WO2025125065A1 - Optoelectronic component and optoelectronic arrangement - Google Patents

Abstract

The invention relates to an optoelectronic component. According to one embodiment, the optoelectronic component (1) comprises a semiconductor chip (3), which is designed to emit a primary radiation (34), and a conversion element (4), which is designed to convert the primary radiation (34) into a secondary radiation (42), wherein an aspect ratio of a height (x) of the conversion element and an edge length (z) of an illuminated surface (11) of the optoelectronic component (1) is at most 1, and wherein the optoelectronic component (1) is designed to increase a conversion efficiency of the conversion element (4). In particular, the semiconductor chip (3) is a mini-LED or a micro-LED. The invention further relates to an optoelectronic arrangement.

Description

Description

OPTOELECTRONIC COMPONENT AND OPTOELECTRONIC ARRANGEMENT

An optoelectronic component is specified. Furthermore, an optoelectronic arrangement is specified.

One problem to be solved is to provide an optoelectronic component with increased efficiency. Another problem is to provide an optoelectronic arrangement with increased efficiency.

An optoelectronic component is specified. The optoelectronic component is, for example, a radiation-emitting optoelectronic component. During operation, the optoelectronic component generates electromagnetic radiation, in particular electromagnetic radiation with a wavelength in the wavelength range between UV radiation and infrared radiation, for example in the green, yellow, yellow-orange, red and/or infrared wavelength range. The optoelectronic component has at least one component, in particular a plurality of components, or is composed thereof.

According to at least one embodiment, the optoelectronic component comprises a semiconductor chip configured to emit primary radiation. The semiconductor chip may comprise an active semiconductor layer sequence containing an active region that can generate the primary radiation during operation of the optoelectronic component. Primary radiation refers here and below to electromagnetic radiation of a first Wavelength or a first wavelength range emitted by the semiconductor chip. The semiconductor chip is, for example, a light-emitting diode chip or a laser diode chip. For example, the semiconductor chip emits blue primary radiation. For example, the primary radiation has a wavelength of 450 nm.

In particular, the semiconductor chip comprises or consists of the semiconductor layer sequence, passivation layers and contacts. In other words, the at least one semiconductor chip is not a package, but rather the pure semiconductor chip. In addition, the semiconductor chip can have a chip substrate. In this case, the active semiconductor layer sequence is arranged on the chip substrate. For example, the chip substrate comprises or consists of sapphire.

In particular, the semiconductor chip emits the primary radiation via an emission surface. The emission surface can also be referred to as the luminous surface of the semiconductor chip. For example, the emission surface is a surface of an outer layer of the semiconductor layer sequence, in particular a surface of the semiconductor layer sequence facing away from the chip substrate. The emission surface can have an edge length. The edge length of the emission surface can correspond to the edge length of the semiconductor chip.

According to at least one embodiment, the optoelectronic component comprises a conversion element which is designed to convert the primary radiation into secondary radiation. Secondary radiation refers here and below to electromagnetic radiation of a second wavelength or a second Wavelength range that is generated in the conversion element by converting primary radiation into secondary radiation and emitted by the optoelectronic component. In other words, the conversion element converts electromagnetic radiation of the first wavelength range into electromagnetic radiation of the second wavelength range. The first wavelength range differs, for example, at least partially from the second wavelength range. For example, the second wavelength range comprises wavelengths that have lower energy than the wavelengths of the first wavelength range.

In particular, the conversion element converts the primary radiation completely into secondary radiation. In the case of full conversion, no primary radiation is transmitted through the conversion layer. In this context, “none” means that so little primary radiation is transmitted that it no longer perceptibly influences the electromagnetic radiation emitted by the optoelectronic component. For example, a maximum of 10%, in particular a maximum of 5%, for example a maximum of 1% of the primary radiation is transmitted through the conversion element. The optoelectronic component then only emits the secondary radiation during operation. For example, the optoelectronic component emits green, yellow, red or infrared electromagnetic radiation without any blue component.

In particular, the conversion element is a conversion element surrounding the semiconductor chip. For example, the conversion element is arranged such that it covers a main surface, in particular the emission surface, of the semiconductor chip, in particular completely. In addition, the conversion element can cover the side surfaces of the semiconductor layer sequence, in particular completely. In this case, the conversion element can be larger than the semiconductor chip, for example twice as large, three times as large or four times as large. In other words, a main emission surface of the conversion element in plan view is twice as large, three times as large or four times as large as the emission surface of the semiconductor chip. The conversion element can then have a height above the semiconductor chip and a thickness in lateral regions next to the semiconductor chip. It should be noted here that the thickness of the conversion element corresponds to the height of the conversion element on the semiconductor chip and the height of the semiconductor chip.

According to at least one embodiment, an aspect ratio of a height of the conversion element on the semiconductor chip and an edge length of a luminous area of the optoelectronic component is at most 1. Hereinafter, the luminous area of the optoelectronic component is understood to mean an area of the optoelectronic component that is configured to couple out the secondary radiation generated in the conversion element. In particular, the luminous area of the optoelectronic component is a main area of the optoelectronic component, for example of the conversion element, that extends perpendicular to the height of the conversion element.

An aspect ratio of at most 1 means in particular that the conversion element on the semiconductor chip is at most as high as the luminous area is wide. In particular, the aspect ratio is at most 0.5, for example 0.2 or 0.1. In other words, the conversion element is thinner than the luminous surface is wide.

According to at least one embodiment, the optoelectronic component is designed to increase a conversion efficiency of the conversion element. In particular, the optoelectronic component is designed to maintain or increase a conversion efficiency of the conversion element as the height of the conversion layer decreases. The conversion efficiency of the conversion element is a measure of the proportion of primary radiation converted into secondary radiation. The more primary radiation is converted into secondary radiation, the higher the conversion efficiency of the conversion element. The conversion efficiency of the conversion element can be expressed as a percentage of the electromagnetic radiation coupled out of the optoelectronic component as secondary radiation. Alternatively, the conversion efficiency of the optoelectronic component can be expressed via the color saturation of the coupled-out electromagnetic radiation. The greater the color saturation, the higher the conversion efficiency of the conversion element.

In particular, the reduction of unwanted transmission of primary radiation through the conversion element is a key aspect for increasing the conversion efficiency, for example for thin conversion elements.

