Optoelectronic component

Abstract

Optoelectronic device (10) with an active layer having a multiple quantum well structure (5), wherein the multiple quantum well structure (5) contains quantum well layers (51) which Al x1 In y1 Ga 1-x1-y1 N with 0 ≤ x1 < 0.03, 0 ≤ y1 ≤ 0.1 and x1 + y1 ≤ 1, and contains barrier layers (52) that Al x2 In y2 Ga 1-x2-y2 N with 0 ≤ x2 ≤ 1, 0 ≤ y2 ≤ 0.02 and x2 + y2 ≤ 1, where - the barrier layers (52) have a spatially varying aluminium content x2, - a maximum value of the aluminium content in the barrier layers (52) x2,max ≥ 0.05, and - a minimum value of the aluminium content in the barrier layers (52) x2,min < 0.05 - the multiple quantum well structure (5) is arranged between an n-type semiconductor region (6) and a p-type semiconductor region (4), - in a direction pointing from the n-type semiconductor region (6) to the p-type semiconductor region (4), an intermediate layer (53) is arranged between a barrier layer (52) and the subsequent quantum well layer (51) and immediately precedes the subsequent quantum well layer (51), wherein the intermediate layer (53) is Al x3 In y3 Ga 1-x3-y3 N with 0 ≤ x3 < 0.03, 0 ≤ y3 ≤ 0.02 and x3 + y3 ≤ 1, and - the barrier layers (52) in the direction pointing from the n-type semiconductor region (6) to the p-type semiconductor region (4) each directly adjoin a preceding quantum well layer (51), wherein the aluminium content in the barrier layers (52) decreases from an interface to the preceding quantum well layer (51) in the form of one or more steps or continuously to the minimum value x2,min and increases again from the minimum value in the form of one or more steps or continuously.

Description

[0001] The application relates to an optoelectronic device emitting, in particular, violet or ultraviolet radiation, which has an active layer with a quantum well structure comprising nitride compound semiconductor materials, in particular AlInGaN.

[0002] Quantum well structures made of nitride compound semiconductors, particularly AlInGaN, are frequently used as active layers in LEDs or laser diodes, which typically emit in the blue spectral range. Depending on the composition of the semiconductor material, emission in the violet or ultraviolet spectral range is also possible. To achieve efficient emission in the ultraviolet range, it is necessary to use barrier layers in the quantum well structure that exhibit a comparatively large electronic band gap. In the AlInGaN material system, this can be achieved by increasing the aluminum content. However, the lattice constant of nitride compound semiconductor materials decreases with increasing aluminum content. This can lead to comparatively high tensile stresses when growing layers with a high aluminum content.This results in the risk of defects forming, especially cracks forming in the semiconductor layers.

[0003] The publication DE 10 2012 104 671 A1 relates to a method for producing an active zone for an optoelectronic semiconductor chip and an optoelectronic semiconductor chip.

[0004] The publication DE 10 2013 200 507 A1 describes an optoelectronic semiconductor device with an active zone for generating light.

[0005] Document US 2010 / 0187497A1 describes a semiconductor device comprising an underlying layer and a light-emitting layer formed on the underlying layer, in which a barrier layer of InAlGaN and a quantum well layer of InGaN are arranged alternately on top of each other.

[0006] Document CN 1 03 872 198 A relates to a light-emitting diode structure comprising a substrate, a buffer layer, an N-type conductive layer, a voltage relief layer, a luminescent area, an electron blocking layer, a P-type conductive layer and a P-type contact layer from bottom to top.

[0007] The invention is based on the objective of providing an optoelectronic component with an active layer that is particularly suitable for emitting radiation in the ultraviolet spectral range and is characterized by a reduced risk of defect formation.

[0008] This problem is solved by an optoelectronic component with the features of claim 1. Advantageous embodiments and further developments of the invention are the subject of the dependent claims.

[0009] According to at least one embodiment, the optoelectronic device has an active layer that has a multiple quantum well structure, wherein the multiple quantum well structure comprises quantum well layers and barrier layers. The barrier layers have a larger electronic band gap than the quantum well layers, at least in certain regions. The quantum well layers preferably comprise Al x1 In y1 Ga 1-x1-y1 N with 0 ≤ x1 < 0.03, 0 ≤ y1 ≤ 0.1 and x1 + y1 ≤ 1. Preferably, the aluminum content in the quantum well layers x1 = 0. Furthermore, preferably the indium content in the quantum well layers y1 > 0. The quantum well layers preferably contain InGaN, in particular In y1 Ga 1-y1 N with 0 < y1 ≤ 0,1.

