Organic light-emitting device and method for manufacturing an organic light-emitting device

Abstract

Organic light-emitting device (100) comprising: - a substrate (1), - a first electrode (2) arranged above the substrate (1), - an electrical contact (3) arranged next to the first electrode (2) and serving to contact a second electrode (6), - at least one organic functional layer stack (5) configured to emit radiation, wherein the organic functional layer stack (5) is arranged at least above the first electrode (2) and at least partially above the electrical contact (3), - wherein the second electrode (6) is arranged above the organic functional layer stack (5), - wherein a current path (4) is formed between the second electrode (6) and the electrical contact (3) within the organic functional layer stack (5), - wherein the side walls of the current path (4) are metallically formed.- wherein the current path (4) is formed and filled with the material of the second electrode (6) on the side surfaces and throughout its entire diameter,- wherein the organic functional layer stack (5) is arranged between the first electrode (2) and the electrical contact (3), and- wherein the organic functional layer stack (5) completely covers the electrical contact (3).

Description

[0001] The invention relates to an organic light-emitting component. Furthermore, the invention relates to a method for producing an organic light-emitting component.

[0002] Organic light-emitting devices, such as organic light-emitting diodes (OLEDs), typically feature a cathode as a second electrode, which is directly and mechanically connected to an electrical contact. The cathode is positioned, at least in some areas, above the organic functional layer stack and connected to an electrical contact, such as metal traces, located alongside the organic functional layer stack. In other words, the second electrode and the electrical contact are usually directly and mechanically connected. This necessitates a structured application of the organic functional layer stack.

[0003] One challenge to be solved is to overcome the aforementioned disadvantages. Another challenge is to provide an organic light-emitting device that is faster, easier, and / or more cost-effective to manufacture.

[0004] This problem or these problems are solved by an organic light-emitting component according to independent claim 1. Advantageous embodiments and further developments of the invention are the subject of dependent claims. Furthermore, this problem or these problems are solved by a method for producing an organic light-emitting component according to claim 9. Advantageous embodiments and further developments of the method are the subject of dependent claims 10 to 15.

[0005] In at least one embodiment, the organic light-emitting device comprises a substrate. The device has a first electrode arranged above the substrate. The device has an electrical contact. The electrical contact is arranged next to the first electrode. In particular, the electrical contact is spaced laterally from the first electrode. The electrical contact is configured for, or serves to contact, a second electrode. The device comprises at least one stack of organic functional layers. The stack of organic functional layers is configured for the emission of radiation. The stack of organic functional layers is arranged at least above the first electrode. In addition, the stack of organic functional layers is arranged at least partially above the electrical contact. The device has a second electrode, which is arranged above the stack of organic functional layers.

[0006] According to at least one embodiment, the organic light-emitting component is designed as an organic light-emitting diode (OLED).

[0007] According to at least one embodiment, the organic light-emitting component comprises a substrate. The substrate can, for example, comprise one or more materials in the form of a layer, a plate, a film, or a laminate, selected from glass, quartz, plastic, metal, silicon wafer, ceramic, or coated paper. Particularly preferably, the substrate comprises or is made of glass, for example, in the form of a glass layer, glass film, or glass plate.

[0008] According to at least one embodiment, the organic light-emitting component has a first and a second electrode. In particular, at least one electrode can be transparent. Here and in the following, "transparent" refers to a layer that is permeable to visible light. The transparent layer can be clearly translucent or at least partially light-scattering and / or partially light-absorbing, so that the transparent layer can, for example, also be diffusely or milkily translucent. A layer referred to here as transparent is particularly preferably as light-transmitting as possible, so that, in particular, the absorption of light generated in the organic functional layer stack during operation of the organic light-emitting component is as low as possible.

