Semiconductor structure, method for producing a semiconductor structure and light-emitting component

Abstract

Semiconductor structure comprising: a plurality of discrete encapsulated semiconductor nanoparticles (7); and a plurality of discrete semiconductor-free nanoparticles (8), wherein the discrete encapsulated semiconductor nanoparticles (7) and the discrete semiconductor-free nanoparticles (8) form an agglomerate (9).

Description

Technical field

[0001] The invention relates to a semiconductor structure. It further relates to a method for manufacturing a semiconductor structure. It further relates to a light-emitting device containing a semiconductor structure. background

[0002] Networks of semiconductor structures with bonded insulator coatings and methods for fabricating networks of semiconductor structures with bonded insulator coatings are described in US Patents Nos. 9,478,717, 9,249,354, and 9,722,147. Even in these networks, there is a high number of thinly coated semiconductor nanoparticles on the outside and around the periphery of the formed network, making the particles susceptible to degradation. Summary

[0003] Embodiments provide a semiconductor structure with improved properties. Further embodiments provide a method for manufacturing a semiconductor structure with improved properties and a light-emitting device with a semiconductor structure with improved properties.

[0004] According to embodiments, a semiconductor structure is provided comprising a plurality of discrete encapsulated semiconductor nanoparticles. In particular, the semiconductor nanoparticles can be used as a converting material for converting the wavelength of electromagnetic radiation passing through at least a portion of the converting material.

[0005] "Wavelength conversion" here and in the following means that incident electromagnetic radiation of a first wavelength range is converted into electromagnetic radiation of a second wavelength range, which preferably includes longer wavelengths than the incident electromagnetic radiation. In general, wavelength-converting materials absorb electromagnetic radiation from the incident range, convert the absorbed radiation at least partially into electromagnetic radiation of the second wavelength range by a molecular and / or atomic mechanism, and re-emit the converted radiation. In particular, wavelength conversion does not refer to scattering or absorption alone.

[0006] "Encapsulated semiconductor nanoparticles" are understood to mean that they are encapsulated in an encapsulation material. The encapsulation is intended, in particular, to protect the semiconductor nanoparticles from external influences such as oxygen or water, as these external influences can lead to oxidation and thus to degradation of the semiconductor nanoparticles. The semiconductor nanoparticles, or a large proportion of them, are at least partially, and preferably completely, surrounded by the encapsulation material. This means that the semiconductor nanoparticles can be surrounded by the encapsulation material on all sides. Furthermore, the semiconductor nanoparticles can be in direct contact with the encapsulation material. In addition, at least the majority of the semiconductor nanoparticles are individually encapsulated, i.e., each semiconductor nanoparticle comprises at least one layer of the encapsulation material.

[0007] "Discrete encapsulated semiconductor nanoparticle" means that each encapsulated semiconductor nanoparticle has a finite size and is fundamentally distinguishable from every other nanoparticle. Furthermore, each individual encapsulated semiconductor nanoparticle is referred to as a discrete nanoparticle even if it is connected to or adheres to another nanoparticle, as long as the individual spatial shape of each nanoparticle remains distinguishable.

[0008] The discrete encapsulated semiconductor nanoparticles can be understood as three-dimensional objects. For example, they can be spherical and / or elongated particles, and it should be noted that the discrete semiconductor nanoparticles are not limited to a specific spatial shape. Rather, they can encompass any regular or irregular three-dimensional shape and can have zero, one, or multiple edges.

[0009] According to at least one embodiment of the semiconductor structure, the semiconductor structure comprises a plurality of discrete semiconductor-free nanoparticles. The term semiconductor-free means that no semiconductor nanoparticle is present in the semiconductor-free nanoparticles.

[0010] "Discrete semiconductor-free nanoparticles" means that each semiconductor-free nanoparticle has a finite size and is fundamentally distinguishable from every other nanoparticle. Furthermore, each individual semiconductor-free nanoparticle is referred to as a discrete nanoparticle even if it is bound to or adheres to another nanoparticle, as long as the individual spatial shape of each nanoparticle remains distinguishable.

[0011] The discrete semiconductor-free nanoparticles can be understood as three-dimensional objects. They are not limited to a specific spatial shape. Rather, they can encompass any regular or irregular three-dimensional shape and have zero, one, or multiple edges. For example, they can be spherical and / or elongated particles.

[0012] The semiconductor-free nanoparticles can be smaller than, larger than, or the same size as the encapsulated semiconductor nanoparticles. Furthermore, a mixture of different sizes of semiconductor-free nanoparticles within the semiconductor structure is also possible. In this case, the semiconductor-free nanoparticles can be smaller than, larger than, or the same size as the encapsulated semiconductor nanoparticles.

[0013] According to at least one embodiment, the discrete encapsulated semiconductor nanoparticles and the discrete semiconductor-free nanoparticles form an agglomerate.

[0014] An agglomerate is understood to be a composite of numerous discrete nanoparticles. Here and in the following, the term "discrete nanoparticles" refers to both encapsulated semiconductor nanoparticles and semiconductor-free nanoparticles. The composite of discrete nanoparticles within the agglomerate can be formed by point-to-point connections between the individual discrete nanoparticles. These point-to-point connections can be, for example, non-covalent or covalent chemical bonds or interactions. The point-to-point connections are limited to a specific region on the surface of a nanoparticle. In other words, the nanoparticles are not connected across their entire surface. These point-to-point connections can form a network between the individual discrete nanoparticles.

[0015] Within the agglomerate, the spatial shape of the individual discrete nanoparticles can be discerned. Therefore, random gaps and / or spaces may exist between the individual discrete nanoparticles. The presence of these random gaps and / or spaces can be attributed to the spatial shape of the discrete nanoparticles. The random gaps and / or spaces are finite regions surrounded by at least two discrete nanoparticles. They may be located in the center of the agglomerate as well as at its periphery. The random gaps and / or spaces are filled with the surrounding atmosphere. In particular, the random gaps and / or spaces may be filled with air.

[0016] The size of the agglomerate is large compared to the average size of the discrete nanoparticles. For example, the agglomerate can have a size of 100 nm to 40 µm, while the corresponding discrete nanoparticles can each have a size of approximately 50 nm.

[0017] According to one embodiment, the agglomerate is self-supporting. This means that the agglomerate can be free of an additional support or substrate. The stability of the agglomerate is achieved through point-to-point connections between the individual discrete nanoparticles. In particular, point-to-point connections between the encapsulated semiconductor nanoparticles and the semiconductor-free nanoparticles lead to increased mechanical stability. Particularly high stability is achieved when small semiconductor-free nanoparticles are point-to-point connected to the encapsulated semiconductor nanoparticles. Small semiconductor-free nanoparticles means that the semiconductor-free nanoparticles in the agglomerate are smaller than the encapsulated semiconductor nanoparticles.In this case, the small semiconductor-free nanoparticles can be arranged in some of the random gaps and / or spaces between semiconductor nanoparticles in the agglomerate, resulting in a more complex and therefore more stable network.

