same amount of second nanoparticles can be present in the structure compared to the first nanoparticles.

[0010] According to at least one embodiment, the second nanoparticles are non-chromophoric in the first and second wavelength ranges. Here and hereinafter, non-chromophoric means that the second nanoparticles are not electronically excitable in a particular wavelength range. Thus, the second nanoparticles absorb significantly less electromagnetic radiation in both the first and second wavelength ranges than particles that are chromophoric in at least one of the wavelength ranges. In other words, the second nanoparticles absorb significantly less electromagnetic radiation in both the excitation and emission wavelength ranges of the first nanoparticles.

[0011] As defined herein, "absorb significantly less electromagnetic radiation" means that the second nanoparticles absorb less electromagnetic radiation energy in the first and second wavelength ranges than particles that are chromophoric in at least one of the first and second wavelength ranges. In particular, the second nanoparticles absorb at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% less electromagnetic radiation energy than the chromophore particles.

[0012] It should be noted that the second nanoparticles may be chromophoric at wavelength ranges different from the first and second wavelength ranges, for example, the second nanoparticles may be chromophoric rather than emissive in an ultraviolet (UV) wavelength range, such as 250 nm to 400 nm, but non-chromophoric in a first wavelength range of 400 nm to 490 nm (inclusive) and a second wavelength range of 500 nm to 2000 nm (inclusive).

[0013] In particular, the second nanoparticles can be configured or designed to have an equal or greater affinity for the decomposition species, for example, by exhibiting chemical reactivity with the decomposition species that are likely to decompose the first nanoparticles. In other words, the non-chromophore material of the second nanoparticles can block the decomposition species that would normally decompose the outermost surface of the first nanoparticles. Examples of decomposition species include, but are not limited to, oxygen, water, high temperatures, and combinations thereof. In the presence of the decomposition species, the second nanoparticles can consume the decomposition species through a chemical reaction before they can react with the first nanoparticles. Thus, the second nanoparticles can function as a protective screen between the first nanoparticles and the decomposition species. Alternatively, the material of the second nanoparticles can exhibit a physical affinity for species that are likely to decompose the first nanoparticles, such as, but not limited to, water, and absorb the decomposition species before they can reach the surface of the first nanoparticles.

[0014] For example, a second nanoparticle can stabilize the dissolution of the outermost shell of a first nanoparticle, such as a multishell quantum dot, through one or more of the following mechanisms: The second nanoparticle can prevent or delay the dissolution of the outermost shell by providing a constant level of dissolved ions of the same species as the outermost shell near the first nanoparticle. Furthermore, the second nanoparticle can also provide a source of outermost shell monomers for redepositing shell material on partially eroded first nanoparticles. Furthermore, the second nanoparticle can provide a reservoir of harmful redox equivalents photogenerated during material aging, such as photooxidation via the Auger process. Furthermore, the second nanoparticle can scavenge superoxide, hydroxyl radicals, and other reactive oxygen species.

[0015] According to at least one embodiment, a structure includes first nanoparticles comprising at least one semiconductor material, the first nanoparticles being chromophoric in a first wavelength range and emissive in a second wavelength range, and the structure further includes a plurality of second nanoparticles, the second nanoparticles being non-chromophoric in both the first and second wavelength ranges.

[0016] In the structures described herein, the second nanoparticles provide a barrier to degradation of the first nanoparticles by having an affinity for degradative species that are likely to degrade the first nanoparticles, either by chemically reacting with or chemically absorbing the degradative species, thereby blocking the degradative species and thereby stabilizing the first nanoparticles under environmentally harsh conditions, such as high humidity and temperature.

[0017] According to at least one embodiment, the first nanoparticle comprises a core and at least one shell. The core and / or shell comprises at least one semiconductor material. In further embodiments, the core comprises a different semiconductor material than the shell. In particular, the at least one shell is epitaxially grown on the core. Furthermore, the first nanoparticle may comprise additional shells and / or layers. For example, the first nanoparticle is a quantum dot, in particular a core-shell quantum dot.

[0018] According to at least one embodiment, the first nanoparticles comprise a core-shell-shell structure, for example, the first nanoparticles are CdSe / CdS / ZnS photoluminescent quantum dots.

[0019] According to at least one embodiment, the first nanoparticles have a diameter of between 20 nm and 50 nm inclusive.

[0020] According to at least one embodiment, the second nanoparticles have a diameter of 2 nm to 50 nm, inclusive. In particular, the second nanoparticles are smaller than or comparable in size to the first nanoparticles. In other words, the second nanoparticles are within the same order of magnitude as the first nanoparticles.

[0021] According to at least one embodiment, the second nanoparticles are at least one of metal particles, semiconductor particles, chalcogenide particles, pnictide particles, and combinations thereof. In particular, the second nanoparticles include or consist of Zn-containing particles.

[0022] The metallic particles comprise or consist of a metal, such as a d-block transition metal of the periodic table.

[0023] The semiconductor particles comprise or consist of a semiconductor material, such as a II-VI or III-V semiconductor.

[0024] Chalcogenide particles include or consist of chalcogenides. Chalcogenides are chemical compounds consisting of at least one chalcogen anion of a Group 16 element of the periodic table and at least one or more electropositive elements, such as a metal. For example, chalcogenides can be oxides, sulfides, selenides, tellurides, and / or polonides.

[0025] For example, the chalcogenide particles may include or consist of zinc oxide, particularly nano-ZnO. A second nanoparticle formed from ZnO may have a different band structure than the outermost shell of a first nanoparticle, particularly one containing a related material such as ZnS. This difference in band structure results in a different redox potential. Second nanoparticles with a different band structure, and therefore a different redox potential than the outermost shell of the first nanoparticle, are particularly advantageous for providing a reservoir of damaging redox equivalents to capture reactive oxygen species in the vicinity of the first nanoparticle.

[0026] Alternatively, or in addition, the chalcogenide particles may comprise or consist of zinc sulfide, particularly nano-ZnS. Secondary nanoparticles formed from ZnS are particularly advantageous for primary nanoparticles containing an outermost shell of ZnS. In addition to providing a reservoir for damaging redox equivalents to capture reactive oxygen species, the secondary nanoparticles of ZnS may be located near the primary nanoparticles to retard dissolution of the outermost shell of the primary nanoparticles. 2+ ions and S 2-A level of dissolved ZnS may be provided in the form of ions. Additionally, secondary nanoparticles of ZnS can provide a source of ZnS monomers for redepositing onto the partially eroded primary nanoparticles.

