Evaporation source, method of coating at least two layers on a substrate and OLED device

Abstract

An evaporation source for depositing at least two layers on a substrate is described, including a first vapor distribution pipe with a row of first nozzles for depositing a first material onto the substrate, a second vapor distribution pipe with a row of second nozzles for depositing a second material onto the substrate, and a third vapor distribution pipe with a plurality of third nozzles for depositing a third material onto the substrate, wherein the row of first nozzles is configured to direct the first material onto a first region in the substrate plane, the row of second nozzles is configured to direct the second material onto a second region in the substrate plane not substantially overlapping with the first region, and the plurality of third nozzles is configured to direct the third material onto a third region in the substrate plane substantially covering both the first region and the second region.

Description

EVAPORATION SOURCE, METHOD OF COATING AT LEAST TWO LAYERS ON A SUBSTRATE AND OLED DEVICETECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to methods and apparatuses for coating substrates with a stack of layers. More particularly, embodiments of the present disclosure relate to evaporation sources for depositing materials of an OLED layer stack on a substrate. Organic layers of an OLED layer stack can be deposited on a substrate. Embodiments of the present disclosure specifically relate to evaporation sources as well as to methods of OLED display manufacturing by thermal evaporation. Embodiments of the present disclosure relate to OLED devices. Embodiments of the present disclosure specifically relate to bilayer emitting layer OLED devices.BACKGROUND

[0002] An organic light-emitting diode (OLED) is a light-emitting diode in which an electroluminescent layer is a film of organic compounds that emits light in response to an electric current. Since OLEDs emit light directly without involving backlight and color filters, the color gamut and viewing angles possible with OLED displays are greater than those of traditional LCD displays. Furthermore, OLEDs can be manufactured on flexible substrates, and, accordingly, they can be utilized in a variety of applications. OLEDs are used in the manufacture of television screens, computer monitors, mobile phones, other hand-held devices, etc., for displaying information. OLEDs can also be used for general space illumination. An OLED display, for example, may include layers of organic material situated between two electrodes that are deposited on a substrate in a manner so as to form a matrix display panel having individually energizable pixels.

[0003] Organic materials are deposited on a substrate in a vacuum processing chamber for OLED manufacturing. The materials to be deposited are evaporated using evaporation sources, and the evaporated materials are directed onto a substrate by nozzles. Organic materials are typically evaporated in an evaporation source at temperatures between 250°C and 500°C. OLED performance can be improved by using a bilayer emitting layer consisting of two stacked co-evaporation layers.

[0004] Organic evaporators can be used for the production of organic light-emitting diodes (OLED). Also, other applications utilize evaporators for depositing organic layers, for example, onto large area substrates. An OLED display, for example, may include a plurality of layers of organic material situated between two electrodes.

[0005] In view of the above, improved evaporation sources, and device manufacturing methods adapted for OLED manufacturing would be beneficial.SUMMARY

[0006] In light of the above, evaporation sources, methods for depositing at least two layers on a substrate with an evaporation source, and an OLED display device are provided according to the independent claims. Further aspects, benefits, and features of the present disclosure are apparent from the claims, the description, and the accompanying drawings.

[0007] According to an aspect, an evaporation source for depositing at least two layers on a substrate that is moved relative to the evaporation source in a substrate plane is provided. The evaporation source comprises a first vapor distribution pipe with a row of first nozzles for depositing a first material onto the substrate, a second vapor distribution pipe with a row of second nozzles for depositing a second material onto the substrate, and a third vapor distribution pipe with a plurality of third nozzles for depositing a third material onto the substrate, wherein the row of first nozzles is configured to direct the first material onto a first region in the substrate plane, the row of second nozzles is configured to direct the second material onto a second region in the substrate plane not substantially overlapping with the first region, and the plurality of third nozzles is configured to direct the third material onto a third region in thesubstrate plane substantially covering both the first region and the second region.

[0008] In particular, the first, second, and third vapor distribution pipes may be configured to deposit, onto the substrate that is moved past the evaporation source, a first mixed material layer comprising the first material and the third material and, on top of the first mixed material layer, a second mixed material layer comprising the second material and the third material.

[0009] In some embodiments, the plurality of third nozzles is provided as a single row of third nozzles arranged between the row of first nozzles and the row of second nozzles, the single row of third nozzles configured to direct the third material onto the third region in the substrate plane that substantially covers both the first region and the second region.

[0010] In some embodiments, the evaporation source comprises a shielding device configured to restrict vapor plumes emitted by at least one of the first nozzles, the second nozzles, and the third nozzles in a lateral direction. The shielding device may be arranged and shaped to reduce or prevent an overlap between the first region and the second region in the substrate plane and / or to ensure an overlap or coverage of the third region with both the first and second regions in the substrate plane.

[0011] According to another aspect, a method for depositing at least two layers on a substrate with an evaporation source is provided. The evaporation source comprises a first vapor distribution pipe with a row of first nozzles, a second vapor distribution pipe with a row of second nozzles, and a third vapor distribution pipe with a plurality of third nozzles. The method comprises: transporting the substrate past the evaporation source in a substrate plane while directing a first material toward the substrate from the first nozzles, a second material toward the substrate from the second nozzles, and a third material toward the substrate from the third nozzles; wherein the row of first nozzles directs the first material onto a first region in the substrate plane, the row of second nozzles directs the second material onto a second region in the substrate plane not substantially overlapping with the first region, and the plurality of third nozzles directs the third material onto a third region in the substrate plane substantially covering both the first region and the second region, so that a first mixed material layer comprising the first material and the third material and a second mixed material layercomprising the second material and the third material are deposited on top of each other on the substrate.

[0012] The first, second and / or third materials can comprise or consist of organic materials. The third material can be a dopant material. The first and / or second materials can be or include a host material.

[0013] According to another aspect, an OLED device, particularly manufactured according to a method of any of the embodiments described herein, is provided. The OLED display device comprises a substrate with a plurality of pixels formed thereon. The plurality of pixels respectively comprises an anode layer, a cathode layer, and a co-evaporated bilayer emitting layer consisting of two stacked co-evaporation layers between the anode layer and the cathode layer. The bilayer emitting layer comprises a first mixed material layer comprising a first host material and a first dopant material and a second mixed material layer directly on top of the first mixed material layer comprising a second host material and the first dopant material.

[0014] Embodiments are also directed at apparatuses for carrying out the disclosed methods and include apparatus parts for performing each described method aspect. The method aspects may be performed by way of hardware components, a computer programmed by appropriate software, by any combination of the two or in any other manner. Furthermore, embodiments are also directed at methods for operating the described apparatus. The methods for operating the described apparatuses include method aspects for carrying out every function of the apparatus. Embodiments are also directed at methods of manufacturing processed substrates, particularly coated substrates, in a vacuum deposition system described herein and substrates manufactured in accordance with the methods and / or using the systems described herein, such as OLED substrates, particularly OLED displays. Also other devices than OLED displays can be manufactured with the apparatuses and methods described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure,briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

[0016] FIG. 1 shows a schematic view of a vacuum deposition system with an evaporation source according to embodiments;

[0017] FIG. 2 shows a schematic view of an evaporation source according to embodiments in a vertical sectional plane;

[0018] FIG. 3 shows a schematic view of an evaporation source according to embodiments in a horizontal sectional plane;

[0019] FIG. 4 shows a schematic view of an evaporation source according to embodiments in a horizontal sectional plane;

[0020] FIG. 5 shows a schematic view of an evaporation source according to embodiments in a horizontal sectional plane;

[0021] FIG. 6 shows a schematic view of an evaporation source according to embodiments in a horizontal sectional plane;

[0022] FIG. 7 shows a schematic view of an evaporation source according to embodiments in a horizontal sectional plane; and

[0023] FIG. 8 shows a schematic view in a vertical sectional plane of a layer deposited by an evaporation source according to embodiments.DETAILED DESCRIPTION

[0024] Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with any other embodiment to yield yet a further embodiment. It is intended that the present disclosure includes such modifications and variations. Within the following description of the drawings, the same reference numbers refer to the same or to similarcomponents. Generally, only the differences with respect to the individual embodiments are described. Unless specified otherwise, the description of a part or aspect in one embodiment can apply to a corresponding part or aspect in another embodiment as well.