[0018] According to at least one embodiment, the semiconductor structure comprises a plurality of discrete encapsulated semiconductor nanoparticles and a plurality of discrete semiconductor-free nanoparticles, wherein the discrete encapsulated semiconductor nanoparticles and the discrete semiconductor-free nanoparticles form an agglomerate.

[0019] In addition to encapsulating the semiconductor nanoparticles, the agglomerate, which comprises encapsulated semiconductor nanoparticles and semiconductor-free nanoparticles, provides additional protection for the semiconductor nanoparticles against degradation, going beyond the individual encapsulation layer alone.

[0020] According to at least one embodiment, the encapsulated semiconductor nanoparticles each comprise a semiconductor nanoparticle and an encapsulation. Furthermore, the encapsulation can comprise or consist of the same material as the semiconductor-free nanoparticles.

[0021] According to at least one embodiment of the semiconductor structure, each of the plurality of discrete encapsulated semiconductor nanoparticles comprises a quantum dot. That is, the semiconductor nanoparticle within the encapsulated semiconductor nanoparticles comprises or consists of a quantum dot. The quantum dot can comprise or consist of at least one semiconductor material. Each quantum dot can, for example, comprise a core comprising a first semiconductor material and optionally at least one shell comprising a second, different semiconductor material, the shell at least partially, and preferably completely, surrounding the core.The semiconductor materials can include, for example, Group II-VI, Group III-V, Group IV-VI, Group I-III-VI, and Group II-IV-VI semiconductors, as well as alloys or mixtures thereof, in particular CdSe, InAs, ZnSe, InP, GaP, CdS, ZnS, HgTe, PbSe, PbS, and ternary and doped materials such as CuInS₂, as well as alloys or mixtures thereof. The semiconductor particle can, for example, have a diameter between 2 nm inclusive and 50 nm inclusive.

[0022] According to one embodiment, each of the plurality of discrete encapsulated semiconductor nanoparticles comprises an encapsulation which includes an encapsulation material. An encapsulated semiconductor nanoparticle can, for example, have a diameter of 5 nm inclusive to 100 nm inclusive, and in particular 50 nm.

[0023] It is possible for each encapsulation to contain more than one semiconductor nanoparticle. However, it is preferred that each encapsulation contains only one semiconductor nanoparticle.

[0024] According to at least one embodiment of the semiconductor structure, the discrete semiconductor-free nanoparticles comprise the encapsulation material. In particular, the semiconductor-free nanoparticles consist of the encapsulation material.

[0025] Thus, the encapsulated semiconductor nanoparticles contain the same encapsulation material as the semiconductor-free nanoparticles. This is advantageous for agglomerate formation because the identical material on the surface of both the encapsulated semiconductor nanoparticles and the semiconductor-free nanoparticles facilitates the formation of point-to-point connections.

[0026] According to at least one embodiment, the encapsulation material comprises silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, magnesium oxide, hafnium oxide, barium oxide, bismuth oxide, tin oxide, or mixed oxides. In particular, the encapsulation material consists of silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, magnesium oxide, hafnium oxide, barium oxide, bismuth oxide, tin oxide, or mixed oxides. Thus, the encapsulation material comprises optically clear metal oxides, and the semiconductor structure is therefore particularly well-suited for use in light-emitting devices.

[0027] According to at least one embodiment of the semiconductor structure, the agglomerate comprises point-to-point connections between the discrete encapsulated semiconductor nanoparticles and the discrete semiconductor-free nanoparticles. These point-to-point connections can be connections between the individual nanoparticles. The point-to-point connections can be non-covalent or covalent interactions between the individual nanoparticles, for example, van der Waals interactions, ionic interactions, hydrogen bonds, and / or covalent bonds. Preferably, the point-to-point connections are covalent bonds. If the encapsulation material comprises, for example, silicon dioxide, the point-to-point connections are covalent Si-O bonds. The non-covalent or covalent bonds between the individual nanoparticles lead to increased stability of the agglomerate.

[0028] According to at least one embodiment of the semiconductor structure, the concentration of discrete semiconductor-free nanoparticles in the agglomerate is different from or equal to the concentration of discrete encapsulated semiconductor nanoparticles. This means that the concentration of the semiconductor-free nanoparticles can be greater than, equal to, or less than the concentration of the encapsulated semiconductor nanoparticles. In particular, the concentration of the semiconductor-free nanoparticles in the agglomerate is greater than or equal to the concentration of the encapsulated semiconductor nanoparticles. A higher or equal concentration of the semiconductor-free nanoparticles increases the protection of the semiconductor nanoparticles, as the semiconductor-free nanoparticles contribute to the protection in addition to encapsulating the semiconductor nanoparticles.

[0029] According to at least one embodiment, the agglomerate comprises a central region and a peripheral region. The central region refers to the portion of the agglomerate located in the middle and shielded from the environment by at least one further layer of discrete nanoparticles belonging to the agglomerate. This at least one further layer of discrete nanoparticles is referred to as the peripheral region of the agglomerate. The peripheral region is located on the outside of the agglomerate; that is, it has an interface with the environment. In other words, the peripheral region forms the surface of the agglomerate. In this case, the surface of the agglomerate is not necessarily smooth but may be uneven and rough due to the surface composition of discrete nanoparticles. The peripheral region surrounds the central region of the agglomerate. On one side, the peripheral region is in direct contact with the central region.On the side facing away from the central area, the periphery of the agglomerate is surrounded by the ambient atmosphere.

[0030] According to at least one embodiment, the concentration of discrete semiconductor-free nanoparticles in the edge region is equal to or greater than in the central region. The concentration of semiconductor-free nanoparticles in the edge region and in the central region can be expressed as a percentage of the total nanoparticle concentration in the respective region. Therefore, the concentration of semiconductor-free nanoparticles in both the edge region and the central region can range from 0% to 100%. If only encapsulated semiconductor nanoparticles are present in the respective region, the concentration of semiconductor-free nanoparticles is 0%. If no encapsulated semiconductor nanoparticles are present in the respective region, the concentration of semiconductor-free nanoparticles is 100%.For example, the concentration of semiconductor-free nanoparticles in the central region is between 50% and 70%, while the concentration of semiconductor-free nanoparticles at the periphery is above 70%. A higher concentration of semiconductor-free nanoparticles at the periphery thus statistically reduces the number of encapsulated semiconductor nanoparticles at the periphery of the large agglomerate, and therefore provides additional protection against degradation for the encapsulated semiconductor nanoparticles.

