OLED lighting device

Abstract

Organic light-emitting diode (OLED) lighting device (200), comprising: a substrate (210); an auxiliary wiring (220) arranged on the substrate (210); a protective layer (225) covering the auxiliary wiring (220), wherein the auxiliary wiring (220) is arranged between the substrate (210) and the protective layer (225); a first electrode (230) comprising a first layer (230a) having a first resistance and arranged between the auxiliary wiring (220) and the protective layer (225) and in direct contact with the auxiliary wiring (220), and a second layer (230b) arranged on the protective layer (225) covering the first layer (230a) and the protective layer (225) and having a second resistance higher than the first resistance; an organic light-emitting layer (240) arranged on the first electrode (230); and a second electrode (250) which is arranged on the organic light-emitting layer (240).

Description

BACKGROUND 1. Field of the invention

[0001] The present disclosure relates to an organic light-emitting diode (OLED) lighting device, and more particularly to an OLED lighting device capable of preventing a defect caused by the step coating of an electrode and improving an aperture ratio. 2. Description of the state of the art

[0002] Currently, fluorescent lamps or incandescent lamps are mainly used as lighting devices. Incandescent lamps, despite a high color rendering index, have very low energy efficiency, while fluorescent lamps have a low color rendering index and contain mercury, which, despite excellent energy efficiency, causes environmental pollution.

[0003] Accordingly, a light-emitting diode (LED) has been proposed as a lighting device that can replace fluorescent lamps or incandescent lamps. Such an LED is made of an inorganic light-emitting material, and its light-emitting efficiency exhibits a maximum value in a blue wavelength band and decreases toward a red wavelength band and a green wavelength band, which has the highest luminosity factor. Accordingly, a method for obtaining white light by combining a red LED, a green LED, and a blue LED exhibits a decrease in light-emitting efficiency. Such a method also exhibits a decrease in color rendering properties due to the narrow width of an emission peak of each LED.

[0004] To overcome such problems, a lighting device configured to emit white light by combining a blue LED and a yellow phosphor has been proposed, rather than combining red, green, and blue LEDs. This is because it is more efficient to use the blue LED, which has higher light emission efficiency than the green LED, and to use a fluorescent material that receives blue light to emit yellow light for the other colors.

[0005] However, the lighting device configured to emit white light by combining the blue LED with the yellow phosphor has a limitation in improving the light emission efficiency because the fluorescent material emitting yellow light has poor light emission efficiency.

[0006] To solve the decline in light emission efficiency, an OLED lighting device was proposed that uses an OLED made of an organic light-emitting material. Generally, compared to an inorganic light-emitting diode, an OLED exhibits quite excellent light emission efficiency in the green and red wavelength ranges. Furthermore, due to a relatively broad emission peak in the blue, red, and green wavelength ranges, an OLED exhibits improved color rendering properties compared to an inorganic light-emitting diode. Consequently, the light generated by the lighting device incorporating an OLED is more similar to sunlight.

[0007] The OLED comprises an anode, a cathode, and an organic light-emitting layer disposed between the anode and the cathode. Since the distance between the anode and the cathode is narrow, the OLED used as a lighting device is prone to pinholes due to foreign substance penetration. Furthermore, cracking, a graded internal structure of the OLED, and the roughness of the stacked layers pose a risk of the anode coming into direct contact with the cathode, causing a short circuit between the anode and the cathode. Furthermore, a short circuit between the anode and the cathode may also occur if the organic light-emitting layer is formed thinner than a predetermined thickness due to a process failure or a process error during the formation of the organic light-emitting layer.

[0008] When a short circuit occurs between the anode and cathode in the lighting device, a short-circuit region forms a low-resistance current path. As a result, current flows only in the short-circuit region, and little or no current flows through other regions of the OLED, causing a reduction in the OLED's emission output or OLED emission failure.

[0009] As a result, the light from the lighting device has a luminance below a predetermined value, causing deterioration in the quality of the lighting device or failure of the lighting device. Furthermore, pixels corresponding to the short-circuit area become defective pixels, causing a decrease in the quality of the lighting device.

[0010] US 8 772 820 B2 and US 2016 / 0 172 618 A1 disclose light-emitting devices.

[0011] US 2017 / 0194387 A1 discloses a blue organic light-emitting device. SUMMARY OF THE INVENTION

[0012] It is an object of the invention to provide an organic light-emitting diode (OLED) lighting device capable of preventing a defect caused by the step coating of an electrode and improving the aperture ratio.

[0013] The problem is solved by the subject matter of the independent claim. Advantageous embodiments and further developments are the subject matter of dependent claims.

[0014] For this purpose, a first electrode having a double-layer structure was introduced into the OLED lighting device according to embodiments of the present disclosure. A first layer of the first electrode may be made of a transparent, low-resistance conductive material for creating a current path, and a second layer of the first electrode may be disposed on a protective layer configured to cover auxiliary wiring of the first layer of the first electrode and made of a transparent, high-resistance conductive material.

[0015] As a result, the first layer of the first electrode, which is made of a transparent conductive material with low resistance, can be disposed under the protective layer, thus maintaining the film quality characteristics. Furthermore, the OLED lighting device according to embodiments of the present disclosure can implement a short-circuit prevention function by means of the second layer of the first electrode with high resistance disposed on the first layer of the first electrode and the protective layer. Therefore, it is not necessary to design an additional short-circuit prevention resistance circuit, thereby improving the aperture ratio.

[0016] Furthermore, in the OLED light device according to embodiments of the present disclosure, since the second layer of the first electrode is coated to completely cover the entire upper portions of the first layer of the first electrode and the protective layer and has a flat surface, the step coating caused by the auxiliary wiring can be completely removed, thereby avoiding dysfunction of the organic light-emitting layer and the second electrode caused by the step coating.

[0017] The OLED lighting device according to embodiments of the present disclosure may include a substrate; auxiliary wiring disposed on the substrate; a protective layer covering the auxiliary wiring, the auxiliary wiring disposed between the substrate and the protective layer; a first electrode including a first layer having a first resistance and disposed between the auxiliary wiring and the protective layer and in direct contact with the auxiliary wiring, and a second layer disposed on the protective layer and covering the first layer and the protective layer and having a second resistance higher than the first resistance; an organic light-emitting layer disposed on the first electrode; and a second electrode disposed on the organic light-emitting layer.