An undesired transmission of primary radiation through the conversion element can be caused by a reduction in the height of the conversion elements. A thin conversion element can increase the absorption of primary radiation and thus prevent complete conversion. Anything below 100% absorption of primary radiation leads to undesirable transmission of primary radiation, which reduces the conversion efficiency of the conversion element and thus the color purity and color saturation of the optoelectronic component.

Therefore, the most important consideration for achieving increased conversion efficiency is that the color of the optoelectronic component has the highest possible color purity and color saturation. Means of increasing conversion efficiency are thus increasing the absorption of primary radiation in the conversion element and/or reducing the unwanted transmission of primary radiation through the conversion element.

According to at least one embodiment, the optoelectronic component comprises a semiconductor chip which is configured to emit primary radiation, and a conversion element which is configured to convert the primary radiation into secondary radiation, wherein an aspect ratio of a height of the conversion element and an edge length of a luminous surface of the optoelectronic component is at most 1, and wherein the optoelectronic component is configured to increase a conversion efficiency of the conversion element.

One of the ideas underlying such an optoelectronic component is to ensure full conversion of primary radiation into secondary radiation with a reduced height of the conversion element. A conversion element with an aspect ratio of at most 1 has a height adapted to the lateral dimensions of the conversion element, which leads to simplified processing during structuring and to improved dissipation of the conversion heat from the optoelectronic component. In order to counteract a resulting reduction in color saturation due to the lower absorption of blue light, the conversion efficiency of the conversion element is increased, for example by increasing the absorption of the primary radiation and/or reducing the unwanted transmission of primary radiation through the conversion element. This advantageously makes it possible to provide an efficient optoelectronic component for applications with limited lateral dimensions.

According to at least one embodiment, the conversion element has a height of at most 100 pm, in particular of at most 50 pm, for example of at most 20 pm or at most 10 pm or at most 5 pm. In particular, the height of the conversion element depends on the lateral dimensions of the optoelectronic component, in particular of the luminous surface of the optoelectronic component. The height of the conversion element is in particular selected such that the aspect ratio is at most 1, in particular at most 0.2, for example at most 0.1. A conversion element with a height of at most 100 pm can advantageously have a lower aspect ratio and thus better structuring ability and improved dissipation of the conversion heat.

According to at least one embodiment, the semiconductor chip is a mini-LED or a micro-LED. Here and in the following, LED means a light-emitting diode.

Mini-LEDs can have a width, a length, a thickness and/or a diameter less than or equal to 100 gm and greater than or equal to 50 gm. In particular, mini-LEDs, for example rectangular mini-LEDs, have an edge length, in particular in plan view of the layers of the layer stack, of a luminous area less than or equal to 100 gm and greater than or equal to 50 gm. A mini-LED is, for example, a light-emitting diode in which a growth substrate has been removed, so that a thickness of the micro-LED is, for example, in the range from 1.5 gm inclusive to 50 gm inclusive.

Micro-LEDs can have a width, a length, a thickness and/or a diameter of less than or equal to 50 gm, in particular less than or equal to 20 gm, for example of 20 gm or 10 gm or 5 gm. In particular, micro-LEDs, for example rectangular micro-LEDs, have an edge length, in particular in plan view of the layers of the layer stack, of a luminous area of less than or equal to 50 gm, in particular less than or equal to 20 gm, for example of 20 gm or 10 gm or 5 gm. A micro-LED is, for example, a light-emitting diode in which a growth substrate has been removed, so that a thickness of the microLED is, for example, in the range from 1.5 gm inclusive to 10 gm inclusive.

Mini-LEDs and micro-LEDs have a small lateral dimension and can therefore be advantageously used in optoelectronic components for applications with limited lateral dimensions. According to at least one embodiment, the semiconductor chip is an InGaN semiconductor chip. In particular, the semiconductor chip is an InGaN semiconductor chip that emits primary radiation in the blue wavelength range, for example, 450 nm. An InGaN semiconductor chip can advantageously be provided cost-effectively.

According to at least one embodiment, the optoelectronic component emits secondary radiation with a color saturation of at least 95%, in particular of at least 98%, during operation. Color saturation is a measured value for the intensity and purity of a color tone compared to an unsaturated color tone. For example, spectral colors are colors with maximum color saturation. In particular, the electromagnetic radiation emitted by the optoelectronic component has a color saturation of at least 95%, in particular of at least 98%. The color saturation can be greater than 98%, for example 99% or 99.5%. In general, a color saturation of 95% to 98% is sufficient, and an increase in the color saturation beyond this no longer perceptibly influences the light emitted by the optoelectronic component. With a color saturation of at least 95%, the optoelectronic component can advantageously be used in applications that have corresponding color saturation specifications, for example automotive applications such as taillights or direction indicators.

According to at least one embodiment, the conversion element comprises or consists of a conversion material. In particular, the ability of the conversion element to convert primary radiation into secondary radiation convert, attributed to the conversion material . For example, the conversion material in the conversion element is in the form of particles . The conversion element can consist of particles of the conversion material , for example in the form of a ceramic . Alternatively, the particles can be dispersed in a matrix material , for example a polymer such as silicone . Alternatively, the particles can be arranged as a dense pack and held together by the matrix material . In particular, it is advantageous here to use as little matrix material as possible in order to keep the height of the conversion element as low as possible .

According to at least one embodiment, the conversion material comprises a phosphor. In particular, the phosphor is an inorganic phosphor.

According to at least one embodiment, the phosphor has grain sizes of at most 10 pm, in particular of at most 5 pm, for example of 1 pm. Here and below, the grain size of a phosphor is understood to mean, in particular, a diameter of a phosphor particle. For example, the phosphor has grain sizes of at least 1 pm.

In particular, the phosphor having a particle size of 10 pm or less serves to increase the conversion efficiency of the conversion element. By reducing the particle size compared to the commonly used 20 pm, the absorption per phosphor particle can be increased. As a result, the primary radiation is used more efficiently for conversion. At the same time, the scattering within the Conversion element, so that the mean path length of the primary radiation in the conversion element can increase. As a result, a comparable or increased conversion efficiency can be achieved with a reduced height of the conversion element. For example, it is possible that a 70% reduction in the grain size can result in a 50% reduction in the height of the conversion element.