[0031] According to at least one embodiment, the discrete semiconductor-free nanoparticles are located at least partially in gaps and / or spaces between the discrete encapsulated semiconductor nanoparticles. The arrangement of semiconductor-free nanoparticles in gaps and / or spaces within the agglomerate is possible for all sizes of semiconductor-free nanoparticles. The smaller the semiconductor-free nanoparticles are compared to the encapsulated semiconductor nanoparticles, the more likely it is that the semiconductor-free nanoparticles will be arranged in the random gaps and / or spaces. The more semiconductor-free nanoparticles are located in the random gaps and / or spaces, the more complex and thus more stable the network that forms the semiconductor structure becomes.

[0032] According to at least one embodiment, each of the plurality of discrete semiconductor nanoparticles comprises an additional passivation layer. In particular, the passivation layer is located between the surface of the semiconductor nanoparticle, for example, a quantum dot, and the encapsulation surrounding the semiconductor nanoparticle. The passivation layer can be in direct contact with both the semiconductor nanoparticle and the encapsulation. The passivation layer provides the semiconductor nanoparticles with additional protection against degradation. The passivation layer can, for example, comprise ZnS.

[0033] Further embodiments of the invention relate to a method for producing a semiconductor structure. The method described here is preferably used for producing the semiconductor structure described herein. Features and embodiments of the method are therefore also disclosed for the semiconductor structure and vice versa.

[0034] According to one embodiment of the method for fabricating a semiconductor structure, the method comprises the fabrication of a plurality of discrete semiconductor nanoparticles. The fabrication of the plurality of discrete semiconductor nanoparticles includes, for example, the formation of a quantum dot, such as a core particle. Optionally, the growth of a shell on the core particle may be included. Optionally, an additional passivation layer may be applied to the outside of the shell.

[0035] According to at least one embodiment, the method for producing a semiconductor structure comprises encapsulating each of the plurality of discrete semiconductor nanoparticles to form discrete encapsulated semiconductor nanoparticles. Encapsulation is understood to mean the formation of a layer of encapsulation material on the surface of a particle. For example, the semiconductor particles, and optionally a surfactant, are dissolved in a solvent, and an encapsulation material or a starting material, such as monomers, is added to the encapsulation. The encapsulation can be understood as a polymerization of the monomers. If the encapsulation material is, for example, silicon dioxide, the monomer can be, for example, a silicate monomer. Optionally, subsequent addition of monomers can be used to increase the amount of encapsulation material on the surface of the semiconductor nanoparticles.The encapsulation material can be in direct contact with the surface of the semiconductor nanoparticle and can optionally be bonded to the semiconductor nanoparticle.

[0036] In general, encapsulation can be carried out as follows: preparing an initial solution comprising a semiconductor nanoparticle and an initial solvent; Preparing a second solution comprising a surfactant and a second solvent; Adding the first solution and a bifunctional linker to the second solution, thereby producing a third solution; Adding a catalyst, water and an encapsulation material or an encapsulation starting material to the third solution; which produces an encapsulated semiconductor nanoparticle.

[0037] The encapsulation material can comprise or consist of silicon dioxide, titanium dioxide, zirconium dioxide, aluminum dioxide, magnesium dioxide, hafnium dioxide, barium dioxide, bismuth dioxide, tin oxide, or mixed oxides. The encapsulation can be in direct contact with the surface or the optional passivation layer of the semiconductor nanoparticle. The encapsulation material can partially or completely surround the semiconductor nanoparticle. Preferably, the encapsulation material completely surrounds the semiconductor nanoparticle on all sides.

[0038] The encapsulation of discrete semiconductor nanoparticles leads to the formation of three-dimensional particles that are not limited to a specific spatial shape. For example, spherical and / or elongated particles are formed. The encapsulated semiconductor nanoparticles are discrete, meaning that each encapsulated semiconductor nanoparticle has a finite size and is fundamentally distinguishable from every other nanoparticle.

[0039] According to one embodiment, each semiconductor nanoparticle has its own encapsulation. This means that additives are used in the encapsulation of the semiconductor nanoparticles to ensure the formation of individual encapsulated semiconductor nanoparticles. Examples of additives include surfactants such as sodium dioctyl sufosuccinate, Igepal, or Triton X, and bases such as ammonium hydroxide or mineral bases such as potassium hydroxide or sodium hydroxide in water. Such additives can also contribute to shaping the encapsulation.

[0040] According to at least one embodiment, the method comprises the production of a plurality of discrete semiconductor-free nanoparticles. The production of semiconductor-free nanoparticles is similar to the encapsulation of semiconductor nanoparticles. To nucleate semiconductor-free nanoparticles, a different nucleation site than that of the semiconductor nanoparticles may be necessary. For this purpose, a precursor, for example, an alkoxy metal precursor, can be used. This precursor can be identical to the starting material, for example, a monomer, of the encapsulation material. Subsequently, this precursor reacts with further molecules of the starting material of the encapsulation material. A semiconductor-free nanoparticle is formed in which the precursor becomes part of the encapsulation material.

[0041] The fabrication of a large number of discrete semiconductor-free nanoparticles leads to the formation of three-dimensional particles that are not limited to a specific spatial shape. For example, spherical and / or elongated particles can be formed. The fabricated semiconductor-free nanoparticles are discrete, meaning that each semiconductor-free nanoparticle has a finite size and is distinguishable from every other nanoparticle.

[0042] According to at least one embodiment, the method comprises the condensation of the plurality of discrete encapsulated semiconductor nanoparticles and the plurality of discrete semiconductor-free nanoparticles into an agglomerate. The formation of the agglomerate can be described as a network of discrete nanoparticles. This network can be formed via point-to-point connections between the individual discrete nanoparticles. In other words, the connected or agglomerated nanoparticles form a network.

[0043] Condensation is a chemical reaction that combines at least two reactants, releasing water or other small molecules. The condensation of a multitude of nanoparticles leads to the formation of point-to-point connections between the discrete nanoparticles. For example, point-to-point connections form between encapsulated semiconductor nanoparticles and semiconductor-free nanoparticles. In this case, condensation occurs between the encapsulated semiconductor nanoparticles and the semiconductor-free nanoparticles. The point-to-point connections formed during condensation can be non-covalent or covalent bonds. In particular, covalent bonds are formed between the discrete nanoparticles.