[0010] The barrier layers preferably contain Al x2 In y2 Ga 1-x2-y2N with 0 ≤ x2 ≤ 1, 0 ≤ y2 ≤ 0.02 and x2 + y2 ≤ 1, wherein the aluminum content x2 varies spatially in the barrier layers. The aluminum content varies in the direction perpendicular to the principal planes of the barrier layers, or in other words, in the growth direction of the barrier layers. The maximum value of the aluminum content x2 in the barrier layers is preferably x2,max ≥ 0.05. Furthermore, the minimum value of the aluminum content x2,min in the barrier layers is preferably x2,min < 0.05.

[0011] Because the aluminum content x2 in the barrier layers of the quantum well structure is not constant, but varies spatially and exhibits a maximum value x2,max ≥ 0.05 and a minimum value x2 < 0.05, a large electronic band gap can be achieved. However, the aluminum content averaged over the thickness of the barrier layer is advantageously lower than the maximum value x2,max ≥ 0.05. This reduces tensile stresses in the barrier layers and thus prevents the risk of defects and / or cracking occurring in the barrier layers.

[0012] The barrier layers advantageously exhibit the maximum value x2,max of the aluminum content at at least one interface with an adjacent quantum well layer. This has the advantage that the barrier layers have a large electronic band gap at the interface with the respective adjacent quantum well layer. In this way, a large barrier height is achieved at the interface with the quantum well layer.

[0013] In a preferred embodiment, the maximum value x2,max of the aluminum content is x2,max ≥ 0.1, particularly preferably x2,max ≥ 0.2. Such a high aluminum content is advantageous for a quantum well structure intended for the emission of radiation in the ultraviolet spectral range.

[0014] In particular, the aluminum content in the barrier layers can initially decrease from an interface with the preceding layer in one or more steps or continuously to the minimum value x2,min. Subsequently, the aluminum content can increase again from this minimum in one or more steps or continuously.

[0015] According to at least one embodiment, the barrier layers have the minimum value of the aluminium content x2,min in at least one area that is at least 1 nm away from an adjacent quantum well layer.

[0016] The minimum value of the aluminium content in the barrier layers is preferably x2,min ≤ 0.02, particularly preferably x2,min = 0. In particular, the barrier layers can contain GaN in the region of the minimum value of the aluminium content.

[0017] In a preferred embodiment of the optoelectronic device, the active layer is arranged between an n-type semiconductor region and a p-type semiconductor region, with an intermediate layer being arranged between a barrier layer and the subsequent quantum well layer in the direction from the n-type semiconductor region to the p-type semiconductor region. The direction from the p-type semiconductor region to the n-type semiconductor region typically corresponds to the growth direction of the semiconductor layer sequence. Thus, in this embodiment, an intermediate layer is arranged at the interfaces where a quantum well layer follows a barrier layer in the growth direction. The intermediate layer preferably comprises Al x3 In y3 Ga 1-x3-y3N with 0 ≤ x3 < 0.03, 0 ≤ y3 ≤ 0.02 and x3 + y3 ≤ 1. The thickness of the intermediate layer is advantageously less than 1.5 nm, particularly preferably less than 1 nm. Compared to the subsequent barrier layer, the intermediate layer has a comparatively low aluminum content x3 ≤ 0.03, preferably x3 ≤ 0.01, and particularly preferably x3 = 0. Furthermore, the indium content y3 ≤ 0.02 in the intermediate layer is also very low or preferably y3 = 0. In particular, the intermediate layer can be a GaN layer.

[0018] Inserting an intermediate layer between a barrier layer and the subsequent quantum well layer has the particular advantage of preventing the quantum well layer from growing directly on the barrier layer with its high aluminum content. It has proven advantageous not to grow quantum well layers, especially those containing indium, directly on barrier layers with a high aluminum content, as this could lead to unfavorable reactions between indium and aluminum.

[0019] According to a further advantageous embodiment, the barrier layers, in the direction from the n-type semiconductor region to the p-type semiconductor region, each directly adjoin a preceding quantum well layer. At these interfaces, no intermediate layer is arranged. Rather, it is advantageous if there is an abrupt transition at these interfaces from the material of the quantum well layer to the material of the barrier layer in order to avoid an increased probability of holes being found in the barrier layers.