[0025] FIG. 1 shows a vacuum deposition system 1000 with an evaporation source 101 according to embodiments described herein in a schematic top view. The vacuum deposition system 1000 includes a first vacuum chamber 1001 that houses the evaporation source 101 , and, optionally, one or more further vacuum chambers that may house one or more further evaporation sources, e.g., a second evaporation source 102 and / or a third evaporation source 103. The vacuum deposition system 1000 may include at least five or at least ten evaporation sources, for coating the substrate with a plurality of layers. The evaporation sources may be configured to coat vertically or essentially vertically oriented substrates 10 that are transported past the evaporation sources on a substrate transportation track 1013. A plurality of materials, that may include one or more inorganic materials, such as, e.g., metals, and one or more organic materials, can be deposited in succession onto the substrate for providing a layer stack on the substrate, particularly an OLED layer stack. For example, the vacuum deposition system 1000 may include ten or more evaporation sources for coating the substrate with a plurality of layers.

[0026] In the present disclosure, a "vacuum deposition system" is to be understood as a system or arrangement configured for vacuum deposition of materials on a substrate. A "vacuum chamber" or “vacuum processing chamber” is to be understood as a chamber configured for vacuum deposition. The term "vacuum", as used herein, can be understood in the sense of a technical vacuum having a vacuum pressure of less than, for example, 10 mbar. Typically, the pressure in a vacuum chamber as described herein may be between 10-5 mbar and about 10-8 mbar, particularly between 10-5 mbar and 10-7 mbar.

[0027] The vacuum deposition system 1000 may include a substrate transportation track 1013 configured to move a substrate 10 along a substrate transport path T past the evaporation source 101 and past the optional further evaporation sources. The substrate transportation track 1013 may extend at least partially through the firstvacuum chamber 1001 and through the optional further vacuum chambers and may include a substrate transportation system configured for substrate transport, e.g., a roller transportation system, one or more linear motors and / or a magnetic levitation system suitable for moving the substrate relative to and past the evaporation sources. The substrate may be carried by a substrate carrier 1020 during the transport and / or deposition. A surface of the substrate, particularly the surface facing the evaporation sources, more in particular the evaporation source 101 , may be in a substrate plane 1010.

[0028] Accordingly, an in-line system is provided that allows the deposition of a plurality of layers on a substrate in succession, while the substrate is moved through the vacuum deposition system 1000 past a plurality of evaporation sources.

[0029] Embodiments described herein particularly relate to deposition of materials, e.g. for display manufacturing on large area substrates. According to some embodiments, large area substrates or carriers supporting one or more substrates may have a size of 0.5 m2or larger, particularly of 1 m2or larger. For instance, the deposition system may be adapted for processing large area substrates, such as substrates of GEN 4.5, which corresponds to approximately 0.67 m2of substrate (0.73 m x 0.92 m), GEN 5, which corresponds to approximately 1 .4 m2substrates (1.1 m x 1 .3 m), GEN 6, which corresponds to approximately 2.7 m2(1.5 m x 1.8 m), GEN 7.5, which corresponds to approximately 4.29 m2substrates (1.95 m x 2.2 m), GEN 8.5, which corresponds to approximately 5.7 m2substrates (2.2 m x 2.5 m), or even GEN 10, which corresponds to approximately 8.7 m2substrates (2.85 m x 3.05 m). Even larger generations such as GEN 11 and GEN 12 and corresponding substrate areas can similarly be implemented. According to yet further implementations, half-sizes of the above-mentioned substrate generations can be processed. Alternatively or additionally, semiconductor wafers may be processed and coated in deposition systems according to the present disclosure.

[0030] FIG. 2 shows an evaporation source 101 according to embodiments described herein in a vertical sectional plane. The evaporation source 101 may have crucibles 112 configured to evaporate same or different source materials to be deposited onto the substrate and vapor distribution pipes configured to direct theevaporated source materials towards the substrate through a plurality of nozzles. For instance, a vapor distribution tube or vapor distribution pipe may provide a line source with a plurality of nozzles that are arranged in a row (or “line array”), one above the other along a longitudinal direction of the vapor distribution pipe. The row of nozzles may be provided along a longitudinal direction (typically an essentially vertical direction) of the vapor distribution pipe to provide an essentially vertical line source. Each vapor distribution pipe may have a plurality of nozzles, e.g., a row of nozzles, particularly one single nozzle row or nozzle rows suitable to coat substrates having an essentially vertical orientation. In some embodiments, not shown in FIG. 2, but exemplarily in FIGS. 4 and 7, at least one vapor distribution pipe has a plurality of rows of nozzles, in particular two vertical nozzle rows suitable to coat substrates having an essentially vertical orientation. The plurality of rows of nozzles may be parallel to each other. Each vapor distribution pipe is configured to coat substrates with an evaporated source material evaporated in an associated evaporation crucible, e.g., a host material or a dopant material.

[0031] An “essentially vertical direction” as used herein relates to a direction that corresponds to the direction of gravity or deviates from the direction of gravity by less than 10°.

[0032] For instance, the source material to be deposited may be an organic material for organic light emitting diode (OLED) production. The organic material may be a host material or a dopant material. The host material and a dopant material may form an emitting layer, particularly an emitting layer of a bilayer emitting layer. The bilayer emitting layer may comprise a first bilayer emitting layer and a second bilayer emitting layer. The first bilayer emitting layer may form a recombination zone and the second bilayer emission layer may form a triplet-triplet-fusion zone of the bilayer emitting layer. In operation of the OLED, light is emitted. The light emission may include a delayed emission in the triplet-triplet-fusion zone.

[0033] The host material may be an anthracene derivative, a benzonitrile derivative, an acridine derivative, a triazine derivative, a fluorene derivative, a thiophene derivative and / or a diphenylsilane derivative. The dopant material may be an anthracene derivative, a perylene derivative, a carbazole derivative, a fluorenederivative, a triazine derivative, an aniline derivative, a styrene derivative and / or an oxygen-bridged boron derivative.

[0034] As is schematically depicted in FIG. 2, the evaporation source 101 includes a first vapor distribution pipe 110. Further vapor distribution pipes of the evaporation source are not shown in the vertical sectional view of FIG. 2, but are shown, e.g., in the horizontal sectional view of FIG. 3. The first vapor distribution pipe 110 has a row of first nozzles 111 that may be arranged along the longitudinal direction of the first vapor distribution pipe 110, e.g., above one another in an essentially vertical line array. The evaporation source 101 may, for example, be a line source for substrate coating in an essentially vertical orientation. The evaporation source 101 may be configured to deposit at least three materials onto the substrate with three or more vapor distribution pipes arranged adjacent to each other.