[0044] In particular, the condensation of encapsulated semiconductor nanoparticles and semiconductor-free nanoparticles leads to increased stability of the agglomerate forming the semiconductor structure, as for example in Fig. Figure 5, which will be discussed later, shows that stability can be significantly increased by arranging small semiconductor-free nanoparticles in some of the random gaps and spaces within the agglomerate. Small semiconductor-free nanoparticles mean that they are smaller than the encapsulated semiconductor nanoparticles used to form the agglomerate. In this case, the small semiconductor-free nanoparticles are arranged in some of the random gaps and / or spaces within the agglomerate, resulting in a more complex and therefore more stable network.

[0045] The presence of semiconductor-free nanoparticles within the agglomerate provides an additional barrier for the protection of the semiconductor nanoparticles, beyond their encapsulation. The agglomerate comprises a central region and a peripheral region. The central region is located in the middle of the agglomerate and is shielded from the surrounding region by at least one further layer of discrete nanoparticles belonging to the agglomerate, the so-called peripheral region. The concentration of semiconductor-free nanoparticles in the peripheral region can be equal to or greater than in the central region, thus also influencing the number of encapsulated semiconductor nanoparticles in the respective regions. In particular, in the condensed structure, the number of encapsulated semiconductor nanoparticles in the peripheral region of the agglomerate can be statistically reduced.Since the outer region of the agglomerate is more exposed to environmental conditions than the central region of the agglomerate, reducing the number of encapsulated semiconductor nanoparticles in the outer region of the agglomerate reduces the degradation of the semiconductor structure.

[0046] The number of encapsulated semiconductor nanoparticles at the edge of the agglomerate can be influenced during its formation, as statistical reduction may not be sufficient. To reduce the number of encapsulated semiconductor nanoparticles at the edge of the agglomerate—for example, to increase the concentration of semiconductor-free nanoparticles at the edge—the agglomerate can be formed in stages. First, an agglomerate of encapsulated semiconductor nanoparticles can be formed. Then, a layer of semiconductor-free nanoparticles can be deposited onto the surface of the initially formed agglomerate of encapsulated semiconductor nanoparticles. In this way, the central region of the formed agglomerate can contain the encapsulated semiconductor nanoparticles, while at the edge, the semiconductor-free nanoparticles efficiently shield the semiconductor nanoparticles from degradation.

[0047] Optionally, the encapsulated semiconductor nanoparticles can be treated with multiple layers of semiconductor-free nanoparticles to form more complex networks. This results in a periphery comprising multiple layers of predominantly semiconductor-free nanoparticles, making it thicker than a periphery comprising only a single layer. The thicker periphery provides better protection for the encapsulated semiconductor nanoparticles, which are primarily located in the central region.

[0048] Alternatively, a gradient in the concentration of semiconductor-free nanoparticles can be established both within the agglomerate and at its periphery and central regions. For example, at the beginning of the agglomeration process, no or only a small amount of semiconductor-free nanoparticles can be added to the encapsulated semiconductor nanoparticles. During the agglomeration process, the amount of semiconductor-free nanoparticles added to the reaction solution can be increased. The agglomerate can then contain only a small amount of semiconductor-free nanoparticles in the central region and a high amount of semiconductor-free nanoparticles at the periphery. In this way, the concentration of semiconductor-free nanoparticles can gradually increase from the center of the agglomerate to its surface, thus forming a gradient.

[0049] Alternatively, semiconductor-free nanoparticles can be pre-aggregated into small agglomerates, each containing only a few nanoparticles. For example, these small agglomerates can contain up to 10 semiconductor-free nanoparticles. The small agglomerates can then be exposed to encapsulated semiconductor nanoparticles. This creates a large agglomerate with thicker layers of semiconductor-free nanoparticles surrounding the encapsulated semiconductor nanoparticles, thus better protecting the semiconductor nanoparticles from degradation.

[0050] Alternatively or additionally, the encapsulated semiconductor nanoparticles can be pretreated with a strong base to activate their surface towards a reaction with incoming semiconductor-free nanoparticles. This increases the bonding between the encapsulated semiconductor nanoparticles and the semiconductor-free nanoparticles and reduces the self-agglomeration of the encapsulated semiconductor nanoparticles. In the resulting agglomerate, the encapsulated semiconductor nanoparticles are therefore further apart and, for example, surrounded by semiconductor-free nanoparticles, thus being better protected against degradation.

[0051] According to one embodiment, the stability of the formed agglomerate can be influenced during condensation. The stability of the agglomerate can be closely linked to the network formed within it. For example, compact or extended networks can be formed. Compact networks may have fewer random gaps and / or spaces, while extended networks may have more. Parameters that influence whether a compact or extended network forms within the agglomerate include, for example, the pH of the reaction suspension and the size of the reacting nanoparticles.

[0052] For example, the pH of the reaction suspension of encapsulated semiconductor nanoparticles and semiconductor-free nanoparticles can be adjusted to favor either compact or extended networks. For example, pH values ​​below 7 can promote the formation of extended networks.

[0053] Alternatively, a mixture of different sizes of semiconductor nanoparticles and semiconductor-free nanoparticles can be used to form the agglomerate. For example, both small and large semiconductor-free nanoparticles can be used simultaneously to form a more compact network, with the smaller semiconductor-free nanoparticles occupying some of the random gaps and / or spaces, while the larger semiconductor-free nanoparticles tend to form a protective layer on the outside of the agglomerate. Furthermore, different sizes of semiconductor-free nanoparticles can be added stepwise to the reaction suspension containing semiconductor nanoparticles to unambiguously determine the compactness of each part of the agglomerate.

[0054] According to at least one embodiment of the method for fabricating a semiconductor structure, the encapsulation of the discrete semiconductor nanoparticles and the fabrication of the discrete semiconductor-free nanoparticles are carried out sequentially or simultaneously. Consecutive encapsulation of the semiconductor nanoparticles and fabrication of the semiconductor-free nanoparticles means that both process steps can be performed independently of each other. For example, the encapsulation of the semiconductor nanoparticles is carried out before the fabrication of the semiconductor-free nanoparticles, or vice versa. In particular, the encapsulation of the semiconductor nanoparticles can be performed concurrently with the fabrication of the semiconductor-free nanoparticles, but in different reaction vessels. Therefore, the properties of both the encapsulated semiconductor nanoparticles and the semiconductor-free nanoparticles can be tailored independently of each other.For example, both the size and the surface properties of the nanoparticles can be adjusted.

[0055] Simultaneous encapsulation of semiconductor nanoparticles and fabrication of semiconductor-free nanoparticles means that both process steps can be performed in a single step. The fabrication of semiconductor-free nanoparticles can then be carried out in situ with the encapsulation of the semiconductor nanoparticles. In particular, the fabrication of semiconductor-free nanoparticles and the encapsulation of semiconductor nanoparticles can be performed in the same reaction vessel. This process can be referred to as co-fabrication. To fabricate semiconductor-free nanoparticles and encapsulate semiconductor nanoparticles simultaneously, a precursor can be used to nucleate the semiconductor-free nanoparticles.