[0009] Alternatively, both electrodes can be transparent. This allows the light generated in the at least one organic functional layer stack to be emitted in both directions, i.e., through both electrodes. If the organic light-emitting device has a substrate, this means that light can be emitted both through the substrate, which is then also transparent, and in the direction away from the substrate. Furthermore, in this case, all layers of the organic light-emitting device can be transparent, so that the organic light-emitting device forms a transparent OLED.Furthermore, it is also possible that one of the two electrodes between which the organic functional layer stack is arranged is non-transparent and preferably reflective, so that the light generated between the two electrodes can only be emitted in one direction through the transparent electrode. If the electrode located on the substrate is transparent and the substrate is also transparent, it is referred to as a bottom emitter, while if the electrode facing away from the substrate is transparent, it is referred to as a top emitter.

[0010] For example, a transparent conductive oxide (TCO Transparent Conductive Oxide), such as ITO, can be used as a material for a transparent electrode.

[0011] Transparent electrically conductive oxides (TCOs) are transparent, electrically conductive materials, typically metal oxides such as zinc oxide, tin oxide, cadmium oxide, titanium oxide, indium oxide, indium tin oxide (ITO), or aluminum zinc oxide (AZO). In addition to binary metal-oxygen compounds such as ZnO, SnO₂, or In₂O₃, ternary metal-oxygen compounds such as Zn₂SnO₄, CdSnO₃, ZnSnO₃, MgIn₂O₄, GaInO₃, Zn₂In₂O₅, or In₄Sn₃O₄ also belong to this group. 12 or mixtures of different transparent, conductive oxides belong to the group of TCOs. Furthermore, TCOs do not necessarily have a stoichiometric composition and can also be p- or n-doped.

[0012] Furthermore, a transparent electrode can also have a metal layer made of a metal or alloy, for example, one or more of the following materials: silver, platinum, gold, magnesium, or an alloy of silver and magnesium. Other metals are also possible. The metal layer is so thin that it is at least partially transparent to the light generated by the organic functional layer stack, for example, a thickness of less than or equal to 50 nm.

[0013] A reflective electrode can be made from a metal such as aluminum, barium, indium, silver, gold, magnesium, calcium, or lithium, as well as compounds, combinations, and alloys thereof. In particular, a reflective electrode can consist of silver, aluminum, or alloys containing these metals, for example, Ag:Mg, Ag:Ca, or Mg:Al.

[0014] In particular, the electrodes can be nanostructured electrodes, for example silver nanowires, or made of graphene.

[0015] In particular, the first electrode can be configured as the anode, in which case the second electrode is configured as the cathode. Alternatively, the first electrode can be configured as the cathode, in which case the second electrode is configured as the anode.

[0016] The electrodes can also consist of a combination of at least one or more TCO layers and at least one or more metal layers.

[0017] According to at least one embodiment, at least one organic functional layer stack is arranged above the first electrode and / or the substrate. The fact that a layer or stack is arranged or applied "on" or "over" another layer or stack can mean, here and in the following, that one layer or stack is in direct mechanical and / or electrical contact with the other layer. It can also mean that one layer is arranged indirectly on or over the other layer. In this case, further layers can be arranged between the two layers.

[0018] According to at least one embodiment, the organic light-emitting device comprises at least one organic functional layer stack. In particular, the organic light-emitting device comprises exactly one organic functional layer stack. During operation of the organic light-emitting device, radiation is generated in the organic functional layer stack. A wavelength of the radiation or the wavelength maximum is preferably located in the infrared and / or ultraviolet and / or visible spectral range, particularly at wavelengths between and including 420 nm and 680 nm.

[0019] The organic functional layer stack can comprise layers of organic polymers, organic oligomers, organic monomers, small organic nonpolymeric molecules, or combinations thereof. The organic functional layer stack can additionally include further functional layers configured as hole transport layers to enable effective hole injection into the at least one organic functional layer stack. Suitable materials for a hole transport layer include, for example, tertiary amines, carbazole derivatives, camphorsulfonic acid-doped polyaniline, or polystyrenesulfonic acid-doped polyethylene dioxide thiophene. The organic functional layer stack can further comprise at least one functional layer configured as an electron transport layer.In general, the organic functional layer stack can include additional layers selected from hole injection layers, hole transport layers, electron injection layers, electron transport layers, hole blocking layers, and electron blocking layers. In particular, the layers of the organic functional layer stack can be entirely or predominantly organic functional layers. Furthermore, it is also possible for individual layers of the organic functional layer stack to include or be composed of inorganic materials.