According to at least one embodiment, the conversion material comprises a semiconductor nanocrystal. The semiconductor nanocrystal is in particular a particle with a diameter between 1 nm and 50 nm, for example between 2 nm and 20 nm, for example between 2 nm and 10 nm. Due to their small size, semiconductor nanocrystals have different properties than a bulk material formed from the same material. It is possible for the semiconductor nanocrystal to be spherical, rod-shaped, or cuboid-shaped. In particular, the semiconductor nanocrystal is a nanoparticle with a predominantly crystalline structure, for example a semiconductor nanoparticle or a quantum dot. In particular, the semiconductor nanocrystal is made up of atoms in a monocrystalline or polycrystalline arrangement. The semiconductor nanocrystal is formed, for example, from at least one semiconductor material. The semiconductor nanocrystal can comprise or be formed from at least one of the semiconductor materials CdSe, CdS, InP, GaP, or GaAs. In particular, semiconductor nanocrystals serve as conversion material in the conversion element to increase the conversion efficiency of the conversion element. Semiconductor nanocrystals Compared to phosphors, they can exhibit significantly increased material absorption and, at the same time, have significantly smaller dimensions in the nm range. As a result, increased conversion efficiency can be achieved with a reduced height of the conversion element.

According to at least one embodiment, the optoelectronic component further comprises a filter element on a side of the conversion element facing away from the semiconductor chip. In particular, the filter element is designed to filter incident electromagnetic radiation. For example, the filter element removes selected wavelengths or wavelength ranges, for example those of the primary radiation, from the incident electromagnetic radiation or prevents transmission of these selected wavelengths or wavelength ranges through the filter element. The radiation coupled out of the optoelectronic component can then be free of these selected wavelengths or wavelength ranges. The filter element is arranged in particular in direct mechanical contact with the conversion element, for example with a radiation exit surface of the conversion element. For example, the filter element has a thickness of at least 50 pm, in particular between 50 pm inclusive and 100 pm inclusive.

A filter element on the conversion element serves to increase the conversion efficiency of the conversion element. The filter element can filter the electromagnetic radiation coupled out of the conversion element and thus reduce a proportion of primary radiation in the radiation coupled out of the optoelectronic component. electromagnetic radiation. As a result, the color saturation of the electromagnetic radiation emitted by the optoelectronic component can advantageously be increased, so that a conversion element with a low height can be used.

According to at least one embodiment, the filter element is designed to absorb the primary radiation. Such a filter element can also be referred to as an absorbing filter element or absorption filter. In particular, the filter element comprises or consists of a material that at least partially, in particular completely, absorbs the primary radiation transmitted through the conversion element. For example, the filter element comprises or consists of gallium phosphide. Gallium phosphide can absorb radiation in the blue wavelength range and transmit lower-energy radiation, for example radiation in the green wavelength range. In particular, the filter element absorbs the primary radiation but is permeable to the secondary radiation. For example, the filter element absorbs at least 90%, in particular 95%, for example 99% of the primary radiation transmitted through the conversion element.

A filter element that absorbs primary radiation serves to increase the conversion efficiency of the conversion element. Absorption of primary radiation can reduce or prevent unwanted transmission of primary radiation and increase the color saturation of the electromagnetic radiation emitted by the optoelectronic component. According to at least one embodiment, the filter element is designed to reflect the primary radiation and transmit the secondary radiation. Such a filter element can also be referred to as a wavelength-selective interference filter. In particular, the filter element comprises a plurality of layers made of different materials. For example, the filter element comprises a layer stack of alternating first and second layers, wherein the first layers comprise a material with a high refractive index and the second layers comprise a material with a low refractive index. The first layers can comprise nickel oxide or titanium oxide and the second layers can comprise silicon oxide. For example, the filter element is a dielectric mirror such as a Bragg mirror.

In particular, the filter element reflects the primary radiation but is transparent to the secondary radiation. For example, the filter element reflects at least 90%, in particular 95%, for example 99% of the primary radiation transmitted through the conversion element.

A filter element that reflects primary radiation and transmits secondary radiation serves to increase the conversion efficiency of the conversion element. Reflection of the primary radiation can reduce or prevent the undesired transmission of the primary radiation and increase the color saturation of the electromagnetic radiation emitted by the optoelectronic component. In addition, the reflected primary radiation can be available again for conversion in the conversion element, thereby increasing the conversion efficiency of the conversion element. is immediately increased. This also makes the property of the conversion element to completely convert primary radiation on its first pass through the conversion element, and thus the height of the conversion element, less relevant. Furthermore, a filter element designed as a wavelength-selective interference filter can advantageously be non-conductive and non-absorbent, thereby preventing additional heating of the conversion element.

According to at least one embodiment, the optoelectronic component further comprises a mirror layer on a side of the semiconductor chip facing away from an emission surface of the semiconductor chip, wherein the mirror layer is configured to reflect the primary radiation and secondary radiation. In particular, the mirror layer extends, for example completely, on the side of the semiconductor chip facing away from the emission surface of the semiconductor chip and on a side of the conversion element facing away from the luminous surface of the optoelectronic component. For example, the mirror layer comprises a layer made of a metal such as silver or aluminum or a dielectric mirror such as a Bragg mirror. Alternatively, the mirror layer can comprise a combination of a layer made of a metal and a dielectric mirror, wherein the dielectric mirror is arranged between the layer made of the metal and the semiconductor chip. A mirror layer made of a layer made of a metal and a dielectric mirror can advantageously further increase the reflectivity of the mirror layer.

In particular, the mirror layer reflects the

Primary radiation and secondary radiation. For example the mirror layer reflects at least 90%, in particular 95%, for example 99% of the primary radiation and the secondary radiation that impinges on the mirror layer.

A mirror layer on a side of the semiconductor chip facing away from the emission surface of the semiconductor chip serves to increase the conversion efficiency of the conversion element. The mirror layer reflects the primary radiation and the secondary radiation that does not pass through the conversion element toward the luminous surface of the optoelectronic component. As a result, secondary radiation reflected by the mirror layer can be coupled out via the luminous surface, increasing the proportion of secondary radiation in the electromagnetic radiation emitted by the optoelectronic component.

In addition, primary radiation reflected by the mirror layer can pass through the conversion element again and is thus available again for conversion in the conversion element, which immediately increases the conversion efficiency of the conversion element.