[0027] Pnictide particles include or consist of pnictides. Pnictides are chemical compounds consisting of at least one pnictogen anion of a Group 15 element of the periodic table and at least one or more electropositive elements, such as a metal. For example, pnictides can be nitrides, phosphides, arsenides, antimonides, and / or bismuthides.

[0028] According to at least one embodiment, the first nanoparticle and the second nanoparticle are closely spaced within the structure. In other words, the first nanoparticle and the second nanoparticle are very close or closely spaced to each other. In particular, the first nanoparticle and the second nanoparticle are separated from each other by less than 30 μm. For example, the distance between the first nanoparticle and the second nanoparticle is between 0 μm and 30 μm (inclusive). In other words, the first nanoparticle and the second nanoparticle may be in direct contact or may be spaced apart by up to 30 μm. The second nanoparticle positioned closely to the first nanoparticle provides a barrier to decomposition species, enhancing the stability of the first nanoparticle.

[0029] According to at least one embodiment, the first nanoparticles and the second nanoparticles are co-located within the structure. In other words, the first nanoparticles and the second nanoparticles are co-located or co-located, for example, close to each other. In particular, the co-located nanoparticles have an inter-nanoparticle distance of 0 μm to 30 μm (inclusive). The co-location of the first nanoparticles and the second nanoparticles enhances the stability of the structure, particularly the stability of the first nanoparticles, against decomposition species.

[0030] According to at least one embodiment, the structure further comprises an encapsulant. In particular, the encapsulant is provided to protect the first nanoparticles and / or the second nanoparticles from degradation. The encapsulant can at least partially or completely surround the first nanoparticles and / or the second nanoparticles. The first nanoparticles and / or the second nanoparticles may be surrounded by the encapsulant on all sides. In particular, the first nanoparticles and / or the second nanoparticles may be in direct contact with the encapsulant material.

[0031] According to at least one embodiment, the encapsulant comprises a material that includes or consists of metal oxides and mixtures thereof, for example, the encapsulant material includes or consists of silica.

[0032] According to at least one embodiment, a first nanoparticle and a second nanoparticle are co-encapsulated within an encapsulant. The co-encapsulated nanoparticles are co-located or co-encapsulated within the encapsulant material such that the encapsulant material at least partially or completely surrounds both the first nanoparticle and the second nanoparticle. In other words, the encapsulant forms a layer at least partially or completely around both the first nanoparticle and the second nanoparticle. In particular, the second nanoparticle is encapsulated within the encapsulant material in close proximity to the first nanoparticle so that the first and second nanoparticles can move together within the encapsulant. In particular, structures containing co-encapsulated nanoparticles exhibit different properties than structures containing first nanoparticles encapsulated in the encapsulant material that are subsequently treated with a chemical compound. Furthermore, the nanoscale size of the second nanoparticles may provide a means of encapsulating the second nanoparticle in the same vicinity as the first nanoparticle. This may be in contrast to ions or small molecules, which tend to diffuse somewhat freely through encapsulant materials such as silica.

[0033] According to at least one embodiment, the first nanoparticles and the second nanoparticles are spaced apart within the encapsulation. In particular, the first nanoparticles are not in direct contact with any of the second nanoparticles. The distance between the first nanoparticles and the second nanoparticles within the encapsulation is at most 30 μm. Thus, even if the first nanoparticles and the second nanoparticles are not in direct physical contact, the mere proximity of the second nanoparticles to the first nanoparticles is sufficient to create a preservative effect within the structure.

[0034] According to at least one embodiment, each second nanoparticle directly contacts the first nanoparticle and at least one of the additional second nanoparticles of the plurality of second nanoparticles. The first nanoparticle and the second nanoparticle are so close that their surfaces are in contact. In other words, the first nanoparticle and the second nanoparticle form an aggregate. In particular, the aggregate may be formed by electrostatic attraction between the first nanoparticle and the second nanoparticle, or by applying heat to the first nanoparticle and the second nanoparticle. In particular, the first nanoparticle and the second nanoparticle are in electronic contact with each other. The second nanoparticle in direct contact with the first nanoparticle can enhance the preservation effect of the second nanoparticle in the structure.

[0035] According to at least one embodiment, the second nanoparticles are bonded to the first nanoparticles by at least one method, such as aggregation, non-covalent bonding, covalent bonding, melting, sintering, agglomeration, and combinations thereof. In particular, the second nanoparticles are bonded to the first nanoparticles prior to encapsulating the first nanoparticles and / or the second nanoparticles in the encapsulant material. In this case, the first nanoparticles and the second nanoparticles form a pre-aggregate prior to encapsulation.

[0036] As used herein, aggregating first and second nanoparticles refers to combining the first and second nanoparticles to form an aggregate. The aggregate may be formed by aggregating the first and second nanoparticles, e.g., into a cluster. In particular, aggregating does not necessarily mean that the first and second nanoparticles are combined in a stoichiometric manner.

[0037] As used herein, a non-covalent bond between a first nanoparticle and a second nanoparticle means that a physical and / or chemical interaction occurs between the first nanoparticle and the second nanoparticle, resulting in a non-covalent bond between the first nanoparticle and the second nanoparticle. A non-covalent bond can include any bond that is a non-covalent bond, such as a dative bond, an ionic bond, a hydrogen bond, a dipole-dipole interaction, an intercalation, and a van der Waals interaction.

[0038] For example, the first nanoparticles and the second nanoparticles can be prepared so that the two nanoparticle types are oppositely charged. Oppositely charged nanoparticles can aggregate to form heterostructures. In particular, the first nanoparticles and / or the second nanoparticles can include binding ligands, such as organic ligands, and charged ligands on their surfaces. The organic ligands can be positively or negatively charged. Alternatively, the first nanoparticles can include an encapsulant surrounding the naturally negatively charged first nanoparticles. In this case, the negatively charged first nanoparticles can bind to the positively charged second nanoparticles through non-covalent bonding based on ionic bonds.

[0039] Alternatively, the first nanoparticle and the second nanoparticle may comprise a ligand with a long hydrophobic chain, such that the first nanoparticle and the second nanoparticle can be non-covalently bound by inserting the hydrophobic ligand.