[0020] In an advantageous embodiment, the quantum well structure is a multiple quantum well structure comprising several periods, each consisting of three layers, where the three layers are the barrier layer, the intermediate layer, and the quantum well layer. The number of periods is advantageously between 3 and 15, preferably between 4 and 8.

[0021] The thickness of the barrier layers in the multiple quantum well structure is preferably between 3 nm and 8 nm, more preferably between 3 nm and 5 nm. The quantum well layers preferably have a thickness between 2 nm and 4 nm.

[0022] The optoelectronic component is preferably a UV-emitting optoelectronic component. In particular, the optoelectronic component can be suitable for emitting UV radiation with a central wavelength of less than 420 nm. A central wavelength between 365 nm and 400 nm is especially preferred. The optoelectronic component emitting in this spectral range can be used, in particular, for curing coatings.

[0023] The invention is described below with reference to exemplary embodiments in connection with the Fig. 1 to 4 explained in more detail.

[0024] They show: Fig. 1 a schematic representation of a cross-section through an optoelectronic component according to a first embodiment, Fig. 2 a schematic representation of the course of the aluminium content in the barrier layer in an exemplary embodiment, Fig. 3 a schematic representation of the course of the aluminium content in the barrier layer in a further embodiment, and Fig. 4 A schematic representation of a cross-section through an optoelectronic component according to a further embodiment.

[0025] Identical or similarly functioning components are marked with the same reference symbols in the figures. The depicted components and their relative sizes are not to be considered to scale.

[0026] The in Fig. The optoelectronic component 10 shown in Figure 1, according to an exemplary embodiment, is an LED chip comprising a p-type semiconductor region 4, an n-type semiconductor region 6, and an active layer arranged between the p-type semiconductor region 4 and the n-type semiconductor region 6, which is suitable for emitting radiation and is a multiple quantum well structure 5. The LED chip 10 is preferably an LED chip emitting in the ultraviolet spectral range. The multiple quantum well structure 5 of the LED chip 10 is preferably suitable for emitting radiation with a central wavelength of less than 420 nm, preferably between 365 nm and 400 nm.

[0027] The LED chip 10 according to the embodiment is a so-called thin-film semiconductor chip, from which a growth substrate originally used for the epitaxial growth of the semiconductor layer sequence 4, 5, 6 was removed and instead the semiconductor layer sequence 4, 5, 6 was connected to a support substrate 1 different from the growth substrate by means of a connecting layer 2, in particular a solder layer.

[0028] In such a thin-film LED chip, the p-type semiconductor region 4 is typically oriented towards the substrate 1. An advantageous reflective layer 3 is arranged between the p-type semiconductor region 4 and the substrate 1. This reflective layer 3 deflects radiation emitted towards the substrate 1 towards a radiation emission surface 9 of the optoelectronic device 10. The reflective layer 3 is, for example, a metal layer containing Ag, Al, or Au.

[0029] For electrical contacting of the optoelectronic component 10, for example a first contact layer 7 can be provided on a back side of the support substrate 1 and a second contact layer 8 on a partial area of ​​the radiation emission surface 9.

[0030] The p-type semiconductor region 4 and the n-type semiconductor region 6 can each be composed of several sublayers and do not necessarily have to consist exclusively of p-doped layers or n-doped layers, but can, for example, also have one or more nominally undoped layers.

[0031] As an alternative to the illustrated embodiment, the optoelectronic device 10 could also have the opposite polarity, that is, the n-type semiconductor region 6 could face a substrate and the p-type semiconductor region 4 a radiation emission surface 9 of the optoelectronic semiconductor chip (not shown). This is generally the case with optoelectronic semiconductor chips where the growth substrate used for the epitaxial growth of the semiconductor layers is not removed, since the n-type semiconductor region is usually grown onto the growth substrate first.

[0032] The semiconductor layer sequence 4, 5, 6 of the optoelectronic device 10 is based on a nitride compound semiconductor. "Based on a nitride compound semiconductor" in this context means that the semiconductor layer sequence, or at least one layer thereof, is a III nitride compound semiconductor material, preferably Al x In y Ga 1-x-y N comprises, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, and x + y ≤ 1. This material does not necessarily have to have a mathematically exact composition according to the formula above. Rather, it can contain one or more dopants as well as additional components that impart the characteristic physical properties of the aluminum. x In y Ga 1-x-y The N-materials do not change substantially. For the sake of simplicity, however, the formula above only includes the essential components of the crystal lattice (In, Al, Ga, N), even though these may be partially replaced by small amounts of other substances.