[0020] According to at least one embodiment, the organic light-emitting component has at least one conductive current expansion structure.

[0021] According to at least one embodiment, the component has an electrical contact. The electrical contact is arranged next to the first electrode. Preferably, the electrical contact is arranged at a laterally spaced distance from the first electrode. In particular, the organic functional layer stack is arranged between the electrical contact and the first electrode. The electrical contact serves to connect the second electrode. Preferably, the electrical contact is an electrical conductor structure arranged on the substrate and serves to indirectly connect the second electrode.

[0022] The electrical contact can be a conductive glass, a conductive ceramic and / or a highly doped semiconductor or a metal.

[0023] According to at least one embodiment, the electrical contact consists of a metal. Alternatively, the electrical contact can also have a layered structure. For example, the electrical contact can have three layers made of two or three different metals. In particular, the electrical contact has a layered structure of chromium-aluminum-chromium, molybdenum-aluminum-molybdenum, or titanium-aluminum-titanium.

[0024] According to at least one embodiment, the electrical contact comprises at least one metal or an alloy of at least two metals. In particular, the metal or alloy of the electrical contact is selected from the group consisting of silver, aluminum, molybdenum, chromium, copper, magnesium, or an alloy of molybdenum-aluminum, chromium-aluminum, silver-magnesium, and combinations thereof. The electrical contact is particularly preferably formed from silver and / or aluminum.

[0025] According to at least one embodiment, the organic functional layer stack is configured as an insulating layer and arranged between the first and second electrodes. In other words, the component described here prevents a short circuit between the first and second electrodes by means of the organic functional layer stack. Preferably, the organic functional layer stack extends over the electrical contact. The electrical contact and the second electrode are then electrically connected to each other via a so-called current path.

[0026] According to at least one embodiment, the organic functional layer stack is arranged between the first electrode and the electrical contact. Preferably, the first electrode and the electronic contact are laterally spaced apart from each other in a side view within the same plane.

[0027] According to at least one embodiment, the organic functional layer stack at least partially or completely covers the electrical contact. Alternatively or additionally, if the electrical contact is partially covered by the organic functional layer stack, the electrical contact has uncovered areas. These uncovered areas can serve for external power supply.

[0028] According to at least one embodiment, a current path or a plurality of current paths are formed between the second electrode and the electrical contact within the organic functional layer stack.

[0029] The current path can be created using a laser. Alternatively, the current path can also be produced by plasma etching or with mechanical micro-drills.

[0030] According to at least one embodiment, the laser has a wavelength in the infrared range. Preferably, the laser has a wavelength of 1064 nm with a tolerance range of 10%, 5%, 3%, 1%, or 0.5% of this value. Current paths with an average diameter of 10.2 ± 10% µm can be generated.

[0031] According to at least one embodiment, the current path is a microvia. Microvias are defined here and in the following as small holes arranged between the electrical contact and the second electrode. The microvias electrically connect the electrical contact and the second electrode. A microvia is defined by a hole diameter of < 200 µm, preferably < 50 µm, for example between 5 and 15 µm, for example 10 µm. The microvia serves to contact the second electrode. The microvia is created, for example, using a laser. In this process, the vapor-deposited second electrode is melted. The molten material, in particular the molten metal of the second electrode, penetrates the underlying organic functional layer stack and thus establishes a local electrical connection. The sidewalls of the current paths or the microvias are preferably metallic.In particular, the current path is formed and filled with the material of the second electrode across the entire diameter of both the side surfaces.