[0040] As described herein, a covalent bond between a first nanoparticle and a second nanoparticle means that a covalent bond is formed between the first nanoparticle and / or the second nanoparticle. In particular, the covalent bond is formed between the ligands of the first nanoparticle and / or the second nanoparticle. The covalent bond between the first nanoparticle and / or the second nanoparticle can be formed by any chemical reaction that bonds two ligands, such as photoreaction chemistry, peptide chemistry, methacrylate chemistry, polyester chemistry, etc. For example, ether or ester bonds, and carbon-carbon bonds, silicon-carbon bonds, sulfur-carbon bonds, phosphorus-carbon bonds, or nitrogen-carbon bonds can be used to link the ligands of the first nanoparticle and / or the second nanoparticle to each other.

[0041] As described herein, bonding a second nanoparticle to a first nanoparticle by melting means that the second nanoparticle in proximity to the first nanoparticle is at least partially melted such that the second nanoparticle is bonded to the surface of the first nanoparticle as an at least partially molten structure. In particular, the structural integrity of the first nanoparticle is not compromised by bonding the second nanoparticle to the first nanoparticle by melting.

[0042] As described herein, sintering of first and second nanoparticles refers to compressing the first and second nanoparticles by heat or pressure to form a solid mass of material without melting the first and / or second nanoparticles to a liquefaction point. The second nanoparticles can form a sintered structure on the surface of the first nanoparticles. In particular, the structural integrity of the first nanoparticles is not compromised by bonding the second nanoparticles to the first nanoparticles by sintering.

[0043] In particular, the first nanoparticles and the second nanoparticles are sintered or at least partially melted by applying a temperature between 90°C and 400°C inclusive.

[0044] In particular, by bonding the second nanoparticles to the first nanoparticles by melting or sintering, there is no organic mediator in the structure, particularly between the first nanoparticles and the second nanoparticles.

[0045] As described herein, agglomeration should be understood as combining first nanoparticles with second nanoparticles. In other words, the first nanoparticles and the second nanoparticles form an agglomerate. In the agglomerate, the spatial shapes of the first nanoparticles and the second nanoparticles can be recognized. Therefore, the spatial shapes of the first nanoparticles and the second nanoparticles remain intact after agglomeration.

[0046] According to at least one embodiment, the surface of the first nanoparticles is partially covered by the second nanoparticles. The first nanoparticles may be at least partially surrounded by the second nanoparticles. In other words, the surface of the first nanoparticles is at least partially modified with the second nanoparticles. In particular, the surface of the first nanoparticles is at least partially in contact with the second nanoparticles.

[0047] According to at least one embodiment, the surface of the first nanoparticles is completely covered by the second nanoparticles, and the first nanoparticles are surrounded by the second nanoparticles such that the entire surface of the first nanoparticles is decorated with the second nanoparticles.

[0048] According to at least one embodiment, the second nanoparticles form a layer around the first nanoparticles. The layer of second nanoparticles can at least partially or completely surround the first nanoparticles. The layer of second nanoparticles can include aggregated second nanoparticles, agglomerated second nanoparticles, covalently bonded second nanoparticles, or non-covalently bonded second nanoparticles. In this case, the shape of the individual second nanoparticles remains distinguishable. Alternatively, the layer of second nanoparticles can include a fused and / or sintered structure.

[0049] In particular, the surface of the layer of second nanoparticles around the first nanoparticles is provided with roughness, in particular the roughness of the layer of second nanoparticles is increased compared to the roughness of the surface of the first nanoparticles.

[0050] In particular, the surface of the layer of second nanoparticles around the first nanoparticles has an increased surface area compared to the surface area or roughness of the surface of the first nanoparticles, which is advantageous for promoting surface reactions.

[0051] According to at least one embodiment, the layer of second nanoparticles has a thickness of 1 nm to 100 nm inclusive, in particular 1 nm to 20 nm inclusive, or 1 nm to 10 nm inclusive, and may comprise one monolayer of second nanoparticles, or two or more monolayers of second nanoparticles.

[0052] According to at least one embodiment, the second nanoparticles include at least one surface moiety. The surface moiety can be organic or inorganic. The surface moiety can be configured or designed to have an affinity for species likely to degrade the first nanoparticles. In particular, the at least one surface moiety is directly or indirectly bonded to the surface of the second nanoparticles. For example, the surface moiety is polyethylene glycol. Due to their affinity for water, the polyethylene glycol-modified second nanoparticles can increase the humidity of the environment near the first nanoparticles, thereby helping to prevent photodegradation of the first nanoparticles. Another class of surface moieties includes at least one of boranes, borohydrides, citrates, oxalates, reducing sugars, aldehydes, or reducing and oxidizing agents such as hydrazine iodide, sulfites, thiosulfates, and dithionates.

[0053] According to at least one embodiment, the second nanoparticles, which include at least one surface moiety, are inert. In this case, the second nanoparticles can be more effectively utilized due to the loading capacity of their surface moieties. In other words, the second nanoparticles do not interact with species that are likely to degrade the first nanoparticles, and therefore do not have affinity for such species. For example, the inert second nanoparticles can be silica nanoparticles or polymer nanoparticles.

[0054] According to at least one embodiment, the second nanoparticles, which include at least one surface moiety, are active. In other words, the second nanoparticles and the surface moiety interact with species that are likely to degrade the first nanoparticles. Therefore, both the second nanoparticles and the surface moiety are beneficial to protecting the first nanoparticles. For example, active second nanoparticles are second nanoparticles that are configured or designed to have equal or greater affinity for degradative species that are likely to degrade the first nanoparticles, such as ZnS or ZnO nanoparticles.

[0055] According to at least one embodiment, at least one surface moiety is dispersed in an encapsulant material surrounding the second nanoparticle and the first nanoparticle. In other words, the surface moiety can be attached to the second nanoparticle before encapsulation and can diffuse into the encapsulant material during or after encapsulation. In particular, the surface moiety is no longer in direct contact with the second nanoparticle during or after encapsulation.

