TW200830933A - High efficiency organic light emitting diode and manufacturing method thereof - Google Patents

Abstract

A high efficiency organic light emitting diode (OLED) and a manufacturing method are disclosed. The OLED apparatus includes a substrate, a first electrically conductive layer, a hole-transporting-layer, a doped emissive-layer, an electron-transporting-layer, an electron-injection-layer and a second electrically conductive layer. The arrangement from bottom to top is the substrate, the first electrically conductive layer, the hole-transporting-layer, the doped emissive-layer, the electron-transporting-layer, the electron-injection-layer and the second electrically conductive layer. The emissive layer is composed of one host material and more than one light-emitting guest materials. The barrier for carrier, hole or electron, to inject into the host is smaller than that into the guest(s).

Description

200830933 VIII. If there is a chemical series in this case, please uncover the chemical formula that can show the characteristics of the invention: IX. Description of the invention: [Technical Field] The present invention relates to an organic light-emitting diode and a method of manufacturing the same, wherein the diode The composition of the middle luminescent layer comprises a host material and more than one guest material, and the energy barrier of the electron or hole carrier injected into the body is less than the energy barrier of the implanted object. [Prior Art] Organic Electroluminescence Display (Organic Electroluminescence Display) is also known as Organic Light Emitting Diode (OLED) in 1987 by Kodak's CW Tang and SA • VanSlyk et al., the first to use vacuum evaporation method, respectively, the hole transport material and the electron transport material are plated on transparent indium tin oxide (ITO) glass, and then vapor-deposited a metal. The electrode forms a self-luminous OLED device, which is new because it has a 咼 度 、, fast response speed, light and thin, full color, no viewing angle difference, no need for liquid crystal display backlight, and saves light source and power consumption. A generation of displays. Please refer to the first figure, which is a structural cross-sectional view of the 200830933 OLED device according to one of the conventional ones. In this embodiment, the OLED device is configured to include a transparent substrate 11 , an indium tin Oxide (IT0), and a hole transport layer 13 (HTL) in order from bottom to top. An organic light emitting layer 14 (electron transporting layer), an electron transport layer 15 (electron transporting Lay er, ETL), an electron injecting layer 16 (electron

Injection Layer, EIL) and a metal cathode 17. When a forward bias voltage is applied, the hole 131 is injected from the anode 12, and the electron 151 φ is injected from the cathode 17, and the potential difference caused by the applied electric field causes the electron 151 and the hole 131 to move in the film, thereby Organic Luminescence • Recombination occurs in layer 14. Part of the energy released by the electron hole combination excites the luminescent molecules of the organic luminescent layer 14 to become an excited state. When the luminescent molecules decay from the excited state to the ground state, a certain proportion of the energy is released in the form of photons, and the emitted Light is organic electroluminescence. Please refer to the second figure, which is a cross-sectional view of a conventional OLED device according to the prior art, which is described in U.S. Patent No. 4,356,429, issued toK.W. . In this embodiment, the OLED device is constructed to sequentially include a transparent substrate 21, a transparent anode 22, a hole injection layer 23, a light-emitting layer 24, and a metal cathode 25 from bottom to top. When a forward bias voltage is applied, the holes are injected from the anode 22, and electrons are injected from the cathode 25, causing electrons and holes to move in the film due to the potential difference caused by the applied electric field, thereby generating in the light-emitting layer 24. 200830933 Coverage. Part of the energy released by the electron hole combination excites the luminescent molecules of the luminescent layer 24 to become an excited state. When the luminescent molecules sorrow from the excited state to the ground state, a certain proportion of the energy is released in the form of photons, and the emitted Light is organic electroluminescence. Please refer to the third figure, which is also a cross-sectional view of a conventional OLED device structure. This structure was proposed by Kodak Company, C. W. Tang, in U.S. Patent No. 4,720,432. In this embodiment, the OLED device has a transparent substrate 31, a transparent anode 32, a hole injection layer 33, an electron-emitting layer 34, and a metal cathode 35, which are sequentially arranged from bottom to top. When a forward biased tortoise is applied, the hole is injected by the anode 32, and the electron is injected from the cathode 35. The potential difference caused by the applied electric field causes the electron and the hole to move in the film, and then Lamination occurs in the luminescent layer 34. Part of the energy released by the combination of the pen holes, the luminescent molecules of the luminescent layer are excited to become an excited state. When the luminescent molecules decay from the excited state to the ground state, a certain proportion of the energy is released in the form of photons, and the Φ is released. The light is organic electroluminescence. Please refer to the fourth figure, which is a conventional OLED device. The structure is proposed by Saito et al., 1992, and U.S. Patent No. 5,085,946. The structure of the OLED device includes a transparent substrate 41, a sequence from bottom to top. The transparent anode 42 , the hole transport layer 43 , the light-emitting layer 44 having an electron transport function, and a metal cathode 45 can generate organic electroluminescence. </ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; An organic electroluminescence can also be produced by the light-emitting layer 53, which has a hole-passing function, an electron-transport layer 54, and a metal cathode 55. Please refer to the sixth picture for c w Tang et al. at J〇urnal 〇f