[0032] The inventors recognized that advantageous properties of the organic light-emitting device could be achieved if the second electrode was not directly contacted by an electrical contact, but rather if both elements were electrically connected via a current path through the organic functional layer stack. The organic light-emitting device can be manufactured easily because no masking process is required for the application of the organic functional layer stack.

[0033] The connection of the second electrode indirectly to the electrical contact, preferably to a contactable conductor surface, preferably occurs only after the second electrode has been applied. This is preferably achieved by means of an additional mask-free, locally applied conductor structure. In other words, the contacting of the second electrode, which is preferably the top electrode, is achieved through the organic functional layer stack by means of local post-treatment. This post-treatment can be carried out using a laser.

[0034] This allows for an electrical connection between the second electrode and the substrate in organic light-emitting devices with an unstructured organic functional layer stack. Furthermore, multiple organic light-emitting devices can be fabricated, for example, in a wafer bundle and subsequently contacted in various ways. Here, the device is contacted via a current path, in particular a microvia, between the second electrode and the substrate or the electrical contact. This results in local processing without mass deposition, for example, using microvias. This also allows for the deposition of unstructured organic functional layer stacks.

[0035] The invention further relates to a method for producing an organic light-emitting component. Preferably, the component described herein is produced using the method described herein. The same definitions and descriptions as above for the organic light-emitting component also apply to the method and vice versa.

[0036] According to at least one embodiment, the method comprises the following process steps: A) Providing a substrate, B) Applying a first electrode, additionally applying an electrical contact that is located adjacent to the first electrode and is positioned on the substrate, C) full-surface application of the organic functional layer stack to the first electrode and the electrical contact, D) Applying the second electrode, E) Restructuring at least the organic functional layer stack in the area of ​​the electrical contact, so that an area of ​​the electrical contact is created which serves for external current injection, F) Generating a current path between the second electrode and the electrical contact in the organic functional layer stack.

[0037] According to at least one embodiment, step C) involves the application of the organic functional layer stack to the entire surface of the first electrode. In other words, the organic functional layer stack is applied to both the first electrode and the electrical contact across its entire surface. Subsequently, the second electrode can be applied as described in step D), or the organic functional layer stack can be restructured as described in step E). In other words, step D) can be performed first, followed by step E). Alternatively, step E) can be performed first, followed by step D). Restructuring can be carried out by dry etching.

[0038] According to at least one embodiment, step D) is performed in a structured manner. The second electrode is therefore not applied to the entire surface of the organic functional layer stack, but rather, for example, in a structured manner using a mask. In particular, at least a partial area above the electrical contact is free of the second electrode. Preferably, the area of ​​the electrical contact that is not covered by the organic functional layer stack is free of the second electrode. The second electrode can be vapor-deposited.

[0039] According to at least one embodiment, the current path is generated by means of a laser. The current path extends from the second electrode to the electrical contact and creates an electrical connection between the two elements.

[0040] Preferably, the laser has a wavelength in the IR range.

[0041] According to at least one embodiment, the laser has a wavelength of 1064 nm with a tolerance of 10% of this value.

[0042] According to at least one embodiment, the current path is configured as a microvia. Additionally or alternatively, the current path has a diameter or average diameter of 10 µm in plan view, with a tolerance of 10%, 5%, 3%, 2%, or 1% of this value.

[0043] According to at least one embodiment, the current path is generated by melting the second electrode. For example, a laser is used to melt the second electrode, which is deposited onto the stack of organic functional layers. Preferably, the second electrode is the cathode. The molten material of the second electrode, preferably a metal, penetrates the underlying stack of organic functional layers. This creates a current path that establishes a local electrical connection between the second electrode and the electrical contact.

[0044] Further advantages, advantageous embodiments and further developments result from the exemplary embodiments described below in conjunction with the figures.

[0045] They show: Fig. 1 a schematic side view of an organic light-emitting component according to one embodiment, Fig. 2A to Fig. 2F a method for producing an organic light-emitting component according to one embodiment.