[0018] In other words, the first electrode having a double-layer structure has been introduced into the OLED lighting device according to embodiments of the present disclosure. The first layer of the first electrode may be made of a transparent conductive material with low resistance to create a current path, and the second layer of the first electrode may be disposed on the protective layer, which is configured to cover the auxiliary wiring and the first layer of the first electrode and may be made of a transparent conductive material with high resistance.

[0019] As a result, since the first layer of the first electrode is made of a transparent metal material different from that of the protective layer, there is no risk of damage to the first layer of the first electrode during the protective layer formation process. Even if the first layer of the first electrode is damaged, the damage will not cause a change in the film quality characteristics, thereby improving the reliability of the OLED lighting device.

[0020] Furthermore, the first layer of the first electrode, which is made of a transparent conductive material with low resistance, can be disposed under the protective layer, thus maintaining the film quality characteristics. Furthermore, the OLED lighting device according to embodiments of the present disclosure can implement a short-circuit prevention function by means of the second layer of the first electrode with high resistance disposed on the first layer of the first electrode and the protective layer, and therefore, it is not necessary to design an additional short-circuit prevention circuit, thereby improving the aperture ratio.

[0021] Furthermore, in the OLED light device according to embodiments of the present disclosure, since the second layer of the first electrode is coated to completely cover the entire upper portions of the first layer of the first electrode and the protective layer and has a flat surface, the step coating caused by the auxiliary wiring can be completely removed, thereby avoiding dysfunction of the organic light-emitting layer and the second electrode caused by the step coating.

[0022] In the OLED lighting device according to embodiments of the present disclosure, the first layer of the first electrode made of a transparent conductive material having a low resistance value of 10 to 700 Ω may be disposed between the auxiliary wiring and the protective layer. Since the transparent conductive material constituting the first layer is different from that of the protective layer, there is no risk of damage to the first layer of the first electrode during a process of forming the protective layer. Even if the first layer of the first electrode is damaged, the damage may not cause a change in the film quality characteristics, thereby improving the reliability of the OLED lighting device.

[0023] Furthermore, since the second layer of the first electrode, which is made of a high-resistance film having a high resistance value of 5,000 to 30,000 Ω, can be disposed on the first layer of the first electrode and the protective layer, the sum of the first resistance and the second resistance can be set to 1,000 to 20,000 Ω. As a result, in the OLED lighting device according to embodiments of the present disclosure, a sharp drop in luminance due to a short circuit of a pixel can be prevented without forming an opening and a resistance pattern in the first electrode, thereby avoiding an increase in cost or a decrease in yield resulting from the addition of a process.

[0024] The first layer of the first electrode, which is made of a transparent conductive material with low resistance, can be disposed under the protective layer, thus maintaining the film quality characteristics. Furthermore, the OLED lighting device according to embodiments of the present disclosure can implement a short-circuit prevention function by means of the second layer of the first electrode with high resistance disposed on the first layer of the first electrode and the protective layer. Therefore, it is not necessary to design an additional short-circuit prevention circuit, thereby improving the aperture ratio.

[0025] Furthermore, the OLED light device according to embodiments of the present disclosure may have a step coating caused by the auxiliary wiring, since the second layer of the first electrode is coated to completely cover the entire upper portions of the first layer of the first electrode and the protective layer and has a flat surface, thereby avoiding malfunction of the organic light-emitting layer and the second electrode caused by the step coating.

[0026] In addition, the OLED light device according to embodiments of the present disclosure may further include a light extraction layer disposed on a back surface of the substrate in contact with an outside air layer to minimize light reflection occurring at a surface boundary between the substrate and the outside air layer, thereby improving light extraction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of an OLED lighting device according to a first embodiment of the present disclosure. Fig. Figure 2 is an enlarged cross-sectional view of section A of Fig. 1 Fig. 3 is a cross-sectional view along the line III-III' of Fig. 2 Fig. 4 is a cross-sectional view of an OLED lighting device according to a second embodiment of the present disclosure. Fig. 5 is a mimetic diagram illustrating a process of manufacturing the OLED lighting device according to the second embodiment of the present disclosure. Fig. 6 is a plan view of an OLED lighting device according to a third embodiment of the present disclosure. Fig. Figure 7 is a cross-sectional view along line VII-VII' of Fig. 6 The Fig. 8 to 12 are cross-sectional views of processes illustrated to explain a method of manufacturing the OLED lighting device according to the third embodiment of the present disclosure. Fig. 13 is a cross-sectional view of an OLED lighting device according to a modification of the third embodiment of the present disclosure. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0027] The aforementioned objects, features, and advantages will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily grasp the technical idea of ​​the present disclosure. In the description of the embodiments, the detailed description of known related configurations or functions is omitted if it is considered that such a description may cause an ambiguous interpretation of the present disclosure. Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals denote like or similar elements.

[0028] Hereinafter, an organic light-emitting diode (OLED) lighting device according to preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0029] Fig. 1 is a plan view of an OLED lighting device according to a first embodiment of the present disclosure. Fig. Figure 2 is an enlarged cross-sectional view of section A of Fig. 1. Fig. 3 is a cross-sectional view along the line III-III' of Fig. 2

[0030] Referring to the Fig. 1 to 3, an OLED lighting device 100 according to the first embodiment of the present disclosure may include a substrate 110, a buffer layer 115 disposed on the substrate 110, and an OLED E disposed on the buffer layer 115.

[0031] The OLED E may include a first electrode 130 disposed on the buffer layer 115, an organic light-emitting layer 140 disposed on the first electrode 130, and a second electrode 150 disposed on the organic light-emitting layer 140. With such a structure, the organic light-emitting layer 140 can emit light when a signal is applied to the first electrode 130 and the second electrode 150 of the OLED E, thereby achieving light emission across the entire substrate 110.

[0032] At this time, auxiliary wiring 120 may be arranged in a matrix form on the substrate 110. The auxiliary wiring 120 may be made of a metal material with excellent conductivity to enable the application of a uniform voltage to the first electrode 130 arranged over the entire substrate 110, thereby enabling the OLED lighting device 100 to emit light with uniform luminance even when implemented as a large lighting device. The auxiliary wiring 120 may be arranged between the buffer layer 115 and the first electrode 130 to be in direct contact with the first electrode 130.

[0033] The first electrode 130 may be made of a transparent conductive material, such as indium tin oxide (ITO), and advantageously transmit emitted light. However, the first electrode 130 may have a very high electrical resistance compared to the metal material. Accordingly, when the OLED lighting device 100 is implemented as a large-area lighting device, the current applied to a wide area may not be uniform due to the high resistance of the transparent conductive material. Such uneven current distribution may make it difficult for the large OLED lighting device 100 to emit light with uniform luminance.