[0056] During the simultaneous encapsulation of semiconductor nanoparticles and the fabrication of the encapsulated semiconductor-free nanoparticles, a selection of factors can be varied to adjust the reactivity to achieve the desired ratio of semiconductor-free nanoparticles to encapsulated semiconductor nanoparticles. These factors can include, for example, the concentration of semiconductor nanoparticles in the reaction solution, the amount of encapsulation material or starting material (such as monomers) added to the reaction solution, and / or the pH of the reaction solution. To shift the ratio of semiconductor-free nanoparticles to encapsulated semiconductor nanoparticles in favor of the encapsulated semiconductor nanoparticles, the concentration of semiconductor nanoparticles added to the reaction solution can be increased.This allows for the formation of more encapsulated semiconductor nanoparticles and fewer semiconductor-free nanoparticles. To shift the ratio of semiconductor-free to encapsulated semiconductor nanoparticles in favor of semiconductor-free nanoparticles, the concentration of semiconductor nanoparticles in the reaction solution can be reduced, the amount of monomer added to the reaction solution can be increased, and / or the pH of the reaction solution can be raised. For example, a higher pH leads to faster hydrolysis and promotes template-free nucleation. Alternatively or additionally, a more reactive encapsulation material can be used. This also allows for the formation of more semiconductor-free nanoparticles and fewer encapsulated semiconductor nanoparticles.

[0057] According to at least one embodiment of the method for producing a semiconductor structure, parameters are variable during the production of the discrete semiconductor-free nanoparticles, wherein the parameters include charge, coating with a surfactant, and degree of gelation. The properties of the semiconductor-free nanoparticles can be tailored by varying these parameters. In particular, the parameters can be varied during the production of the semiconductor-free nanoparticles without the simultaneous encapsulation of semiconductor nanoparticles to achieve improved initial conditions for agglomeration.For example, the semiconductor-free nanoparticles can be designed to have a high degree of negative surface charge to prevent mutual coalescence and promote heterogeneous interactions between different nanoparticles, such as between the semiconductor-free nanoparticles and the encapsulated semiconductor nanoparticles. Coating the encapsulated semiconductor-free nanoparticles with surfactants can, for example, delay the agglomeration process, while increased gelation can promote it. Gelation refers to the promotion of interactions between particles by causing them to cluster and / or bind together around pockets of solvent.

[0058] According to at least one embodiment, the discrete semiconductor-free nanoparticles are produced using an oxide precursor for nanoparticle nucleation. For example, a highly reactive oxide precursor can be used that does not require templating on a nanoparticle surface to nucleate semiconductor-free nanoparticles. According to one embodiment, the oxide precursor is an alkoxy metal precursor. Suitable precursor reagents can be, for example, tetramethoxysilane, tetraethoxysilane (tetraethyl orthosilicate) and longer variants, aluminum trisec butoxide, or aluminum isopropoxide. These precursor reagents are single molecules and not bulk structures. Other precursor reagents are also possible. In particular, the alkoxy metal precursor can be a molecule of the starting material, for example, a monomer, or of the encapsulation material, for example, tetraethyl orthosilicate.

[0059] Other embodiments relate to a light-emitting component. The light-emitting component described herein preferably comprises the semiconductor structure described herein, which is preferably manufactured using the method described herein. Features and embodiments of the light-emitting device are therefore also disclosed for the semiconductor structure and the method for manufacturing a semiconductor structure, and vice versa.

[0060] According to one embodiment of the light-emitting device, the device comprises an active layer stack configured to emit electromagnetic radiation. The active layer stack can have an active region configured to generate electromagnetic radiation during operation of the light-emitting device. The electromagnetic radiation generated in the active region is emitted by a radiation emission surface of the active layer stack and forms a beam path. The electromagnetic radiation emitted by the active layer stack is referred to as primary radiation. In particular, the primary radiation forms the beam path.

[0061] According to at least one embodiment, the light-emitting device further comprises a conversion element in the beam path of the active layer stack, wherein the conversion element comprises a phosphor material and a matrix. In particular, the phosphor material comprises a down-converter material. For example, the matrix comprises or consists of a polymer such as silicone. Alternatively, the matrix may also comprise or consist of silicon oxide. The phosphor material can then be suspended in a liquid silicon oxide suspension or a liquid solution of molecular silicon oxide precursors. Subsequently, the silicon oxide matrix can be condensed / polymerized, encapsulating the phosphor material. When the phosphor material is encapsulated in silicon oxide, the matrix and the encapsulated phosphor material can be fused to form a single structure without a clear boundary.

[0062] According to at least one embodiment, the phosphor material comprises a semiconductor structure consisting of an agglomerate of discrete encapsulated semiconductor nanoparticles and discrete semiconductor-free nanoparticles. In particular, the phosphor material consists of the semiconductor structure comprising an agglomerate of discrete encapsulated semiconductor nanoparticles and discrete semiconductor-free nanoparticles.

[0063] According to one embodiment, the semiconductor nanoparticles in the phosphor material convert the wavelength of the electromagnetic radiation passing through at least part of the conversion element. The incident primary radiation of a first wavelength range is converted into electromagnetic radiation of a second wavelength range. The second wavelength range preferably includes longer wavelengths than the primary radiation.

[0064] The use of the semiconductor structure described here in a conversion element is advantageous due to the high proportion of semiconductor-free nanoparticles in the edge region of the agglomerate. The improved protection of the semiconductor nanoparticles leads to better aging behavior of the phosphor material under harsh conditions, such as at higher power levels or higher humidity.

[0065] According to at least one embodiment, each of the discrete encapsulated semiconductor nanoparticles comprises a quantum dot and an encapsulation comprising an encapsulation material. Each quantum dot can, for example, comprise a core comprising a first semiconductor material and optionally at least one shell comprising a second, different semiconductor material, the shell at least partially, preferably completely, surrounding the core. Each semiconductor nanoparticle can be encapsulated in an encapsulation material. That is, the encapsulation material can be in direct contact with the quantum dot and at least partially, preferably completely, surround the semiconductor nanoparticles. In particular, each semiconductor nanoparticle can have its own encapsulation.

[0066] According to at least one embodiment, the discrete semiconductor-free nanoparticles comprise the encapsulation material. In particular, the semiconductor-free nanoparticles consist of the encapsulation material. "Semiconductor-free" means that no semiconductor nanoparticles are present in the semiconductor-free nanoparticles.

[0067] According to at least one embodiment, the encapsulation material comprises silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, magnesium oxide, hafnium oxide, barium oxide, bismuth oxide, tin oxide, or mixed oxides. In particular, the encapsulation material consists of silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, magnesium oxide, hafnium oxide, barium oxide, bismuth oxide, tin oxide, or mixed oxides.