[0033] The electronic band gaps of nitride compound semiconductor materials can be adjusted, in particular, by varying the aluminum and / or indium content in the semiconductor material. For these types of semiconductors, the band gap increases with increasing aluminum content (x) and decreases with increasing indium content (y).

[0034] The active layer of the optoelectronic semiconductor chip 10, intended for the emission of radiation, is configured as a multiple quantum well structure 5. The multiple quantum well structure 5 comprises a plurality of alternately arranged quantum well layers 51 and barrier layers 52. The quantum well layers 51 have a band gap E QW and the barrier layers 52 at least partially a band gap E B > E QWThe multiple quantum well structure 5 is in particular a periodic sequence of layers having a number N periods, where the number of periods N is, for example, between 3 and 15, preferably between 4 and 8.

[0035] The quantum well layers 51, for example, have a thickness between 2 nm and 4 nm. The thickness of the barrier layers 52 is, for example, between 3 nm and 8 nm, preferably between 3 nm and 5 nm.

[0036] The quantum well layers 51 exhibit, in the embodiment of the multiple quantum well structure 5Al x1 In y1 Ga 1-x1-y1N with 0 ≤ x1 < 0.03, 0 ≤ y1 ≤ 0.1 and x1 + y1 ≤ 1. Due to the low aluminum content x1 < 0.03, preferably x1 = 0, a large difference in the electronic band gap can be achieved compared to the barrier layers 52, which have a higher aluminum content. In other words, comparatively deep quantum wells can be generated. Furthermore, the indium content y1 ≤ 0.1 in the quantum well layer layers 51 is also low, since the electronic band gap would decrease with increasing indium content. Since the optoelectronic device is intended in particular for the emission of very short-wavelength radiation, especially in the UV range, a low indium content in the range between y1 = 0 and y1 = 0.1 is advantageous.

[0037] The barrier layers 52 exhibit, in the embodiment of the optoelectronic component Al x2 In y2 Ga 1-x2-y2N with 0.05 ≤ x2 ≤ 1, 0 ≤ y2 ≤ 0.02 and x2 + y2 ≤ 1. To achieve a large electronic band gap, the barrier layers 52 have a very low indium content y2 ≤ 0.02 or preferably no indium, so that y2 = 0. The material of the barrier layers 52 is therefore preferably Al x2 Ga 1-x2 N with 0 ≤ x2 ≤ 1. Preferably, the aluminum content of the barrier layers 52 has a maximum value x2,max ≥ 0.05 at least at the interfaces where a barrier layer 52 follows the quantum well layer 51 in a direction extending from the n-type semiconductor region 6 to the p-type semiconductor region 4. x2,max ≥ 0.1 or even x2,max ≥ 0.2 is particularly preferred. For example, the barrier layers 52 can have an aluminum content of Al at the interfaces to the adjacent quantum well layers 51. 0,15 Ga 0,85 exhibit N.

[0038] Here, the aluminum content x2 in the barrier layers 52 is not constant, but exhibits a spatial variation in the z-direction, which is perpendicular to the layer planes from the n-type semiconductor region 6 to the p-type semiconductor region. In particular, it is possible that the barrier layers 52 are composed of several sublayers 52a, 52b, 52c, which have different aluminum contents x2.

[0039] The distribution of the aluminium content in the z-direction of the barrier layer 52 is shown for two embodiments in the Fig. 2 and Fig. 3 shown.

[0040] In the exemplary embodiment of the Fig. In the embodiment 2, the barrier layer 52 comprises two outer sublayers 52a, 52c and a middle sublayer 52b arranged between them. The middle sublayer 52b has a lower aluminum content x2 than the outer sublayers 52a, 52c. Preferably, the aluminum content x2 in the outer sublayers 52a, 52c has a maximum value x2,max ≥ 0.05, for example x2,max = 0.15. In the middle sublayer 52c, the aluminum content has a minimum value x2,min < 0.05, preferably x2,min < 0.02, for example x2,min = 0. In the illustrated embodiment, the outer sublayers 52a, 52c are each Al 0,15 Ga 0,85The barrier layer consists of three sublayers, 52a and 52c, and the middle sublayer 52b is a GaN layer. The outer sublayers 52a and 52c can, for example, have a thickness between 1 nm and 2 nm, and the middle sublayer 52b a thickness between 2 nm and 3 nm. The total thickness of the barrier layer 52, composed of the three sublayers, can be approximately 3 nm to 8 nm.

