Light emitting diode and method for producing a light emitting diode

0001A light-emitting diode is indicated. Moreover, a method for producing a light-emitting diode is given.

0002A problem to be solved is to specify a light-emitting diode with a structured luminous surface. A further object to be achieved is to specify a method for producing such a light-emitting diode.

0003According to at least one embodiment, the light-emitting diode comprises a layer sequence with an active layer emitting active radiation. The light-emitting diode can be an organic or an inorganic light-emitting diode.

0004In the case of an inorganic light-emitting diode, for example LED, the layer sequence is, for example, a semiconductor layer sequence based on a III-V compound semiconductor material. The semiconductor material is, for example, a nitride compound semiconductor material such as Al_NIn_{1 nm}Ga_MN, or a phosphide compound semiconductor material such as Al_NIn_{1 nm}Ga_MP, or also an arsenide compound semiconductor material such as Al_NIn_{1 nm}Ga_MAs, where 0≤n≤1, 0≤m≤1 and m + n≤1, respectively. The semiconductor layer sequence can have dopants as well as additional components. However, for the sake of simplicity, only the essential components of the crystal lattice of the semiconductor layer sequence, ie, Al, As, Ga, In, N or P, are given. Preferably, the semiconductor layer sequence is based on AlInGaN.

0005The active layer has, for example, at least one pn junction and / or a quantum well structure in the form of a single quantum head, in short SQW, or in the form of a multiquantump structure, in short MQW.

0006In the case of an organic light-emitting diode, for example OLED, the active layer has, for example, an organic emitter material. Further layers of the layer sequence can then be organic electron transport layers or hole transport layers or electron injection layers or hole injection layers.

0007For example, in operation the light-emitting diode and / or the active layer emits UV radiation or infrared radiation or visible light, such as blue, green, yellow, red or white light.

0008According to at least one embodiment, the light-emitting diode has at least one lead-in element, which is arranged on a first main side of the layer sequence. Electrical current, in particular two-dimensional, is conducted into or out of the layer sequence during operation via the supply element. The supply element preferably forms a first electrode of the light-emitting diode.

0009A main side runs substantially parallel to a main extending direction of the active layer. "Flat" means, in particular, that current is fed into or out of the layer sequence over the entire extent of a partial area of ​​the feed element running parallel to the active layer. At least the partial surface overlaps the top of the first main face completely with the active layer. A main current flow direction is then perpendicular to the main extension direction of the active layer in the area of ​​the partial surface.

0010The supply element is preferably an electrically conductive element which is, for example, a metal such as Al, Ag, Au, In, Ti, Pt, Zr or an oxide, for example a transparent conductive oxide, short TCO such as indium- Tin oxide, short ITO, or BaO_X Or ThO_X Or consists thereof. In this case, the feed element can have a plurality of subregions and / or material layers of different materials. However, the feed element can also have a similar material composition along its entire lateral extent. "Lateral" is here and hereafter a direction parallel to a main extension direction of the active layer.

0011In particular, the feed element is designed as a strip or conductor track with a width of, for example, at least 5 μm or 10 μm or 20 μm. The feed element is preferably a cohesive, in particular simply coherent element, which is, for example, free of perforations. For example, the lead-in element is formed in a plan view of the first main side, rectangular or L-shaped or U-shaped.

0012According to at least one embodiment, a contact area of ​​the feed element protrudes in the lateral direction from the layer sequence. The contact area, in top view, therefore, does not overlap with the layer sequence and, in particular, serves for the external electrical contacting of the feed element.

0013According to at least one embodiment, a tunnel layer is arranged between the active layer or the layer sequence and the feed element. The tunneling layer may comprise or consist of an electrically insulating material such as a ceramic. In particular, the tunneling layer comprises or consists of an oxide of the material of the tunneling element. For example, theTunnel layer alumina, such as Al₂O₃, Or titanium oxide such as TiO₂, Or zirconium oxide such as ZrO₂, Or silicon oxide, such as SiO.sub.2₂, Or consists of. The tunnel layer preferably has an identical material composition along its entire lateral extent.

0014The tunnel layer has, for example, a thickness of at least 0.5 nm or at least 1 nm or at least 2 nm. Alternatively or additionally, the thickness of the tunneling layer is at most 20 nm or 10 nm or 5 nm. The thickness of a layer or element is here and in the following in particular the maximum or average thickness along the entire lateral extent of the layer or of the element.

0015According to at least one embodiment, the lead-in element is partially or completely covered by the active layer and the tunnel layer, in a plan view, on a second main side of the layer sequence opposite the first main side. That is, the tunnel layer, the active layer and the lead-in element all overlap one another in a region. In this region, the tunnel layer is arranged directly between the layer sequence and the feed element.

0016According to at least one embodiment, a current flow between the supply element and the layer sequence is possible only by means of a quantum mechanical tunneling effect. That is, if the tunnel layer is selected to be sufficiently thick, for example thicker than 10 nm or 100 nm or 1 μm, the tunneling layer would have an electrically insulating effect. There would then be no current flow between the supply element and the layer sequence at normally applied operating voltages for light-emitting diodes of, for example, at most 10 V. Due to the small thickness of the tunnel layer, the quantum mechanical tunneling effect occurs through the tunneling layer in the operation according to the invention so that charge carriers can reach the layer sequence or vice versa even at normal operating voltages from the feed element.

0017According to at least one embodiment, at least two partial regions adjoining one another in the lateral direction are formed in the region of the lead-in element. In the subregions, the tunnel layer and / or the feed element are deliberately designed differently so that the tunnel probabilities are different from one another in the different subregions by the tunnel layer. "Specifically designed" in this context means, in particular, that these are not merely production-induced fluctuations in the tunneling probability along the feed element. Rather, the tunnel probabilities in the subareas are intended and controlled differently from each other. In particular, the subregions do not have any geometric shapes,

0018The quantum mechanical tunneling probability depends both on the height of the potential barrier formed by the tunnel layer for charge carriers as well as on the thickness of the tunnel layer. In addition, the tunnel probability increases with the level of the electric field strength in the tunnel layer.

0019In at least one embodiment, the light-emitting diode has a layer sequence with an active layer emitting active radiation, at least one lead element, which is arranged on a first main side of the layer sequence and via which electrical current is conducted into or out of the layer sequence during operation Between the active layer and the lead-in element. The supply element is partly or fully covered by the active layer and the tunnel layer in plan view. A current flow is only possible between the supply element and the layer sequence by means of a tunneling effect. In the region of the feed element, at least two partial regions adjacent to each other in the lateral direction are formed,

0020In the light-emitting diode described here, among other things, the idea is made of utilizing the quantum mechanical tunneleffect in order to influence the intensity of a stream injected into a layer sequence locally. Via the supply element, for example, current below the layer sequence can be guided to an injection area without injection of the current into the layer sequence outside the injection area. This is achieved, for example, by the fact that the tunneling probability outside the injection region is selected by the tunneling layer. In the injection region, on the other hand, the tunnel probability is large, so that the layer sequence is energized there. In this case, the feed element can be used for an observer,

0021A brightness profile along a luminous surface of the light-emitting diode can also be implemented in a simple manner by means of the invention described here. Areas in which the tunnel probability is larger are lighter for an observer, areas where the tunnel probability is less or negligible appear darker to an observer or do not light up at all. The invention thus makes it possible, in a surface light source with an unstructured active layer, to display signatures such as patterns or characters. It is also possible to make the luminous surface appear pixellated or segmented without the active layer having to be structured, that is, to be provided with interruptions or breakthroughs.