Modified OLED device proposed in Applied Physics, vol. 65, p. 361 〇 989) The structure of the LED device includes a transparent substrate 61, a transparent anode 62, and a hole transport layer from bottom to top. 63. A single component luminescent layer 64, a doped dye-containing luminescent layer 65, a single component luminescent layer 66, and a metal cathode 67 may also produce organic electroluminescence. Please refer to the seventh figure, which is a doped OLED device proposed by C. H. Chen et al. in Applied Physics Letters, Vol. 85, pp. 33〇1 (2〇〇4). The structure of the OLED device is from bottom to top. The sequence includes a transparent substrate 71, a transparent anode 72, a hole injection layer 73, a hole transport layer 74, a doped dye-containing light-emitting layer 75, an electron transport layer 76, and an electron-injecting layer. 77 and the "metal cathode 78" can produce organic electricity. Please refer to the eighth figure, which is an OLED device proposed by SeT. Lee et al. in Advaneed Flm Cti〇nal Materials, Vol. 15, i7i6 (2〇〇5). The structure of the LED t is sequentially included from bottom to top. A transparent substrate 81, an anode 82, a hole injection layer 200830933, a hole transport layer 84, a single component light-emitting layer 85, an electron injection layer 86, and a metal cathode 87 can also produce organic electroluminescence. . The inventor has been engaged in research and many practical experiences for many years, and has been researched and designed by many parties. The present invention proposes an organic light emitting diode and a manufacturing method thereof, which can effectively improve the energy efficiency of the organic light emitting diode element. The present invention provides an organic light-emitting diode and a method for fabricating the same, wherein the composition of the light-emitting layer comprises a host material and more than one guest material. The energy barrier of the electron or hole carrier injected into the body is smaller than the energy barrier of the injected object. In order to achieve the above object, an organic light-emitting diode device according to the present invention includes at least one substrate, a first conductive layer, a light-emitting layer containing a Φ-doped dye, and a second conductive layer, wherein The composition of the light-emitting layer comprises a host material and more than one guest material, wherein the energy barrier of the electron or the hole injected into the body is smaller than the energy barrier of the injected object, and the high-efficiency component effect can be produced, thereby effectively improving the yield of the fabricated component. With quality. The component structure is such that the first conductive layer is on the substrate, the light emitting layer is above the first conductive layer, and the second conductive layer is above the light emitting layer. In order to provide a better understanding and understanding of the technical features of the present invention and the effects achieved by the reviewers, the following examples are provided to facilitate the use of the preferred embodiments and related drawings, with detailed explanations such as Rear. DETAILED DESCRIPTION OF THE INVENTION In order to make the above objects, features, and advantages of the present invention more comprehensible, the organic light-emitting diode device and the method of manufacturing the same according to the present invention are specifically described in the following, and the related drawings are attached. In the following, the detailed description of 200830933 is as follows, wherein the same elements will be denoted by the same element symbols. Please refer to the tenth-figure, which is a cross-sectional view showing the structure of a preferred embodiment of the present invention. In this embodiment, the structure of the 〇LE: includes a substrate 121, a first layer 122, a hole transport layer 123, a doped dye-containing hair 124, and an electron transport layer 125, which are sequentially arranged from bottom to top. --- Electron injection layer 126 and a conductive layer 127. The first conductive layer 122 is located on the substrate 121. The hole transport layer 123 is located above the first conductive layer 122, and the light-emitting layer 124 containing the dopant is located above the hole transport layer ι23. The electron-layer 125 is located above the light-emitting layer 124. The injection layer 126 is above the bit transfer layer 125, and the second conductive layer 127 is above the electron layer 126. As described above, the doped dye-containing luminescent layer 124 comprises a bulk material and more than one guest material, which may be a fluorescent luminescent material, a phosphorescent luminescent material, whereby the luminescent layer 124 emits light, wherein the layer comprises a main body The material and more than one guest material, the energy barrier of the sub- or hole carrier injected into the host material is less than the energy barrier of the injected material. At the same time, the hole transport layer 123 can generally be N, N'-bis-(1 -naphthy)-N, N'-dipheny 1-1, 1 '-bi-pheny 4'-diamine (NPB) and other hole transport materials. The electron transport layer may generally be an electron transport material such as 1,3,5, tris (N-phenyl-benzimidazol-200830933 benzene (TPBi) ^ tris (8-hydroxyquinoline) alumi- num (Alq3); the electron injection layer 126 is generally The material is injected into the electrons such as lithium fluoride (LiF); the second conductive layer 127 is generally a conductive material such as A1; the substrate 121 is generally a glass substrate, a plastic substrate or a metal substrate; and the first conductive layer 122 is generally oxidized. Indium tin oxide (IT0) layer or indium zinc oxide (IZ0) layer. Please refer to the fifteenth figure, which is a flow chart of the method for manufacturing the LED device according to the preferred embodiment of the present invention. The method includes the following steps: Step S151: providing a substrate; Step S152: forming a first conductive layer on the substrate; Step S153: forming a hole transport layer on the first conductive layer; 9 Step S154: forming a light-emitting layer containing a doped dye, located in the electric &gt;Square; ⑩ Step S155: forming an electron transport layer disposed over the light emitting layer; forming a step S156 the electron injection layer, an electron transporting layer located above, and.