According to at least one embodiment, the optoelectronic component comprises the mirror layer and the filter element, which is designed to reflect the primary radiation and to transmit the secondary radiation. The mirror layer and the filter element in combination serve to increase the conversion efficiency of the conversion element. The secondary radiation reflected at the mirror layer can be coupled out via the luminous surface of the optoelectronic component and the proportion of secondary radiation in the electromagnetic radiation emitted by the optoelectronic component can be increased, while the primary radiation is reflected by both the mirror layer and is also reflected by the filter element and can thus pass through the conversion element several times and is repeatedly available for conversion in the conversion element, thereby directly increasing the conversion efficiency of the conversion element. The mirror layer and the filter element in combination can thus be used particularly advantageously for conversion elements with low heights.

According to at least one embodiment, the optoelectronic component further comprises a deflecting mirror on a side of the conversion element facing away from the semiconductor chip, wherein the deflecting mirror is configured to reflect the primary radiation. In particular, the deflecting mirror reflects at least 90%, in particular 95%, for example 99% of the primary radiation incident on the deflecting mirror. The deflecting mirror can have the same materials and the same structure as the mirror layer. For example, the deflecting mirror has a layer made of a metal, in particular with a thickness between 50 nm inclusive and 150 nm inclusive, for example of 100 nm.

A deflecting mirror serves to increase the conversion efficiency of the conversion element. By reflecting the primary radiation, the deflecting mirror can extend the light path of the primary radiation in the conversion element, thereby increasing the absorption and conversion of the primary radiation in the conversion element. As a result, the primary radiation is used more efficiently for conversion, and primarily secondary radiation is emitted by the optoelectronic component. According to at least one embodiment, the deflecting mirror is arranged above an emission surface of the semiconductor chip. In particular, the deflecting mirror is arranged exclusively above the emission surface of the semiconductor chip. Alternatively, the deflecting mirror can extend slightly laterally beyond the emission surface of the semiconductor chip. In particular, a portion of the side of the conversion element facing away from the semiconductor chip is free of the deflecting mirror.

The arrangement of the deflecting mirror above the emission surface of the semiconductor chip serves to increase the conversion efficiency of the conversion element. Primary radiation emitted by the semiconductor chip passes through the conversion element mainly on a direct path from the semiconductor chip through the conversion element. The deflecting mirror arranged above the emission surface blocks and reflects the primary radiation. This lengthens the light path of the primary radiation and increases the absorption of the primary radiation in the conversion element. As a result, mainly secondary radiation is emitted from the optoelectronic component.

According to at least one embodiment, a side of the deflection mirror facing the semiconductor chip has a planar surface. In particular, the primary radiation is reflected at the planar surface in such a way that a beam path of the reflected primary radiation is guided substantially away from the side of the conversion element facing away from the semiconductor chip. Advantageously, this allows the light path of the primary radiation in the conversion element to be lengthened and the absorption of the primary radiation to be increased. According to at least one embodiment, a side of the deflecting mirror facing the semiconductor chip has at least one inclined surface. In particular, the deflecting mirror has two inclined side surfaces. For example, the deflecting mirror has a triangular cross-section in a sectional view. In particular, the primary radiation is reflected at the inclined surface such that a beam path of the reflected primary radiation runs substantially parallel to a main direction of extension of the conversion element. Advantageously, this makes it possible to lengthen the light path of the primary radiation in the conversion element and to increase the absorption of the primary radiation.

According to at least one embodiment, the optoelectronic component comprises the mirror layer and the deflecting mirror. The mirror layer and the deflecting mirror in combination serve to increase the conversion efficiency of the conversion element. The deflecting mirror can prevent unwanted transmission of primary radiation. In addition, both the deflecting mirror and the mirror layer lengthen the light path of the primary radiation in the conversion element and thus increase the absorption and conversion of primary radiation. The mirror layer can also be used to couple out secondary radiation particularly efficiently. This results in increased conversion efficiency and improved brightness of the optoelectronic component.

According to at least one embodiment, the optoelectronic component further comprises a substrate. The substrate can represent the mechanically supporting component of the optoelectronic component. In particular, the substrate serves for mechanical fastening and/or electrical connection for optical and/or electronic components of the optoelectronic device, for example for the semiconductor chip. For example, the substrate comprises or consists of sapphire or a plastic film.

According to at least one embodiment, the substrate is transparent at least to the secondary radiation. In particular, the substrate transmits at least 90%, in particular 95%, for example 99% of the secondary radiation. For example, the substrate is transparent to the secondary radiation and to the primary radiation. In particular, the substrate comprises or consists of sapphire or a plastic film. A transparent substrate can advantageously be used to couple the electromagnetic radiation emitted by the optoelectronic component through the substrate.

According to at least one embodiment, the optoelectronic component further comprises a reflection layer on a side of the conversion element facing away from the semiconductor chip, wherein the reflection layer is configured to reflect at least secondary radiation, and wherein the optoelectronic component is configured to emit secondary radiation through the substrate. In particular, the reflection layer is arranged on all sides of the conversion element that are free from the substrate. For example, the reflection layer reflects at least 90%, in particular 95%, for example 90% of the secondary radiation. In addition, the reflection layer can be configured to reflect the primary radiation. The reflection layer can have the same materials and the same structure as the mirror layer. This arrangement of the optoelectronic component serves to increase the conversion efficiency of the conversion element. With this arrangement, an arrangement with a reversed beam path can be realized. The semiconductor chip emits primary radiation away from the substrate into the conversion element, which is mirrored with a reflective layer. As a result, the primary radiation is used more efficiently for conversion and mainly secondary radiation is coupled out through the transparent substrate. In addition, the optoelectronic component can be optically separated from neighboring components by the reflective layer.

According to at least one embodiment, a filter element is arranged between the substrate and the semiconductor chip, the filter element is designed to reflect the primary radiation and to transmit the secondary radiation, and the semiconductor chip is at least partially, in particular completely, transparent to the primary radiation and the secondary radiation. In particular, the filter element is a wavelength-selective interference filter. For example, the partial transparency of the semiconductor chip is achieved in that the chip substrate is transparent to the primary radiation and the secondary radiation. Alternatively, the semiconductor chip can also be free of a chip substrate. In this case, too, the semiconductor chip is at least partially transparent to the primary radiation and the secondary radiation.

