Method for Producing a Light-Emitting Device, and Light-Emitting Device

Abstract

A method for producing a light-emitting device and light-emitting device are disclosed. In an embodiment the method includes providing a carrier layer comprising a substrate, applying a first electrode layer, applying a layer sequence for generating light, applying a second electrode layer and structuring at least one layer for varying an optical thickness in a first region of the light-emitting device differently from the layer in a second region of the light-emitting device, wherein the second region is laterally arranged relative to the first region.

Claims

1-20. (canceled)

21. A method for producing a light-emitting device having at least two laterally arranged regions of differing optical thicknesses, the method comprising: providing a carrier layer comprising a substrate; applying a first electrode layer; applying a layer sequence for generating light; applying a second electrode layer; and structuring at least one layer for varying an optical thickness in a first region of the light-emitting device differently from the layer in a second region of the light-emitting device, wherein the second region is laterally arranged relative to the first region.

22. The method according to claim 21, further comprising inserting an interlayer, extending laterally over the first region, into the layer sequence for varying the optical thickness of the first region.

23. The method according to claim 21, wherein a thickness in a vertical direction of at least one layer in the first region is constructed differently from a thickness in a vertical direction of the layer in the second region.

24. The method according to claim 23, wherein a growth rate of the layer in the first region is different from a growth rate of the layer in the second region.

25. The method according to claim 21, further comprising applying an auxiliary layer to a side of the light-emitting device facing away from the carrier layer, wherein the auxiliary layer comprises a substrate.

26. The method according to claim 21, wherein a first microcavity structure for varying the optical thickness in the first region is constructed on a surface of the substrate in the first region.

27. The method according to claim 21, wherein a second microcavity structure for varying the optical thickness in the first region is constructed inside the substrate in the first region.

28. A light-emitting device having at least two laterally arranged regions of differing optical thicknesses, the light-emitting device comprising: a carrier layer comprising a substrate; a first electrode layer; a layer sequence for generating light; and a second electrode layer; wherein the carrier layer, the first electrode layer, the layer sequence, and the second electrode layer are arranged one above the other in a vertical direction, wherein an optical thickness of at least one layer in a first region of the light-emitting device is constructed differently from an optical thickness of the layer in a second region of the light-emitting device that is laterally arranged relative to the first region.

29. The light-emitting device according to claim 28, wherein the layer sequence comprises an interlayer, and wherein the interlayer extends laterally over the first region.

30. The light-emitting device according to claim 28, wherein a thickness in a vertical direction of at least one layer in the first region is constructed differently from a thickness in a vertical direction of the layer of the second region.

31. The light-emitting device according to claim 28, further comprising an auxiliary layer having a substrate, wherein the auxiliary layer is arranged on a side of the light-emitting device facing away from the carrier layer.

32. The light-emitting device according to claim 28, wherein a surface of the substrate in the first region has a first microcavity structure unlike a surface of the substrate in the second region.

33. The light-emitting device according to claim 28, wherein the substrate in the first region has a second microcavity structure unlike the substrate in the second region.

34. The light-emitting device according to claim 28, wherein the light-emitting device is configured to differ in: a brightness of light emitted by the light-emitting device; and/or a color of light emitted by the light-emitting device; and/or a direction of light emitted by the light-emitting device in the regions of the different optical thicknesses.

35. The light-emitting device according to claim 28, wherein the light-emitting device is configured to differ in: a brightness of light reflected by the light-emitting device; and/or a color of light reflected by the light-emitting device; and/or a direction of light reflected by the light-emitting device in the regions of the different optical thicknesses.

36. The light-emitting device according to claim 28, wherein a number of regions of the differing optical thicknesses amounts to less than 100.

37. The light-emitting device according to claim 28, wherein a color of light emitted by the light-emitting device is the same, in at least one direction, in each of the regions of the differing optical thicknesses.

38. The light-emitting device according to claim 28, wherein a composition of at least one of the layers in the regions of the different optical thicknesses is the same.

39. The light-emitting device according to claim 28, wherein the light-emitting device comprises at least two laterally arranged segments that are operable separately from one another.