[0068] According to at least one embodiment, each of the plurality of discrete encapsulated semiconductor nanoparticles comprises an additional passivation layer. This additional passivation layer is located on the surface of the semiconductor nanoparticle, for example, a quantum dot. Specifically, the passivation layer is situated between the surface of the semiconductor nanoparticle and the encapsulation surrounding the semiconductor nanoparticle. The passivation layer can be in direct contact with both the surface of the semiconductor nanoparticle and the encapsulation. The passivation layer provides further protection against degradation of the semiconductor nanoparticles. List of characters

[0069] Advantageous embodiments and further developments of the semiconductor structure, the method for manufacturing a semiconductor structure and the light-emitting component will become apparent from the embodiments described below in conjunction with the figures.

[0070] In the characters: Fig. 1A and Fig. Figure 1B shows a schematic representation of encapsulated semiconductor nanoparticles and a semiconductor structure according to a reference example; Fig. 2A to Fig. Figure 2C shows transmission electron microscope (TEM) images of encapsulated semiconductor nanoparticles and a semiconductor structure according to a reference example; Fig. 3A and Fig. Figure 3B shows a schematic representation of encapsulated semiconductor nanoparticles and semiconductor-free nanoparticles according to one embodiment and a semiconductor structure according to one embodiment; Fig. 4A and Fig. Figure 4B shows TEM images of encapsulated semiconductor nanoparticles and semiconductor-free nanoparticles according to one embodiment and a semiconductor structure according to one embodiment; Fig. Figure 5 shows curves for wet high temperature operating life (WHTOL); and Fig. Figure 6 shows a schematic representation of a light-emitting component according to one embodiment.

[0071] In the exemplary embodiments and figures, identical or similarly functioning components are designated with the same reference numerals. The elements depicted in the figures and their relative sizes are not to be considered to scale. Rather, individual elements may be shown in an exaggerated size for better illustration and / or understanding. Detailed description of illustrative designs

[0072] Fig. 1A and Fig. Figure 1B shows a variety of encapsulated semiconductor nanoparticles 3 , which form an agglomerate that has a semiconductor structure 4 according to a reference example.

[0073] In Fig. 1A is a variety of encapsulated semiconductor nanoparticles 3 Shown before agglomeration. Each encapsulated semiconductor nanoparticle 3 comprises a semiconductor nanoparticle 1 and an encapsulation 2 Each of the encapsulated semiconductor nanoparticles 3 is discrete, i.e., finite in size and distinct from any other encapsulated semiconductor nanoparticle 3 distinguishable. In the case of the semiconductor nanoparticle 1 It could, for example, be a quantum dot. The encapsulation material of the encapsulation 2 It could be silicon dioxide, for example.

[0074] In Fig. 1B is a semiconductor structure 4The semiconductor structure is shown. 4 is an agglomerate of encapsulated semiconductor nanoparticles 3 The encapsulated semiconductor nanoparticles 3 are connected via point-to-point connections, forming a network of encapsulated semiconductor nanoparticles 3 form.

[0075] Fig. 2A to Fig. 2C show transmission electron microscope (TEM) images of encapsulated semiconductor nanoparticles 3 and a semiconductor structure 4 according to the reference example.

[0076] Fig. Figure 2A shows a variety of encapsulated semiconductor nanoparticles 3 before agglomeration. Each encapsulated semiconductor nanoparticle 3 is discrete and not combined with other encapsulated semiconductor nanoparticles 3 connected by point-to-point links.

[0077] Fig. Figure 2B shows a TEM image of a semiconductor structure 4, with an enlargement of the edge region of the semiconductor structure 4 in Fig. 2C. The semiconductor structure 4 exhibits a high proportion of thinly coated semiconductor nanoparticles 1 on the outside and around the periphery of the agglomeration, as in Fig. 2C can be detected, which makes these particles more susceptible to degradation.

[0078] Fig. 3A and Fig. 3B shows a variety of encapsulated semiconductor nanoparticles 7 and semiconductor-free nanoparticles 8 according to one embodiment and a semiconductor structure 9 according to one embodiment.

[0079] In Fig. 3A is a variety of encapsulated semiconductor nanoparticles 7 and semiconductor-free nanoparticles 8 shown before agglomeration. Both the encapsulated semiconductor nanoparticles 7 as well as the semiconductor-free nanoparticles 8are discrete. That means they are finite in size and distinguishable from each other. The encapsulated semiconductor nanoparticles 7 Each comprises a semiconductor nanoparticle 5 and an encapsulation 6 . In the case of the semiconductor nanoparticle 5 It could, for example, be a quantum dot. The encapsulation material of the encapsulation 6 Silicon oxide, for example, could be used. The semiconductor-free nanoparticles 8 are free of semiconductor nanoparticles. Preferably, the semiconductor-free nanoparticles comprise 8 the encapsulation material of the encapsulation 6 the encapsulated semiconductor nanoparticles 7 or consist of them. For example, semiconductor-free nanoparticles include 8 silicon oxide or consist of it.

[0080] In Fig. 3B is a semiconductor structure 9 shown. The semiconductor structure 9is caused by condensation of both the encapsulated semiconductor nanoparticles 7 as well as the semiconductor-free nanoparticles 8 The condensation reaction leads to the formation of point-to-point connections between the encapsulated semiconductor nanoparticles. 7 and the semiconductor-free nanoparticles 8 as well as between the nanoparticles 7 , 8 of the same type. The semiconductor structure 9 can be described as an agglomerate or a network of encapsulated semiconductor nanoparticles 7 and the semiconductor-free nanoparticles 8 be described. In the semiconductor structure 9 is the individual spatial shape of the individual nanoparticles 7 , 8 to detect. Between at least two nanoparticles 7 , 8 are random gaps and / or spaces 10 formed. The semiconductor structure 9 has a central area 12and a border area 11 up. The edge area 11 surrounds the central area 12 and forms a layer on the central area 12 from which have a thickness of at least one nanoparticle 7 , 8 exhibits the edge area 11 can a higher concentration of semiconductor-free nanoparticles 8 as encapsulated semiconductor nanoparticles 7 encompass. Thus, in the marginal area 11 the semiconductor structure 9 a protective layer made of semiconductor-free nanoparticles 8 trained. The central area 12 Encapsulated semiconductor nanoparticles can then be used 7 include those that extend through the marginal area 11 are protected from degradation.

[0081] Fig. 4A and Fig. Figure 4B shows transmission electron microscope (TEM) images of encapsulated semiconductor nanoparticles. 7 and semiconductor-free nanoparticles 8according to one embodiment and a semiconductor structure 9 according to one embodiment.