[0035] The row of first nozzles 111 includes a plurality of nozzles, particularly twenty or more nozzles. Each nozzle has a main evaporation direction. A “main evaporation direction” of a nozzle can be understood as a direction that is defined by the nozzle opening and by the nozzle channel of the nozzle (typically corresponding to a direction of the nozzle channel). A substantially cone-shaped vapor plume emitted by a nozzle is generally centered around the main evaporation direction of the nozzle, e.g., with a maximum of vapor particles of the plume propagating along the main evaporation direction. Specifically, a vapor plume emitted by a nozzle is defined by a main evaporation direction and by an opening angle of the plume. A vapor plume can be rotationally symmetrical with respect to the main evaporation direction, and / or a vapor plume can be shaped by a shaping device to be symmetrical or to be asymmetrical relative to the main evaporation direction or relative to the nozzle axis.

[0036] The nozzles of the row of first nozzles 111 provide a first main evaporation direction M1 relative to the substrate surface if the nozzle channels of the nozzles of the row are essentially parallel to each other and arranged one above the other. Parallel vapor plumes propagating in the first main evaporation direction M1 are schematically depicted in FIG. 2. Accordingly, the row of first nozzles 111 is characterized by a (common) main evaporation direction of the nozzles. The row of first nozzles 111 of FIG. 2 has the first main evaporation direction M1. Other rows ofnozzles described herein are defined by a respective main evaporation direction that is common among the nozzles of the respective row.

[0037] The evaporation source 101 may further include a rotation drive 113 for rotating the evaporation source 101 around a rotation axis R1. Furthermore, a controller 114 for controlling the rotational movement of the evaporation source 101 may be provided.

[0038] FIG. 3 shows a schematic view of an evaporation source 101 according to embodiments described herein in a horizontal sectional plane. The evaporation source 101 includes a first vapor distribution pipe 110 with a row of first nozzles 111 , a second vapor distribution pipe 120 with a row of second nozzles 121 , and a third vapor distribution pipe 130 with a plurality of third nozzles 131 , particularly a row of third nozzles 131. The first vapor distribution pipe 110 with the row of first nozzles 111 is configured to emit first vapor plumes 31 directed towards the substrate plane 1010, particularly onto a first region 21 in the substrate plane 1010. The second vapor distribution pipe 120 with the row of second nozzles 121 is configured to emit second vapor plumes 32 directed towards the substrate plane 1010, particularly onto a second region 22 in the substrate plane 1010. The third vapor distribution pipe 130 with the plurality of third nozzles 131 is configured to emit third vapor plumes 33 directed towards the substrate plane 1010, particularly onto a third region of the substrate plane 1010. The third region of the substrate plane 1010 substantially covers the first region 21 and the second region 22. Particularly, the third region may substantially comprise both the first region and the second region in the substrate plane without being substantively larger than the combined first and second regions. In particular, the third region of the substrate plane 1010 may be essentially congruent with a deposition area, the deposition area being defined as an area in the substrate plane consisting of the first region and the second region. The overlap area of the third region and the deposition area may be at least 80%, 90%, 95%, or 99% of the third region. The overlap area of the third region and the deposition area may be at least 80%, 90%, 95%, or 99% of the deposition area. The third region may not extend substantially beyond the deposition area. The first region 21 and the second region 22 may not substantially overlap, in particular, may be substantially distinct from each other. In particular, the overlap area of the first region 21 and the second region 22 may be lessthan 20%, 15%, 12%, 10%, 8%, 5%, 2% or 1 % of the first region 21. The overlap area of the first region 21 and the second region 22 may be less than 20%, 15%, 12%, 10%, 8%, 5%, 2% or 1 % of the second region 22. The overlap area of the first region 21 and the second region 22 may be less than 20%, 15%, 12%, 10%, 8%, 5%, 2% or 1 % of a total area of the first region 21 and of the second region 22.

[0039] As is depicted in FIG. 3, as the substrate moves along the substrate transport path T, in the first region 21 of the substrate plane 1010, a first mixed layer comprising a first material emitted by the first vapor distribution pipe 110 and a third material emitted by the third vapor distribution pipe 130 is formed. In the second region 22, a second mixed layer comprising a second material emitted by the second vapor distribution pipe 120 and the third material emitted by the third vapor distribution pipe 130 is formed.

[0040] The third material may be a dopant material. The dopant material may act as an emitter of the first mixed layer and / or of the second mixed layer. The third material may have a concentration in the first mixed layer not exceeding 20%, 18%, 15%, 12%, 11 %, 10%, 9%, 8%, 7%, 6%, 5%, 2% or 1 %. The third material may have a concentration in the second mixed layer not exceeding 20%, 18%, 15%, 12%, 11 %, 10%, 9%, 8%, 7%, 6%, 5%, 2% or 1 %. The concentration of the third material in the first mixed layer may be different from the concentration of the third material in the second mixed layer.

[0041] The first vapor distribution pipe 110, the second vapor distribution pipe 120, and the third vapor distribution pipe 130 may be mounted on a source body 301 to be rotatable around the rotation axis R1 with the source body 301 . In some embodiments, the first vapor distribution pipe 110, the second vapor distribution pipe 120 and the third vapor distribution pipe 130 are mounted adjacent to each other to provide a front side 60 of the evaporation source 101 that includes the nozzle rows and can be directed toward the substrate for coating the substrate by rotating the evaporation source to a deposition position that is exemplarily shown in FIG. 3.

[0042] The third vapor distribution pipe 130 may be arranged between the first vapor distribution pipe 110 and the second vapor distribution pipe 120. For example, the third vapor distribution pipe 130 may be mounted between the first vapordistribution pipe 110 and the second vapor distribution pipe 120, so that the plurality of third nozzles 131 may act as a center row of nozzles arranged between two rows of nozzles of the first and second vapor distribution pipes. A distance between the first nozzles 111 and the third nozzles 131 may be 30 cm or less, particularly 10 cm or less, in order to improve the overlap ratio between the first and third materials. A distance between the second nozzles 121 and the third nozzles 131 may be 30 cm or less, particularly 10 cm or less, in order to improve the overlap ratio between the second and third materials.

[0043] Each vapor distribution pipe may be in fluid communication with, i.e. may have a have vapor path from, a respective evaporation crucible that is configured to evaporate a respective source material. The evaporation crucibles may be mounted at the evaporation source 101 so as to be rotatable together with the source body 301 .

[0044] The front side 60 of the evaporation source as used herein includes the first, second, and third rows of nozzles arranged adjacent to each other. During the material deposition onto the substrate, the front side 60 of the evaporation source generally faces toward the substrate. For example, the front side 60 of the evaporation source can be defined as extending along a connection line that connects geometric centers of the vapor distribution pipes of the evaporation source in a horizontal sectional plane.

[0045] The row of first nozzles 111 and the row of second nozzles 121 may be tilted such that vapor plumes emitted by the first and second vapor distribution pipes respectively overlap with third vapor plumes emitted by the third vapor distribution pipe to form the first and the second mixed material layer, respectively, on the substrate 10.