40. The light-emitting device according to claim 39, wherein at least one region is assigned to at least one segment.

41. A method for producing a light-emitting device having at least two laterally arranged regions of differing optical thicknesses, the method comprising: providing a carrier layer comprising a substrate; applying a first electrode layer; applying a layer sequence for generating light; applying a second electrode layer; and structuring at least one layer for varying an optical thickness in a first region of the light-emitting device differently from the layer in a second region of the light-emitting device, wherein the second region is laterally arranged relative to the first region, wherein an interlayer extends laterally over the first region for varying the optical thickness in the first region, and wherein the interlayer is a transparent metal layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Further features, embodiments and expedient aspects will become apparent from the ensuing description of the exemplary embodiments in conjunction with the drawings.

[0051] FIG. 1 shows a first exemplary embodiment of a light-emitting device in a schematic plan view;

[0052] FIG. 2 shows the light-emitting device of FIG. 1 in a schematic sectional view; and

[0053] FIG. 3 shows a second exemplary embodiment of a light-emitting device in a schematic sectional view.

[0054] Identical, similar or identically acting elements are provided in the drawings with the same reference numerals. The drawings and the relative sizes of the elements shown in the drawings compared to one another should not be seen as being to scale. In fact, individual elements and in particular layer thicknesses may be shown exaggeratedly large for better illustration and/or better comprehension.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0055] A first exemplary embodiment of a light-emitting device 1 is shown in schematic plan view in FIG. 1. The light-emitting device 1 comprises two segments 1a, 1b that can be operated separately from one another and that are arranged laterally adjacent to one another. In operation of one of the two segments 1a, 1b, the picture of an arrow, for instance, appears for an observer.

[0056] As shown in the schematic sectional view of FIG. 2, the light-emitting device 1 has a carrier layer 2, which comprises a substrate 3. The carrier layer 2 forms a bottom face of the light-emitting device 1, through which the light generated by the light-emitting device 1 (a so-called bottom emitter) exits. The carrier layer 2 in this context is constructed as transparent. The substrate 3 is a glass substrate, for example.

[0057] The light-emitting device 1, on a side of the carrier layer 2 facing away from the bottom face, has a first electrode layer 5a, a layer sequence 7 for generating light, and a second electrode layer 9. The first electrode layer 5a is subdivided into two separate electrodes (not shown in further detail here) for separate operation of the segments 1a, 1b.

[0058] The electrode layers 5a, 9 have a conductive oxide, metal, or metal oxide, for example, such as aluminum, silver or indium tin oxide. The electrodes 9, 11 form a cathode and anode for electrical contacting of the light-emitting device 1.

[0059] The first electrode layer 5a is constructed as transparent in particular. For example, the first electrode layer 5a in this context is constructed of indium tin oxide (ITO). In other exemplary embodiments, the first electrode layer 5a is for instance thin metal layers, metal net structures, or graphene.

[0060] The light-emitting device 1 for instance also comprises electrical contact feeders 21, which can be constructed as transparent or nontransparent. For example, the electrical contact feeders and/or the second electrode layer 9 has or consists of one of the following materials: molybdenum/aluminum (Mo/Al), molybdenum (Mo), chromium/aluminum/chromium (Cr/Al/Cr), silver/magnesium (Ag/Mg), aluminum (Al).

[0061] The layer sequence 7 comprises semi-organic semiconductor material, in particular organic layers for emitting light that contain an emitter material, and for supplying charge carriers. The light-emitting device 1 is in particular an organic light-emitting diode chip with an active region provided for generating light (for the sake of simplification of illustration, this is not explicitly shown in the drawings).

[0062] In this exemplary embodiment, the light-emitting device 1 further comprises insulator layers 23, arranged in the vertical direction between the two electrode layers 5a, 9. The insulator layers 23 are constructed of polyimide, for example. In other exemplary embodiments, the insulator layers 23 can be dispensed with, for instance in suitable masking processes.

[0063] The light-emitting device 1 in this exemplary embodiment furthermore has a coating 25. The coating 25 is, for example, a thin-film coating (TFE). Alternatively, the coating can be constructed as a so-called cavity encapsulation, for instance by means of SiNOx and ATO.

[0064] The light-emitting device 1 further has an auxiliary layer 4, which, for example, likewise comprises a substrate 3. The auxiliary layer 4 is arranged on a side of the light-emitting device 1 facing away from the bottom face and, for example, forms a top face of the light-emitting device 1. The auxiliary layer 4 comprises an adhesive 27, for example.