0022The tunneling layer between the feed element and the layer sequence preferably also serves as a passivation or encapsulation and provides an improved tightness of the light-emitting diode against air and / or water.

0023According to at least one embodiment, the partial regions have a lateral extent along at least one main direction of the active layer of at least 10 μm or at least 20 μm or at least 50 μm. The area of ​​the subregions is, for example, at least 100 μm² Or 400 μm² Or 1000 μm². With such a size or area in the lateral direction, the subregions defined here differ from any random subregions caused by production tolerances with different tunnel probabilities.

0024According to at least one embodiment, a tunnel probability averaged over the entire area of ​​a first subarea is at most 95% or at most 80% or at most 70% or at most 50% or at most 10% of the tunneling probability averaged over an entire area of ​​the second subarea.

0025The current passing through the tunnel layer in a partial region depends both on the area of ​​the corresponding partial region as well as on the tunnel probability in the partial region. By adjusting the area and the tunnel probability, it is thus possible to control how bright or strong the active layer radiates in a current-supplied region. Furthermore, a difference in brightness between two partial regions can be varied by changing the applied voltage. This is due to the non-linearity of the tunneling probability through the tunneling layer and the non-linearity of the current-voltage characteristic of the layer sequence.

0026According to at least one embodiment, the light-emitting diode has a single tunnel layer and / or a single active layer. The tunnel layer and the active layer preferably overlap completely and differ, for example in their lateral extent, by at most 10% or 5%.

0027According to at least one embodiment, the active layer and / or the tunnel layer are simply designed to be cohesive. In particular, the active layer and / or the tunnel layer thus have no interruptions such as breakthroughs. The appearance of a segmented or structured luminous surface can thus be achieved without structuring the active layer or the tunnel layer. Through-feeds for energization are not necessary with the light-emitting diode described here. According to at least one embodiment, the supply element directly adjoins the tunnel layer, ie is in direct mechanical contact with the tunnel layer. The tunnel layer and the feed element preferably lie flat on one another.

0028According to at least one embodiment, the feed element has different materials adjoining the tunnel layer in the different subregions. As a result, the height of a tunnel barrier or potential barrier between the feed element and the tunnel layer in the different partial regions is different. For example, the boundary region between the tunnel layer and the feed element is formed over the whole area with a material in the first partial region and is formed over the whole area with another material in the second partial region.

0029The height of the tunnel barrier is determined, inter alia, by the difference between the exit work of the material of the tunnel layer and the material adjacent to the tunnel layer. Materials with low ejection steps, such as Al, In, Ca, Mo, K or alloys, are suitable for the materials adjacent to the tunneling layer in the second partial area. In the first partial area, materials with high discharge work can be bound to the tunnel layer, such as Au, Pt, Pd.

0030According to at least one embodiment, the tunnel layer has different thicknesses in the different partial regions. The thickness of a partial region is, for example, the thickness of the tunnel layer averaged over the entire area of ​​the partial region. The difference in the thickness of the tunnel layer in the different subregions, from which a perceptible brightness difference occurs in the different subregions, also depends on the material of the tunnel layer and the feed element. For example, the difference in the thickness of the tunnel layer is in the different subregionsAt least 0.5 nm or at least 1 nm or at least 2 nm.

0031According to at least one embodiment, the side of the tunnel layer facing away from the active layer is flat along its entire lateral extent within the manufacturing tolerance. "Level" here and in the following means that a surface or boundary surface is free of intentionally introduced steps or dislocations. However, steps and displacements may occur due to manufacturing tolerances.

0032According to at least one embodiment, the tunnel layer and / or the feed element have different structurings with peaks and / or edges within the different subregions. In operation, different electric field strengths then develop between the supply element and the layer sequence in the different partial regions. In the area of ​​peaks and edges, particularly high field strengths can form during operation, so that the tunnel probability is increased there. The tunnel probabilities in the sub-areas can be specifically influenced by the targeted introduction of structurings such as pyramidal elevations. The patterning can be effected, for example, by means of isotropic etching.

0033According to at least one embodiment, an electrically conductive contact element is arranged between the tunnel layer and the layer sequence in the region of the feed element. In top view, for example to the second main side of the layer sequence, the contact element overlaps with the second partial region of the feed element partially or completely. In particular, current, which is fed into the second partial region of the feed element through the tunnel layer, reaches at least partially or completely first into the contact element before it enters the layer sequence.

0034According to at least one embodiment, the contact element is in direct mechanical and electrical contact with the tunnel layer and / or the layer sequence. Via the contact element, current can thus be injected directly into the tunnel layer or into the layer sequence.

0035According to at least one embodiment, the contact element produces a lateral current distribution of the tunnel current which passes through the tunneling layer in the second partial region during operation.

0036According to at least one embodiment, the contact element has an identical material composition along the entire lateral extent. The contact element is designed, for example, in one piece and / or simply integrally. For example, the contact element comprises or consists of a metal such as Al, Ag, Au, Cu, Ti, Pt, Mg, or graphene. It is also possible for the contact element to be transparent, for example a transparent conductive oxide or consisting thereof.

0037According to at least one embodiment, the contact element has a constant thickness along its entire lateral extent and within the manufacturing tolerance even on a side facing the active layer.

0038According to at least one embodiment, the light-emitting diode has a plurality of supply elements. Each supply element can in this case be designed in accordance with the previously described supply element. In particular, the feed elements can be electrically insulated from one another in the lateral direction.

0039According to at least one embodiment, each of the supply elements is assigned one of the above-described contact elements in one-to-one fashion. In particular, this means that a tunnel current only occurs between the elements assigned to one another. Each contact element, viewed in top view, at least partially or completely overlaps with the second partial region of the associated feed element.

0040According to at least one embodiment, the different contact elements are spaced laterally from each other by electrically insulating regions. Preferably, no direct current flow takes place between two adjacent contact elements during operation. The gap between two adjacent contact elements can be formed, for example, by a cavity or by the tunnel layer.

0041According to at least one embodiment, each contact element defines the size of an image point of a pixellated luminous surface in plan view of the light-emitting diode. If, during operation, the layer sequence is energized via one of the contact elements, a light emission in the active layer only occurs directly in the immediate region directly above the contact element due to the preferably low lateral electrical conductivity within the layer sequence. The area or image point of the luminous surface, which appears luminous to an observer, then corresponds, in terms of its size and geometric shape, predominantly to the size and geometric shape of the contact element.

0042If, for example, a plurality of contact elements are arranged in a matrix-like manner on the first main side of the layer sequence, these contact elements can define a pixellated luminous surface of a display. The control of each contact element preferably takes place via the associated feed element.

0043According to at least one embodiment, the feed elements can be controlled individually or independently of one another for the activation or deactivation of the image points. For example, the feed elements can be energized via direct current or pulse width modulation.