[0034] The auxiliary wiring 120 may be arranged in a matrix form over the entire substrate 110 to enable the application of a uniform voltage to the first electrode 130 arranged over the entire substrate 110, thereby enabling the large OLED lighting device 100 to emit light with uniform luminance. For this purpose, the auxiliary wiring 120 may be made of any material selected from Al, Au, Cu, Ti, W, Mo, and Cr, or alloys thereof. The auxiliary wiring 120 may have a single-layer structure or a multi-layer structure.

[0035] The substrate 110 can be divided into a plurality of pixels P by the auxiliary wiring 120 arranged in a matrix form. Since the auxiliary wiring 120 has a much lower resistance than the first electrode 130, the voltage for the first electrode 130 can be applied to the first electrode 130 via the auxiliary wiring 120 instead of being applied directly to the first electrode 130. In this way, the first electrode 130 formed over the entire substrate 110 can be divided into the plurality of pixels P by the auxiliary wiring 120.

[0036] A protective layer 125 may be disposed on the first electrode 130 to cover the auxiliary wiring 120. Since the auxiliary wiring 120 is made of opaque metal, light cannot be emitted from a region where the auxiliary wiring 120 is formed. Therefore, the protective layer 125 may be provided only on portions of a top surface of the first electrode under which the auxiliary wiring 120 is disposed, allowing light to be emitted only from light-emitting regions of the pixels P.

[0037] In addition, the protective layer 125 may be formed to surround the auxiliary wiring 120. The protective layer 125 may be made of an inorganic material such as SiO x or SiN x . Alternatively, the protective layer 125 may be made of an organic material, such as photoacrylic, or may be composed of multiple layers, including an inorganic layer and an organic layer.

[0038] The organic light-emitting layer 140 and the second electrode 150 may be arranged sequentially on the first electrode 130 and the protective layer 125.

[0039] The organic light-emitting layer 140 may be made of an organic light-emitting material that emits white light. For example, the organic light-emitting layer 140 may be made of an organic blue light-emitting layer, an organic red light-emitting layer, and an organic green light-emitting layer. Alternatively, the organic light-emitting layer 140 may have a tandem structure including a blue light-emitting layer and a yellow-green light-emitting layer. However, it should be understood that the organic light-emitting layer 140 according to embodiments of the present disclosure is not limited thereto and may be configured in various forms.

[0040] Although not shown in the drawings, the OLED E may further include: an electron injection layer and a hole injection layer that inject electrons and holes, respectively, into the organic light-emitting layer 140; an electron transport layer and a hole transport layer that transport injected electrons and holes, respectively, to the organic light-emitting layer 140; and a charge generation layer that generates charges such as electrons and holes.

[0041] The organic light-emitting layer 140 may be made of a material that emits light in a visible light range by receiving and combining holes and electrons from the hole-transport layer and the electron-transport layer, respectively. Here, it is preferable to use an organic material with excellent quantum efficiency for fluorescence or phosphorescence. The organic material may be, for example, an 8-hydroxyquinoline aluminum complex (Alq3), a carbazole-based compound, a dimerized styryl compound, a bismethyl-8-hydroxyquinoline-paraphenylphenol aluminum complex (Balq), a 10-hydroxybenzoquinoline metal compound, benzoxazole-, benzthiazole-, and benzimidazole-based compounds, an anthracene-based compound, a pyrene-based compound, a poly(p-phenylenevinylene) (PPV)-based polymer, a spiro compound, polyfluorene, and lubrene, but is not limited to these.

[0042] The second electrode 150 may be made of metal such as Ca, Ba, Mg, Al or Ag, or an alloy thereof.

[0043] The first electrode 130, the organic light-emitting layer 140, and the second electrode 150 can form the OLED E. Here, when voltage is applied to the first electrode 130, which is an anode of the OLED E, and the second electrode 150, which is a cathode of the OLED E, an electron and a hole can be injected from the second electrode 150 and the first electrode 130, respectively, into the organic light-emitting layer 140 to generate an exciton in the organic light-emitting layer 140. When the exciton decays, light can be generated and emitted toward the substrate 110 according to an energy difference between a lowest unoccupied molecular orbital (LUMO) and a highest occupied molecular orbital (HOMO) of the organic light-emitting layer 140.

[0044] In addition, the OLED lighting device 100 according to the first embodiment of the present disclosure may further include an encapsulation layer 160 arranged to cover the second electrode 150 disposed on the substrate 110 provided with the OLED E.

[0045] The encapsulation layer 160 may include an adhesive layer 162 and a base layer 164 disposed on the adhesive layer 162. In this way, the encapsulation layer 160 may be disposed on the substrate 110 provided with the OLED E, and the base layer 164 may adhere to the OLED E through the adhesive layer 162, thereby making it possible to seal the OLED lighting device 100.

[0046] At this time, a photocurable adhesive or a thermosetting adhesive can be used as the adhesive layer 162. The base layer 164, which is arranged to prevent moisture or air from permeating from the outside, can be made of any material as long as it is capable of performing a function of preventing moisture or air permeation. For example, the base layer 164 can be made of a polymer material such as polyethylene terephthalate (PET) or a metal material such as aluminum foil, an Fe-Ni alloy, an Fe-Ni-Co alloy, or the like.

[0047] Referring to the Fig. 2 and Fig. 3, in the OLED lighting device 100 according to the first embodiment, the first electrode 130 may be arranged within the pixel P defined by the auxiliary wiring 120 arranged in a matrix form, and the auxiliary wiring 120 may be electrically connected to the first electrode 130 through a resistance pattern 132 having a relatively high resistance.

[0048] Accordingly, in the OLED lighting device 100 according to the first embodiment, a signal applied to the auxiliary line 120 can be applied to the first electrode 130 via the resistance pattern 132. Thus, it is possible to ensure a sufficiently long signal path if an opening 135 of the first electrode 130 is arranged to surround the edges of the pixel P such that the resistance pattern 132 is sufficiently long. As a result, it is possible to create a short-circuit prevention resistor of a desired size by a design change applied to the opening 135 of the first electrode 130.

[0049] In this way, the opening 135 can be formed by partially removing the first electrode 130 disposed over the auxiliary wiring 120 and the substrate 110, whereby the resistance pattern 132 can be formed from the same material as the first electrode 130.