[0065] The light-emitting device 1 of FIG. 2 is in an off state, for example, in which at least the segment 1a is not in operation. The light-emitting device 1 is constructed such that for an observer in the off state, the result is the appearance of a color, for example, of the segment 1a, the segment 1b, or an entire light exit face of the light-emitting device 1, depending on the viewing direction. For example, light in a first direction 31, for example, the vertical direction, appears yellow to the observer. Light in a second direction 33, for instance the lateral direction, appears blue to the observer. The second direction 33 can, in a deviation from this, form an angle of approximately 80 with the first direction 31, for example. For example, light in a further direction 35, between the first direction and the second direction 31, 33, can assume an arbitrary further color, for example, green, depending on an observation angle.

[0066] For that purpose, at least one layer 3, 5a, 7, 9 of the light-emitting device 1 has structuring for varying an optical thickness of the light-emitting device 1, as will be explained hereinafter in conjunction with FIG. 3.

[0067] FIG. 3 shows a second exemplary embodiment of a light-emitting device 1 in a schematic sectional view. The second exemplary embodiment represents various possibilities for the aforementioned structuring, which can be constructed both individually and in combination in a light-emitting device, for instance as shown in FIG. 1. For example, in this context, four laterally arranged regions 11a, 11b, 11c, 11d of differing optical thickness are shown, each with a possible form of the structuring. In particular, it would be conceivable for the possibilities shown to be combined in the vertical direction as well.

[0068] For varying the optical thickness, the light-emitting device 1 in the first region 11a has an interlayer 13, which extends laterally over the first region 11a. The interlayer 13 is arranged in particular in the layer sequence 7 and is surrounded in the vertical direction by material of the layer sequence 7. It is possible for the same emitter material to be used in the layer sequence 7 in each of the regions 11a, 11b, 11c, 11d of differing optical thickness. The interlayer is in particular a transparent metal layer, which can be vapor deposited, for instance. The interlayer 13 is constructed of aluminum, for instance, the thickness of which amounts to 2 nm, for example, in the vertical direction. The interlayer 13 has the effect for instance that the color angle course described in conjunction with FIG. 2 results for the observer when the light-emitting device 1 is in the off state. For example, additionally or alternatively, the interlayer 13 can engender a change in color or brightness.

[0069] The first region 11a, for example, has one shape. For instance, the first region can for that purpose assume the shape of the segment is (see FIG. 1). In particular, the first region 11a can be assigned to the segment 1a, so that the image of the arrow can be perceived by an observer, for instance both in operation of the light-emitting device 1 and in an off state of the light-emitting device 1. In this context, a region assigned to the segment 1b has an emission characteristic different from the first region 11a. In particular, for this purpose, the layer sequence 7 for varying the optical thickness in the region assigned to the segment 1b is constructed differently from the layer sequence 7 in the laterally adjacent first region 11a.

[0070] For varying the optical thickness, a first electrode layer 5b of the light-emitting device 1, in the second region 11b, has a thickness in the vertical direction that differs from the thickness in the vertical direction of the first electrode layer 5a in the first region 11a. In particular, the first electrode layer 5b, differing in thickness in the vertical direction, extends laterally over the second region 11b. This has the effect that travel paths passing through the respective first electrode layer 5a, 5b differ in the regions 11a, 11b. Advantageously, the result, for instance depending on a wavelength of the light, is constructive and/or destructive interferences, which leads to what for the observer is a different perceptible color and/or brightness in the respective regions 11a, 11b. This effect can for instance occur independently of an operating state of the light-emitting device 1.

[0071] In other exemplary embodiments, alternatively or in addition, a thickness in the vertical direction of the layer sequence 7 can differ in the respective regions 11a, 11b. It is furthermore conceivable that alternatively or in addition, a thickness in the vertical direction of the second electrode layer 9 differs in the respective regions 11a, 11b. In this case, the light-emitting device 1 is then, for example, a so-called top emitter or a so-called transparent OLED.

[0072] The differing thickness in the vertical direction of the corresponding layer in the respective regions 11a, 11b can be achieved for instance by changing the growth rates of the layer in the respective regions 11a, 11b.