Step S157: forming a second conductive layer 'being above the electron injection layer; S wherein the composition of the light-emitting layer comprises the host material and more than one of the guest materials, and the energy barrier of the electron or hole injection body is less than that of the injected user 200830933 Energy barrier. The hole transport layer can generally be a hole transport material such as NPB, and the electron transport layer can generally be an electron transport material such as TPBi or Alq3; the electron injection layer can generally be an electron injection material such as LiF; and the second conductive layer can generally be a conductive material such as A1. Material; the substrate can generally be a glass substrate, a plastic substrate or a metal substrate. Referring to Table 1, the luminous efficacy comparison table of the examples and comparative examples according to the present invention is shown. 200830933 [Embodiment 1] Embodiment 1 is an OLED device manufactured by applying the present invention. The device structure can be referred to the twelfth figure, and the energy diagram can be referred to the fourteenth figure. The fabrication process is as follows: ITO The transparent conductive glass is ultrasonically pulverized and cleaned with detergent, deionized water, acetone and isopropanol, and placed in boiling hydrogen peroxide for surface treatment. After φ, the surface is dried by nitrogen flow, and then placed. In a vacuum chamber, the vacuum is up to 1 (T5Torr pressure, hot-drafting, 45 nm NPB hole transport layer 123, 30 nm • luminescent layer 124, 40 nm The TPBi electron transport layer 125, the 0.5 nm LiF electron injection layer 126, and the 150 nm aluminum electrode 127 are on the ITO transparent conductive glass. The luminescent layer 124 is a dye-doped luminescent layer, and the host material is DPASN, noisy. The guest dye is Rubrene with a doping concentration of 0.5 wt%. At a luminance of 100 cd/m2, the energy conversion efficiency is 9.5 lm/W, the maximum luminance is 18,100 cd/m2, and the CIE color coordinate is (0.32, 0.36). 〆*s, Ο〆13 200830933

[Example 2]

ΐ In order to compare the difference between the method of the present invention and the OLED i device manufactured by the prior art, the embodiment 2 is attached to the conventional OLED device, and the device structure is as shown in the twelfth figure. Compared with the embodiment 1, the OLED is The light-emitting layer 124 of the device structure is a light-emitting layer containing a doping dye, the host material is ADN, the doped guest dye is Rubrene, and the doping concentration is 0.3 wt%, and the energy level diagram is referred to the sixteenth figure, due to the electron And the energy barrier of the hole injection into the host material ADN) • The energy barrier of the injection of the guest material Rubrene makes the performance of the OLED device greatly reduced, and the luminous efficacy of each of the OLED devices is shown in Table 1.