[0056] According to at least one embodiment, the second nanoparticle comprises two surface moieties, a first surface moiety bound to the second nanoparticle by a second surface moiety. The second surface moiety can be bound to the surface of the second nanoparticle by a non-covalent or covalent bond. The second surface moiety can be a polymeric or molecular species that has an affinity for the first surface moiety. The first surface moiety can be bound to the second nanoparticle by forming a non-covalent or covalent bond with the second surface moiety. This is particularly advantageous for first surface moieties that have little or no binding affinity to the surface of the second nanoparticle.

[0057] According to at least one embodiment, the structure includes at least one internal payload species proximate to the first nanoparticle, the internal payload species including, for example, ions such as copper(I), iron(II), and mercury, configured or designed to have an affinity for or greater than an affinity for a degrading species likely to degrade the first nanoparticle.

[0058] According to at least one embodiment, at least one internal payload species is located inside the second nanoparticle. In other words, the internal payload species is not attached to the surface of the second nanoparticle, but is substitutionally or interstitially incorporated into the lattice of the second nanoparticle. The second nanoparticle can function as a buffer, providing a flow of ions of the internal payload species in the vicinity of the first nanoparticle. Note that the internal payload species exerts its effect when released near the first nanoparticle, not when bound to and / or within the second nanoparticle. In particular, the second nanoparticle functions as a carrier for bringing the internal payload species near the first nanoparticle, which functions as a sustained-release drug.

[0059] According to at least one embodiment, at least one of the second nanoparticles includes a first internal payload species and at least one of the second nanoparticles includes a second internal payload species. In particular, the first and second internal payload species differ from each other in at least one of composition and charge number. In this context, composition should be understood as including one or more elements, in particular one metal element. Two different internal payload species in close proximity to the first nanoparticle may increase the beneficial effect of the internal payload species on protection against degradation.

[0060] According to at least one embodiment, the first nanoparticles are encapsulated in a first encapsulant, and the second nanoparticles are encapsulated in a second encapsulant, with the first and second encapsulants being in direct contact with each other. In other words, the encapsulated first nanoparticles and the encapsulated second nanoparticles form agglomerates or aggregates, or are fused together so that the encapsulated nanoparticles are in close proximity to each other. Thus, the structure may be a collection of pre-encapsulated nanoparticles. In particular, the first nanoparticles may be individually encapsulated, and multiple second nanoparticles may be encapsulated together in one encapsulant, or alternatively, each second nanoparticle may be individually encapsulated. In particular, at least one of the first and second encapsulants may comprise or consist of an encapsulant material selected from the group consisting of metal oxides and mixtures thereof. In particular, the first nanoparticles and / or the second nanoparticles may be uniformly encapsulated.

[0061] According to at least one embodiment, the first encapsulant and the second encapsulant comprise the same encapsulant material. In particular, the encapsulant material of the first encapsulant and the second encapsulant is selected from the group consisting of metal oxides and mixtures thereof. For example, the encapsulant material of the first encapsulant and the second encapsulant is silica.

[0062] Another embodiment relates to an optoelectronic device. In a further embodiment, the optoelectronic device described herein comprises at least one structure as described above. Accordingly, features and embodiments of the optoelectronic device are also disclosed for the structure, and vice versa.

[0063] According to at least one embodiment, an optoelectronic device comprises a semiconductor chip configured to emit primary radiation and a conversion element configured to convert at least a portion of the primary radiation into secondary radiation, the conversion element including at least one structure described above.

[0064] The semiconductor chip may comprise an active layer stack including an active region that emits primary radiation during operation of the device. For example, the semiconductor chip may be a light-emitting diode chip or a laser diode chip. The primary radiation generated within the semiconductor chip may be emitted through a radiation-emitting surface of the semiconductor chip. In particular, during operation, the semiconductor chip emits primary radiation in the visible wavelength range, such as wavelengths greater than 400 nm. For example, the semiconductor chip emits primary radiation in the wavelength range of 400 nm to 490 nm (inclusive), such as 450 nm.

[0065] The structures within the conversion element are configured to at least partially or completely convert the primary radiation into secondary radiation. In particular, the secondary radiation has a wavelength range that is at least partially different or completely different from the wavelength range of the primary radiation. For example, the wavelength range of the secondary radiation is within the visible or infrared wavelength range, e.g., within the wavelength range of 500 nm to 2000 nm, inclusive.

[0066] The features of the structure have already been disclosed in relation to the structure and also apply to structures in optoelectronic devices.

[0067] Such optoelectronic devices can be used to emit white or colored light. The co-location of the non-chromophoric second nanoparticles and the chromophoric, emissive first nanoparticles within the conversion element provides structures with improved stability in environmentally challenging conditions, such as high humidity and temperature. Thus, the optoelectronic devices described herein have extended operating lifetimes under corrosive conditions.

[0068] Another embodiment relates to a method for manufacturing a structure. The methods described herein can be used to manufacture the above-mentioned structures, which can be used in the above-mentioned optoelectronic devices. Accordingly, features and embodiments of the methods are also disclosed for the structures and optoelectronic devices, and vice versa.

[0069] According to at least one embodiment, a method of fabricating a structure includes providing first nanoparticles comprising at least one semiconductor material. The first nanoparticles are chromophoric in a first wavelength range and emissive in a second wavelength range. The method further includes providing a plurality of second nanoparticles. The second nanoparticles are non-chromophoric in the first wavelength range and the second wavelength range. The method further includes closely disposing the first nanoparticles and the second nanoparticles.

[0070] The steps of the methods for fabricating the structures described herein are not limited to this order, however, according to further embodiments, the steps are performed in this order.

[0071] Such methods can produce structures in which a first nanoparticle is protected from a degradative species by bringing the first nanoparticle into close proximity with a second nanoparticle that has an equal or greater affinity for the degradative species that is likely to degrade the first nanoparticle.

[0072] According to at least one embodiment, the method further includes bonding the second nanoparticles to the first nanoparticles by at least one method, such as aggregation, non-covalent bonding, covalent bonding, melting, sintering, agglomeration, and combinations thereof. In particular, the second nanoparticles at least partially or completely cover the surface of the first nanoparticles. The second nanoparticles can form a layer around the first nanoparticles by, for example, aggregation, non-covalent bonding, covalent bonding, agglomeration, and combinations thereof. Alternatively, the second nanoparticles can form a layer around the first nanoparticles that includes a fused or sintered structure of the second nanoparticles.