[0041] The step-like progression of the aluminum content x2 in this embodiment ensures that, due to the high aluminum content of the outer sublayers 52a, 52c of the barrier layers 52, an advantageously high electronic band gap is achieved at the interfaces with the adjacent quantum well layers 51. This is advantageous, in particular, for enabling the emission of very short-wavelength radiation in the UV range. On the other hand, the lower aluminum content in the middle sublayer 52c reduces the mechanical stresses in the barrier layer 52 and thus decreases the risk of crystal defects, such as dislocations or cracks, forming in the barrier layer 52.

[0042] The first sublayer 52a, which grows first during the epitaxial growth of the barrier layer 52, exhibits tensile stress as it grows on an underlying semiconductor layer with a larger lattice constant due to its comparatively small lattice constant, which is caused by the high aluminum content x2,max. This tensile stress would lead to the formation of defects with increasing layer thickness. Such defect formation can be effectively reduced by inserting the middle sublayer 52b after the first sublayer has reached a thickness of no more than 2 nm or preferably no more than 1 nm.

[0043] In Fig. Figure 3 schematically illustrates another embodiment of the aluminum content x2 in the barrier layer 52. The barrier layer 52 has a first outer sublayer 52a, a middle sublayer 52b, and a second outer sublayer 52c. Unlike the previous embodiment, the outer sublayers 52a and 52c do not have a constant aluminum content, but rather a gradient of aluminum content. For example, the aluminum content in the first outer sublayer 52a can decrease from the maximum value x2,max to the minimum value x2,min and increase again in the second outer sublayer from the minimum value x2,min to the maximum value x2,max. Fig. Figure 3 shows an example of a linear gradient of the aluminium content x2 in the outer sublayers.

[0044] Alternatively, it is also possible that the aluminum content decreases or increases non-linearly. In particular, it is possible that the aluminum content decreases or increases in stages.

[0045] It is also conceivable that the middle sublayer 52b is omitted, so that the barrier layer 52 has only two sublayers 52a and 52c. For example, the aluminum content in the first sublayer 52a can decrease stepwise or continuously to a minimum value x2,min and subsequently increase again stepwise or continuously in an immediately adjacent second sublayer 52c. The profile of the aluminum content need not necessarily be symmetrical with respect to the center point of the barrier layer 52; rather, the barrier layer 52 can also exhibit an asymmetrical profile of the aluminum content x2.

[0046] With regard to the aluminum content in the barrier layer 52, various configurations are possible, wherein the aluminum content preferably has a minimum value x2,min inside the barrier layer 52 and a maximum value x2,max at the interfaces to the adjacent semiconductor layers.

[0047] In Fig. Figure 4 shows a further embodiment of the optoelectronic component 10. This embodiment differs from the embodiment of the Fig. 1. This is achieved by arranging an intermediate layer 53 in the z-direction, i.e., in the growth direction of the semiconductor layer sequence, in front of each quantum well layer 51, pointing from the n-type semiconductor region 6 to the p-type semiconductor region 4. In this embodiment, the periods of the multiple quantum well structure 5 thus each have three layers: the intermediate layer 53, the quantum well layer 51 following the intermediate layer 53, and the barrier layer 52 following the quantum well layer 51. As in the previous embodiment, the number of periods N is advantageously between 3 and 15, preferably between 4 and 8.

[0048] The intermediate layer 53 is a comparatively thin layer, the thickness of which is preferably no more than 1.5 nm, and particularly preferably no more than 1 nm. The intermediate layer comprises Al x3 In y3 Ga 1-x3-y3N with 0 ≤ x3 < 0.03, 0 ≤ y3 ≤ 0.02 and x3 + y3 ≤ 1. Preferably, the aluminum content x3 = 0 and / or the indium content y3 = 0. The thin intermediate layer with the comparatively low or preferably no aluminum content has the advantage that, during the growth of the quantum well layer 53, which typically has an indium content, no undesired reaction occurs between indium and aluminum or their precursor materials in the gas phase.