[0082] In Fig. 4A is a TEM image of the result of an in situ co-production of encapsulated semiconductor nanoparticles. 7 and semiconductor-free nanoparticles 8 shown. In situ means that the reactions that cause encapsulation are shown. 6 around the semiconductor nanoparticles 5 form, which include a CdSe core, a CdS shell and an optional ZnS passivation layer, and the generation of the semiconductor-free nanoparticles 8 the process is carried out in the same reaction vessel. The material for encapsulation 6 and the semiconductor-free nanoparticles 8 It includes silicon oxide. As can be seen, a variety of semiconductor-free nanoparticles are used. 8 as well as encapsulation 6 for the semiconductor nanoparticles 5 formed, which are the encapsulated semiconductor nanoparticles7 form.

[0083] In Fig. 4B is a TEM image of a semiconductor structure 9 shown. The semiconductor structure 9 contains encapsulated semiconductor nanoparticles 7 and semiconductor-free nanoparticles 8 The semiconductor structure 9 is the result of a condensation of encapsulated semiconductor nanoparticles 7 and semiconductor-free nanoparticles 8 As can be seen, there is a high proportion of semiconductor-free nanoparticles. 8 in the marginal area 11 the semiconductor structure 9 arranged. The semiconductor nanoparticles 5 This provides better protection from the surrounding atmosphere.

[0084] A semiconductor structure can be manufactured, for example, according to the following embodiment: The multitude of discrete semiconductor nanoparticles 5, comprising a CdSe core, a CdS shell and an optional ZnS passivation layer, were manufactured as follows: Cadmium oxide is dissociated in the presence of octadecylphosphonic acid and the mixed solvent system trioctylphosphine oxide / trioctylphosphine at 280 °C under an argon atmosphere. The system is cooled to 120 °C and degassed under vacuum before the reaction is heated to 360 °C for particle formation. Elemental selenium dissolved in trioctylphosphine is rapidly injected to induce the nucleation of the CdSe nanoparticles. Aliquots are taken at regular intervals from the resulting reaction mixture and analyzed by UV-Vis absorption until the desired particle color is achieved, typically around 560 nm at the lowest energy absorption feature.

[0085] For CdS shell growth on CdSe nanoparticles, cadmium oxide is dissociated in the presence of the surfactants octadecylphosphonic acid and hexylphosphonic acid, and the same phosphine-based mixed solvent system, at 280 °C under an argon atmosphere. The dissociated cadmium solution is cooled, degassed, and heated to 320 °C in the same manner. Elemental sulfur, dissolved in trioctylphosphine, is injected into the reaction solution along with CdSe nanoparticles dispersed in toluene. Aliquots are withdrawn at regular intervals, and the reaction is quenched by cooling to room temperature once the desired final color is reached, typically with an emission maximum around 625 nm.

[0086] To apply an optional additional passivation layer of ZnS, zinc acetate, octadecylamine, and oleic acid are added to a trioctylphosphine oxide solvent, which is then degassed under vacuum at 120 °C until a clear solution is obtained. The reaction mixture is heated to 235 °C under an argon atmosphere. The CdS-passivated CdSe nanoparticles are dispersed in trioctylphosphine along with elemental sulfur, and the solution is injected into the hot Zn-containing reaction. Heating is continued for 3 to 4 hours until maximum quantum efficiency is achieved. These particles, as well as CdSe and CdSe / CdS particles, are similarly isolated from the respective reaction solutions by treating the cooled solutions with toluene and flocculating the particles upon addition of an alcoholic non-solvent such as 2-propanol.

[0087] The semiconductor nanoparticles 5The following steps were taken: The surfactant Igepal CO-520 is dissolved in cyclohexane. Semiconductor nanoparticles dispersed in cyclohexane at nearly saturated concentration are added along with pure cyclohexane while stirring continuously. Aminopropyltrimethoxysilane is added to the solution and incubated with the particles. Ammonium hydroxide (28% w / w) and tetraethyl orthosilicate are added. Subsequent hourly additions of tetraethyl orthosilicate are optionally made to increase the amount of silicon dioxide on the nanoparticles. Typically, the reaction is stirred overnight before purification, which consists of repeated suspension and centrifugal isolation of the particles from toluene, methanol, and / or 2-propanol.

[0088] The semiconductor-free nanoparticles 8 are used as above for the encapsulation of semiconductor nanoparticles 5described, produced, with the exception that the reaction mixture does not contain semiconductor nanoparticles. 5 to be added. All other conditions are identical.

[0089] The in situ production of semiconductor-free nanoparticles 8 with the encapsulation of semiconductor nanoparticles 5 is used as above for the encapsulation of semiconductor nanoparticles 5 described and carried out. To create semiconductor-free nanoparticles 8 To generate self-nucleation in situ, in addition to encapsulating the semiconductor nanoparticles, the reaction must be modified to enhance self-nucleation. This can be achieved, for example, by significantly reducing the ratio of semiconductor nanoparticles to encapsulation material or by using a more reactive encapsulation material.

[0090] The encapsulated semiconductor nanoparticles 7 and the semiconductor-free nanoparticles 8were used to form an agglomerate 9 condensed, as above for the encapsulation of semiconductor nanoparticles 5 described: Equal volumes of semiconductor-free nanoparticles suspended in toluene 8 and encapsulated semiconductor nanoparticles 7 The substances are combined in identical concentrations. Igepal CO-520 and aqueous ammonium hydroxide are added, followed by tetraethyl orthosilicate. All ratios are approximately the same as described above, and the particles are washed and isolated in a similar manner.

[0091] Fig. Figure 5 shows wet high temperature operating life (WHTOL) curves for the accelerated aging of semiconductor structure samples. These samples were exposed to 85 °C at 85% relative humidity in silicon-cured OSRAM 3030 LED packages driven at 65 mA. The y-axis shows the down-converted normalized red power (OUT) in watts. The x-axis shows the exposure time t in hours. Curve 7-1 shows the power as a function of exposure time for a light-emitting diode with a semiconductor structure. 4 contains encapsulated semiconductor nanoparticles 3 Curve 7-2 shows the power as a function of exposure time for a light-emitting diode with a semiconductor structure. 9 according to one embodiment containing encapsulated semiconductor nanoparticles 7 and semiconductor-free nanoparticles 8This includes the persistence of the red light output of the LED, which is part of the semiconductor structure. 9 The presence of this structure can be observed particularly during long exposure times. Even during very short exposure times, the semiconductor structure produced according to the method described here is visible. 9 significantly more robust in this challenge.