[0073] According to at least one embodiment, the method further includes applying an encapsulant. The encapsulant may be applied before, during, or after placing the first nanoparticle and the second nanoparticle in close proximity. For example, the first nanoparticle and / or the second nanoparticle may be encapsulated before placing the nanoparticles in close proximity. Alternatively, the first nanoparticle and the second nanoparticle may be encapsulated together and thus placed in close proximity in the encapsulant. In this case, the first nanoparticle and the second nanoparticle are co-encapsulated. In particular, this co-encapsulation may include mixing the first nanoparticle and the second nanoparticle before forming the encapsulant around the nanoparticle. Such a method may be sufficient to provide a statistically distributed, random co-encapsulation of the first nanoparticle and the second nanoparticle. Alternatively, the first nanoparticle and the second nanoparticle may be placed in close proximity, i.e., pre-assembled, for example, by binding the second nanoparticle to the surface of the first nanoparticle prior to encapsulation.

[0074] According to at least one embodiment, the method further includes encapsulating a first nanoparticle in a first encapsulant, encapsulating a second nanoparticle in a second encapsulant, and placing the first encapsulant and the second encapsulant in direct contact with each other, i.e., both the first nanoparticle and the second nanoparticle are encapsulated before placing the first nanoparticle and the second nanoparticle in close proximity.

[0075] Advantageous embodiments and developments of the structure, the optoelectronic device and the method for manufacturing the structure will become apparent from the exemplary embodiments described below in conjunction with the figures. [Brief explanation of the drawings]

[0076] [Figure 1] 1A-1D depict schematic illustrations of structures according to different illustrative embodiments; [Figure 2] 1A-1D depict schematic illustrations of methods for manufacturing structures according to different illustrative embodiments; [Figure 3]1 shows a transmission electron microscope (TEM) micrograph of a structure according to an exemplary embodiment. [Figure 4A] 1A-1D depict schematic illustrations of structures according to different illustrative embodiments; [Figure 4B] 1A-1D depict schematic illustrations of structures according to different illustrative embodiments; [Figure 5A] 1A-1D depict schematic illustrations of methods for manufacturing structures according to different illustrative embodiments; [Figure 5B] 1A-1D depict schematic illustrations of methods for manufacturing structures according to different illustrative embodiments; [Figure 5C] 1A-1D depict schematic illustrations of methods for manufacturing structures according to different illustrative embodiments; [Figure 6] 1A-1D depict schematic illustrations of structures according to different illustrative embodiments; [Figure 7A] 1A-1D depict schematic illustrations of methods for manufacturing structures according to different illustrative embodiments; [Figure 7B] 1A-1D depict schematic illustrations of methods for manufacturing structures according to different illustrative embodiments; [Figure 8] 1A-1D depict schematic illustrations of structures according to different illustrative embodiments; [Figure 9] 1A-1D depict schematic illustrations of methods for manufacturing structures according to different illustrative embodiments; [Figure 10] 1A-1D depict schematic illustrations of structures according to different illustrative embodiments; [Figure 11] 1A-1D depict schematic illustrations of methods for manufacturing structures according to different illustrative embodiments; [Figure 12] 1A-1D depict schematic illustrations of structures according to different illustrative embodiments; [Figure 13] 1A-1D depict schematic illustrations of methods for manufacturing structures according to different illustrative embodiments; [Figure 14] 1 shows a schematic diagram of an optoelectronic device according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0077] In the exemplary embodiments and figures, similar or similarly acting components are given the same reference numerals. The elements shown in the figures and their size relationships to one another should not be considered to be to scale. Rather, for better representation and / or deeper understanding, individual elements may be shown with exaggerated dimensions.

[0078] FIG. 1 shows a schematic diagram of a structure 1. The structure 1 includes first nanoparticles 2. The first nanoparticles 2 include at least one semiconductor material. For example, the first nanoparticles are photoluminescent quantum dots, such as CdSe / CdS / ZnS core-shell-shell quantum dots. The first nanoparticles 2 are chromophoric in a first wavelength range and emissive in a second wavelength range. In other words, the first nanoparticles 2 can absorb electromagnetic radiation in a first wavelength range and emit electromagnetic radiation in a second wavelength range. For example, the first wavelength range includes wavelengths of 400 nm to 490 nm (inclusive), and the second wavelength range includes wavelengths of 500 nm to 2000 nm (inclusive), particularly wavelengths of 500 nm to 700 nm (inclusive).

[0079] The structure further includes a plurality of second nanoparticles 3. The second nanoparticles 3 are non-chromophoric in the first and second wavelength ranges. In other words, the second nanoparticles 3 do not absorb wavelengths in either the first or second wavelength range. Alternatively, the second nanoparticles 3 absorb significantly less electromagnetic radiation in both the first and second wavelength ranges than particles that are chromophoric in the wavelength ranges. For example, the second nanoparticles 3 are metal particles, semiconductor particles such as II-VI semiconductors, chalcogenide particles such as nano-ZnS or nano-ZnO, pnictide particles, and combinations thereof. The second nanoparticles 3 are co-located with the first nanoparticles 2 within the structure 1, meaning that the second nanoparticles 3 are located in close proximity to the first nanoparticles 2. Specifically, the distance between the first nanoparticles 2 and the second nanoparticles 3 is 0 μm to 30 μm (inclusive). The second nanoparticles 3 have an affinity to decomposition species that are likely to decompose the first nanoparticles 2, either by blocking the decomposition species, chemically reacting with the decomposition species, and / or by absorbing the decomposition species.

[0080] Optionally, the structure 1 may include an encapsulant 4 that at least partially or completely surrounds the first nanoparticle 2 and the second nanoparticle 3. In this case, the first nanoparticle 2 and the second nanoparticle 3 may be co-encapsulated within the encapsulant 4. The encapsulant 4 may include or consist of an encapsulant material that includes or consists of a metal oxide such as silica.

[0081] The structure 1 according to Figure 1 can be produced according to Figure 2 by mixing first nanoparticles 2 with second nanoparticles 3 before forming encapsulation 4 around the nanoparticles, thereby providing a statistically well-distributed random co-encapsulation of the second nanoparticles 3 with the first nanoparticles 2.