0044According to at least one embodiment, a first partial region of a feed-through element crosses a contact element of another feed element in plan view, for example, as viewed on the second main side of the layer sequence. This means in particular that at least one lead element overlaps the top view with two contact elements. However, only the contact element which is also overlapping with the second partial region of the feed element is assigned to the feed element. The contact element, which only overlaps with the first partial region of the feed element, is, for example, one-sidedly assigned to another feed element.

0045According to at least one embodiment, the tunneling probability in the first partial region is at most 1% or at most 0.5% or at most 0.1% or at most 0.05% of the tunnel probability in the second partial region.

0046Preferably, in the first partial region, a current flow between the feed element and the contact element (s) arranged above the first partial region is minimally small. The tunnel current in the first subregion is thus preferably not sufficient to produce a luminaire visible for an observer in the active layer lying above it. This is also due to the non-linearity of the current-voltage characteristic of the layer sequence.

0047According to at least one embodiment, a contact element, which is arranged in a one-to-one relationship, is arranged above each partial region of a feed element. Thus, at least two contact elements are unambiguously assigned to each supply element. The current which flows through the different partial regions into the assigned contact elements can then be distributed in the lateral direction via the contact elements. The current intensity again depends on the tunnel probabilities in the subareas as well as on the area of ​​the subregions.

0048According to at least one embodiment, the contact elements of the different partial regions are likewise laterally spaced apart from one another by electrically insulating regions, for example by the tunnel layer. Therefore, no direct current flow takes place between the contact elements of the different partial regions.

0049According to at least one embodiment, the light-emitting diode has a single lead-in element which extends completely or almost completely along the entire lateral extension of the active layer. Preferably, the lead-in element covers, in plan view, at least 90% or 95% or 99% of the active layer of the layer sequence.

0050According to at least one embodiment, the tunnel layer directly adjoins the layer sequence so that when the light-emitting diode is energized, an observer perceives a patterned light-emitting surface in the region of the lead-in element due to the different current densities in the different partial regions. In this case, there is no lateral current distribution by means of contact elements. Only the size and area of ​​the subregions of the lead-in element or of the tunnel layer therefore determine the size and area of ​​the areas of the active layer that have different luminous intensities. This again is due to the low lateral conductivity within the layer sequence. For example, the surface resistance in the entire layer sequence is at least 100 Ω / □ or 1,000 Ω / □ or 10,000 Ω / □.

0051According to at least one embodiment, the side of the feed element facing and / or facing away from the tunnel layer is planar along the entire lateral extent within the manufacturing tolerance. For example, the feed element has a constant thickness along the entire lateral extent.

0052According to at least one embodiment, the tunnel layer is planar along its entire lateral extent on a side facing the layer sequence within the manufacturing tolerance.

0053According to at least one embodiment, the supply element has a plurality of electrically conductive material layers stacked one above the other. The various material layers have, for example, different materials or material compositions.

0054According to at least one embodiment, the number of material layers in the different partial regions is different, so that the side of the feed element facing the tunnel layer has a step in the transition region from aPart region into a directly adjacent partial region. In particular, in the different partial regions, therefore, different numbers of different material layers are removed or stacked one above the other. The height of the step between two adjacent partial regions then corresponds to the height or thickness of the material layers additionally removed or applied in the one partial region. The material layers may, for example, comprise one or more of the following materials: Al, Ag, Au, In, ITO, Pt. In particular, mixtures of transparent and non-transparent material layers are conceivable.

0055The thickness of the feed element is, for example, at least 50 nm or 100 nm or 150 nm. Alternatively or additionally, the thickness of the feed element is at most 400 nm or at most 300 nm or at most 200 nm.

0056According to at least one embodiment, the tunnel layer has a constant thickness within the scope of the manufacturing tolerance in the region of the entire feed element. If, for example, the lead-in element is formed on the side facing the layer sequence, the tunneling layer conforms to the steps of the lead-in element in a conformal or positive-locking manner.

0057Moreover, a method for producing a light-emitting diode is given. The method is particularly suitable for producing a light-emitting diode described here. That is, all the features disclosed in connection with the light-emitting diode are also disclosed for the method and vice versa.

0058According to at least one embodiment, the method for producing a light-emitting diode comprises a step A) in which a substrate is provided. The substrate can be transparent or intransparent, flexible or rigid and / or in the form of a film. The substrate may be, for example, a glass substrate, a plastic substrate, a ceramic substrate, a metal substrate or a semiconductor substrate. In particular, the substrate is self-supporting and suitable for applying or growing further layers.

0059In a subsequent step B) at least one lead-in element is arranged on the substrate. The supply element can, for example, be vaporized or sputtered. A structuring of the feed element can take place via etching, a shadow mask process or ablation.

0060In a further step C), a tunneling layer is arranged on the substrate. For example, the tunneling layer and the substrate then at least partially enclose the lead-in element. The application of the tunneling layer can be carried out, for example, by atomic layer deposition, for short ALD, or physical or chemical vapor deposition, for short, PVD or CVD. It is also possible to apply the tunnel layer by vapor deposition or a screen printing template and a printing process. Furthermore, the tunnel layer can also be produced by oxidation, such as anodic oxidation, of the feed element.

0061In a further step D), a layer sequence with an active layer emitting active radiation is formed on the substrate. If, for example, the layer sequence is an organic layer sequence, it can be applied in solution, the solvent subsequently being evaporated. An inorganic layer sequence with an active layer can be effected, for example, by embracing a substrate from the growth substrate. After the layer sequence has been applied, the tunnel layer and the feed element are preferably arranged between the substrate and the layer sequence.

0062In the steps B) and / or C), the feed element and / or the tunnel layer is selectively structured in the region of the feed element in such a way that at least two subregions lying side by side in the lateral direction are produced in which the tunnel layer and / or the feed element are designed in a different manner. As a result, during tunneling the tunnel probabilities are different in the different partial regions.

0063According to at least one embodiment, the steps A) to D) are carried out in the sequence indicated and in separate process steps. Alternatively, however, steps D), C) and B) can also be carried out in this order. The lead-in element and the tunnel layer are then formed on a side of the layer sequence facing away from the substrate.

0064According to at least one embodiment, a contact element is applied to the tunnel layer or the layer sequence so that the contact element is arranged in the finished light-emitting diode between the tunnel layer and the layer sequence. The contact element can be applied or patterned by means of lithography, printing, microablation, a masking process.

0065According to at least one embodiment, a plurality of different material layers are layered one over the other in the area of ​​the feed element in step B). Subsequently, in the differentA plurality of material layers are removed so that, in the different partial regions, the uppermost layers of the feed element viewed from the substrate have different material compositions. In this way, the feed element receives a side which is deliberately provided with steps and faces the layer sequence. Alternatively, however, the different material layers can also be patterned in superimposition, so that later selective removal is no longer necessary.

0066According to at least one embodiment, the partial regions are selectively coated with different material layers in step B). The material layers preferably have the same thickness within the production tolerance. After coating in the different partial regions, the uppermost layers viewed from the substrate have different material compositions in the partial regions. In this case, the feed element is preferably flat on a side remote from the substrate along its entire lateral extent. The material layers are thus arranged laterally side by side and not one above the other. This can be done by printing, lifting or structured disposition.