[0050] However, in the OLED lighting device 100 according to the first embodiment, light cannot be emitted from regions where the auxiliary line 120, the opening 135 of the first electrode 130, and the resistance pattern 132 are arranged, and thus these regions may be covered with the protective film 125, thereby causing a reduction in the overall aperture ratio of the OLED lighting device 100.

[0051] In particular, since the resistance pattern 132 must have a predetermined width and length to obtain a predetermined resistance value, the resistance pattern 132 must occupy a certain area within the pixel P regardless of the area of ​​the pixel P. As a result, the aperture ratio of the OLED lighting device 100 according to the first embodiment can be reduced compared to that of an OLED lighting device not provided with the short-circuit prevention resistor.

[0052] Therefore, when the OLED lighting device 100 is implemented as a high-resolution lighting device with a small pixel size, the aperture ratio of the OLED lighting device may be reduced below a predetermined value, thereby causing a quality defect of the OLED lighting device 100.

[0053] In other words, if a short-circuit prevention resistance is generated by the opening 135 of the first electrode and the resistance pattern 132, the aperture ratio of the pixel P may be reduced, and therefore it is difficult to manufacture a high-resolution OLED lighting device 100.

[0054] To solve this problem, in the OLED lighting device according to the second embodiment of the present disclosure, a high-resistance film having a high resistance value of 1,000 to 20,000 Ω can be applied to the first electrode, thereby eliminating the opening of the first electrode and the resistance pattern, and preventing the generation of short-circuit resistance. As a result, it is possible to solve the problem of a reduction in the aperture ratio.

[0055] The OLED lighting device according to the second embodiment will be described in detail with reference to the accompanying drawings.

[0056] Fig. 4 is a cross-sectional view of the OLED lighting device according to the second embodiment of the present disclosure. In Fig. 4, the same reference numerals are assigned to substantially the same elements as in the first embodiment.

[0057] As in Fig. 4, the OLED lighting device 100 according to the second embodiment of the present disclosure may include a substrate 110, a buffer layer 115 disposed on the substrate 110, and an auxiliary wiring 120 disposed on the buffer layer 115.

[0058] A first electrode 130 made of a high-resistance film having a high resistance value of 1,000 to 20,000 Ω may be disposed on the buffer layer 115 on which the auxiliary wiring 120 is disposed, and a protective layer 125 may be disposed on the first electrode 130 to cover the auxiliary wiring 120.

[0059] An organic light-emitting layer 140 and a second electrode 150 may be sequentially stacked on the protective layer 125 and the first electrode 130, and the encapsulation layer 160 may be disposed on the second electrode 150.

[0060] The OLED lighting device 100 according to the second embodiment can use the high-resistance film having a high resistance value of 1,000 to 20,000 Ω as the first electrode 130 arranged between the auxiliary wiring 120 and the protective layer 125, thereby avoiding a sharp drop in luminance due to a short circuit between the first electrode 130 and the second electrode 150 without generating an additional short-circuit resistance.

[0061] For this purpose, the first electrode 130 may comprise a binder and a conductive material.

[0062] The binder may comprise at least one selected from tetraethylorthosilicate (TEOS), silsesquioxane (SSQ) and polysiloxane.

[0063] The conductive material may comprise at least one selected from poly(3,4-ethylenedioxythiophene) (PEDOT), a carbon nanotube (CNT), graphene, a Cu nanoconductor, an Ag nanoconductor, and an Au nanoconductor.

[0064] At this time, the first electrode 130 can ensure a high resistance of 1,000 to 20,000 Ω by controlling the amount of conductive material added to the binder in an optimal proportion.

[0065] As in the Fig. 2 and Fig. As shown in Figure 3, the first electrode 130 may be made of a material with relatively good conductivity, such as ITO, and thus have a resistance value of approximately 20 Ω. The second electrode 150 may also be made of metal and have a resistance value of approximately 0.1 Ω.

[0066] On the other hand, the organic light-emitting layer 140 may have a resistance value of approximately 1 MΩ. Therefore, if no short-circuit prevention resistor is provided, the resistance of the organic light-emitting layer 140 may be much higher than that of the first electrode 130 and the second electrode 150, and thus the total resistance of the respective pixels may be substantially the same as that of the organic light-emitting layer 140.

[0067] On the other hand, as in Fig. 4, in the OLED lighting device 100 according to the second embodiment of the present disclosure, even if the first electrode 130 and the second electrode 150 of one pixel of the plurality of pixels of the OLED E are in contact with each other and short-circuited, the resistance of the organic light-emitting layer 140 is removed from the short-circuited pixel, and only the resistance caused by the transparent conductive material having a high resistance of the first electrode 130 and the resistance of the second electrode 150 can remain therein.

[0068] That is, in the second embodiment of the present disclosure, the first electrode 130 may have a resistance of 1,000 to 20,000 Ω, and the organic light-emitting layer 140 may have a resistance of about 1 MΩ. Thus, even if the resistance of the organic light-emitting layer 140 is removed from the pixel short-circuited by the contact between the first electrode 130 and the second electrode 150, the resistance of the first electrode 130, which is made of a high-resistance film, can be maintained in the short-circuited pixel, and this resistance is not negligibly small compared to the total resistance of the other pixels.

[0069] Therefore, even if the pixel is short-circuited by the contact between the first electrode 130 and the second electrode 150, the resistance of the OLED E of the short-circuited pixel can be removed, and accordingly, the resistance value of the pixel can become zero. Thus, the total resistance of the short-circuited pixel can be substantially the same as the resistance of the first electrode 130.

[0070] Here, the resistance of the first electrode 130 can be significantly higher than the resistance of the organic light-emitting layer 140. Therefore, the largest current between the first electrode 130 and the second electrode 150 cannot flow through the short-circuited pixel, but some current can flow through the other pixels. At this time, the current flowing through the short-circuited pixel differs in magnitude from that flowing through the other pixels because the total resistance of the short-circuited pixel is different from that of the other pixels, but the current can flow through all the pixels, thereby avoiding a sharp drop in the luminance of the organic light-emitting layer 140 of the plurality of pixels or emission failure.

[0071] As a result, the OLED lighting device 100 according to the second embodiment of the present disclosure can prevent a sharp drop in luminance due to a short circuit of a pixel without forming an opening and a resistance pattern in the first electrode 130 by using the resistance film having a high resistance value of 1,000 to 20,000 Ω as the first electrode 130 arranged between the auxiliary wiring 120 and the protective layer 125, thereby avoiding an increase in cost or a decrease in yield due to the addition of a process.