[0046] The embodiments described herein may include a shielding device with an idle shield 202 and additionally a shaper shield 201 that is connected to the idle shield 202, particularly integrated with the idle shield 202, to form a continuous shielding surface that partially surrounds the evaporation source 101. A rotation drive is configured to rotate the evaporation source relative to both the idle shield 202 and the shaper shield 201. In other words, the shaper shield 201 is not mounted at the evaporation source to be rotatable with the evaporation source, but is connected to the idle shield 202 to form a part of the shielding device that is stationary with respect to the rotation of the evaporation source. The shaper shield 201 may include (at least) anessentially vertically oriented first slit. In the embodiments shown in FIGS. 3-7, an opening angle of the first vapor plumes 31 is restricted by an edge of the shaper shield 201 and an opening angle of the second vapor plumes 32 is restricted by another edge of the shaper shield 201 . The shaper shield 201 may define a lateral edge of the first region 21 and / or a lateral edge of the second region 22, particularly by restricting the opening angle of the first and / or second vapor plumes.

[0047] The third nozzles 131 may be arranged such that the vapor plumes emitted by the third nozzles 131 do at least substantially or completely overlap with the vapor plumes emitted by the first and second nozzles in the substrate plane. In particular, an opening angle of the third vapor plumes 33 may be wider in a lateral direction than the opening angle of the first vapor plumes 31 and / or the opening angle of the second vapor plumes 32. The lateral direction as used herein is generally a horizontal direction parallel to the substrate transport direction T along which the substrate moves relative to and past the evaporation source.

[0048] A smaller opening angle of the first and / or second vapor plumes as compared to the third vapor plumes 33 can, e.g., be ensured by a shielding device configured to laterally restrict the first and / or second vapor plumes, such as by the shaper shield 201 shown in FIG. 3. The opening angle in a lateral direction of the first vapor plumes 31 and / or of the second vapor plumes 32 may be smaller than 90°, 75°, 60°, 50°, 40° or 30°, particularly under consideration of the shielding device, that may restrict the opening angle of the first or second vapor plumes, and / or may exceed 5°, 10°, 20 ° or 25°. The opening angle in a lateral direction of the third vapor plumes may be smaller than 100°, 90°, 75°, 60°, or 45° and may exceed 5°, 10°, 20 ° or 25°. The first vapor plumes 31 , the second vapor plumes 32 and / or the third vapor plumes 33 may optionally have different opening angles. The opening angle of the third vapor plumes 33 in the lateral direction may be larger than the opening angles of the first and second vapor plumes.

[0049] According to embodiments described herein, the evaporation source is configured to coat a substrate with (at least) two layers above one another by moving the substrate past the evaporation source, particularly along the transport path T, the two layers being mixed material layers each comprising (at least) one material,particularly a host material, and a shared further material, particularly a dopant material, each mixed material layer co-deposited with (at least) two vapor distribution pipes. A compact and space-saving vacuum deposition system can be provided, and a reduced number of evaporation sources may be provided for coating the substrate with two mixed layers, e.g., with a bilayer emitting layer, as exemplarily used in an OLED layer stack. An interval from depositing the first mixed material layer to depositing the second mixed material layer can be reduced. A short interval between the deposition of the mixed material layers may provide for reduced contamination of an interface between the mixed material layers, in particular between the layers of a bilayer emitting layer. Contaminations of an interface between the mixed material layers may particularly be due to outgas from the vacuum deposition system. In the vacuum system vacuum-use plastics parts may outgas plasticizers, exemplarily dioctyl phthalate (DOP) or (di-isononyl phthalate). In some embodiments, fluorocarbons from grease, O-rings and / or PTFE-parts may contaminate the interface between the mixed material layers. In some embodiments, silicone from grease, O-rings and / or adhesives may contaminate the interface between the mixed material layers. According to embodiments described herein, since the two mixed-material layers are (co-)deposited with a single evaporation source using a shared vapor distribution pipe, the two mixed material layers are deposited immediately after one another. Accordingly, contaminations at an interface between the two mixed-material layers can be reduced, and a high-quality OLED display device can be provided.

[0050] FIG. 4 shows another embodiment of an evaporation source as described herein. In FIG. 4, the third vapor distribution pipe 130 includes a plurality of third nozzles 131 provided as two rows of nozzles adjacent to each other. A first row of third nozzles 132 and a second row of third nozzles 133 are arranged between the row of first nozzles 111 and the row of second nozzles 121. The first row of third nozzles 132 is configured to direct the third material onto a first part of the third region that substantially overlaps with or is substantially congruent with the first region 21. The second row of third nozzles 133 is configured to direct the third material onto a second part of the third region that substantially overlaps with or is substantially congruent with the second region 22. The first part of the third region and the second part of the third region may not substantially overlap.

[0051] According to some embodiments, an amount or flux of third material deposited by the first row of third nozzles 132 may differ from an amount or flux of third material deposited by the second row of third nozzles 133. Particularly, the concentration of third material in the first mixed layer may differ from the concentration of third material in the second mixed layer. For some materials, a predetermined concentration of the third material may differ for the first mixed layer and the second mixed layer. An opening angle of first third vapor plumes 34 of the first row of third nozzles 132 in the lateral direction may be similar to an opening angle of the first vapor plume 31 . An opening angle of second third vapor plumes 35 of the second row of third nozzles 133 in the lateral direction may be similar to the opening angle of the second vapor plume 32.

[0052] In some embodiments, as shown in FIG. 5, which can be combined with other embodiments described herein, the evaporation source 101 further includes a shaping device 203 configured to limit opening angles of vapor plumes emitted by at least one of the first, second, and third rows of nozzles. For example, the shaping device 203 may be arranged in front of the row of first nozzles and / or the row of second nozzles and may be configured to reduce or prevent an overlap between the vapor plumes emitted from the first nozzles and the vapor plumes emitted from the second nozzles onto the substrate. In particular, the shaping device may be arranged between a first vapor plume propagation space of the first vapor plumes and a second vapor plume propagation space of the second vapor plume. A vapor plume propagation space may be understood as a space through which vapor plumes propagate after emission by the respective nozzles. Alternatively or additionally, the shaping device 203 may be arranged in front of the row of first nozzles and the plurality of third nozzles and may be configured to ensure that the third vapor plumes emitted by the third nozzles 131 cover the first region 21 defined by the first vapor plumes 31 in the substrate plane 1010. Alternatively or additionally, the shaping device 203 may be arranged in front of the row of second nozzles 121 and the plurality of third nozzles 131 and may be configured to ensure that the third vapor plumes emitted by the third nozzles 131 cover the second region 22 defined by the second vapor plumes 32 in the substrate plane 1010. Particularly, the shaping devices 203 and / or the shaper shield 201 may define the first region 21 , the second region 22 and / or the third region in thesubstrate plane 1010 by laterally limiting the first, second, and / or third vapor plumes emitted by the first, second and third vapor distribution pipes.

[0053] The opening angles of the vapor plumes can be restricted and / or shaped by shaping devices 203 that may be arranged in front of one or more rows of nozzles, as is schematically depicted in FIGS. 5 -7. For example, one or more shaping devices 203 are arranged in front of the vapor distribution pipe(s) for shaping vapor plumes emitted by the row of first nozzles, for shaping vapor plumes emitted by the row of second nozzles and / or for shaping vapor plumes emitted by the third nozzles. In some embodiments, the vapor plumes may be shaped to be asymmetrical relative to respective main evaporation directions of the respective row of nozzles. In FIGS. 5 and 6, the shaping devices limit the opening angle of the first vapor plumes 31 , of the second vapor plumes 32 and of the third vapor plumes 33.