[0049] At the interfaces of the multiple quantum well structure 5, where a barrier layer 52 follows a quantum well layer 51 in the z-direction pointing from the n-type semiconductor region 6 to the p-type semiconductor region 4, preferably no intermediate layer is arranged. In other words, an intermediate layer 53 immediately precedes the quantum well layers 51 in the growth direction, but no intermediate layer immediately follows the quantum well layers 51. At the interfaces where a barrier layer 52 follows a quantum well layer 51 in the growth direction, it is advantageous if the barrier layer 52 directly adjoins the quantum well layer 53. It has been found that this influences the electronic band structure in such a way that the probability of finding holes in the barrier layers 52 is reduced. In this way, the efficiency of radiation generation in the multiple quantum well structure can be improved.

[0050] With regard to further advantageous embodiments, in particular the embodiments of the barrier layers 52 and the associated advantages, the exemplary embodiment corresponds to the Fig. 4 otherwise the previously described embodiments. Reference symbol list 1 Carrier substrate 2. Compound layer 3 Mirror layer 4 p-type semiconductor range 5 multiple quantum well structure 6 n-type semiconductor range 7 first contact layer 8 second contact layer 9 Radiation emission surface 10 optoelectronic component 51 Quantum well layer 52 Barrier layer 52a Sublayer of the barrier layer 52b Sublayer of the barrier layer 52c Sublayer of the barrier layer 53 Intermediate shift

Claims

[1] Optoelectronic device (10) with an active layer having a multiple quantum well structure (5), wherein the multiple quantum well structure (5) contains quantum well layers (51) which Al x1 In y1 Ga 1-x1-y1 N with 0 ≤ x1 < 0.03, 0 ≤ y1 ≤ 0.1 and x1 + y1 ≤ 1, and contains barrier layers (52) that Al x2 In y2 Ga 1-x2-y2 N with 0 ≤ x2 ≤ 1, 0 ≤ y2 ≤ 0.02 and x2 + y2 ≤ 1, where - the barrier layers (52) have a spatially varying aluminium content x2, - a maximum value of the aluminium content in the barrier layers (52) x2,max ≥ 0.05, and - a minimum value of the aluminium content in the barrier layers (52) x2,min < 0.05 - the multiple quantum well structure (5) is arranged between an n-type semiconductor region (6) and a p-type semiconductor region (4), - in a direction pointing from the n-type semiconductor region (6) to the p-type semiconductor region (4), an intermediate layer (53) is arranged between a barrier layer (52) and the subsequent quantum well layer (51) and immediately precedes the subsequent quantum well layer (51), wherein the intermediate layer (53) is Al x3 In y3 Ga 1-x3-y3 N with 0 ≤ x3 < 0.03, 0 ≤ y3 ≤ 0.02 and x3 + y3 ≤ 1, and - the barrier layers (52) in the direction pointing from the n-type semiconductor region (6) to the p-type semiconductor region (4) each directly adjoin a preceding quantum well layer (51), wherein the aluminium content in the barrier layers (52) decreases from an interface to the preceding quantum well layer (51) in the form of one or more steps or continuously to the minimum value x2,min and increases again from the minimum value in the form of one or more steps or continuously. [2] Optoelectronic device according to claim 1, wherein the barrier layers (52) have the maximum value x2,max of the aluminium content at the interface to the preceding quantum well layer (51). [3] Optoelectronic component according to one of the preceding claims, wherein the maximum value of the aluminium content in the barrier layers (52) is x2,max ≥ 0.

1. [4] Optoelectronic component according to one of the preceding claims, wherein the maximum value of the aluminium content in the barrier layers (52) is x2,max ≥ 0.

2. [5] Optoelectronic device according to one of the preceding claims, wherein the barrier layers (52) have the minimum value x2,min of the aluminium content in a region that is at least 1 nm away from an adjacent quantum well layer (51). [6] Optoelectronic component according to one of the preceding claims, wherein the minimum value of the aluminium content in the barrier layers (52) x2,min is < 0.

02. [7] Optoelectronic device according to one of the preceding claims, wherein the minimum value of the aluminium content in the barrier layers (52) is x2,min = 0. [8] Optoelectronic device according to one of the preceding claims, wherein the intermediate layer (53) is less than 1.5 nm thick. [9] Optoelectronic device according to one of the preceding claims, wherein the intermediate layer (53) comprises GaN. [10] Optoelectronic device according to one of the preceding claims, wherein the optoelectronic device (10) is suitable for emitting UV radiation with a central wavelength of less than 420 nm. [11] Optoelectronic device according to claim 10, wherein the central wavelength is between 365 nm and 400 nm.

Images