[0046] In the exemplary embodiments and figures, identical, similar, or similarly functioning elements may be designated with the same reference numerals. The depicted elements and their relative sizes are not to be considered to scale. Rather, individual elements such as layers, components, building elements, and areas may be exaggerated for clarity and / or better understanding.

[0047] The Fig. Figure 1 shows a schematic representation of an organic light-emitting component. 100 according to one embodiment. The organic light-emitting component 100 is here configured as an organic light-emitting diode (OLED). The component 100 a substrate 1on. The substrate 1 It could be made of glass, for example. On the substrate 1 can a first electrode 2 , for example, the anode, should be applied laterally to the first electrode. 2 An electrical contact can be spaced apart. 3 be arranged. The electrical contact 3 It can, for example, be made of an alloy of aluminum and chromium. The electrical contact 3 used to contact the second electrode 6 Above the first electrode 2 is an organic functional layer stack 5 arranged. The organic functional layer stack 5 is designed to emit radiation. The organic functional layer stack 5 This does not only extend over the first electrode. 2 , but additionally, at least in some areas, via the electrical contact 3Alternatively, the organic functional layer stack can be 5 also completely over the electrical contact 3 extend. Should the organic functional layer stack 5 via the electrical contact 3 to extend completely, the organic functional layer stack can 5 Restructuring can also occur in areas above the electrical contact. This can be done, for example, using a mask. On the organic functional layer stack 5 is the second electrode 6 arranged. The electrical contact 3 and the second electrode 6 are over at least one power path 4 , here using the example of two current paths 4 shown, electrically connected. The current path 4is preferably formed as a microvia. In comparison to conventional components, the organic functional layer stack is therefore more extensive. 5 not only via the first electrode 2 , but also via electrical contact 3 The organic functional layer stack 5 Here, it acts as a so-called insulating layer between the first and second electrodes. The second electrode 6 and the electrical contact 3 are not directly electrically or mechanically connected to each other, but rather between the electrical contact 3 and the second electrode 6 is the organic functional layer stack 5 arranged within which the electric current path 4 is or will be produced.

[0048] The Fig. 2A to Fig. Figure 2F discloses a method for manufacturing an organic light-emitting device according to one embodiment. Fig. 2A shows the provision of a substrate 1 , which is formed from glass, for example. On the substrate 1 will be, as in Fig. 2B shown, the first electrode 2 Applied laterally and / or next to the first electrode. 2 An electrical contact is made 3 applied. The electrical contact serves to connect the second electrode. 6 Above the first electrode 2 and the electrical contact 3 An organic functional layer stack 5 is applied. Preferably, the organic functional layer stack is applied 5 entire surface ( Fig. 2C). Therefore, both the first electrode 2 as well as the electrical contact 3 completely from the organic functional layer stack5 covered. Then the second electrode can be inserted. 6 , in particular directly and / or in a structured manner, are applied, followed by the organic functional layer stack 5 be restructured (dashed lines of the Fig. 2D).

[0049] In other words, areas of the electrical contact will then be affected. 3 uncovered again, which can later be used for external power supply ( Fig. 2D). Restructuring the organic functional layer stack 5 This can be done, for example, by etching. Applying the second electrode 6 This can be done by deposition in a vacuum. The second electrode 6 and the electrical contact 3 are, as in Fig. 2E are shown, not electrically connected. Therefore, there is no direct electrical contact between them. Subsequently, treatment can be used. 8, for example by means of a laser, at least one current path 4 between the second electrode 6 and the electrical contact 3 in the organic functional layer stack 5 can be generated. The second electrode can be created using a laser. 6 The second electrode is irradiated, thus melting the metal. The molten metal can then penetrate the underlying stacks of organic functional layers. 5 penetrate and thus create a local electrical connection between the second electrode 6 and generate the electrical contact 3. The one not from the organic functional layer stack 5 The covered area of ​​electrical contact 3 can serve for external power supply. For example, the electrical contact can be connected by means of a bond wire.