[0072] Also, since the OLED lighting device 100 according to the second embodiment of the present disclosure uses the high-resistance film having a high resistance value of 1,000 to 20,000 Ω as the first electrode 130 disposed between the auxiliary wiring 120 and the protective layer 125, it is not necessary to form an opening and a resistance pattern in the first electrode 130, thereby avoiding a reduction in the aperture ratio resulting from the formation of the opening and the resistance pattern.

[0073] As described above, the OLED lighting device 100 according to the second embodiment of the present disclosure can solve a problem of a reduction in the aperture ratio by using the high-resistance film having a high resistance value of 1,000 to 20,000 Ω as the first electrode 130 disposed between the auxiliary wiring 120 and the protective layer 125, but may cause a change in the film quality characteristics of the first electrode 130 during a process of forming the protective layer 125 on the first electrode 130 composed of the introduced high-resistance film to improve the aperture ratio.

[0074] Fig. 5 is a mimetic diagram illustrating a process of manufacturing the OLED lighting device according to the second embodiment of the present disclosure, and the manufacturing process will be described in detail with reference to Fig. 5 described.

[0075] As in Fig. 5, the buffer layer 115 and the auxiliary wiring 120 may be formed on the substrate 110 to manufacture the OLED lighting device 100 according to the second embodiment of the present disclosure, and then a first electrode 130 made of the high-resistance film having a high resistance value of 1,000 to 20,000 Ω may be formed on the auxiliary wiring 120 and the buffer layer 115.

[0076] Thereafter, a protective film material may be deposited on the entire upper surface of the first electrode 130, and then, in order to cover the auxiliary wiring 120, the protective layer 125 may be formed by patterning the protective film material by means of a dry etching method using a photomask that selectively covers only a region in which the protective layer is to be formed.

[0077] However, when a dry etching process is performed to form the protective layer 125, since the first electrode 130 consisting of the high resistance film may be a binder on SiO x -base which is substantially the same as the protective film material, the first electrode consisting of the high-resistance film may be damaged during patterning of the protective film material by the dry etching process.

[0078] As a result, there has been a problem that the thickness of the first electrode 130 is less than a predetermined value or a change in the film quality characteristics (surface roughness, resistance, and the like) of the first electrode 130 deteriorates the reliability of the OLED lighting device.

[0079] To solve this problem, a first electrode having a double-layer structure was introduced into an OLED lighting device according to a third embodiment of the present disclosure. A first layer of the first electrode may be made of a low-resistance transparent conductive material for creating a current path, and a second layer of the first electrode may be disposed on a protective layer configured to cover auxiliary wiring and the first layer of the first electrode and made of a high-resistance transparent conductive material.

[0080] As a result, the first layer of the first electrode, which is made of a transparent conductive material with low resistance, can be disposed under the protective layer, and the film quality characteristics can thus remain unchanged. Furthermore, the OLED lighting device according to the third embodiment of the present disclosure can implement a short-circuit prevention function by means of the second layer of the first electrode with high resistance disposed on the first layer of the first electrode and the protective layer, and thus, it is not necessary to design an additional short-circuit prevention resistance circuit, thereby improving the aperture ratio.

[0081] The OLED lighting device according to the third embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0082] Fig. 6 is a plan view of the OLED lighting device according to the third embodiment of the present disclosure. Fig. Figure 7 is a cross-sectional view along line VII-VII' of Fig. 6.

[0083] Referring to the Fig. 6 and Fig. 7, an OLED lighting device 200 according to the third embodiment of the present disclosure may include a substrate 210, an auxiliary wiring 220, a protective layer 225, a first electrode 230, an organic light-emitting layer 240, and a second electrode 250.

[0084] The substrate 210 may be made of a transparent glass material. Alternatively, the substrate 210 may be made of a polymer material with flexible properties.

[0085] The auxiliary wiring 220 may be arranged on the substrate 210. At this time, a buffer layer 215 may further be arranged between the substrate 210 and the auxiliary wiring 220. The buffer layer 215 may serve to shield permeation of moisture and air from a lower portion of the substrate 210. For this purpose, the buffer layer 215 may be made of an inorganic material, such as SiO x , SiN x or the like.

[0086] The auxiliary wiring 220 can be arranged in a matrix form on the substrate 210 to divide the substrate 210 into multiple pixels and enable the application of a uniform voltage to the first electrode 230, thereby enabling the large OLED lighting device 100 to emit light with a uniform luminance. For this purpose, the auxiliary wiring 220 can be made of any material selected from Al, Au, Cu, Ti, W, Mo, and Cr, or alloys thereof. The auxiliary wiring 220 can have a single-layer structure or a multi-layer structure.

[0087] Since the auxiliary wiring 220 has a much lower resistance than the first electrode 230, the voltage for the first electrode 230 can be applied to the first electrode 230 via the auxiliary wiring 220 instead of being applied directly to the first electrode 230. Therefore, the first electrode 230 formed over the entire substrate 210 can be divided into the plurality of pixels by the auxiliary wiring 220.

[0088] The protective layer 225 may be formed to surround the auxiliary wiring 220. The protective layer 225 may be made of an inorganic material such as SiO x , SiN x or the like.

[0089] The first electrode 230 may be disposed between the auxiliary wiring 220 and the protective layer 225 to be in direct contact with the auxiliary wiring 220. The first electrode 230 may include a first layer 230a having a first resistance and a second layer 230b configured to cover the first layer 230a and the protective layer 225 and having a second resistance higher than the first resistance.

[0090] The first layer 230a of the first electrode 130 may be made of a transparent conductive material comprising any one selected from ITO, indium zinc oxide (IZO), and indium tin zinc oxide (ITZO) having relatively good conductivity, and accordingly, the first resistor may have a low resistance value of 10 to 700 Ω.

[0091] The second layer 230b of the first electrode 230 may cover entire upper portions of the first layer of the first electrode and the protective layer and have a flat surface.

[0092] The second layer 230b of the first electrode 230 may include a binder and a conductive material.

[0093] The binder may comprise at least one selected from TEOS, SSQ and polysiloxane.

[0094] The conductive material may comprise at least one selected from PEDOT, a CNT, graphene, a Cu nanoconductor, an Ag nanoconductor, and an Au nanoconductor.