[0082] In a further embodiment of the structure 1 according to FIG. 1, the first nanoparticles 2 are CdSe / CdS / ZnS photoluminescent quantum dots and the second nanoparticles 3 are nano-ZnS particles. Optionally, the first nanoparticles 2 and the second nanoparticles 3 are co-encapsulated within a silica encapsulant 4. In this case, the nano-ZnS stabilizes the decomposition of the ZnS layer of the multi-shell quantum dots through one or more of several mechanisms. The nano-ZnS stabilizes the decomposition of the ZnS layer of the multi-shell quantum dots by providing a certain level of dissolved ZnS (Zn 2+ and S 2- Nano-ZnS can provide a reservoir of harmful redox equivalents photogenerated during material aging, for example, during photooxidation via the Auger process. Nano-ZnS can scavenge superoxide, hydroxyl radicals, and other reactive oxygen species. Nano-ZnS can also provide a source of ZnS monomers for redepositing onto partially corroded quantum dots.

[0083] Figure 3 shows a TEM micrograph of a structure 1 comprising CdSe / CdS / ZnS primary nanoparticles 2 co-encapsulated in a silica encapsulant 4 with nano-ZnS secondary nanoparticles 3. The mere proximity of the nano-ZnS secondary nanoparticles 3 is sufficient to create a preservative effect on the CdSe / CdS / ZnS primary nanoparticle 2 composite system.

[0084] The structure 1 according to FIGS. 4A and 4B differs from the structure according to FIG. 1 in that each secondary nanoparticle 3 is in direct contact with at least one of a first nanoparticle 2 and a further secondary nanoparticle 3. The first nanoparticles 2 and the second nanoparticles 3 form an aggregate. Optionally, this aggregate may be encapsulated in an encapsulant 4. The surface of the first nanoparticles 2 may be partially (FIG. 4A) or completely (FIG. 4B) covered by the second nanoparticles 3. In other words, the second nanoparticles 3 form a layer around the first nanoparticles 2. The layer of second nanoparticles 3 may have a thickness of 1 nm to 100 nm (inclusive), for example, a thickness of 1 nm to 20 nm (inclusive), or a thickness of 1 nm to 10 nm (inclusive).

[0085] The structure 1 according to Figures 4A and 4B can be produced by forming an aggregate of first nanoparticles 2 and second nanoparticles 3 according to Figures 5A and 5B and optionally encapsulating the aggregate with an encapsulant 4.

[0086] The assembly can be prepared such that the second nanoparticles 3 are bound to the first nanoparticles 2 by at least one of aggregation, non-covalent bonding, covalent bonding, and agglomeration. For example, the first nanoparticles 2 and the second nanoparticles 3 can be prepared such that the nanoparticles 2, 3 are oppositely charged, taking into account the binding and charged ligands. Oppositely charged nanoparticles 2, 3 can be aggregated into the structure 1. Alternatively, to achieve an even higher level of control, the first nanoparticles 2 and the second nanoparticles 3 can be covalently bound, for example, via organic ligands attached to the surfaces of the first nanoparticles 2 and the second nanoparticles 3 that chemically react with each other.

[0087] As shown in FIG. 5C, two different types of second nanoparticles 3, 3′ may be provided to form an aggregate with the first nanoparticles 2. The two different types of second nanoparticles 3, 3′ differ from each other in at least one of size, composition, and shape. For example, the second nanoparticles 3 have a different composition from the second nanoparticles 3′. In this case, the structure 1 comprises a mixed layer of the two types of second nanoparticles 3, 3′ on the surface of the first nanoparticles 2.

[0088] 6 shows a structure 1 that differs from the structure 1 according to FIGS. 4A and 4B in that the second nanoparticles 3 are partially melted or lightly sintered relative to the first nanoparticles 2. The partially melted or lightly sintered second nanoparticles 3 form a molten or sintered structure 5 that at least partially or completely surrounds the first nanoparticles 2. The molten or sintered structure 5 may have the form of a layer surrounding the first nanoparticles 2, having a thickness of 1 nm to 100 nm (inclusive), for example a thickness of 1 nm to 20 nm (inclusive), or a thickness of 1 nm to 10 nm (inclusive).

[0089] The structure according to FIG. 6 can be fabricated according to FIG. 7A by providing a second nanoparticle 3 adjacent to a first nanoparticle 2. For example, by applying a temperature between 90° C. and 400° C. (inclusive), the second nanoparticle 3 is melted and / or sintered to the surface of the first nanoparticle 2 to form a fused or sintered structure 5. Further application of temperature results in multiple sintering events, increasing the coverage of the first nanoparticle 2 with the fused or sintered structure 5. In further embodiments, the surface of the first nanoparticle 2 is completely covered by the fused or sintered structure 5. Optionally, the first nanoparticle 2 and the second nanoparticle 3 may be co-encapsulated within the encapsulant 4 after various degrees of melting or sintering.

[0090] Instead of using one type of second nanoparticles 3, as shown in Figure 7B, two different types of second nanoparticles 3, 3' may be provided and fused and / or sintered to the first nanoparticles 2, thereby forming a fused or sintered structure 5' on the surface of the first nanoparticles 2. The fused or sintered structure 5' is a mixed layer of both types of second nanoparticles 3, 3'.

[0091] 8 shows a structure 1 comprising a first nanoparticle 2 encapsulated in a first encapsulant 6 and a second nanoparticle 3 encapsulated in a second encapsulant 7. The first encapsulant 6 and the second encapsulant 7 are in direct contact, thus bringing the first nanoparticle 2 and the second nanoparticle into close proximity. The first encapsulant 6 and the second encapsulant 7 may comprise the same encapsulant material, for example, silica.

[0092] The structure 1 according to Figure 8 can be produced by encapsulating first nanoparticles 2, specifically uniformly, in first encapsulants 6 and second nanoparticles 3, specifically uniformly, in second encapsulants 7, according to Figure 9. Each second nanoparticle 3 can be encapsulated individually, or multiple second nanoparticles 3 can be encapsulated together. The pre-encapsulated nanoparticles 2, 3 are then mixed and agglomerated or aggregated or fused to form the structure 1.