[0054] In some embodiments, the shaping device 203 may be mounted at a front side of one or more vapor distribution pipes to be rotatable together with the evaporation source 101. For example, in the embodiments shown in FIGS. 5-7, shaping devices 203 that protrude from the vapor distribution pipes to limit the opening angles of the vapor plumes emitted by the rows of nozzles are mounted at the evaporation source 101. The shaping device 203 may include shaping surfaces extending between adjacent nozzle rows in a longitudinal direction of the vapor distribution pipes. The shaping device 203 may include shaping surfaces with a bend structure, particularly to limit opening angles of two adjacent rows of vapor plumes. According to some embodiments, the shaping device 203 may limit the opening angle of the first vapor plumes 31 and / or the second vapor plumes 32 to a maximum angle of, e.g., 50°, or 40° or less. The shaping device 203 may optionally limit the maximum opening angle of the first vapor plumes 31 to a different maximum opening angle than the opening angle of the second vapor plumes 32.

[0055] In some embodiments, the evaporation source 101 may include an idle shield 202 that partially surrounds the evaporation source 101 , e.g., by an angle of 90° or more or 120° or more, wherein a rotation drive is configured to rotate the evaporation source 101 relative to the idle shield 202 to an idle position, in which the first, second, and third rows of nozzles are directed toward the idle shield 202.

[0056] In some embodiments, the shaping device 203 may include a second shielding plate 204 configured to shape the third vapor plumes 33 such that the third region does not substantially cover an intermediate region between the first region 21 and the second region 22. The intermediate region may particularly be a region in the substrate plane 1010 between the first region 21 and the second region 22 or at an interface between the first region 21 and the second region.

[0057] In the embodiment shown in FIG. 6, the second shielding plate 204 divides the third vapor plumes 33 respectively into two laterally spaced plume parts, with the intermediate region in the substrate plane not being covered by either of the two plume parts of the third vapor plumes. One part of the third vapor plumes 33 substantially overlaps with the first vapor plumes 31 in the substrate plane 1010, particularly to form the first mixed layer. Another part of the third vapor plumes 33 substantially overlaps with the second vapor plumes 32, particularly to form the second mixed material layer. The region of the third vapor plumes covered by the second shielding plate 204 may correspond to an opening angle of at least 1 °, 3°, 5° and of at most 8°, 10°, 15°, or 20°.

[0058] In some embodiments, the second shielding plate 204 is connected to the idle shield 202. In particular, the second shielding plate 204 is not rotatable, while the distribution pipes may optionally be rotatable. In some embodiments, the shaping device 203 includes the second shielding plate 204. In particular, a rotation of the evaporation source 101 may lead to a rotation of the shaping device 203 with the second shielding plate 204.

[0059] The evaporation source 101 can be rotated to the idle position when no substrate is being transported past the evaporation source 101 , in order to avoid a stray coating of, e.g., chamber surfaces. In the idle position, the first, second, and third materials may be directed toward an inner surface of the idle shield 202 that can act as a shutter, blocking vapor propagation paths of the nozzle rows. Optionally, the idle shield 202 may be at least partially cooled, such that the vapor materials hitting the inner surface of the idle shield 202 condense on the idle shield and accumulate thereon without being substantively reflected.

[0060] In some embodiments, which can be combined with other embodiments described herein, the row of first nozzles, the row of second nozzles, and the pluralityof third nozzles respectively includes twenty or more nozzles arranged one above the other in an essentially vertical nozzle array, and the first, second, and third vapor distribution pipes may be configured as vertical line sources arranged adjacent to each other on a common rotatable source body of the evaporation source. The third vapor distribution pipe 130 may be arranged between the second vapor distribution pipe 120 and the first vapor distribution pipe 110, and the row of third nozzles 131 may be arranged between the row of second nozzles 121 and the row of first nozzles 111.

[0061] FIG. 7 is a schematic view of an evaporation source 101 according to embodiments described herein in a horizontal sectional plane. The configuration of the vapor nozzles is similar to the embodiment shown in FIG. 4. In particular, the third vapor distribution pipe 130 includes a first row of third nozzles 132 and a second row of third nozzles 133. A shaping device 203 that may be attached to the third vapor distribution pipe, may be positioned between the first row of third nozzles 132 and the second row of third nozzles 133. The shaping device 203 may protrude from the third vapor distribution pipe 130. The shaping device 203 can ensure a separation of vapor plumes of the first row of third nozzles 132 and of the second row of third nozzles 133.

[0062] In particular, the shaping device 203 can limit opening angles of the vapor plumes of the first row of third nozzles 132 and of the second row of third nozzles 133. The opening angles of the vapor plumes of the first row of third nozzles 132 and the second row of third nozzles 133 may further be limited by additional shaping devices, similar to the embodiments of FIGS. 5 and 6, that protrude from the vapor distribution pipes, in particular between the row of first nozzles 111 and the first row of third nozzles 132 and / or between the row of second nozzles 121 and the second row of third nozzles 133. In FIG. 7, the opening angle of the vapor plumes of the first row of third nozzles 132 and the second row of third nozzles 133 are limited by a second shielding plate 204. In particular, the second shielding plate 204 shields the vapor plumes emitted by the first row of third nozzles 132 and by the second row of third nozzles 133 such that the third region does not substantially cover the intermediate region between the first region and the second region in the substrate plane 1010.

[0063] Exemplarily, the vapor plumes of the first row of third nozzles 132 substantially cover the first region 21 in the substrate plane and the vapor plumes ofthe second row of third nozzles 133 substantially cover the second region 22 in the substrate plane 1010. The shaping device 203 and the second shielding plate 204 may avoid an overlap of the vapor plumes of the first row of third nozzles 132 and of the second row of third nozzles 133 in the substrate plane 1010. Alternatively or additionally, the shaper shield 201 , the shaping device 203 and / or the second shielding plate 204 may be configured to ensure an overlap between vapor plumes emitted from the row of first nozzles 111 and the first row of third nozzles 132 in the substrate plane 1010 and / or to ensure an overlap between vapor plumes emitted from the row of second nozzles 121 and the second row of third nozzles 133 in the substrate plane 1010.

[0064] In some embodiments, the evaporation source 101 includes a shield arrangement that partially surrounds the evaporation source 101 and includes an idle shield 202 and the shaper shield 201 , and the rotation drive may be configured to rotate the evaporation source 101 relative to the shield arrangement between an idle position, in which the first, second, and third rows of nozzles are directed toward the idle shield 202, and a deposition position, in which at least one of the first, second, and third rows of nozzles are aligned with one or more openings provided in the shaper shield 201 . The one or more openings provided in the shaper shield 201 may be configured as one or more vertical slit openings.

[0065] In some embodiments, a height of the evaporation source 101 and of the shield arrangement is 150 cm or more, particularly 200 cm or more, and an inner shielding surface of the shield arrangement that is directed toward the evaporation source may be 1 m2or more, particularly 2 m2or more.