[0095] At this time, the second layer 230b of the first electrode 230 can ensure a high resistance of 5,000 to 30,000 Ω by controlling the amount of conductive material added to the binder at an optimal ratio. That is, it is preferable to control the resistance of the second layer 230b of the first electrode 230 to be higher than that of the first electrode 130 of the second embodiment (130 of Fig. 4) to set the sum of the first resistance and the second resistance to 1,000 to 20,000 Ω.

[0096] For this purpose, the second layer 230b of the first electrode 230 may preferably contain 5 to 30 parts by weight of the conductive material relative to 100 parts by weight of the binder. If the amount of the conductive material is less than 5 parts by weight relative to 100 parts by weight of the binder, the amount of conductive material to be added is insufficient, which may result in a loss of conductivity. In contrast, if the amount of the conductive material is more than 30 parts by weight relative to 100 parts by weight of the binder, the resistance of the second layer 230b may be reduced due to excessive addition of the conductive material, and thus, in this case, it may be difficult to ensure a high resistance value of 5,000 to 30,000 Ω.

[0097] In addition, the second layer 230b of the first electrode 230 may further include an additive such as a leveling agent and a surfactant. Such an additive may be added in an amount of 2 parts by weight or less with respect to 100 parts by weight of the binder.

[0098] As in the Fig. 3 and Fig. As shown in Figure 4, according to the first and second embodiments of the present disclosure, the protective layer 125 can partially reduce the step coating caused by the auxiliary wiring 120, but it is difficult to completely remove the step coating caused by the auxiliary wiring 120. As a result, the organic light-emitting layer 140 and the second electrode 150 stacked on the first electrode 130 can be separated.

[0099] On the other hand, as in the Fig. 6 and Fig. 7, in the OLED lighting device 200 according to the third embodiment of the present disclosure, the second layer 230b of the first electrode 230 may be coated to cover the entire upper portions of the first layer 230a of the first electrode 230 and the protective layer 225 and have a flat surface, so that the step coating caused by the auxiliary wiring 220 is completely removed, thereby avoiding interrupted malfunction of the organic light-emitting layer 240 and the second electrode 250 caused by the step coating.

[0100] The organic light-emitting layer 240 may be disposed on the first electrode 230, and the second electrode 250 may be disposed on the organic light-emitting layer 240.

[0101] The organic light-emitting layer 240 may be made of an organic light-emitting material that emits white light. For example, the organic light-emitting layer 240 may be made of an organic blue light-emitting layer, an organic red light-emitting layer, and an organic green light-emitting layer. Alternatively, the organic light-emitting layer 240 may have a tandem structure including a blue light-emitting layer and a yellow-green light-emitting layer. However, it should be understood that the organic light-emitting layer 240 of the present disclosure is not limited thereto and may be configured in various forms.

[0102] Although not shown in the drawings, the OLED E may further include: an electron injection layer and a hole injection layer that inject electrons and holes into the organic light-emitting layer 240; an electron transport layer and a hole transport layer that transport injected electrons and holes, respectively, to the organic light-emitting layer 240; and a charge generation layer that generates charges such as electrons and holes.

[0103] The organic light-emitting layer 240 can be made of a material that emits light in a visible light range by receiving and combining holes and electrons from the hole-transport layer and the electron-transport layer, respectively. Here, it is preferable to use an organic material with excellent quantum efficiency for fluorescence or phosphorescence. The organic material can be, for example, an 8-hydroxyquinoline aluminum complex (Alq3), a carbazole-based compound, a dimerized styryl compound, a bismethyl-8-hydroxyquinoline-paraphenylphenol aluminum complex (Balq), a 10-hydroxybenzoquinoline metal compound, benzoxazole-, benzthiazole-, and benzimidazole-based compounds, an anthracene-based compound, a pyrene-based compound, a poly(p-phenylenevinylene) (PPV)-based polymer, a spiro compound, polyfluorene, and lubrene, but is not limited to these.

[0104] The second electrode 250 may be made of metal such as Ca, Ba, Mg, Al or Ag or an alloy thereof.

[0105] At this time, the first electrode 230, the organic light-emitting layer 240, and the second electrode 250 can form the OLED E. Here, when voltage is applied to the first electrode 230, which is an anode of the OLED E, and the second electrode 250, which is a cathode of the OLED E, an electron and a hole can be injected from the second electrode 250 and the first electrode 230 into the organic light-emitting layer 240, respectively, to generate an exciton in the organic light-emitting layer 240. When the exciton decays, light can be generated according to an energy difference between a LUMO and a HOMO of the organic light-emitting layer 240 and emitted toward the substrate 210.

[0106] In addition, the OLED lighting device 200 according to the third embodiment of the present disclosure may further include an encapsulation layer 260.

[0107] The encapsulation layer 260 may be arranged to cover an upper portion of the substrate 210 150 on which the OLED E is arranged, so that the OLED E is sealed.

[0108] The encapsulation layer 260 may include an adhesive layer 262 and a base layer 264 disposed on the adhesive layer 262. In this way, the encapsulation layer 260, including the adhesive layer 262 and the base layer 264, may be disposed on the substrate 210 having the OLED E, and the base layer 264 may be adhered to the OLED E by the adhesive layer 262, thereby making it possible to seal the OLED lighting device 200.

[0109] At this time, a photocurable adhesive or a thermosetting adhesive can be used as the adhesive layer 262. The base layer 264, which is arranged to prevent moisture or air from permeating from the outside, can be made of any material as long as it can perform a function of preventing moisture or air permeation. For example, the base layer 264 can be made of a polymer material such as PET, or a metal material such as aluminum foil, an Fe-Ni alloy, an Fe-Ni-Co alloy, or the like.

[0110] In the OLED lighting device 200 according to the third embodiment of the present disclosure, the buffer layer 215 and the auxiliary wiring 220 may be disposed on the substrate 210. Also, a first layer 230a of the first electrode 230 made of a transparent conductive material with relatively good conductivity, such as ITO, may be disposed on the auxiliary wiring 220 and the buffer layer 215, and a second layer 230b of the first electrode 230 made of a high-resistance film with a high resistance value of 5,000 to 30,000 Ω may be disposed on the first layer 230a of the first electrode 230 and the protective layer 225. Accordingly, the first electrode 230 may have a double-layer structure including the first layer 230a and the second layer 230b.