This arrangement of the optoelectronic component serves to increase the conversion efficiency of the conversion element. The filter element between the substrate and the semiconductor chip reflects primary radiation back into the conversion element. In combination with the at least partially With a transparent semiconductor chip, secondary radiation can also be coupled out through the semiconductor chip. This can advantageously reduce partial shadowing and improve the lateral homogeneity of the radiation coupled out of the optoelectronic component. At the same time, the size of the optoelectronic component can be reduced.

Furthermore, an optoelectronic arrangement comprising at least two, in particular a plurality, of optoelectronic components is specified. Preferably, the optoelectronic component described above is suitable and intended for use in the optoelectronic arrangement described here. Features and embodiments described in connection with the optoelectronic component also apply to the optoelectronic arrangement, and vice versa.

According to at least one embodiment, the optoelectronic arrangement comprises at least two, in particular a plurality, of optoelectronic components. The optoelectronic components each comprise a semiconductor chip which is configured to emit primary radiation, and a conversion element which is configured to convert the primary radiation into secondary radiation, wherein an aspect ratio of a height of the conversion element and an edge length of a luminous surface of the optoelectronic component is at most 1, and wherein the optoelectronic component is configured to increase a conversion efficiency of the conversion element. In addition, each of the optoelectronic components can comprise any of the above-mentioned have the characteristics specified with the optoelectronic component.

In particular, each of the optoelectronic components of the optoelectronic arrangement emits secondary radiation in the same wavelength range, for example, in the red wavelength range. Alternatively, the individual optoelectronic components of the optoelectronic arrangement can each emit secondary radiation with a different wavelength range. For example, one or some of the optoelectronic components emits green secondary radiation, and another or some of the optoelectronic components emits red secondary radiation.

According to at least one embodiment, each of the optoelectronic components forms a pixel of the optoelectronic arrangement. In particular, the pixels of the optoelectronic arrangement are spaced apart from one another by a distance corresponding to at most three times the size of a pixel, in particular an edge length of a luminous area of an optoelectronic component. For example, the optoelectronic components of the optoelectronic arrangement each comprise the reflection layer, and the distance between the pixels corresponds to at most twice the size of a pixel.

In an optoelectronic arrangement with more than one pixel, in addition to the undesired transmission of primary radiation through the conversion elements of the individual optoelectronic components, crosstalk between neighboring pixels can also occur. "Crosstalk" refers to unwanted radiation emission due to the absorption and conversion of radiation from neighboring pixels by a conversion element. For example, the primary radiation from one pixel is coupled into the conversion element of a neighboring pixel, absorbed, and converted, resulting in unwanted emission of secondary radiation from the neighboring pixels. Similarly, secondary radiation from one pixel can be coupled into the conversion element of a neighboring pixel, absorbed, and converted, resulting in unwanted emission of secondary radiation from the neighboring pixels.

A reduction of crosstalk can be achieved by reducing the thickness of the conversion element, which in turn can result in the undesired transmission of primary radiation through the conversion element.

Therefore, the most important consideration for achieving efficient conversion in an optoelectronic device with at least two small optoelectronic components is that the color of each pixel has the highest possible color purity and color saturation and a minimum of crosstalk between neighboring pixels.

According to at least one embodiment, the optoelectronic arrangement comprises at least two, in particular a plurality, of optoelectronic components described herein, wherein each of the optoelectronic components forms a pixel of the optoelectronic arrangement. One of the ideas behind such an optoelectronic arrangement is to increase the number of pixels on a given area. This can be achieved by reducing the size of the pixels. As a result, smaller optoelectronic components are required. By using filter elements, mirror layers, deflecting mirrors and/or reflection layers, increased conversion efficiency and suppression of the transmission of primary radiation can be achieved. In combination with adapted properties of the conversion element, such as a smaller grain size and/or the component geometry, small, thin and highly pixelated optoelectronic arrangements can be provided.

According to at least one embodiment, the optoelectronic components have a common substrate. In other words, the optoelectronic components are arranged on the common substrate. In particular, the optoelectronic components in this case are free of their own substrate. The common substrate can be transparent, whereby an arrangement in the reverse beam path can be realized. For example, the common substrate is a SmartVis film or a sapphire substrate. A common substrate can advantageously serve as a mechanical carrier and/or for electrical contacting for the at least two optoelectronic components.

According to at least one embodiment, the mirror layer extends over the common substrate, in particular completely. In particular, regions of the substrate between the pixels also have the mirror layer. A mirror layer extending over the common substrate can advantageously increase the brightness of the optoelectronic device, which in particular enables the use of the optoelectronic device in taillights or direction indicators.

According to at least one embodiment, the mirror layer is laterally limited to the size of the respective pixel. In particular, regions of the substrate between the pixels are free of the mirror layer. For example, the mirror layers of the optoelectronic components are limited to the luminous area of the respective optoelectronic component. A mirror layer laterally limited to the size of the respective pixel can advantageously increase the edge contrast of the individual pixels and reduce crosstalk between the pixels.

According to at least one embodiment, the optoelectronic arrangement is used in display applications and automotive applications. In particular, the optoelectronic arrangement is used in displays with red and green pixels by conversion, as well as in taillights and direction indicators in automotive applications. Furthermore, the optoelectronic arrangement can be used as a pixelated arrangement based on InGaN technology.

Further advantageous embodiments, refinements and developments of the optoelectronic component and the optoelectronic arrangement emerge from the following exemplary embodiments shown in conjunction with the figures. Figures 1, 2A, 2B, 2C, 3A, 4A, 5A, 5B, 6A, 6B, 7A and 7B each show a schematic sectional view of an optoelectronic component according to various embodiments,

Figure 3B shows a transmission curve of a filter element of an optoelectronic component according to an embodiment,

Figure 4B shows a reflection curve and a transmission curve of a filter element of an optoelectronic component according to one embodiment, and Figures 8A, 8B and 8C each show a schematic sectional view of an optoelectronic arrangement according to various embodiments.

Identical, similar, or functionally identical elements are provided with the same reference symbols in the figures. The figures and the relative sizes of the elements shown in the figures are not to scale. Rather, individual elements, particularly layer thicknesses, may be exaggerated for clarity and/or clarity.