[0073] For varying the optical thickness, the substrate 3 of the light-emitting device 1, assigned to the carrier layer 2, in the third region 11c has a first microcavity structure 15 on its surface. Constructing the first microcavity structure 15 comprises for instance applying material and/or deforming and/or removing the substrate 3 in the third region 11c. For example, the surface can for this purpose be subjected to coherent radiation or sandblasting. Alternatively or in addition, a kind of relief can be generated on the surface of the substrate 3 by means of embossing. In particular, the first microcavity structure 15 comprises a plurality of laterally adjacent partial faces of different optical thickness. For example, in FIG. 3, three partial faces are shown having a first optical thickness; they are separated laterally from one another by two partial faces of a second optical thickness. A lateral extent of partial faces generated by application or deformation can amount for instance to 40 m to 50 m. A lateral extent of partial faces generated by removal can for instance amount to 10 m.

[0074] The laterally adjacent partial faces in particular form a pattern or rather an ordered structure, so that an emission characteristic of the light-emitting device 1 in the third region 11c is varied. In particular in this context, a light outcoupling in the third region 11c relative to the first region 11a can differ in brightness and/or color and/or angle. Furthermore, an index of refraction can differ in the regions 11a, 11c.

[0075] Alternatively, for instance in the event that the light-emitting device 1 is constructed as a top emitter, or in addition, for instance in the case that the light-emitting device 1 is constructed as a transparent OLED, the substrate 3 assigned to the auxiliary layer 4 can have the first microcavity structure 15.

[0076] For varying the optical thickness, the substrate 3 of the light-emitting device 1 in the fourth region 11d, which substrate is assigned to the carrier layer 2, has a second microcavity structure 17. Constructing the second microcavity structure 17 in particular comprises constructing channels inside the substrate 3 in the fourth region 11d. For example, for that purpose the substrate 3 can be subjected to coherent radiation. The second microcavity structure 17 analogously to the third region 11c in particular comprises a plurality of laterally adjacent partial faces of differing optical thickness. A lateral extent of the partial faces can for instance amount to 1 m.

[0077] In this context, because of the greater lateral extent, what for the observer is a perceptible edge of the third region 11c has a coarser resolution than an edge of the fourth region 11d, for instance.

[0078] The laterally adjacent partial faces in particular form a pattern or rather an ordered structure, so that an emission characteristic of the light-emitting device 1 in the third region 11c is varied. In particular in this context, a light outcoupling in the fourth region 11d relative to the first region 11a can differ in brightness and/or color and/or angle. Furthermore, an index of refraction can differ in the regions 11a, 11d.

[0079] Alternatively, for instance in the event that the light-emitting device 1 is constructed as a top emitter, or in addition, for instance in the case that the light-emitting device 1 is constructed as a transparent OLED, the substrate 3 assigned to the auxiliary layer 4 can have the second microcavity structure 17.

[0080] The construction of the light-emitting device 1 and the effect achieved in the regions 11b, 11c, 11d was in each case set in relation to the first region 11a. In a departure from this, the construction and the effect in the regions 11b, 11c, 11d can differ from this analogously to the region 11a. It is furthermore conceivable that in the regions 11a, 11b, 11c, 11d, the construction and the effect are at least partially the same.

[0081] The regions 11a, 11b, 11c, 11d can furthermore be arranged independently of the segments 1a, 1b. Moreover, a plurality of segments 1a, 1b can, for example, be assigned to one of the regions 11a, 11b, 11e, 11d. Furthermore, a plurality of regions 11a, 11b, 11c, 11d can, for example, be assigned to one of the segments 1a, 1b.

[0082] In this context, it is for instance conceivable to locate a plurality of regions 11a, 11b, 11e, 11d of different effect in an ordered structure and for instance to assign them to the segment 1a. Advantageously, the light-emitting device 1 can thus have first emission characteristics in operation and second emission characteristics when it is not in operation. For example, these characteristics can be superimposed on one another to the observer in the event of high frequency triggering of the light-emitting device.

[0083] In particular in this context, the use of different light sources and color filters can be dispensed with, so that a contribution is made to high lateral resolution of the light-emitting device 1 as well as to its economical production. Advantageously, a lateral generation of signatures on a single OLED is made possible. The light-emitting device is in particular simple to produce, and in particular for each segment, various emission characteristics can be established, such as color, angle dependency, and brightness. Small dimensions that can be achieved by means of microcavities make especially precise imaging of signatures possible. Chronologically different triggering is possible by means of single contacting of the segments. An angle-dependent change in the appearance of the light-emitting device 1 can in particular also occur in the off state.