0067According to at least one embodiment, the tunnel layer is applied by means of a screen printing template. The screen printing template preferably has partial regions in which the size and / or the density of perforations in the screen printing template are different. If, for example, the material of the tunnel layer is pressed by means of a pressure squeegee through the screen printing template, different transmission rates of the material of the tunnel layer occur in the different subregions of the printing template. In this way, for example, the thickness of the tunnel layer produced in the different subregions of the screen printing template is of a different magnitude when the contact pressure is the same.

0068A light-emitting diode described here, as well as a method for producing a light-emitting diode described here, will be explained in more detail below with reference to drawings by means of exemplary embodiments. Identical reference symbols indicate the same elements in the individual figures. However, there are not shown any scale references here; rather, individual elements can be shown in an exaggerated manner for an exaggerated understanding.

0069Show it:

0070<figref>1A</figref> to <figref>2C</figref>, <figref>4A</figref> to <figref>4D</figref>, <figref>9A</figref> to <figref>9F</figref>, <figref>11A</figref> to <figref>11E</figref> Various exemplary embodiments of light-emitting diodes in side view and top view,

0071<figref>3</figref> An organic light-emitting diode from the prior art,

0072<figref>5A</figref> and <figref>5B</figref> Various exemplary embodiments of a supply element of a light-emitting diode described here,

0073<figref>5A</figref> to <figref>8F</figref> Various positions in exemplary embodiments of methods for producing lead elements of a light-emitting diode described here,

0074<figref>10A</figref> and <figref>10B</figref> Various positions in exemplary embodiments for producing a light-emitting diode,

0075<figref>12A</figref> and <figref>12B</figref> Tables with numerical examples on different tunnel layers.

0076In the embodiment of FIG <figref>1A</figref> Is a light-emitting diode <figref>100</figref> In a side cross-sectional view. The light-emitting diode<figref>100</figref> Comprises a substrate <figref>7</figref> On which a plurality of feed elements <figref>3</figref> Is arranged laterally next to one another. The substrate<figref>7</figref> Is, for example, a glass substrate or plastic substrate. The feed elements<figref>3</figref> Are parallel to a main direction of the substrate in the lateral direction <figref>7</figref> From each other. Each feed element<figref>3</figref> Has two subregions arranged next to one another <figref>31</figref>, <figref>32</figref> on. The thickness of the lead elements<figref>3</figref> Is constant along the entire lateral direction. In the different subareas<figref>31</figref>, <figref>32</figref> Of the feed elements <figref>3</figref> Have the feed elements <figref>3</figref> Different material compositions. For example, the first section is<figref>31</figref> Of Au or In, the second subregion <figref>32</figref> Is formed, for example, from Al.

0077On the feed elements <figref>3</figref> Is a tunnel layer <figref>2</figref> Directly applied. The tunnel layer<figref>2</figref> In this case also filling spaces between adjacent feed elements <figref>3</figref> And isolates the lead elements <figref>3</figref> Electrically from each other. The tunnel layer<figref>2</figref> Is in the region of the feed elements <figref>3</figref> With a thickness of, for example, at least 2 nm and at most 20 nm. At the tunnel layer<figref>2</figref> It is, for example, an electrically insulating layer, such as an Al₂O₃-Layer. The tunnel layer<figref>2</figref> Is designed to be simply cohesive along its entire lateral extent, ie, it does not have any openings in the vertical direction perpendicular to the lateral direction.

0078On the tunnel layer <figref>2</figref> Is in <figref>1A</figref> A plurality of contact members <figref>4</figref> directly Respectively. The contacts<figref>4</figref> Are not in direct contact with the feed elements <figref>3</figref>, But are through the tunnel layer <figref>2</figref> From the feed elements <figref>3</figref> In the vertical direction, perpendicular to the lateral direction. Current, or charge carriers carried by a contact element<figref>4</figref> Into a feed element <figref>3</figref> Or the other way round, always have the tunnel layer <figref>2</figref> Cross. The contacts<figref>4</figref> Are preferably electrically conductive and consist, for example, of a metal or a TCO.

0079In the embodiment of FIG <figref>1A</figref> Is to each feed element <figref>3</figref> A contact element <figref>4</figref> Unambiguously assigned and vertically above the corresponding supply element <figref>3</figref> Respectively. The contacts<figref>4</figref> Are arranged one below the other in the lateral direction, so that there is no direct current flow between two adjacent contact elements <figref>4</figref> is possible. On the contacts<figref>4</figref> And the tunnel layer <figref>2</figref> Is a layer sequence <figref>1</figref> With an active layer emitting active radiation <figref>10</figref> Directly applied. With the layer sequence<figref>1</figref> It is, for example, an organic layer sequence, the active layer comprises, for example, organic emitter molecules. However, an inorganic layer sequence is also possible. The layer sequence<figref>1</figref> Has a first main page <figref>11</figref> And one of the first main page <figref>11</figref> Opposite second main page <figref>12</figref> , Wherein the contact elements <figref>4</figref>, The tunnel layer <figref>2</figref> And the feed elements <figref>3</figref> On the first main page <figref>11</figref> Are arranged.

0080In the embodiment of FIG <figref>1A</figref> Are the tunnel layer <figref>2</figref>, The active layer <figref>10</figref> The feed elements <figref>3</figref> And the contact elements <figref>4</figref> In each case simply connected together. In particular, the active layer<figref>10</figref> No vias or breakthroughs.

0081On the second main page <figref>12</figref> Of the layer sequence <figref>1</figref> Is a second, simply contiguous contact layer <figref>5</figref> Which has an electrical counter-contact or a counter-electrode to the contact elements <figref>4</figref> Or the feed elements <figref>3</figref> . In the present example, the second contact layer is<figref>5</figref> For example, from a transparent material, such as a TCO. The second contact layer covers the entire active layer<figref>10</figref> And / or all the feed elements <figref>3</figref>.

0082On the second contact layer <figref>5</figref> Is a thin film encapsulation <figref>6</figref> Applied to the layer sequence <figref>1</figref> Encapsulated and protected against external influences. The light-emitting diode<figref>100</figref> of the <figref>1A</figref> Is designed as a so-called top emitter. The contacts<figref>4</figref>, The feed elements <figref>3</figref> And / or the substrate <figref>7</figref> Can in this case be reflective of one of the active layer <figref>10</figref> Emitted electromagnetic radiation. The electromagnetic radiation is transmitted to the substrate<figref>7</figref> Remote luminous surface <figref>13</figref> Of the light-emitting diode <figref>100</figref> From the light-emitting diode <figref>100</figref> Coupled.

0083In the embodiment of FIG <figref>1B</figref> Is the light-emitting diode <figref>100</figref> of the <figref>1A</figref> In top view of the luminous surface <figref>13</figref> shown. The substrate can be seen<figref>7</figref>, On which the layer sequence <figref>1</figref> is trained. Below the layer sequence<figref>1</figref> Are the feed elements <figref>3</figref> , Each of which is partially associated with the layer sequence <figref>1</figref> Overlap A respective contact area of ​​the feed elements<figref>3</figref> Protrudes in the lateral direction from the layer sequence <figref>1</figref> out. The contact regions are for the electrical contacting of the feed elements<figref>3</figref> educated.