[0092] Fig. Figure 6 shows a schematic representation of a light-emitting component. 13 according to one embodiment. The light-emitting component 13 includes an active layer stack 14 , which is designed to emit electromagnetic radiation. The active layer stack 14 includes a radiation emission surface 15 The radiation emission surface 15 The emitted electromagnetic radiation forms the beam path. In the beam path of the active layer stack 14 is a conversion element 16arranged. In other words, the conversion element is 16 above the active layer stack 14 arranged so that the beam path passes through at least part of the conversion element 16 The conversion element 16 can come into direct contact with the active layer stack 14 stand, preferably with the radiation emission surface 15 , or the conversion element 16 and the active layer stack 14 They can be spaced apart from each other (not shown here). This means that there is space between the active layer stack. 14 and the conversion element 16 There may be additional layers or spaces.

[0093] The conversion element 16 is designed to determine the wavelength of the active layer stack 14 to convert emitted electromagnetic radiation. In particular, the conversion element absorbs 16the incident electromagnetic radiation and re-emits electromagnetic radiation with a different, preferably longer, wavelength.

[0094] The conversion element 16 It comprises a phosphor material and a matrix. The matrix can be made of or comprise silicone. The phosphor material is configured to absorb and re-emit electromagnetic radiation. The phosphor material can form the semiconductor structure. 9 comprise or consist of an agglomerate of encapsulated semiconductor nanoparticles 7 and semiconductor-free nanoparticles 8 includes. In particular, the semiconductor nanoparticles 5 They are quantum dots.

[0095] The invention is not limited to the exemplary embodiments described therein. Rather, the invention encompasses every new feature and every combination of features, including in particular every combination of features in the claims and every combination of features in the exemplary embodiments, even if that feature or combination of features is not explicitly stated in the claims or exemplary embodiments.

[0096] The present patent application claims priority from US patent application 16 / 294,780, the disclosure of which is hereby incorporated by reference. Reference symbol list 1 Semiconductor nanoparticle 2 Encapsulation 3 encapsulated semiconductor nanoparticles 4 agglomerate 5 semiconductor nanoparticles 6 Encapsulation 7 encapsulated semiconductor nanoparticles 8 semiconductor-free nanoparticles 9 agglomerate 10 gaps or spaces 11 Edge area 12 central area 13 light-emitting component 14 active shift stacks 15 radiation emission area 16 Conversion element QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 9478717

[0002] US 9249354

[0002] US 9722147

[0002] US 16294780

[0096]

Claims

[1] Semiconductor structure, comprising: a variety of discrete encapsulated semiconductor nanoparticles (7); and (8) a variety of discrete semiconductor-free nanoparticles wherein the discrete encapsulated semiconductor nanoparticles (7) and the discrete semiconductor-free nanoparticles (8) form an agglomerate (9). [2] Semiconductor structure according to claim 1, wherein each of the plurality of discrete encapsulated semiconductor nanoparticles (7) comprises a quantum dot (5) and an encapsulation (6) comprising an encapsulation material. [3] Semiconductor structure according to claim 2, wherein the discrete semiconductor-free nanoparticles (8) comprise the encapsulation material. [4] Semiconductor structure according to at least one of claims 2 or 3, wherein the encapsulation material comprises silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, magnesium oxide, hafnium oxide, barium oxide, bismuth oxide, tin oxide or mixed oxides. [5] Semiconductor structure according to at least one of claims 2 to 4, wherein each of the plurality of discrete semiconductor nanoparticles (5) comprises an additional passivation layer. [6] Semiconductor structure according to at least one of the preceding claims, wherein the agglomerate (9) comprises point-to-point connections between the discrete encapsulated semiconductor nanoparticles (7) and the discrete semiconductor-free nanoparticles (8). [7] Semiconductor structure according to at least one of the preceding claims, wherein a concentration of the discrete semiconductor-free nanoparticles (8) in the agglomerate (9) is different from or equal to a concentration of the discrete encapsulated semiconductor nanoparticles (7). [8] Semiconductor structure according to at least one of the preceding claims, wherein the agglomerate (9) comprises a central region (12) and a peripheral region (11). [9] Semiconductor structure according to claim 8, wherein the concentration of discrete semiconductor-free nanoparticles (8) in the edge region (11) is equal to or greater than in the central region (12). [10] Semiconductor structure according to at least one of the preceding claims, wherein the discrete semiconductor-free nanoparticles (8) are arranged at least partially in gaps and / or spaces (10) between the discrete encapsulated semiconductor nanoparticles (7). [11] Method for producing a semiconductor structure, the method comprising: Production of a large number of discrete semiconductor nanoparticles (5); Encapsulating each of the plurality of discrete semiconductor nanoparticles (5) to form discrete encapsulated semiconductor nanoparticles (7); Production of a variety of discrete semiconductor-free nanoparticles (8); and Condensing the multitude of discrete encapsulated semiconductor nanoparticles (7) and the multitude of discrete semiconductor-free nanoparticles (8) to form an agglomerate (9). [12] Method according to claim 11, wherein the encapsulation of the discrete semiconductor nanoparticles (5) and the fabrication of the discrete semiconductor-free nanoparticles (8) are carried out sequentially or simultaneously. [13] Method according to at least one of claims 11 or 12, wherein parameters are variable in the production of the discrete semiconductor-free nanoparticles (8), and wherein the parameters comprise a charge, a coating with a surfactant and a degree of gelation. [14] Method according to at least one of claims 11 to 13, wherein the discrete semiconductor-free nanoparticles (8) are produced using an oxide precursor for nucleating nanoparticles. [15] Method according to claim 14, wherein the oxide precursor is an alkoxy metal precursor. [16] Light-emitting component (13), comprising: an active layer stack (14) configured to emit electromagnetic radiation; and a conversion element (16) in a beam path of the active layer stack, comprising a phosphor material and a matrix, wherein the phosphor material comprises a semiconductor structure comprising an agglomerate (9) of discrete encapsulated semiconductor nanoparticles (7) and discrete semiconductor-free nanoparticles (8). [17] Light-emitting device (13) according to claim 16, wherein each of the discrete encapsulated semiconductor nanoparticles (7) comprises a quantum dot (5) and an encapsulation (6) comprising an encapsulation material. [18] Light-emitting device (13) according to claim 17, wherein the discrete encapsulated semiconductor-free nanoparticles (8) comprise the encapsulation material. [19] Light-emitting device (13) according to at least one of claims 17 or 18, wherein the encapsulation material comprises silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, magnesium oxide, hafnium oxide, barium oxide, bismuth oxide, tin oxide or mixed oxides. [20] Light-emitting device (13) according to at least one of claims 17 to 19, wherein each of the plurality of discrete encapsulated semiconductor nanoparticles (7) comprises an additional passivation layer.