[0111] At this time, the first layer 230a of the first electrode 230, made of a transparent conductive material with a low resistance value of 10 to 700 Ω, can be disposed between the auxiliary wiring 220 and the protective layer 225. Therefore, even if a protective film is deposited on the entire surface of the first layer 230a of the first electrode 230 and then the protective film material is selectively patterned by a dry etching process using a photomask, there is no risk of damage to the first layer 230a of the first electrode 230 because the first layer 230a of the first electrode 230 is made of a transparent metal material different from the protective film material. Even if the first layer 230a of the first electrode 230 is damaged, the damage cannot cause a change in the film quality characteristics, thereby improving the reliability of the OLED lighting device 200.

[0112] Furthermore, since the second layer 230b of the first electrode 230 made of the high-resistance film having a high resistance value of 5,000 to 30,000 Ω is disposed on the first layer 230a of the first electrode 230 and the protective layer 225 in the same manner as in the OLED lighting device according to the second embodiment of the present disclosure, the sum of the first resistance and the second resistance can be set to 1,000 to 20,000 Ω. As a result, the OLED lighting device 200 according to the third embodiment of the present disclosure can prevent a sharp drop in luminance due to a short circuit of a pixel without forming an opening and a resistance pattern in the first electrode 230, thereby avoiding a cost increase or yield reduction due to the addition of a process.

[0113] The first layer 230a of the first electrode 230, made of a transparent conductive material with low resistance, can be disposed under the protective layer, thus maintaining the film quality characteristics. Furthermore, the OLED lighting device 200 according to the third disclosure of the present invention can implement a short-circuit prevention function by means of the second layer 230b of the first electrode 230 with high resistance disposed on the first layer 230a of the first electrode 230 and the protective layer 225. Thus, it is not necessary to design an additional short-circuit prevention resistance circuit, thereby improving the aperture ratio.

[0114] Furthermore, the OLED lighting device 200 according to the third embodiment of the present disclosure can cause complete step coating by the auxiliary wiring 220, since the second layer 230b of the first electrode 230 is coated to completely cover the entire upper portions of the first layer 230a of the first electrode 230 and the protective layer 224 and has a flat surface, thereby avoiding interrupted malfunction of the organic light-emitting layer 240 and the second electrode 250 caused by the step coating.

[0115] Hereinafter, a method of manufacturing the OLED lighting device according to the third embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0116] The Fig. 8 to 12 are cross-sectional views of processes illustrated to explain the method of manufacturing the OLED lighting device according to the third embodiment of the present disclosure.

[0117] As in Fig. As shown in FIG. 8, after forming a metal layer (not shown) by depositing a metal material comprising any one selected from Al, Au, Cu, Ti, W, Mo, and Cr, or alloys thereof, on the substrate 210, selective patterning may be performed using a photomask to form the auxiliary wiring 220 consisting of a single layer or multiple layers. At this time, the auxiliary wiring 220 may be arranged in a matrix form over the entire substrate 210, but the matrix form is only an example. The auxiliary wiring 220 may be arranged in a mesh form, a hexagonal shape, an octagonal shape, a circular shape, or the like.

[0118] A buffer layer 215 may further be formed on the entire surface of the substrate 210 before the auxiliary wiring 220 is formed. The buffer layer 215 may serve to shield the permeation of moisture and air from a lower portion of the substrate 210. For this purpose, the buffer layer 215 may be made of an inorganic material, such as SiO x , SiN x or the like.

[0119] As in Fig. As shown in Figure 9, the first layer 230a of the first electrode 230 may be formed by depositing a transparent conductive material comprising any one selected from ITO, IZO, and ITZO, which have relatively good conductivity, on the substrate 210 on which the auxiliary wiring 220 is formed, and performing selective patterning with a photomask. Accordingly, the first layer 230a of the first electrode 230 may be in direct contact with the auxiliary wiring 220 and include the first resistor having a low resistance value of 10 to 700 Ω.

[0120] As in Fig. 10, a protective film material such as SiO x or SiN x, may be deposited on the first layer 230a of the first electrode 230, and then the protective layer 225 may be formed to cover the auxiliary wiring 20 by patterning the protective film material by a dry etching method using a photomask that selectively covers only a region in which the protective layer is to be formed.

[0121] At this time, according to the third embodiment of the present disclosure, when selective patterning is performed by the dry etching method using the photomask, there is no risk of damage to the first layer 230a of the first electrode 230 of the first layer, since the first electrode 230 is made of a transparent metal material different from the protective film material. Even if the first layer 230a of the first electrode 230 is damaged, the damage may not cause a change in the film quality characteristics, thereby improving the reliability of the OLED lighting device 200.

[0122] As in Fig. 11, a high-resistance film having a second resistance higher than the first resistance may be applied to the substrate where the first layer 230a of the first electrode 230 and the protective layer 225 are formed, and cured to form the second layer 230b of the first electrode 230.

[0123] At this point, the high-resistance film may include a binder, a conductive material, and a solvent. That is, the high-resistance film may be applied to the substrate 210 in a liquid state by mixing the binder and conductive material with a solvent such as propylene glycol monomethyl ether acetate (PGMEA), and then solidified through a curing process. During the curing process, the solvent may evaporate and be removed.

[0124] The binder may comprise at least one selected from TEOS, SSQ and polysiloxane.

[0125] The conductive material may comprise at least one selected from PEDOT, a CNT, graphene, a Cu nanoconductor, an Ag nanoconductor, and an Au nanoconductor.

[0126] At this time, the second layer 230b of the first electrode 230 can ensure a high resistance value of 5,000 to 30,000 Ω by controlling the amount of conductive material added to the binder at an optimal ratio. At this time, it is possible to set the sum of the first resistance and the second resistance to 1,000 to 20,000 Ω by adjusting the resistance of the second layer 230b of the first electrode 230 to have a high resistance value of 5,000 to 30,000 Ω.

[0127] For this purpose, the second layer 230b of the first electrode 230 may preferably comprise 5 to 30 parts by weight of the conductive material with respect to 100 parts by weight of the binder.

[0128] As in Fig. As shown in Figure 12, after forming the organic light-emitting layer 230 by depositing an organic light-emitting material on the second layer 230b of the first electrode 230, a metal such as Ca, Ba, Mg, Al, and Ag may be deposited on the organic light-emitting layer 240 and selectively etched to form the second electrode 250. The first electrode 230, the organic light-emitting layer 240, and the second electrode 250 may form the OLED E.