0084Also, the contacts are <figref>4</figref> As dashed elements in the <figref>1B</figref> Made visible. Each contact element<figref>4</figref> In this case partially overlaps with a feed element which is assigned to it in a one-to-one fashion <figref>3</figref>. In particular, each contact element overlaps<figref>4</figref> Completely the second subregion <figref>32</figref> Of the associated feed element <figref>3</figref>. Moreover, in the<figref>1B</figref> That some of the feed elements <figref>3</figref> In the first section <figref>31</figref> With two contact elements <figref>4</figref> Overlap

0085In the exemplary embodiments of FIGS <figref>1A</figref> and <figref>1B</figref> Is a tunneling probability from the feed element <figref>3</figref> Through the tunnel layer <figref>2</figref> Into the associated contact element <figref>4</figref> In the first section <figref>31</figref> For example at most 1% of the tunnel probability in the second sub-range <figref>32</figref>. Correspondingly, flows in the first subregion<figref>31</figref> In operation almost no current from the feed element <figref>3</figref> In the contact element <figref>4</figref>. Only in the second part<figref>32</figref> There is a significant current flow from the supply element <figref>3</figref> In the contact element <figref>4</figref>. Inside the contact element<figref>4</figref> The current can then be distributed in the lateral direction during operation and into the layer sequence <figref>1</figref> Can be injected. Due to a low lateral electrical conductivity in the layer sequence<figref>1</figref> It occurs only in one immediately above the contact element <figref>4</figref> Area of ​​the active layer <figref>10</figref> To significant radiation generation. The contacts<figref>4</figref> In operation, the size of a luminous pixel or pixel of the light-emitting diode <figref>100</figref> define.

0086In the embodiment of FIG <figref>1B</figref> Can advantageously be provided in the interior of the housing, by means of further contact elements <figref>4</figref> Surrounded contact elements <figref>4</figref> Can be energized in a simple manner. The internal contact element<figref>4</figref> Assigned feed element <figref>3</figref> Overlapped in top view with a contact element which is not assigned to it <figref>4</figref>. Since this overlap but only in the first part<figref>31</figref> The supply element is energized <figref>3</figref> This contact element <figref>4</figref> Not.

0087The embodiment of FIG <figref>1C</figref> Essentially corresponds to the exemplary embodiment of the invention <figref>1A</figref>. In contrast to the<figref>1A</figref> Are now the contact elements <figref>4</figref>, The feed elements <figref>3</figref> And the substrate <figref>7</figref> Transparent. The second contact layer<figref>5</figref> Is formed from a reflective material such as Al or Ag. Radiation in the active layer<figref>10</figref> Of the layer sequence <figref>1</figref> Is generated, the light-emitting diode exits <figref>100</figref> In operation then over the substrate <figref>7</figref>. It is the light-emitting diode<figref>100</figref> A so-called bottom emitter.

0088In the embodiment of FIG <figref>1D</figref> Is, in contrast to the exemplary embodiment of FIG <figref>1C</figref> Now also the second contact layer <figref>5</figref> Transparent. In this case, the light-emitting diode<figref>100</figref> Two opposite luminous surfaces <figref>13</figref> , Via which electromagnetic radiation is coupled out during operation. It is the light-emitting diode<figref>100</figref> A so-called top-bottom emitter.

0089In the embodiment of FIG <figref>1E</figref> Are the contact elements <figref>4</figref>, The tunnel layer <figref>2</figref> And the feed elements <figref>3</figref> On the first main page <figref>11</figref> Of the layer sequence <figref>1</figref> The substrate <figref>7</figref> Is on the second main page <figref>12</figref> Of the layer sequence <figref>1</figref> educated. The second contact layer<figref>5</figref> Is in this case between substrate <figref>7</figref> And layer sequence <figref>1</figref> appropriate. The light-emitting diode<figref>100</figref> of the <figref>1E</figref> Is again designed as a bottom emitter, ie, the substrate <figref>7</figref> And the second contact layer <figref>5</figref> Are transparent, the contact elements <figref>4</figref> Are designed to be reflective, for example. The functional principle of the light-emitting diode<figref>100</figref> of the <figref>1E</figref> Corresponds to the functional principle of the light-emitting diodes of the preceding exemplary embodiments. In the embodiment of FIG<figref>1F</figref> Is a light-emitting diode <figref>100</figref> , In which both on the first main page <figref>11</figref> As well as on the second main page <figref>12</figref> Of the layer sequence <figref>1</figref> Supply elements <figref>3</figref>, A tunnel layer <figref>2</figref> And the feed elements <figref>3</figref> Unambiguously associated contact elements <figref>4</figref> Are applied. In contrast to the previous exemplary embodiments, therefore, there is no simply coherent, extending over the entire extent of the layer sequence<figref>1</figref> Extending second contact layer <figref>5</figref> available.

0090In the embodiment of FIG <figref>2A</figref> to <figref>2C</figref> Is a light-emitting diode <figref>100</figref> In top view of the luminous surface <figref>13</figref> shown. In<figref>2A</figref> Is one of the luminous area <figref>13</figref> Generated light image. The light image comprises a circle and two concentric rings around the circle. In total, there are therefore three different image areas or image points. The image areas should have different brightness during operation. This is in<figref>2A</figref> By the varying shades of the image areas.

0091In <figref>2 B</figref> It is shown how the different energization and different brightness of the three image areas is realized. For demonstration purposes, the layer sequence is used<figref>1</figref> away. Only the supply elements can be seen<figref>3</figref> As well as the contact elements <figref>4</figref>. The contacts<figref>4</figref> Have the desired shape and size of the image regions. In particular, the contact elements<figref>4</figref> Ie as a circle and two concentric rings, which are spaced apart from one another in the lateral direction and electrically insulated from each other. Into each contact element<figref>4</figref> A feed line element which is assigned one-to-one is protruded <figref>3</figref> , Wherein the contact element <figref>4</figref> With the second subregion <figref>32</figref> Of the associated feed element <figref>3</figref> Completely overlapped. Only in the second part<figref>32</figref> The tunneling probability is sufficiently high so that there is a significant current flow between the feed element <figref>3</figref> And the associated contact element <figref>4</figref> Comes In this way, each contact element can be<figref>4</figref> Or each associated image region independently of the further contact elements <figref>4</figref> Via the feed elements <figref>3</figref> To be controlled.

0092The product of the supplied current density into the supply elements <figref>3</figref> And area of ​​the subregions <figref>32</figref> Determines how much current is in the associated contact elements <figref>4</figref> Respectively. The larger this current and the smaller the area of ​​the contact element<figref>4</figref> The brighter the illuminated image area illuminates during operation.

0093In the embodiment of FIG <figref>2 B</figref> The outer luminous surface, ie, the outer concentric ring, has the largest area, the inner circular image area has the smallest area. Correspondingly, the inner image area shines brightest during operation.

0094In the exemplary embodiment of the following <figref>2C</figref> Are merely the substrate <figref>7</figref> And the supply elements applied thereto <figref>3</figref> shown. The contacts<figref>4</figref> And the tunnel layer <figref>2</figref> Are removed.