[0093] FIG. 10 shows a structure 1 having an intermediate structure 10 of a second nanoparticle 3 including surface moieties 8 and 9, where a first surface moiety 8 is bound to the second nanoparticle 3 by a second surface moiety 9. The second surface moiety 9 may be a polymeric or molecular species that has an affinity for binding to the first surface moiety. The first surface moiety 8 may be an organic or inorganic molecule or species. For example, the first surface moiety 8 may be polyethylene glycol, which, due to its affinity for water, can increase the humidity of the environment near the first nanoparticle 2. Alternatively, the first surface moiety 8 may be a reducing agent or oxidizing agent, such as borane, borohydride, citrate, oxalate, reducing sugar, aldehyde, or hydrazine iodide, sulfite, thiosulfate, and dithionite.

[0094] In the exemplary embodiment of FIG. 10 , the second nanoparticles 3 themselves may be inert, meaning that they do not interact with species likely to degrade the first nanoparticles 2. In this case, the second nanoparticles 3 are more utilized due to the loading capacity of their surface moieties. Alternatively, the second nanoparticles 3 may be active, meaning that they interact with species likely to degrade the first nanoparticles 2. In either case, the nanoscale size of the second nanoparticles 3 provides a means of encapsulating the second nanoparticles 3 with surface moieties 8, 9 in the same vicinity as the first nanoparticles 2. This is in contrast to ions or small molecules that may be somewhat free to diffuse through a surrounding medium, such as a silica encapsulant.

[0095] 10 can be produced by preparing an intermediate structure 10 comprising a second nanoparticle 3 modified with surface moieties 8, 9 by bonding the second surface moieties 9 to the surface of the second nanoparticle 3 and by bonding the first surface moieties 8 to the second surface moieties 9, according to FIG. 11. The second nanoparticle 3 modified with surface moieties 8, 9 is then placed in proximity to the first nanoparticle 2 and optionally encapsulated together with the first nanoparticle 2 within an encapsulant 4.

[0096] 12 illustrates a structure 1 in which at least one of the second nanoparticles 3 includes an internal payload species A and at least one of the second nanoparticles 3 includes a second internal payload species B. The first internal payload species A and the second internal payload species B differ from each other in at least one of composition and charge number. Each internal payload species A and B is located within the second nanoparticle 3 rather than attached to the surface of the second nanoparticle 3. Specifically, the internal payload species A and B are substitutionally or interstitially incorporated into the lattice of the second nanoparticle 3. Examples of internal payload species A and B include copper(I), iron(II), mercury, and combinations thereof.

[0097] 12, the second nanoparticles 3 can function as a buffer to provide a flow of ions of the internal payload species A and B in the vicinity of the first nanoparticles 2. Note that the internal payload species A and B exert their effect when released in the vicinity of the first nanoparticles, not when bound on and / or in the second nanoparticles 3. In particular, the second nanoparticles 3 function as a carrier to bring the internal payload species A and B in the vicinity of the first nanoparticles 2, which function as a sustained release drug.

[0098] A structure 1 according to Figure 12 can be produced by mixing first nanoparticles 2 with second nanoparticles 3 containing internal payload species A, B, before forming an encapsulation 4 around the nanoparticles 2, 3 according to Figure 13. During and after encapsulation, the second nanoparticles 3 provide internal payload species A, B in close proximity to the first nanoparticles 2.

[0099] 14 shows a schematic diagram of an optoelectronic device 100 comprising a semiconductor chip 101 having an active layer stack and an active region (not explicitly shown here). During operation, the semiconductor chip 101 emits primary radiation, for example from the radiation emission surface 102. Specifically, the primary radiation is electromagnetic radiation in a first wavelength range. For example, the semiconductor chip 101 emits electromagnetic radiation in the visible wavelength range, in particular the blue wavelength range, for example in the wavelength range of 400 nm to 490 nm (inclusive), such as 450 nm.

[0100] The conversion element 103 is disposed on the radiation emitting surface 102 of the semiconductor chip 101. Specifically, the conversion element is disposed in direct contact with the radiation emitting surface 102. The conversion element 103 is configured or designed to absorb the primary radiation and convert at least a portion of the primary radiation into secondary radiation. The secondary radiation is electromagnetic radiation having a wavelength range that is at least partially or completely different from that of the primary radiation. Specifically, the secondary radiation is electromagnetic radiation in a second wavelength range, for example having a wavelength between 500 nm and 2000 nm (inclusive), such as between 500 nm and 700 nm (inclusive).

[0101] The transduction element 103 includes or consists of at least one structure 1. For example, the transduction element 103 includes at least one structure 1, particularly multiple structures 1, as shown in connection with Figures 1, 3, 4A, 4B, 6, 8, 10, and 12. Specifically, the at least one structure 1 may be embedded in a matrix material such as silicone, polysiloxane, or epoxy.

[0102] The features and example embodiments described in connection with the figures can be combined with each other according to further example embodiments, even if not all combinations are explicitly described. Furthermore, the example embodiments described in connection with the figures can have alternative or additional features as described in the summary section.

[0103] The present invention is not limited to the above exemplary embodiments by its description based on them, but rather includes any novel feature and any combination of features, and in particular includes any combination of features in the claims and in the exemplary embodiments, even if the feature or combination itself is not explicitly set forth in the claims or in the exemplary embodiments.

[0104] This patent application claims priority to U.S. Patent Application No. 17 / 530,568, the disclosure of which is incorporated herein by reference. [Explanation of symbols]

[0105] 1 structure 2. The First Nanoparticles 3, 3' Second nanoparticle 4. Encapsulation 5, 5' Fused or sintered structure 6. First Encapsulation 7 Secondary Encapsulation 8 First surface portion 9 Second surface part 10 Intermediate structure A. First internal payload type B Second internal payload type 100 Optoelectronic Devices 101 Semiconductor Chip 102 Radiation emitting surface 103 Conversion Factors

Claims

1. Structure (1), First nanoparticles (2) comprising at least one semiconductor material, said first nanoparticles (2) being chromophoric in a first wavelength range and emissive in a second wavelength range; a plurality of second nanoparticles (3, 3'), the second nanoparticles (3, 3') being non-chromophoric in the first wavelength range and the second wavelength range; an encapsulate (4), wherein the first nanoparticles (2) and the second nanoparticles (3, 3') are co-encapsulated within the encapsulate (4); each second nanoparticle (3, 3') of the plurality of second nanoparticles (3, 3') is in direct contact with the first nanoparticle (2) and at least one further second nanoparticle (3, 3') of the plurality of second nanoparticles (3, 3'); the first nanoparticles (2) and the second nanoparticles (3, 3') form aggregates, and / or a physical and / or chemical interaction occurs between the first nanoparticles (2) and the second nanoparticles (3, 3'), resulting in a non-covalent bond between the first nanoparticles (2) and the second nanoparticles (3, 3'); and / or a covalent bond is formed between the first nanoparticles (2) and / or the second nanoparticles (3, 3'), and / or the second nanoparticles (3, 3') are bonded to the surface of the first nanoparticles (2) in an at least partially fused structure, and / or the second nanoparticles (3, 3') form a sintered structure on the surface of the first nanoparticles (2), and / or the first nanoparticles (2) and the second nanoparticles (3, 3') form agglomerates; Structure (1).