[0129] Thereafter, an adhesive layer 262 may be formed by applying an adhesive made of a photocurable adhesive material or a thermosetting adhesive material to the substrate 210 on which the OLED E is formed, and then a base layer 264 may be disposed on the adhesive layer 262. In this state, the base layer 264 may be bonded to the OLED E by thermocompression to seal the OLED E formed on the substrate 210. At this time, the adhesive layer 262 and the base layer 264 may form the encapsulation layer 260.

[0130] Fig. 13 is a cross-sectional view of an OLED lighting device according to a modification of the third embodiment of the present disclosure. The OLED lighting device according to the modification of the third embodiment of the present disclosure has the same configuration as that according to the third embodiment of the present disclosure, except that the OLED lighting device according to the modification of the third embodiment further includes a light extraction layer. Thus, the description of the same configuration is omitted.

[0131] Referring to Fig. 13, the OLED lighting device 200 according to the modification of the third embodiment of the present disclosure may further include a light extraction layer 270 disposed on a back surface of the substrate 210.

[0132] The light extraction layer 270 may be disposed at a surface boundary between the substrate 210 and an outside air layer to reduce the light reflection occurring at the surface boundary between the substrate 210 and the outside air layer, thereby improving the extraction efficiency of the light emitted from this organic light-emitting layer 240.

[0133] The light extraction layer 270 can be configured in various forms. For example, the light extraction layer 270 can be composed of multiple layers, and the refractive index of the multiple light extraction layers 270 can be reduced from the substrate 210 toward the outside air layer to reduce the angle of the light totally reflected at the surface boundary between the substrate 210 and the outside air layer, thereby improving the light extraction efficiency.

[0134] The light extraction layer 270 may include light scattering particles 275 to scatter incident light at a surface boundary between the light extraction layer 270 and the outside air layer, thereby minimizing the light reflected at the surface boundary between the light extraction layer 270 and the outside air layer.

[0135] For this purpose, the light-scattering particles 275 may be randomly dispersed in the light-extraction layer 270. At this time, it is preferable to use light-scattering particles with a high reflection index as the light-scattering particles 275. Specifically, the light-scattering particles 275 may include at least one selected from TiO2, Ba-TiO3, ZrO2, ZnO, SiO2, and SiO.

[0136] Therefore, the light extraction layer 270 can be configured in any currently known structures as long as it is capable of improving the light extraction efficiency by minimizing the reflection of light incident at the surface boundary between the light extraction layer 270 and the outside air layer.

[0137] At this point, as in Fig. As shown in Figure 13, the light extraction layer 270 may be disposed on the back side of the substrate 210, but the location of the light extraction layer 270 is not limited thereto. That is, although not shown in the drawings, the light extraction layer 270 may also be disposed between the substrate 210 and the buffer layer 215.

[0138] Therefore, in the OLED lighting device 200 according to the modification of the third embodiment of the present disclosure, the light extraction layer 270 may be disposed on the back surface of the substrate 210, which is in contact with the outside air layer, to minimize the light reflection occurring at the surface boundary between the substrate 210 and the outside air layer, thereby improving the light extraction efficiency. [Description of reference symbols] 200 OLED lighting device 210 Substrat 215 Buffer layer 220 Auxiliary wiring 225 protective layer 230 first electrode 230a first layer of the first electrode 230b second layer of the first electrode 240 organic light-emitting layer 250 second electrode 260 encapsulation layer 262 Adhesive layer 264 Base layer

Claims

[1] Organic light-emitting diode, OLED, lighting device (200), comprising: a substrate (210); an auxiliary wiring (220) arranged on the substrate (210); a protective layer (225) covering the auxiliary wiring (220), the auxiliary wiring (220) being arranged between the substrate (210) and the protective layer (225); a first electrode (230) comprising a first layer (230a) having a first resistance and disposed between the auxiliary wiring (220) and the protective layer (225) and in direct contact with the auxiliary wiring (220), and a second layer (230b) disposed on the protective layer (225) and covering the first layer (230a) and the protective layer (225) and having a second resistance higher than the first resistance; an organic light-emitting layer (240) disposed on the first electrode (230); and a second electrode (250) arranged on the organic light-emitting layer (240). [2] The OLED lighting device (200) of claim 1, wherein the first layer of the first electrode (230a) comprises any material selected from indium tin oxide, ITO, indium zinc oxide, IZO, and indium tin zinc oxide, ITZO. [3] The OLED lighting device (200) according to claim 1 or 2, wherein the first resistor has a resistance value of 10 to 700 Ω, and the second resistor has a resistance value of 5000 to 30000 Ω. [4] The OLED lighting device (200) according to any one of claims 1 to 3, wherein the first electrode (230) has a resistance value of 1000 to 20000 Ω by the sum of the first resistance and the second resistance. [5] The OLED lighting device (200) according to any one of claims 1 to 4, wherein the second layer of the first electrode (230b) is configured to cover the entire upper portions of the first layer of the first electrode and the protective layer (225) and has a flat surface. [6] The OLED lighting device according to any one of claims 1 to 5, wherein the second layer of the first electrode (230b) comprises 5 to 30 parts by weight of a conductive material with respect to 100 parts by weight of a binder. [7] The OLED lighting device (200) according to claim 6, wherein the binder comprises at least one selected from tetrahydrothorosilicate, TEOS, silsesquioxane, SSQ, and polysiloxane. [8] The OLED lighting device (200) according to claim 6 or 7, wherein the conductive material comprises at least one selected from poly(3,4-ethylenedioxythiophene), PEDOT, a carbon nanotube, CNT, graphene, a Cu nanoconductor, an Ag nanoconductor, and an Au nanoconductor. [9] OLED lighting device (200) according to one of claims 1 to 8, further comprising: a light extraction layer (270) arranged between the substrate (210) and a buffer layer (215), or on a back side of the substrate (210). [10] The OLED lighting device (200) of claim 9, wherein the light extraction layer (270) comprises light scattering particles. [11] The OLED lighting device (200) according to claim 10, wherein the light scattering particles comprise at least one selected from TiO2, BaTiO3, ZrO2, ZnO, SiO2 and SiO. [12] OLED lighting device (200) according to one of claims 1 to 11, further comprising: a buffer layer (215) arranged between the substrate (210) and the auxiliary wiring (220); and an encapsulation layer (260) disposed on the second electrode (250), wherein the encapsulation layer (260) is configured to seal the first electrode (230), the organic light-emitting layer (240), and the second electrode (250) stacked on the substrate (210).

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