0095In <figref>3</figref> Is a light-emitting diode <figref>100</figref> From the prior art. Unlike the light-emitting diode described in this invention<figref>100</figref> The light emitting diode <figref>3</figref> No supply elements <figref>3</figref> Or contact elements <figref>4</figref> on. Rather is on the first main page<figref>11</figref> Of the layer sequence <figref>1</figref> A planar first contact layer <figref>50</figref> And on the second main page <figref>12</figref> Of the layer sequence <figref>1</figref> A planar second contact layer <figref>5</figref> Respectively. The second contact layer<figref>5</figref> Is at the side faces of the layer sequence <figref>1</figref> On the substrate <figref>7</figref> And is electrically conductively connected there to a contact area. The contact layer is also the same<figref>50</figref> In the lateral direction from the layer sequence <figref>1</figref> And is electrically conductively connected to a contact area. For electrical insulation between the firstContact layer <figref>50</figref> And second contact layer <figref>5</figref> Is at the side faces of the layer sequence <figref>1</figref> An insulating layer <figref>9</figref> Respectively.

0096In the embodiment of FIG <figref>4A</figref> A top emitter is again shown, in which the luminous surface <figref>13</figref> On a substrate <figref>7</figref> Opposite side of the light-emitting diode <figref>100</figref> is trained. Unlike in the exemplary embodiments of the<figref>1A</figref> to <figref>2C</figref> The light-emitting diode <figref>100</figref> Now a single, simply integrally formed feed element <figref>3</figref> Which extends almost along the entire lateral extent of the layer sequence <figref>1</figref> Respectively. The feed element<figref>3</figref> Has laterally adjacent partial regions <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> With different tunnel probabilities through the tunnel layer <figref>2</figref> on. The tunnel layer<figref>2</figref> In the exemplary embodiment of the invention <figref>4A</figref> Directly to the layer sequence <figref>1</figref>, An additional contact element <figref>4</figref> Is not used.

0097The different subareas <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> Of the feed element <figref>3</figref> Have, for example, differently to the tunnel layer <figref>2</figref> Bordering materials, so that the tunnel barriers and thus the tunnel probabilities are different. In this way, the different subregions are obtained<figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> Different current or different current densities into the overlying layer sequence <figref>1</figref>, Which is why the active layer <figref>10</figref> In the different subareas <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> Radiation. For an observer, the illuminated surface is lit.<figref>13</figref> Of the light-emitting diode <figref>100</figref> In operation then in the different subareas <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> Differently strong, which is indicated by the differently thick arrows in the <figref>4A</figref> .

0098The embodiment of FIG <figref>4B</figref> Essentially corresponds to the exemplary embodiment of the invention <figref>4A</figref>, Except that the second contact layer <figref>5</figref> Reflective and the light-emitting diode <figref>100</figref> Is operated as a bottom emitter.

0099In the <figref>4C</figref> Is the second contact layer <figref>5</figref> As well as the feed element <figref>3</figref> Transparent. The light-emitting diode<figref>100</figref> Is operated as a top-bottom emitter.

0100In the embodiment of FIG <figref>4D</figref> Are, as in the embodiment of FIG <figref>4C</figref> The second contact layer <figref>5</figref> And the substrate <figref>7</figref> Transparent. The feed element<figref>3</figref> Is in some areas <figref>31</figref>, <figref>33</figref> Transparent, in other areas <figref>32</figref>, <figref>34</figref> Reflective. The resulting luminescence image is therefore dependent on whether the observer is on the substrate<figref>7</figref> Or to the second contact layer <figref>5</figref> Looks

0101In the <figref>5A</figref> and <figref>5B</figref> Are two different exemplary embodiments of a feed element used here <figref>3</figref> shown. In the<figref>5A</figref> Is the feed element <figref>3</figref> With a thickness constant within the manufacturing tolerance along the entire lateral extent of the feed element <figref>3</figref> educated. The subareas<figref>31</figref>, <figref>32</figref> Are formed by two adjoining material layers of different materials.

0102On the other hand, <figref>5B</figref> The feed element <figref>3</figref> From three superimposed material layers <figref>301</figref>, <figref>302</figref>, <figref>303</figref> educated. In some areas is the third material layer<figref>303</figref> Removed, in other areas is both the third material layer <figref>303</figref> As well as the second material layer <figref>302</figref> away. This forms steps within the feed element<figref>3</figref>. Depending on which material layer is exposed and thus directly to the tunnel layer<figref>2</figref> , The tunnel probability is different. In this way, different subregions<figref>31</figref>, <figref>32</figref>, <figref>33</figref> With different tunnel probabilities.

0103In the <figref>6A</figref> to <figref>6F</figref> Are various positions in the manufacture of an exemplary embodiment of a feed element <figref>3</figref> For a light-emitting diode <figref>100</figref> Respectively.

0104In the <figref>6A</figref> A carrier is first provided. In the following<figref>6B</figref> Are four material layers <figref>301</figref>, <figref>302</figref>, <figref>303</figref>, <figref>304</figref> Of different materials or material compositions are stacked over one another over the entire surface.

0105<figref>6C</figref> Shows a position in which the fourth material layer, which is furthest apart from the carrier <figref>304</figref> Is partially removed and there is the third material layer <figref>303</figref> Is released.

0106In a further step, illustrated in FIG <figref>6D</figref>, Is also the third material layer <figref>303</figref> Partially removed so that the second material <figref>302</figref> Is partially released.

0107In the <figref>6E</figref> Are additionally trenches in the second material layer <figref>302</figref> So that a feed element <figref>3</figref> With three partial regions spaced laterally from each other <figref>31</figref>, <figref>32</figref>, <figref>33</figref> As well. In the first section<figref>31</figref> Is an outer side of the feed element remote from the carrier <figref>3</figref> By the fourth material layer <figref>304</figref> In the second partial region <figref>32</figref> Through the second material layer <figref>302</figref> And in the third subregion <figref>33</figref> By the third material layer <figref>303</figref>.

0108Subsequently, in <figref>6F</figref> A simply contiguous tunnel layer <figref>2</figref> Over the whole area and directly to the sub-areas <figref>31</figref>, <figref>32</figref>, <figref>33</figref> Respectively. The tunnel layer<figref>2</figref> Has in all areas <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> A constant average thickness. TheTunnel probability through the tunnel layer <figref>2</figref> Is thus only through the tunnel layer <figref>2</figref> Bordering material of the material layers <figref>302</figref>, <figref>303</figref>, <figref>304</figref> certainly.

0109In the embodiment of FIG <figref>7A</figref> to <figref>7F</figref> Are positions in an alternative method for producing an exemplary embodiment of a feed element <figref>3</figref> For a light-emitting diode <figref>100</figref> Respectively. In this case,<figref>7A</figref> A carrier is provided on which in <figref>7B</figref> A first material layer <figref>301</figref> Is applied. On the first material layer<figref>301</figref> Becomes a structured second material layer <figref>302</figref> (<figref>7C</figref>). In<figref>7D</figref> Is on some areas of the second material layer <figref>302</figref> A third material layer <figref>303</figref> Respectively.

0110In <figref>7E</figref> Is finally still on a field of the third material layer <figref>303</figref> A fourth material layer <figref>304</figref> So that a total of three subareas <figref>31</figref>, <figref>32</figref>, <figref>33</figref> In which the uppermost layer of material which is most striking from the carrier has in each case different materials. The application of the material layers is therefore additive, for example by printing or selective disposition.

0111In <figref>7F</figref> Are the subarea <figref>31</figref>, <figref>32</figref>, <figref>33</figref> Again with a tunnel layer <figref>2</figref> overdrawn.