The optoelectronic component 1 of the embodiment of Figure 1 comprises a substrate 2, for example a sapphire substrate or a plastic film. A semiconductor chip 3 is arranged on the substrate 2. The semiconductor chip comprises a semiconductor layer sequence 31 and a chip substrate 33. Alternatively, the semiconductor chip 3 can also be free of a chip substrate 33. The semiconductor chip 3 produces a Primary radiation 34, for example in the blue wavelength range, in the semiconductor layer sequence 31. The primary radiation 34 is emitted via an emission surface 32 of the semiconductor chip 3. The emission surface 32 of the semiconductor chip 3 has an edge length a. The edge length a of the semiconductor chip 3 can be between 50 pm and 100 pm, and the semiconductor chip 3 is a mini-LED. Alternatively, the edge length a can be less than 50 pm, for example 20 pm, 10 pm, or 5 pm, and the semiconductor chip 3 is a micro-LED.

A conversion element 4 is arranged at least on the emission surface 32 of the semiconductor chip 3. The conversion element has a height x above the semiconductor chip 3. The conversion element has a conversion material

41 on , for example a phosphor or a semiconductor nanocrystal .

The conversion element 4 absorbs the primary radiation 34 , converts the primary radiation 34 into secondary radiation 42 and emits the secondary radiation 42 . The secondary radiation

42 can, for example, comprise wavelengths in the green, yellow, red or infrared wavelength range. The conversion element 4 is designed to convert the primary radiation 34 completely into secondary radiation 42. In other words, the electromagnetic radiation emitted by the optoelectronic component 1 consists essentially of the secondary radiation 42. This means that a proportion of primary radiation 34 in the electromagnetic radiation emitted by the optoelectronic component 1 is so small that the primary radiation 34 does not perceptibly influence the color impression of the emitted electromagnetic radiation. The conversion element 4 can additionally cover the side surfaces of the semiconductor chip 3. In this case, the conversion element 4 can be larger than the semiconductor chip 3, for example twice as large, three times as large, or four times as large. In regions adjacent to the semiconductor chip 3, the conversion element has a thickness y. The thickness y is composed of the height x of the conversion element 4 on the semiconductor chip 3 and the height of the semiconductor chip 3.

In the exemplary embodiment of Figure 1, the secondary radiation 42 is coupled out of the optoelectronic component 1 via a radiation exit surface of the conversion element 4. In the exemplary embodiment of Figure 1, the radiation exit surface of the conversion element 4 is the luminous surface 11 of the optoelectronic component 1. The luminous surface 11 has the edge length z.

An aspect ratio of the optoelectronic component is at most 1, in particular at most 0.2, for example at most 0.1. The aspect ratio is calculated from the height x of the conversion element 4 and the edge length z of the luminous surface 11 of the optoelectronic component 1.

The optoelectronic component 1 is designed to increase a conversion efficiency of the conversion element 4. A key aspect here is that the undesired transmission of primary radiation 34 through the conversion element 4 and thus a coupling-out of primary radiation 34 via the luminous surface 11 of the optoelectronic component 1 is prevented. The optoelectronic components 1 of the embodiments of Figures 2A, 2B and 2C essentially correspond to the embodiment shown in Figure 1. The embodiments of Figures 2A, 2B and 2C illustrate a means for increasing the conversion efficiency of the conversion element 4 based on the grain size of the conversion material 41. Figure 2A shows a conversion element 4 made of a conversion material 41 with a grain size of at most 10 pm. In this case, the conversion element 4 has a height xl above the semiconductor chip 3. In the conversion element 4 of Figure 2B, the grain size of the conversion material 41 is reduced compared to the conversion material 41 of the conversion element 4 of Figure 2A. In the conversion element 4 in Figure 2C, the grain size of the conversion material 41 is further reduced compared to the conversion material 41 of the conversion element in Figures 2A and 2B. By reducing the grain size of the conversion material 41, increased absorption per grain can be achieved and, at the same time, the scattering in the conversion element 4 can be increased, so that the mean path length of the primary radiation 34 in the conversion element 4 increases. As a result, the conversion efficiency of the conversion element 4 is increased, as a result of which the height x of the conversion element 4 above the semiconductor chip 3 can be reduced. It can therefore be seen in Figures 2C and 2B that the heights x2 and x3 of the conversion element 4 above the semiconductor chip 3 are also reduced compared to the exemplary embodiment in Figure 2A.

The optoelectronic component 1 of the embodiment of Figure 3A essentially corresponds to the embodiment shown in Figure 1. The embodiment of Figure 3A illustrates a means for increasing the Conversion efficiency of the conversion element 4 using a filter element 5. The filter element 5 is arranged on a side of the conversion element 4 facing away from the semiconductor chip 3. The filter element 5 is designed to absorb primary radiation 34 and transmit secondary radiation 42. In other words, the filter element 5 reduces or prevents the unwanted transmission of primary radiation 34 through the conversion element 4. This is shown in Figure 3B using a transmission curve of the material of the filter element 5. The transmission T is plotted as a function of the wavelength X of the incident electromagnetic radiation. Electromagnetic radiation in the short-wave wavelength range is not transmitted, whereas radiation in the long-wave wavelength range is transmitted. The filter element 5 can also be referred to as an absorption filter or absorbing filter element. For example, the filter element 5 comprises or consists of gallium phosphide.

The optoelectronic component 1 of the embodiment of Figure 4A essentially corresponds to the embodiment shown in Figure 3A. The embodiment of Figure 4A also illustrates a means for increasing the conversion efficiency of the conversion element 4 using a filter element 5. In contrast to the filter element 5 of Figure 3A, the filter element 5 of Figure 4A is designed to reflect primary radiation 34 and transmit secondary radiation 42. In other words, the filter element 5 reduces or prevents the undesired transmission of primary radiation 34 through the conversion element 4. This is shown in Figure 4B using a reflection curve 4-1 and a transmission curve 4-2 of the material of the filter element 5. The Intensity as a function of the wavelength X of the incident electromagnetic radiation. Electromagnetic radiation in the short-wave wavelength range has a high reflectivity (reflection curve 4-1) and a low transmission (transmission curve 4-2), whereas radiation in the long-wave wavelength range has a low reflectivity (reflection curve 4-1) and a high transmission (transmission 4-2). The reflected primary radiation 34 can pass through the conversion element 4 again and can be converted into secondary radiation 42. The filter element 5 can also be referred to as a wavelength-selective interference filter. The filter element 5 can be a dielectric mirror, for example a Bragg mirror.