2. Structure (1), First nanoparticles (2) comprising at least one semiconductor material, said first nanoparticles (2) being chromophoric in a first wavelength range and emissive in a second wavelength range; a plurality of second nanoparticles (3, 3'), the second nanoparticles (3, 3') being non-chromophoric in the first wavelength range and the second wavelength range; an encapsulate (4), wherein the first nanoparticles (2) and the second nanoparticles (3, 3') are co-encapsulated within the encapsulate (4); each second nanoparticle (3, 3') of the plurality of second nanoparticles (3, 3') is in direct contact with the first nanoparticle (2) and at least one further second nanoparticle (3, 3') of the plurality of second nanoparticles (3, 3'); The surface of the first nanoparticles (2) is partially covered by the second nanoparticles (3, 3'). Structure (1).

3. 3. The structure (1) according to claim 1 or 2, wherein the first nanoparticle (2) comprises a core and at least one shell.

4. The structure (1) according to any one of claims 1 to 3, wherein the second nanoparticles (3, 3') comprise particles selected from the group consisting of metal particles, semiconductor particles, chalcogenide particles, pnictide particles, and combinations thereof.

5. the first nanoparticles (2) and the second nanoparticles (3, 3') form aggregates, and / or a physical and / or chemical interaction occurs between the first nanoparticles (2) and the second nanoparticles (3, 3'), resulting in a non-covalent bond between the first nanoparticles (2) and the second nanoparticles (3, 3'); and / or a covalent bond is formed between the first nanoparticles (2) and / or the second nanoparticles (3, 3'), and / or the second nanoparticles (3, 3') are bonded to the surface of the first nanoparticles (2) in an at least partially fused structure, and / or the second nanoparticles (3, 3') form a sintered structure on the surface of the first nanoparticles (2), and / or 3. The structure (1) according to claim 2, wherein the first nanoparticles (2) and the second nanoparticles (3, 3') form agglomerates.

6. 2. The structure (1) according to claim 1, wherein the surface of the first nanoparticles (2) is partially covered by the second nanoparticles (3, 3').

7. The structure (1) according to any one of claims 1 to 6, wherein the surface of the first nanoparticles (2) is completely covered by the second nanoparticles (3, 3').

8. A structure (1) according to any one of the preceding claims, wherein the second nanoparticles (3, 3') comprise at least one surface portion (8, 9).

9. 9. The structure (1) according to claim 8, wherein the second nanoparticles (3, 3') comprise a first surface portion (8) and a second surface portion (9), and the first surface portion (8) is bonded to the second nanoparticles (3, 3') by the second surface portion (9).

10. The structure (1) according to any one of claims 1 to 9, wherein the structure (1) comprises at least one internal payload species (A, B) in proximity to the first nanoparticle (2).

11. 11. The structure (1) according to claim 10, wherein said at least one internal payload species (A, B) is inside said second nanoparticle (3, 3').

12. An optoelectronic device (100), comprising: a semiconductor chip (101) configured to emit primary radiation; a conversion element (103) configured to convert at least a portion of the primary radiation into secondary radiation, An optoelectronic device (100) wherein the conversion element (103) comprises at least one structure (1) according to any one of claims 1 to 11.

13. A method for manufacturing a structure (1), comprising: providing first nanoparticles (2) comprising at least one semiconductor material, said first nanoparticles (2) being chromophoric in a first wavelength range and emissive in a second wavelength range; providing a plurality of second nanoparticles (3, 3'), wherein the second nanoparticles (3, 3') are non-chromophoric in the first wavelength range and the second wavelength range; arranging the first nanoparticles (2) and the second nanoparticles (3, 3') adjacent to each other, wherein each second nanoparticle (3, 3') of the plurality of second nanoparticles (3, 3') is in direct contact with the first nanoparticle (2) and at least one further second nanoparticle (3, 3') of the plurality of second nanoparticles (3, 3'); Binding the second nanoparticles (3, 3') to the first nanoparticles (2) by at least one method selected from the group comprising aggregation, non-covalent bonding, covalent bonding, melting, sintering, agglomeration, and combinations thereof; applying an encapsulant (4), wherein the first nanoparticles (2) and the second nanoparticles (3, 3') are co-encapsulated within the encapsulant (4); A method comprising:

14. A method for manufacturing a structure (1), comprising: providing first nanoparticles (2) comprising at least one semiconductor material, said first nanoparticles (2) being chromophoric in a first wavelength range and emissive in a second wavelength range; providing a plurality of second nanoparticles (3, 3'), wherein the second nanoparticles (3, 3') are non-chromophoric in the first wavelength range and the second wavelength range; arranging the first nanoparticles (2) and the second nanoparticles (3, 3') in close proximity to each other, wherein each second nanoparticle (3, 3') of the plurality of second nanoparticles (3, 3') is in direct contact with the first nanoparticle (2) and at least one further second nanoparticle (3, 3') of the plurality of second nanoparticles (3, 3'), and a surface of the first nanoparticles (2) is partially covered by the second nanoparticles (3, 3'); applying an encapsulant (4), wherein the first nanoparticles (2) and the second nanoparticles (3, 3') are co-encapsulated within the encapsulant (4); A method comprising:

15. 15. The method of claim 14, further comprising bonding the second nanoparticles (3, 3') to the first nanoparticles (2) by at least one method selected from the group comprising aggregation, non-covalent bonding, covalent bonding, melting, sintering, agglomeration, and combinations thereof.

16. 14. The method according to claim 13, wherein the surface of the first nanoparticles (2) is partially covered by the second nanoparticles (3, 3').

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