[0050] According to at least one embodiment, the organic functional layer stack 5 without a mask, i.e., maskless, isolated.

[0051] According to at least one embodiment, the second electrode 6 structured, for example by means of a mask, separated.

[0052] The advantage of this method is that the organic light-emitting component 100 first it can be fully manufactured and then, in the so-called backend process, the contacting between the second electrode takes place. 6 and the electrical contact 3 can be generated.

[0053] The embodiments and their features described in connection with the figures can also be combined with one another according to further embodiments, even if such combinations are not explicitly shown in the figures. Furthermore, the embodiments described in connection with the figures can have additional or alternative features as described in the general section.

[0054] The invention is not limited to the description provided by means of the exemplary embodiments. Rather, the invention encompasses every new feature as well as every combination of features, which in particular includes every combination of features in the claims, even if that feature or combination itself is not explicitly stated in the claims or exemplary embodiments. Reference symbol list 100 organic light-emitting components 1 substrate 2 first electrode 3 electrical contacts 4 Current path 5 organic functional layer stacks 6 second electrode 7 Area of ​​the electrical contact 8 Treatment

Claims

[1] comprising organic light-emitting device (100) - a substrate (1), - a first electrode (2) which is arranged above the substrate (1), - an electrical contact (3) which is arranged next to the first electrode (2) and serves to contact a second electrode (6), - at least one organic functional layer stack (5) configured to emit radiation, wherein the organic functional layer stack (5) is arranged at least over the first electrode (2) and at least partially over the electrical contact (3), - wherein the second electrode (6) is arranged above the organic functional layer stack (5). [2] Organic light-emitting device (100) according to claim 1, wherein the organic functional layer stack (5) is arranged as an insulating layer between the first and second electrode (2, 6). [3] Organic light-emitting device (100) according to one of the preceding claims, wherein the organic functional layer stack (5) is arranged between the first electrode (2) and the electrical contact (3). [4] Organic light-emitting device (100) according to one of the preceding claims, wherein the organic functional layer stack (5) partially covers the electrical contact (3) and the uncovered area of ​​the electrical contact (3) serves for external current supply. [5] Organic light-emitting device (100) according to one of the preceding claims, wherein a current path (4) is formed between the second electrode (6) and the electrical contact (3) within the organic functional layer stack (5). [6] Organic light emitting device (100) according to one of the preceding claims, wherein the current path (4) is generated by means of a laser. [7] Organic light emitting device (100) according to one of the preceding claims, wherein the laser has a wavelength from the IR range. [8] Organic light-emitting device (100) according to any one of the preceding claims, wherein the current path (4) is a microvia. [9] Method for producing an organic light-emitting device (100) according to any one of claims 1 to 8 comprising the steps: A) Providing a substrate (1), B) Applying a first electrode (2) and an electrical contact (3) adjacent to the first electrode to the substrate (1), C) full-surface application of the organic functional layer stack (5) to the first electrode (2) and the electrical contact (3), D) Applying the second electrode (6), E) Restructuring at least the organic functional layer stack (5) in the area of ​​the electrical contact (3) so that an area of ​​the electrical contact (7) is created which serves for external current supply, F) Generating a current path (4) between the second electrode (6) and the electrical contact (3) in the organic functional layer stack (5). [10] Method according to claim 9, wherein step D) is carried out in a structured manner. [11] Method according to claim 9 or 10, wherein the current path (4) is generated by means of a laser. [12] Method according to claim 11, wherein the laser has a wavelength from the IR range. [13] Method according to claim 12, wherein the laser has a wavelength of 1064 nm with a tolerance of 10%. [14] Method according to claims 9 to 13, wherein the current path (4) is at least one microvia having a diameter of 10 µm with a tolerance of 10%. [15] Method according to claims 9 to 14, wherein the current path (4) is generated by melting the second electrode (6).

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