The optoelectronic component 1 of the embodiment of Figure 5A essentially corresponds to the embodiment shown in Figure 1. The embodiment of Figure 5A illustrates a means for increasing the conversion efficiency of the conversion element 4 using a mirror layer 6. The mirror layer 6 is arranged on the side of the semiconductor chip 3 facing away from the emission surface 32. In particular, the mirror layer 6 is arranged between the semiconductor chip 3, in particular the chip substrate 33, and substrate 2, as well as between the conversion element 4 and substrate 2. The mirror layer 6 can be a layer made of a metal or a dielectric mirror. Alternatively, the mirror layer can comprise a combination of a layer made of a metal and a dielectric mirror, wherein the dielectric mirror is arranged between the layer made of the metal and the semiconductor chip 3. The mirror layer 6 is designed to reflect the primary radiation 34 and to reflect the secondary radiation 42. The reflected primary radiation 34 can then be made available for conversion again. In addition, the coupling out of the secondary radiation 42 from the optoelectronic component 1 can be improved due to the reflection of secondary radiation 42 at the mirror layer 6.

The optoelectronic component 1 of the embodiment in Figure 5B essentially corresponds to the embodiment shown in Figure 5A. The embodiment in Figure 5B likewise illustrates a means for increasing the conversion efficiency of the conversion element 4 using a combination of the mirror layer 6 and a filter element 5. The filter element 5 is a filter element described in connection with Figures 4A and 4B. Due to the combination of the mirror layer 6 and the filter element 5, the primary radiation 34 repeatedly passes through the conversion element 4, thereby increasing the conversion efficiency of the conversion element 4. In addition, secondary radiation 42, which is emitted in the direction of the substrate 2 after the conversion, is reflected by the mirror layer 6 and coupled out via the filter element 5. As a result, the proportion of coupled-out secondary radiation 42 can be increased.

The optoelectronic component 1 of the embodiment of Figure 6A essentially corresponds to the embodiment shown in Figure 5A. The embodiment of Figure 6A also illustrates a means for increasing the conversion efficiency of the conversion element 4 using a combination of the mirror layer 6 and a deflection mirror 7. The deflection mirror 7 is arranged on the side of the conversion element 4 facing away from the semiconductor chip 3, in particular above the emission surface 32 of the semiconductor chip 3. arranged. The deflecting mirror 7 is designed to reflect the primary radiation 34. The primary radiation 34 emitted by the semiconductor chip 3 passes through the conversion element mainly on a direct path from the emission surface 32 to the side of the conversion element 4 facing away from the semiconductor chip 3. The primary radiation 34 is reflected by the deflecting mirror 7 before leaving the conversion element 4 and thrown back into the conversion element 4. This lengthens the light path of the primary radiation 34 and increases the absorption of primary radiation 34 in the conversion element 4. In addition, secondary radiation 42, which is emitted in the direction of the substrate 2 after the conversion, is reflected by the mirror layer 6 and coupled out via the luminous surface 11. This makes it possible to increase the proportion of coupled-out secondary radiation 42.

In the exemplary embodiment of Figure 6A, the side of the deflecting mirror 7 facing the semiconductor chip 3 has a planar surface 71. In particular, the primary radiation 34 is reflected at the planar surface 71 such that a beam path of the reflected primary radiation 34 is guided substantially in the direction of the substrate 2.

The optoelectronic component 1 of the embodiment of Figure 6B essentially corresponds to the embodiment shown in Figure 6A. The embodiment of Figure 6B also illustrates a means for increasing the conversion efficiency of the conversion element 4 by means of the combination of the mirror layer and the deflecting mirror 7. The embodiment of Figure 6B differs from the embodiment of Figure 6A only in that the side of the deflecting mirror 7 facing the semiconductor chip 3 at least one inclined surface 72, for example two inclined surfaces 72. In particular, the primary radiation 34 is reflected at the inclined surface 72 in such a way that a beam path of the reflected primary radiation 34 runs substantially parallel to a main extension direction of the conversion element 4.

The optoelectronic component 1 of the embodiment of Figure 7A illustrates a means for increasing the conversion efficiency of the conversion element 4 using an arrangement in the reverse beam path. The optoelectronic component has a substrate 2 that is transparent to at least the secondary radiation 42. A reflection layer 8 is arranged on the side of the conversion element 4 facing away from the semiconductor chip 3. The reflection layer 8 can be arranged such that all sides of the conversion element 4 that are free of the substrate 2 are covered by the reflection layer. The reflection layer 8 is designed to reflect at least the secondary radiation 42. The semiconductor chip 3 thus emits primary radiation 34 into the conversion element 4 mirrored with the reflection layer 8, and the secondary radiation 42 is coupled out of the optoelectronic component 1 through the transparent substrate 2.

The optoelectronic component 1 of the embodiment of Figure 7B essentially corresponds to the embodiment shown in Figure 7A. The embodiment of Figure 7B also illustrates a means for increasing the conversion efficiency of the conversion element 4 using an arrangement in the reversed beam path. In addition to the embodiment of Figure 7A, the optoelectronic component 1 of the embodiment of Figure 7B shows a filter element 5 which is arranged between the semiconductor chip 3 and the substrate 2 and between the conversion element 4 and the substrate 2. The filter element 5 is a filter element described in connection with Figures 4A and 4B. In addition, the semiconductor chip 3 is at least partially transparent to the primary radiation 34 and the secondary radiation 42. For example, the chip substrate 33 is transparent or the semiconductor chip 3 does not have a chip substrate 33. As a result, secondary radiation 42 can also be coupled out through the surface of the semiconductor chip 3, while the primary radiation 34 can pass through the conversion element 4 several times, thus increasing the conversion efficiency. An embodiment of the optoelectronic component 1 according to the embodiment of Figure 7B reduces partial shadowing and improves lateral homogeneity of the secondary radiation 42. At the same time, this embodiment also allows a reduction in the size of the optoelectronic component 1.

The optoelectronic arrangement 10 of the embodiment of Figure 8A has two optoelectronic components 1 as described in connection with Figure 1. The optoelectronic arrangement 10 can have a plurality of optoelectronic components 1. The optoelectronic components 1 of the embodiment of Figure 8A can additionally have the means for increasing the conversion efficiency of the conversion element 4, as described in connection with Figures 2A-C, 3A-B, 4A-B, 5A-B and 6A-B. The optoelectronic components 1 are arranged on a common substrate 2. The optoelectronic components 1 form pixels 110 of the optoelectronic arrangement 10. The respective pixels 110 have a distance b from one another, which in From the embodiment of Figure 8A corresponds to three times the size of an optoelectronic component 1, in particular three times the edge length a of the luminous surface 11.