0112In the <figref>8A</figref> to <figref>8F</figref> Are different positions in a further alternative method for producing an exemplary embodiment of a feed element <figref>3</figref> For a light-emitting diode <figref>100</figref> Respectively.

0113For this purpose, <figref>8A</figref> Again provided a carrier to which in the <figref>8B</figref> to <figref>8E</figref> Successively material layers <figref>301</figref>, <figref>302</figref>, <figref>303</figref>, <figref>304</figref> Laterally adjacent to each other. The material layers<figref>301</figref>, <figref>302</figref>, <figref>303</figref>, <figref>304</figref> Have in each case the same thickness within the production tolerance, so that the resulting feed element <figref>3</figref> Along the entire lateral extent, a constant thickness within the manufacturing tolerance.

0114In the <figref>8F</figref> A position is shown in which the lead-in element <figref>3</figref> A single layer of tunneling <figref>2</figref> Is applied.

0115In the embodiment of FIG <figref>9A</figref> Is a light-emitting diode <figref>100</figref> Shown as the light-emitting diode <figref>100</figref> of the <figref>4B</figref> Is formed as a bottom emitter. In contrast to the<figref>4B</figref> The tunneling probability is through the tunnel layer <figref>2</figref> in <figref>9A</figref> But not by a variation of the material of the feed element <figref>3</figref> In the lateral direction. Rather, the feed element<figref>3</figref> in the <figref>9A</figref> Along its entire lateral extent with the same material composition. For this purpose,<figref>9A</figref> The thickness of the tunnel layer <figref>2</figref> Along the lateral extent, so that in each subregion <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> The tunnel layer <figref>2</figref> Has a different thickness. Due to the different thicknesses, tunnel tunnels are subject to different tunnel probabilities<figref>2</figref>. In this way, again, that is through the tunnel layer<figref>2</figref> In the layer sequence <figref>1</figref> And thus the emitted brightness in the different partial regions <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> differently.

0116In <figref>9B</figref> Is essentially the same embodiment as in FIG <figref>9A</figref> Respectively. In the embodiment of FIG<figref>9B</figref> Is however the feed element <figref>3</figref> Reflective, the second contact layer <figref>5</figref> But radiolucent. In<figref>9B</figref> Is the light-emitting diode <figref>100</figref> As a top emitter.

0117In <figref>9C</figref> Is the light-emitting diode <figref>100</figref> As a top-bottom emitter with a transparent feed element <figref>3</figref> And a transparent contact layer <figref>5</figref> educated.

0118In the embodiment of FIG <figref>9D</figref> Are the tunnel layer <figref>2</figref> And the feed element <figref>3</figref> On a substrate <figref>7</figref> Opposite side of the layer sequence <figref>1</figref> educated. However, the functional principle still corresponds to that of the light-emitting diodes<figref>100</figref> of the <figref>9A</figref> to <figref>9C</figref>. In the embodiment of FIG<figref>9E</figref> Is essentially the same light-emitting diode <figref>100</figref> as in <figref>9A</figref> shown. In addition, however, is between the tunnel layer<figref>2</figref> And the layer sequence <figref>1</figref> In each section <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> A corresponding subregion <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> One-way contact element <figref>4</figref> Respectively. The contacts<figref>4</figref> Are in direct contact with the layer sequence <figref>1</figref> And the tunnel layer <figref>2</figref>. The individual contact elements<figref>4</figref> Cover the assigned subarea <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> In plan view, but do not project laterally over the respective subregion <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> Out. In particular, the contact elements<figref>4</figref> Are electrically insulated from each other, so that between the contact elements <figref>4</figref> No direct electric current flow is possible. The contacts<figref>4</figref> Care within the divisions <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> For a lateral current distribution and thus for a more homogeneous luminance within the subregions <figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref>.

0119In the embodiment of FIG <figref>9F</figref> Is an embodiment of a light-emitting diode <figref>100</figref> In top view. For example, the light-emitting diode is<figref>100</figref> In order to provide a light - emitting diode with the functional principle of one of the light - emitting diodes <figref>9A</figref> to <figref>9E</figref>. Through partial areas<figref>31</figref>, <figref>32</figref>, <figref>33</figref>, <figref>34</figref> With the different tunnel probabilities can be a luminous surface <figref>13</figref> With a lettering. In the embodiment of FIG<figref>9F</figref> The lettering "OLED" is brighter than the corresponding background.

0120In the <figref>10A</figref> to <figref>10B</figref> Are positions in process steps for producing a tunneling layer <figref>2</figref> With different thicknesses in different subregions <figref>31</figref>, <figref>32</figref> shown.

0121In <figref>10A</figref> Is a substrate <figref>7</figref> With a feed element arranged thereon <figref>3</figref> shown. Over the feed element<figref>3</figref> Is also a screen printing stencil <figref>8th</figref> With two areas <figref>81</figref>, <figref>82</figref> Respectively. In the different areas<figref>81</figref>, <figref>82</figref> The screen printing template has perforations <figref>80</figref> With different sizes and densities. In the first section<figref>81</figref> Is the density of the breakthroughs <figref>80</figref> As well as the lateral extent of the breakthroughs <figref>80</figref> Smaller than in the second range <figref>82</figref>. Is now the tunnel layer material<figref>2</figref> With the aid of a pressure squeegee through the screen printing stencil <figref>8th</figref> Pressed, the <figref>10B</figref> Illustrated tunnel layer <figref>2</figref> With two subareas <figref>31</figref>, <figref>32</figref>, In which the thickness of the tunnel layer <figref>2</figref> Is different. Size and geometric shape of the subareas<figref>31</figref>, <figref>32</figref> Correspond to the size and geometric shape of the areas <figref>81</figref>, <figref>82</figref> The screen printing stencil <figref>8th</figref>.

0122In the <figref>11A</figref> to <figref>11E</figref> Are further exemplary embodiments of a light-emitting diode <figref>100</figref> In page view.

0123The embodiment of FIG <figref>11A</figref> Essentially corresponds to the exemplary embodiment of the invention <figref>9A</figref>. Other than in<figref>9A</figref> Is in <figref>11A</figref> But not the thickness of the tunnel layer <figref>2</figref> But rather is in the different subareas <figref>31</figref>, <figref>32</figref> The tunnel layer <figref>2</figref> With different structures. In the first section<figref>31</figref> The tunnel layer <figref>2</figref> No intentionally introduced structuring, while in the second subrange <figref>32</figref> Intends pyramidal elevations in the tunnel layer <figref>2</figref> Are introduced. In the area of ​​the peaks and valleys of the pyramids, higher field strengths are generated in the tunnel layer during operation<figref>2</figref>, Reflecting the tunneling probability through the tunnel layer <figref>2</figref> elevated. Therefore it is in operation in the second sub-range<figref>32</figref> To a stronger radiation emission than in the first partial area <figref>31</figref>.

0124In <figref>11A</figref> Forms the first subregion <figref>31</figref> A peripheral region or an outer region of the tunnel layer in the lateral direction <figref>2</figref>. Since in the unstructured first partial region<figref>31</figref> The tunnel layer <figref>2</figref> Thick, can be so an additional protection of the light-emitting diode <figref>100</figref> Before external influences.