[0066] The idle shield 202 may surround the evaporation source by an angle of 90° or more and 270° or less in a cylinder-like or tube-like manner, such that a rotation of the evaporation source around the rotation axis R1 leads to a movement of the nozzle rows past the inner surface of the idle shield. A curvature of the idle shield may be adapted to a curvature of movement trajectories of the nozzle rows during the source rotation.

[0067] In FIG. 8, a schematic layer structure deposited on the substrate 10 is shown. On the substrate 10, a first layer 11 and a second layer 12 are deposited. Thefirst layer 11 may be a first layer of a bilayer emitting layer and the second layer 12 may be a second layer of the bilayer emitting layer, in particular of an OLED bilayer emitting layer structure. The substrate may comprise further layers of an OLED layer stack, that may be deposited prior to a deposition of the bilayer emitting layer. In particular, the substrate may include an anode layer and a cathode layer on opposite sides of the bilayer emitting layer. The OLED layer stack may, for example, comprise an anode layer, optionally a hole injection layer (HIL), one or more organic layers (e.g., comprising the bilayer emitting layer), optionally an electron injection layer (EIL), and / or a cathode layer. The second layer 12 is directly deposited on the first layer 11. In particular, no intermediate layer may be present between the first layer 11 and the second layer 12.

[0068] The substrate 10 may be transported along the transport path, particularly firstly passing the first region and secondly passing the second region. The substrate, or a part or area of the substrate, may be transported from the first region to the second region in at most a second, 0.5 s, 0.2 s or 0.1 s. A short time period between a deposition of the first layer 11 and of the second layer 12 may improve the quality of the bilayer emitting layer, and may, in particular, reduce the risk of contamination or formation of an intermediate layer.

[0069] The first layer 11 may consist of of the first mixed material layer comprising the first material and the third material (and optional further material(s)) that are codeposited. The second layer 12 may consist of the second mixed material layer comprising the second material and the third material (and optional further material(s)) that are co-deposited. The first material and the second material may comprise organic materials, in particular organic semiconductor materials. In some embodiments, the first material and the second material may consist of organic materials, in particular organic semiconductor materials. The first material and the second material may be a host material. The third material may be a dopant material. In particular, the third material may be a material that acts as an emitter in the host materials, in particular in the first material and / or second material, when incorporated in the first material and / or the second material. The dopant material may be an organic material.

[0070] According to some embodiments, the concentration of the third material inthe first mixed layer and / or in the second mixed layer may not exceed 15%, 12%, 10%, 8%, 5%, 2% or 1 %. The concentration of the third material may be substantially similar in the first mixed layer and in the second mixed layer.

[0071] An OLED device, in particular an OLED device manufactured by methods described herein, comprises a substrate and a plurality of pixels. The pixels include an anode layer and a cathode layer. To emit light, the OLED device comprises a bilayer emitting layer between the anode layer and the cathode layer, in particular electrically connected to the anode layer and to the cathode layer.

[0072] The bilayer emitting layer is co-evaporated and comprises two stacked coevaporation layers. The co-evaporated layers may in particular be deposited using an evaporation source as described herein and / or a method for depositing at least two layers as described herein. The co-evaporated layers comprise a first mixed material layer and a second mixed material layer. The second mixed material layer is deposited directly on top of the first mixed material layer. In particular, no intermediate layer is present between the first mixed material layer and the second mixed material layer. The co-evaporated layers may advantageously avoid contamination of an interface between the first mixed material layer and the second mixed material layer, in particular such that no contaminating molecules are present between the first mixed material layer and the second mixed material layer. Co-evaporated layers comprise two or more materials that are deposited essentially simultaneously, particularly using one evaporation source with several vapor distribution pipes as described herein.

[0073] The first mixed material layer may comprise or consist of the first host material and the first dopant material. The second mixed material layer may comprise or consist of the second host material and the first dopant material. A concentration of contaminations in the bilayer emitting layer may not vary substantially throughout the bilayer emitting layer. In particular, the concentration of contaminations in the bilayer emitting layer may vary by less than 10%, 5%, 2% or 1 %. The variation of the concentration of contaminations may be a variation over the area of the bilayer emitting layer or a variation over the thickness of the bilayer emitting layer. In some embodiments, an interface between the first mixed material layer and the second mixed material layer is contamination-free.

[0074] According to some embodiments, the first mixed material layer and the second mixed material layer are deposited on top of each other immediately, exemplarily in less than 1 second, one after the other by the same evaporation source to provide a contamination-free interface between the first mixed material layer and the second mixed material layer.

[0075] The concentration of the first dopant material in the first mixed material layer and / or in the second mixed material layer may not exceed 15%, particularly not 10%. An average concentration of the first dopant material in the first mixed layer may be 10% or less. An average concentration of the first dopant material in the second mixed material layer may be 10% or less.

[0076] In some embodiments, instead of a bilayer emitting layer, another stack of two co-deposited layers can be deposited on the substrate according to the methods and / or apparatuses described herein. The two co-deposited layers include at least one material that is emitted by a shared vapor distribution pipe of the evaporation source, particularly a dopant material.

[0077] Specifically, the following embodiments are described herein:

[0078] Embodiment 1 : An evaporation source for depositing at least two layers on a substrate that is moved relative to the evaporation source in a substrate plane, comprising: a first vapor distribution pipe with a row of first nozzles for depositing a first material onto the substrate, a second vapor distribution pipe with a row of second nozzles for depositing a second material onto the substrate, and a third vapor distribution pipe with a plurality of third nozzles for depositing a third material onto the substrate, wherein the row of first nozzles is configured to direct the first material onto a first region in the substrate plane, the row of second nozzles is configured to direct the second material onto a second region in the substrate plane not substantially overlapping with the first region, and the plurality of third nozzles is configured to direct the third material onto a third region in the substrate plane substantially covering both the first region and the second region.

[0079] Embodiment 2: The evaporation source of embodiment 1 , wherein the first, second, and third vapor distribution pipes are configured to deposit, onto the substratethat is moved past the evaporation source, a first mixed material layer comprising the first material and the third material and, on top of the first mixed material layer, a second mixed material layer comprising the second material and the third material.

[0080] Embodiment 3: The evaporation source of any of embodiments 1 to 2, wherein the first region and the second region are substantially distinct from each other, particularly wherein an overlap area of the first and second regions is less than 10% of the first region and less than 10% of the second region.

[0081] Embodiment 4: The evaporation source of any of embodiments 1 to 3, wherein the third region is essentially congruent with a deposition area consisting of the first region and the second region, particularly wherein an overlap area of the third region and the deposition area is 90% or more of the third region and 90% or more of the deposition area.

[0082] Embodiment 5: The evaporation source according to any of embodiments 1 to 4, wherein the first vapor distribution pipe is in fluid communication with a first host material crucible configured to evaporate a first host material; the second vapor distribution pipe is in fluid communication with a second host material crucible configured to evaporate a second host material; and the third vapor distribution pipe is in fluid communication with a dopant material crucible configured to evaporate a dopant material.

[0083] Embodiment 6: The evaporation source of any of embodiments 1 to 5, wherein the plurality of third nozzles is provided as a single row of third nozzles arranged between the row of first nozzles and the row of second nozzles, the single row of third nozzles configured to direct the third material onto the third region in the substrate plane that substantially covers both the first region and the second region.