14 200830933 The above description is for illustrative purposes only and not as a limitation. Any equivalent modifications or alterations of the present invention are intended to be included in the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural sectional view of a conventional OLED device according to a conventional one; FIG. 2 is a structural sectional view of another 0 LED device according to a conventional one, and FIG. 3 is a structure of a conventional OLED device. FIG. 4 is a structural sectional view of another conventional OLED device; FIG. 5 is a structural sectional view of a conventional OLED device; and FIG. 6 is a structural sectional view of another conventional OLED device; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 8 is a cross-sectional view showing the structure of another OLED device; FIG. 9 is a cross-sectional view showing the structure of another OLED device according to the present invention; FIG. 9 is a cross-sectional view showing the structure of the OLED device of the present invention and its energy level diagram; It is a sectional view of the structure of the OLED device of the present invention and a schematic diagram of its energy level; FIG. 11 is a cross-sectional view of the structure of the OLED device of the present invention and a schematic diagram thereof. 15 200830933 FIG. 12 is a structure of the OLED device of the present invention. FIG. 13 is a cross-sectional view showing the structure of the OLED device of the present invention and its energy level diagram; FIG. 14 is an energy level diagram of the OLED device according to the preferred embodiment of the present invention; FIG fifteen lines which the present invention is preferably a flowchart of a method for producing L E D O Example of embodiment of the device; FIG its sixteenth invention based comparison with the previous art of the difference, give the energy level of the OLED device of FIG embodiment. [Explanation of main component symbols] II, 21, 31, 41, 51, 61, 71, 81, 91, 101, III, 121, 131, substrate; 12: anode; 13, 43, 63, 74, 84, 103 , 123, 133: hole transport layer; 1301: hole; 23, 33, 73, 83: hole injection layer; 14: organic light-emitting layer; 15, 54, 76, 114, 125, 135: electron transport layer; 16 200830933 1501 : electrons; 16, 77, 86, 94, 105, 115, 126, 136: electron injection layer; 17: cathode; 22, 32, 42 , 52 , 62 , 72 , 82 , 92 , 102 , 112 , 122, 132: a first conductive layer; 24: a light-emitting layer;

34, 44: luminescent layer with electron transport function; 53: luminescent layer with hole transmission function; 64, 8 5: single component luminescent layer; 65, 75, 93, 104, 113, 124, 134: doped Light-emitting layer of dye; 25, 35, 45, 55, 67, 78, 87, 95, 106, 116, 127, 137: second conductive layer; S151~S157: process steps. 17

Claims (1)

200830933 X. Patent application scope: 1. An organic light emitting diode device structure, comprising at least: a substrate; a first conductive layer on the substrate; a light emitting layer above the first conductive layer; and a first The second conductive layer is located above the light emitting layer; wherein the light emitting layer comprises a host material and more than one guest material, and the electron or hole carrier is injected into the host material with an energy barrier smaller than that of the implanted guest material. 2. The organic light emitting diode device of claim 1, wherein the light emitting layer is a fluorescent light emitting material, whereby the light emitting layer emits fluorescence. 3. The organic light emitting diode device of claim 1, wherein the light emitting layer is a phosphorescent material, whereby the light emitting layer emits light. 4. The organic light emitting diode device of claim 1, wherein the light emitting layer is simultaneously a fluorescent and phosphorescent material, whereby the light emitting layer emits light. 5. The organic light emitting diode device of claim 1, wherein the first conductive layer and the light emitting layer further comprise at least one functional auxiliary layer. 6. The organic light emitting diode device of claim 1, wherein the light emitting layer and the second conductive layer further comprise at least one functional auxiliary layer. 7. The functional auxiliary layer as described in claim 5, comprising a carrier injection, a carrier transport layer or a carrier block 200830933. 8. The functionality as described in claim 6 The auxiliary layer includes a carrier injection, a carrier transport layer or a carrier blocking layer. 9. A method of fabricating an organic light emitting diode device, comprising: at least one substrate; a first conductive layer on the substrate; a light emitting layer over the first conductive layer; and a second conductive layer, Located above the luminescent layer; wherein the luminescent layer comprises a host material and more than one guest material, and the energy barrier of the electron or hole carrier injected into the host material is less than the energy barrier of the implanted guest material. 10. The method of fabricating an organic light-emitting diode device according to claim 9, wherein the light-emitting layer is a fluorescent light-emitting material, whereby the light-emitting layer emits fluorescence. 11. The method of fabricating an organic light-emitting diode device according to claim 9, wherein the light-emitting layer is a phosphorescent material, whereby the light-emitting layer emits phosphorescence. 12. The method of fabricating an organic light-emitting diode device according to claim 9, wherein the light-emitting layer is simultaneously a fluorescent and phosphorescent material, whereby the light-emitting layer emits light. 13. The method of fabricating an organic light-emitting diode device according to claim 9, wherein the first conductive layer and the light-emitting layer further comprise at least one functional auxiliary layer. 14. The method of fabricating an organic light emitting diode according to claim 9, wherein the light emitting layer and the second conductive layer further comprise at least one functional auxiliary layer. 15. The functional auxiliary layer according to claim 13 of the patent application, comprising a carrier injection, a carrier transport layer or a carrier blocking layer. 16. The functional auxiliary layer as described in claim 14 of the patent application, comprising a carrier injection, a carrier transport layer or a carrier blocking layer. 20