0125In <figref>11A</figref> Is the feed element <figref>3</figref> Remote side of the tunnel layer <figref>2</figref> Are provided with the structuring which corresponds to the feed element <figref>3</figref> Facing side of the tunnel layer <figref>2</figref> Is flat along the entire lateral extension within the manufacturing tolerance. In addition, is on the textured side of the tunnel layer<figref>2</figref> In the region of the structuring in each case one contact element <figref>4</figref> Which reproduces the structuring. Through the contact element<figref>4</figref> A more uniform current distribution occurs along the second partial region <figref>32</figref>. The on the tunnel layer<figref>2</figref> Applied layer sequence <figref>1</figref> Forms the structuring of the tunnel layer <figref>2</figref> Or the contact elements <figref>4</figref> Positively.

0126In the embodiment of FIG <figref>11B</figref> Is in contrast to <figref>11A</figref> The tunnel layer <figref>2</figref> As well as the feed element <figref>3</figref> On a substrate <figref>7</figref> Opposite side of the layer sequence <figref>1</figref> Respectively. In addition, a plurality of laterally spaced supply elements are provided<figref>3</figref> On the tunnel layer <figref>2</figref> Respectively. Each of these feed elements<figref>3</figref> Is thereby individually and independently of the other feed elements <figref>3</figref> Electrically controllable. Each feed element<figref>3</figref> Includes, as in the context of: <figref>11A</figref> Described first subarea <figref>31</figref> And a second subregion <figref>32</figref> With structuring. Between the layer sequence<figref>1</figref> And the tunnel layer <figref>2</figref> Are also contact elements <figref>4</figref> Arranged to the supply elements <figref>3</figref> Are unambiguously assigned. In this way, as in connection with<figref>1A</figref> and <figref>1B</figref> A pixellated display can be implemented.

0127In the embodiment of FIG <figref>11C</figref> Are the contact elements <figref>4</figref>, The feed elements <figref>3</figref> As well as the tunnel layer <figref>2</figref> of the <figref>11B</figref> Back to the substrate <figref>7</figref> Facing side of the layer sequence <figref>1</figref> placed. This is the structuring of the tunnel layer<figref>2</figref> Again on one of the layers <figref>1</figref> Facing side. Structuring within the tunnel layer<figref>2</figref> Are completely of the contact elements <figref>4</figref> Filled, so that of the layer sequence <figref>1</figref> Facing sides of the contact elements <figref>4</figref> Are. Advantageously, the layer sequence can then be used<figref>1</figref> Along the entire lateral extent of constant thickness.

0128The embodiment of FIG <figref>11D</figref> Essentially corresponds to the exemplary embodiment of the invention <figref>11A</figref>. Only on the contact elements<figref>4</figref> Between layers <figref>1</figref> And tunnel layer <figref>2</figref> Is in <figref>11D</figref> .

0129In the embodiment of FIG <figref>11E</figref> Is a light-emitting diode <figref>100</figref> In which the tunnel layer <figref>2</figref> With different structurings. In the second<figref>32</figref> And third sub-range <figref>33</figref> The pyramidal elevations have different heights but almost the same widths. The tips of the pyramidal elevations are therefore in the different subareas<figref>32</figref>, <figref>33</figref> Differently pointed, as a result of which differently strong electric fields form in the tips. In the subareas<figref>32</figref>, <figref>33</figref> There are therefore different tunneling currents during operation. This is also influenced by the different density of pyramidal elevations.

0130In the table of the <figref>12A</figref> Different examples of tunneling probabilities are given by a tunneling layer. The first column contains different materials (<figref>3</figref>) For the feed element <figref>3</figref> Listed. In the second column the material (<figref>2</figref>) Of the tunnel layer <figref>2</figref>, Which is produced by atomic layer deposition. In the third column are different thicknesses (d) of the tunnel layer<figref>2</figref> In nanometers. In the fourth column, current densities (j) measured for a particular voltage are through the tunnel layer<figref>2</figref> In mA / cm² Respectively. In the fifth and sixth columns are possible surfaces (A) of the feed element<figref>3</figref> In cm² And the resulting current (I) through the tunnel layer <figref>2</figref> In mA. In the seventh and eighth column are the discharge work (ΔW) of the material of the feed element<figref>3</figref> And the potential barrier (ΔΦ) to the tunnel layer <figref>2</figref> Respectively.

0131As the table of the <figref>12A</figref> Is the tunneling probability and thus the current density for a feed element <figref>3</figref> Of Al is greater than for Au or In. In addition, the table shows that the current density increases as the thickness of the tunnel layer increases<figref>2</figref> Decreases. In the table of the<figref>12B</figref> Is a more detailed study of the current density or the current as a function of the thickness of the tunnel layer <figref>2</figref> Respectively. As material of the feed element<figref>3</figref> Is chosen here Al. The thickness of the tunnel layer<figref>2</figref> Is varied by about 1% steps. The resulting current density and an area of ​​20 cm² Flowing current decrease with increasing thickness of the tunnel layer <figref>2</figref> from. The resulting current or the resulting current density changes by only 1% per cent by a mere 4%.

0132Tunnel layers <figref>2</figref> For example, by oxidation of the associated feed element <figref>3</figref> Can be produced very accurately with respect to their thickness. In fact, tunneling layers<figref>2</figref> By oxidation to Angström. During slow oxidation, for example, a 10 nm tunneling layer is grown in about 10 hours. Layer thickness of the tunnel layer<figref>2</figref> Can thus be kept constant up to less than 1% deviation.

0133From the table of the <figref>12B</figref> It can be seen that such small variations in the thickness of the tunnel layer have only a small influence on the current density through the tunnel layer <figref>2</figref> to have.

0134The invention is not limited by the description by means of the exemplary embodiments. Rather, the invention encompasses any new feature as well as any combination of features, including, in particular, any combination of features of the claims, even though these features or combination are not explicitly stated in the patent claims or embodiments.

Reference list

<dl><dt>1</dt><dd> Layer sequence</dd><dt>2</dt><dd> Tunnel layer</dd><dt>3</dt><dd> Supply element</dd><dt>4</dt><dd> Contact element</dd><dt>5</dt><dd> Second contact layer</dd><dt>6</dt><dd> Thin film encapsulation</dd><dt>7</dt><dd> Substrate</dd><dt>8th</dt><dd> Screen printing template</dd><dt>9</dt><dd> Insulation layer</dd><dt>10</dt><dd> Active layer</dd><dt>11</dt><dd> First main page</dd><dt>12</dt><dd> Second main page</dd><dt>13</dt><dd> Light area</dd><dt>31</dt><dd> First part</dd><dt>32</dt><dd> Second subarea</dd><dt>33</dt><dd> Third part</dd><dt>34</dt><dd> Fourth section</dd><dt>80</dt><dd> Breakthrough in the screen printing stencil <figref>8th</figref></dd><dt>81</dt><dd> First partial area of ​​the screen printing stencil <figref>8th</figref></dd><dt>82</dt><dd> Second partial area of ​​the screen printing stencil <figref>8th</figref></dd><dt>100</dt><dd> led</dd><dt>301</dt><dd> First material layer</dd><dt>302</dt><dd> Second material layer</dd><dt>303</dt><dd> Third material layer</dd><dt>304</dt><dd> Fourth material layer</dd></dl>