[0084] Embodiment 7: The evaporation source of any of embodiments 1 to 5, wherein the plurality of third nozzles comprises a first row of third nozzles and a second row of third nozzles arranged between the row of first nozzles and the row of second nozzles, the first row of third nozzles configured to direct the third material onto a first part of the third region, that substantially overlaps with the first region, and the second row of third nozzles configured to direct the third material onto a second part of thethird region, that substantially overlaps with the second region.

[0085] Embodiment 8: The evaporation source according to any of embodiments 1 to 7, further comprising a shielding device configured to restrict vapor plumes emitted by at least one of the first nozzles, the second nozzles, and the third nozzles in a lateral direction.

[0086] Embodiment 9: The evaporation source according to embodiment 8, wherein the shielding device is configured to limit vapor plumes emitted by the first nozzles and by the second nozzles to a maximum opening angle of 60° or less in a lateral direction.

[0087] Embodiment 10: The evaporation source according to any of embodiments 8 to 9, wherein the shielding device is configured to laterally limit first vapor plumes emitted by the first nozzles and second vapor plumes emitted by the second nozzles to not substantially overlap with each other in the substrate plane, particularly wherein the shielding device comprises at least one first shielding plate that is arranged in front of at least one of the first, second and third vapor distribution pipes between a first vapor plume propagation space and a second vapor plume propagation space.

[0088] Embodiment 11 : The evaporation source according to any of embodiments 8 to 10, wherein the shielding device comprises at least one second shielding plate configured to shape third vapor plumes emitted by the plurality of third nozzles such that the third region does not substantially cover an intermediate region between the first region and the second region in the substrate plane.

[0089] Embodiment 12: The evaporation source according to any of embodiments 1 to 11 , wherein the first material and the second material comprise an organic material, particularly an organic semiconductor material.

[0090] Embodiment 13: The evaporation source according to any of embodiments 1 to 12, wherein the first, the second, and the third vapor distribution pipe are mounted on a source body that is rotatable around a rotation axis.

[0091] Embodiment 14: The evaporation source according to embodiment 13, further comprising a shield arrangement that partially surrounds the source body andcomprises an idle shield and a shaper shield, the source body being rotatable relative to the shield arrangement between an idle position, in which the first nozzles, the second nozzles, and the third nozzles are directed toward the idle shield, and a deposition position, in which at least one of the first nozzles, the second nozzles, and the third nozzles are aligned with one or more slits in the shaper shield configured to laterally limit vapor plumes emitted by at least one of the first nozzles, the second nozzles, and the third nozzles.

[0092] Embodiment 15: A method for depositing at least two layers on a substrate with an evaporation source comprising a first vapor distribution pipe with a row of first nozzles, a second vapor distribution pipe with a row of second nozzles, and a third vapor distribution pipe with a plurality of third nozzles, the method comprising: transporting the substrate past the evaporation source in a substrate plane while directing a first material toward the substrate from the first nozzles, a second material toward the substrate from the second nozzles, and a third material toward the substrate from the third nozzles; wherein the row of first nozzles directs the first material onto a first region in the substrate plane, the row of second nozzles directs the second material onto a second region in the substrate plane not substantially overlapping with the first region, and the plurality of third nozzles directs the third material onto a third region in the substrate plane substantially covering both the first region and the second region, so that a first mixed material layer comprising the first material and the third material and a second mixed material layer comprising the second material and the third material are deposited on top of each other on the substrate.

[0093] Embodiment 16: The method of embodiment 15, wherein the first region and the second region are defined by a shielding device that limits first vapor plumes emitted by the first nozzles and second vapor plumes emitted by the second nozzles in a lateral direction.

[0094] Embodiment 17: The method of any of embodiments 15 to 16, wherein the first material, the second material and the third material are an organic material.

[0095] Embodiment 18: The method of any of embodiments 15 to 17, wherein the first mixed material layer is a first bilayer emitting layer and the second mixed material layer is a second bilayer emitting layer of an organic light-emitting diode, OLED, andwherein the third material is a dopant material.

[0096] Embodiment 19: The method of any of embodiments 15 to 18, wherein the substrate is transported from the first region to the second region in at most one second.

[0097] Embodiment 20: The method of any of embodiments 15 to 19, wherein a concentration of the third material in the first mixed material layer and in the second mixed material layer does not exceed 15%.

[0098] Embodiment 21 : An OLED display device, particularly manufactured according to the method of any of embodiments 15 to 20, comprising: a substrate; a plurality of pixels respectively comprising: an anode layer, a cathode layer, and a coevaporated bilayer emitting layer consisting of two stacked co-evaporation layers between the anode layer and the cathode layer, the bilayer emitting layer comprising: a first mixed material layer comprising a first host material and a first dopant material; a second mixed material layer directly on top of the first mixed material layer comprising a second host material and the first dopant material.

[0099] Embodiment 22: The OLED display device of embodiment 21 , wherein the first mixed material layer consists of the first host material and the first dopant material; and the second mixed material layer consists of the second host material and the first dopant material.

[0100] Embodiment 23: The OLED display device of any of embodiments 21 to 22, wherein a concentration of contaminations does not substantially vary throughout the bilayer emitting layer, particularly wherein an interface between the first mixed material layer and the second mixed material layer is contamination-free.

[0101] Embodiment 24: The OLED display device of any of embodiments 21 to 23, wherein the first mixed material layer and the second mixed material layer are deposited on top of each other immediately one after the other by the same evaporation source to provide a contamination-free interface between the first mixed material layer and the second mixed material layer.

[0102] Embodiment 25: The OLED display device of any of embodiments 21 to 23,wherein a concentration of the first dopant material in the first mixed material layer and / or in the second mixed material layer does not exceed 15%, particularly does not exceed 10%.

[0103] Embodiment 26: The OLED display device of any of embodiments 21 to 25, wherein an average concentration of the first dopant material in the first mixed layer is 10% or less, and / or an average concentration of the first dopant material in the second mixed material layer is 10% or less.

[0104] Embodiment 27: The OLED display device of any of embodiments 21 to 26, wherein at least one of the first host material and the second host material comprises at least one of an anthracene derivative, a benzonitrile derivative, an acridine derivative, a triazine derivative, a fluorene derivative, a thiophene derivative and a diphenylsilane derivative.

[0105] Embodiment 28: The OLED display device of any of embodiments 21 to 27, wherein the first dopant material comprises at least one of an anthracene derivative, a perylene derivative, a carbazole derivative, a fluorene derivative, a triazine derivative, an aniline derivative, a styrene derivative and an oxygen-bridged boron derivative.

[0106] Thus, in view of the embodiments described herein, improved evaporation sources and improved deposition methods are provided, particularly for the deposition of OLED bilayer emitting layer. Improved OLED devices, in particular manufactured according to the improved deposition methods described herein, are provided. The embodiments described herein provide an improved quality and an integration of the deposition process into one evaporation source.

[0107] While the foregoing is directed to embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

[0108] In particular, this written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the described subject-matter, including making and using any devices or systems and performing any incorporated methods. While various specificembodiments have been disclosed in the foregoing, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims, if the claims have structural elements that do not differ from the literal language of the claims, or if the claims include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

WHAT IS CLAIMED IS:1 . An evaporation source for depositing at least two layers on a substrate that is moved relative to the evaporation source in a substrate plane, comprising: a first vapor distribution pipe with a row of first nozzles for depositing a first material onto the substrate, a second vapor distribution pipe with a row of second nozzles for depositing a second material onto the substrate, and a third vapor distribution pipe with a plurality of third nozzles for depositing a third material onto the substrate, wherein the row of first nozzles is configured to direct the first material onto a first region in the substrate plane, the row of second nozzles is configured to direct the second material onto a second region in the substrate plane not substantially overlapping with the first region, and the plurality of third nozzles is configured to direct the third material onto a third region in the substrate plane substantially covering both the first region and the second region.