The optoelectronic arrangement 10 of the exemplary embodiment in Figure 8B has two optoelectronic components 1 as described in connection with Figure 7A. The common substrate 2 is transparent to at least the secondary radiation 42, and the optoelectronic components 1 have an arrangement with a reversed beam path. The optoelectronic components 1 are at a distance b from one another which, in the exemplary embodiment in Figure 8B, due to the reflection layer 8 which optically separates the optoelectronic components 1, corresponds at most to three times the size of an optoelectronic component 1, in particular at most to three times the edge length a of the luminous surface 11.

The optoelectronic arrangement 10 of the embodiment of Figure 8C essentially corresponds to the embodiment shown in Figure 8B. The optoelectronic components of the embodiment of Figure 8C are described in conjunction with Figure 7B. In this embodiment, the distance b between the optoelectronic components 1 can correspond to at most twice the size of an optoelectronic component 1, in particular at most twice the edge length a of the luminous surface 11.

The features and embodiments described in connection with the figures can be combined with one another according to further embodiments, even if not all combinations are described explicitly. Furthermore, the features and embodiments described in connection with the figures The described embodiments may alternatively or additionally have further features according to the description in the general part. This patent application claims priority from German patent application 10 2023 135 179 . 6, the disclosure of which is hereby incorporated by reference.

The invention is not limited to the embodiments described herein. Rather, the invention encompasses any novel feature and any combination of features, including, in particular, any combination of features in the claims, even if this feature or combination itself is not explicitly stated in the claims or embodiments.

Reference symbol list

1 optoelectronic component

11 Illuminated area

2 Substrat

3 semiconductor chip

31 Semiconductor layer sequence

32 emission area

33 Chip substrate

34 Primary radiation

4 Conversion element

41 Conversion material

42 Secondary radiation

5 filter element

6 mirror layer

7 deflecting mirrors

71 planar surface

72 inclined surface

8 reflective layer

10 Display

110 pixels x Height of the conversion element xl Height of the conversion element x2 Height of the conversion element x3 Height of the conversion element y Thickness of the conversion element z Edge length of the luminous surface a Edge length of the emission surface b Distance

4- 1 Reflection curve

4-2 Transmission Curve

Claims

Patent claims 1. Optoelectronic component (1) comprising - a semiconductor chip (3) which is arranged to emit a primary radiation (34), and - a conversion element (4) which is designed to convert the primary radiation (34) into a secondary radiation (42), wherein an aspect ratio of a height (x) of the conversion element (4) on the semiconductor chip (3) and an edge length (z) of a luminous area (11) of the optoelectronic component (1) is at most 1, and wherein the optoelectronic component (1) is designed to increase a conversion efficiency of the conversion element (4). 2. Optoelectronic component (1) according to the preceding claim, wherein the conversion element (4) has a height (x) of at most 100 pm. 3. Optoelectronic component (1) according to at least one of the preceding claims, wherein the semiconductor chip (3) is a mini-LED or a microLED. 4. Optoelectronic component (1) according to at least one of the preceding claims, wherein the semiconductor chip (3) is an InGaN semiconductor chip. 5. Optoelectronic component (1) according to at least one of the preceding claims, wherein the optoelectronic component (1) emits secondary radiation (42) with a color saturation of at least 95% during operation. 6. Optoelectronic component (1) according to at least one of the preceding claims, wherein the conversion element (4) comprises a conversion material (41), wherein the conversion material (41) comprises a phosphor, wherein the phosphor has grain sizes of at most 10 pm. 7. Optoelectronic component (1) according to at least one of claims 1 to 5, wherein the conversion element (4) comprises a conversion material (41), wherein the conversion material (41) comprises a semiconductor nanocrystal. 8. Optoelectronic component (1) according to at least one of the preceding claims, further comprising - a filter element (5) on a side of the conversion element (4) facing away from the semiconductor chip (3). 9. Optoelectronic component (1) according to the preceding claim, wherein the filter element (5) is configured to absorb the primary radiation (34). 10. Optoelectronic component (1) according to claim 8, wherein the filter element (5) is configured to reflect the primary radiation (34) and to transmit the secondary radiation (42). 11. Optoelectronic component (1) according to at least one of the preceding claims, further comprising - a mirror layer (6) on a side of the semiconductor chip (3) facing away from an emission surface (32) of the semiconductor chip (3), wherein the mirror layer (6) is designed to reflect the primary radiation (34) and the secondary radiation (42). 12. Optoelectronic component (1) according to at least one of the preceding claims, further comprising - a deflecting mirror (7) on a semiconductor chip (3) facing away from the side of the conversion element (4), wherein the deflecting mirror (7) is designed to reflect the primary radiation (34). 13. Optoelectronic component (1) according to the preceding claim, wherein the deflecting mirror (7) is arranged above an emission surface (32) of the semiconductor chip (3). 14. Optoelectronic component (1) according to at least one of claims 12 or 13, wherein a side of the deflection mirror (7) facing the semiconductor chip (3) has a planar surface (71), or wherein a side of the deflection mirror (7) facing the semiconductor chip (3) has at least one inclined surface (72). 15. Optoelectronic component (1) according to at least one of claims 1 to 7, further comprising - a substrate (2) , - a reflection layer (8) on a side of the conversion element (4) facing away from the semiconductor chip (3), wherein the substrate (2) is transparent at least to the secondary radiation (42), wherein the reflection layer (8) is designed to reflect at least the secondary radiation (42), and wherein the optoelectronic component (1) is designed to emit secondary radiation (42) through the substrate (2). 16. Optoelectronic component (1) according to the preceding claim, further comprising - a filter element (5), wherein the filter element (5) is arranged between the substrate (2) and the semiconductor chip (3), wherein the filter element (5) is designed to reflect the primary radiation (34) and to transmit the secondary radiation (42), and wherein the semiconductor chip (3) is at least partially transparent to the primary radiation (34) and the secondary radiation (42). 17. Optoelectronic arrangement (10) comprising at least two optoelectronic components (1) according to at least one of the preceding claims, wherein each of the optoelectronic components (1) forms a pixel (110) of the optoelectronic arrangement (10).