2. The evaporation source of claim 1 , wherein the first, second, and third vapor distribution pipes are configured to deposit, onto the substrate that is moved past the evaporation source, a first mixed material layer comprising the first material and the third material and, on top of the first mixed material layer, a second mixed material layer comprising the second material and the third material.

3. The evaporation source of claim 1 , wherein the first region and the second region are substantially distinct from each other, particularly wherein an overlap area of the first and second regions is less than 10% of the first region and less than 10% of the second region.

4. The evaporation source of claim 1 , wherein the third region is essentially congruent with a deposition area consisting of the first region and the second region, particularly wherein an overlap area of the third region and the deposition area is 90% or more of the third region and 90% or more of the deposition area.

5. The evaporation source according to any of claim 1 , wherein- the first vapor distribution pipe is in fluid communication with a first host material crucible configured to evaporate a first host material;- the second vapor distribution pipe is in fluid communication with a second host material crucible configured to evaporate a second host material; and- the third vapor distribution pipe is in fluid communication with a dopant material crucible configured to evaporate a dopant material.

6. The evaporation source of claim 1 , wherein the plurality of third nozzles is provided as a single row of third nozzles arranged between the row of first nozzles and the row of second nozzles, the single row of third nozzles configured to direct the third material onto the third region in the substrate plane that substantially covers both the first region and the second region.

7. The evaporation source of claim 1 , wherein the plurality of third nozzles comprises a first row of third nozzles and a second row of third nozzles arranged between the row of first nozzles and the row of second nozzles, the first row of third nozzles configured to direct the third material onto a first part of the third region, that substantially overlaps with the first region, and the second row of third nozzles configured to direct the third material onto a second part of the third region, that substantially overlaps with the second region.

8. The evaporation source according to claim 1 , further comprising a shielding device configured to restrict vapor plumes emitted by at least one of the first nozzles, the second nozzles, and the third nozzles in a lateral direction.

9. The evaporation source according to claim 8, wherein the shielding device is configured to limit vapor plumes emitted by the first nozzles and by the second nozzles to a maximum opening angle of 60° or less in a lateral direction.

10. The evaporation source according to claim 8, wherein the shielding device is configured to laterally limit first vapor plumes emitted by the first nozzles and second vapor plumes emitted by the second nozzles to not substantially overlap with each other in the substrate plane, particularly wherein the shielding device comprises at least one first shielding plate that is arranged in front of at least one of the first, secondand third vapor distribution pipes between a first vapor plume propagation space and a second vapor plume propagation space.

11. The evaporation source according to claim 8, wherein the shielding device comprises at least one second shielding plate configured to shape third vapor plumes emitted by the plurality of third nozzles such that the third region does not substantially cover an intermediate region between the first region and the second region in the substrate plane.

12. The evaporation source according to claim 1 , wherein the first material and the second material comprise an organic material, particularly an organic semiconductor material.

13. The evaporation source according to claim 1 , wherein the first, the second, and the third vapor distribution pipe are mounted on a source body that is rotatable around a rotation axis.

14. The evaporation source according to claim 13, further comprising a shield arrangement that partially surrounds the source body and comprises an idle shield and a shaper shield, the source body being rotatable relative to the shield arrangement between an idle position, in which the first nozzles, the second nozzles, and the third nozzles are directed toward the idle shield, and a deposition position, in which at least one of the first nozzles, the second nozzles, and the third nozzles are aligned with one or more slits in the shaper shield configured to laterally limit vapor plumes emitted by at least one of the first nozzles, the second nozzles, and the third nozzles.

15. A method for depositing at least two layers on a substrate with an evaporation source comprising a first vapor distribution pipe with a row of first nozzles, a second vapor distribution pipe with a row of second nozzles, and a third vapor distribution pipe with a plurality of third nozzles, the method comprising: transporting the substrate past the evaporation source in a substrate plane while directing a first material toward the substrate from the first nozzles, a second material toward the substrate from the second nozzles, and a third material toward the substrate from the third nozzles;wherein the row of first nozzles directs the first material onto a first region in the substrate plane, the row of second nozzles directs the second material onto a second region in the substrate plane not substantially overlapping with the first region, and the plurality of third nozzles directs the third material onto a third region in the substrate plane substantially covering both the first region and the second region, so that a first mixed material layer comprising the first material and the third material and a second mixed material layer comprising the second material and the third material are deposited on top of each other on the substrate.

16. The method of claim 15, wherein the first region and the second region are defined by a shielding device that limits first vapor plumes emitted by the first nozzles and second vapor plumes emitted by the second nozzles in a lateral direction.

17. The method of any of claim 15, wherein the first material, the second material and the third material are an organic material.

18. The method of any of claim 15, wherein the first mixed material layer is a first bilayer emitting layer and the second mixed material layer is a second bilayer emitting layer of an organic light-emitting diode, OLED, and wherein the third material is a dopant material.

19. The method of any of claim 15, wherein the substrate is transported from the first region to the second region in at most one second.

20. The method of any of claim 15, wherein a concentration of the third material in the first mixed material layer and in the second mixed material layer does not exceed 15%.21 . An OLED display device, comprising: a substrate; a plurality of pixels respectively comprising:an anode layer, a cathode layer, and a co-evaporated bilayer emitting layer comprising two stacked co-evaporation layers between the anode layer and the cathode layer, the bilayer emitting layer comprising: a first mixed material layer comprising a first host material and a first dopant material; a second mixed material layer directly on top of the first mixed material layer comprising a second host material and the first dopant material.

22. The OLED display device of claim 21 , wherein the first mixed material layer comprises the first host material and the first dopant material; and the second mixed material layer comprises the second host material and the first dopant material.

23. The OLED display device of claim 21 , wherein a concentration of contaminations does not substantially vary throughout the bilayer emitting layer, particularly wherein an interface between the first mixed material layer and the second mixed material layer is contamination-free.

24. The OLED display device of claim 21 , wherein the first mixed material layer and the second mixed material layer are deposited on top of each other immediately one after the other by the same evaporation source to provide a contamination-free interface between the first mixed material layer and the second mixed material layer.

25. The OLED display device of claims 21 , wherein a concentration of the first dopant material in the first mixed material layer and / or in the second mixed material layer does not exceed 15%, particularly does not exceed 10%.

26. The OLED display device of claim 21 , wherein an average concentration of the first dopant material in the first mixed layer is 10% or less, and an average concentration of the first dopant material in the second mixed material layer is 10% or less.

27. The OLED display device of claim 21 , wherein at least one of the first host material and the second host material comprises at least one of an anthracene derivative, a benzonitrile derivative, an acridine derivative, a triazine derivative, a fluorene derivative, a thiophene derivative and a diphenylsilane derivative.

28. The OLED display device of claim 21 , wherein the first dopant material comprises at least one of an anthracene derivative, a perylene derivative, a carbazole derivative, a fluorene derivative, a triazine derivative, an aniline derivative, a styrene derivative and an oxygen-bridged boron derivative.

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