TWI229569B - Light emitting device and method for producing the same - Google Patents

Abstract

The present invention relates to a light emitting device (LED), particularly an organic LED (OLED) with three-wavelengths white-light-emitting properties, which mainly includes, sequentially between a cathode and an anode, a hole transmission layer, an electron blocking layer, a first host material layer, a second host material layer, a third host material layer, a hole barrier layer, and an electron transmission layer, in which the first host material layer is mixed with a first guest luminous material capable of emitting a first color light source (R) under the influence of an externally applied bias voltage, the second host material layer is correspondingly mixed with a second guest luminous material capable of emitting a second color light source (B), and the third host material layer is correspondingly mixed with a third guest luminous material capable of emitting a third color light source (G). Thus, the combination of the three original colors (red, blue, green) can be used to directly obtain a full color source with continuous wave segments and three wavelengths.

Description

1229569

[Technical field to which the invention belongs] The present invention relates to a light-emitting device, and more particularly to an organic electro-optical light-emitting device having three-wavelength white light emission characteristics and a method for manufacturing the same. [Prior technology] Organic light-excitation light-emitting devices (0rganic Light Emitting Deviee; 0LED) have been used by Kodak's c · w · Tang & s · A. VanSiyk e to transfer materials and Electron transmission materials, such as Alq3, are respectively plated on transparent IT0 glass, and then a metal electrode is evaporated to form a self-luminous, high response speed, light weight, thin thickness, low power consumption, wide viewing angle, high Bright and full-colorable organic electro-optic light emitting element το (0LED). Since then, organic electroluminescent devices have been regarded as the star products of the display industry. Everyone hopes that they can be applied to full-color displays or project white light sources to achieve true environmental protection and power saving effects. The ideal state of lighting. Please refer to FIG. 1, which is a cross-sectional view of the structure of a conventional OLED. The organic electroluminescent device (OLED) IO is mainly deposited on a transparent substrate u to form a transparent conductive anode (IT0) 13. A hole transport layer (HTL) 15, a light emitting layer (EML) 17 and a metal cathode 19 are sequentially formed on the 17 () anode 13 and a fluorescent substance is doped in the light emitting layer 17 (Not shown), when the anode 13 and the cathode 19 are subjected to an external bias: holes can be transferred from the ITO anode 13 to the light-emitting layer through the hole transport layer i 5, and the electrons can also be relatively discharged from the cathode 1 9 is transmitted to the light-emitting layer 17 and the electrons and holes in the light-emitting layer 17 can generate excitatory components due to recombination (Rec〇mbi nat i〇n).

Page 5 1229569

Exciton, when the excimer molecule releases energy and returns to the ground state, it can emit light in the light-emitting layer 17 by itself, or re-excite the doped fluorescent light emitting state and project a set range of wavelength light source. Although the above-mentioned first conventional 0LED structure and technology can achieve the effect of a light source, it can only project a monochromatic light source and cannot reach the ultimate goal of projecting a white light source or full color. Please refer to Figure 2, which is a schematic diagram of the energy levels of another conventional 0LED. The technology mainly includes an anode 22 and an electron in addition to the IT0 anode 22, the electron transport layer (ETL) 24 and the cathode 25. The hole transport layer (HTL) 23 between the transmission layers, due to the choice of materials for the electron transport layer 24 and the hole transport layer 23, results in the energy step difference between the electron transport layer 24 and the hole transport layer 23 (EC1-EC2) It will be less than the energy difference between the two conduction bands (EV1-EV2). In this way, the number of electrons transferred to the hole transport layer 23 in the electron transport layer 24 will far exceed the number of electrons transferred to the electron transport layer in the opposite direction. The number of holes, so the recombination of electrons and holes and the placement of the projection light source will occur in the hole transmission layer 23. In addition, in order to facilitate the hole from the anode to transmit and inject into the hole transmission layer 23, in This patent also discloses a hole injection layer provided between the electrode 22 and the hole transmission layer 23. Although the aforementioned Motorola patented technology, a hole that moves faster can be left in the hole transmission layer 23. Improve the luminous efficiency by recombination procedure with electrons However, it can only project a monochromatic light source, and it cannot reach the ultimate goal of projecting a white light source or full color. In order to achieve the ultimate goal of 0LED being used as a white light source and full color, the industry must seek various technical solutions. At present, Mainly can reach ZO multiplication

Page 6 1229569 V. Explanation of the invention (3) There are three solutions for the effect: 1. Color conversion method: It mainly uses blue light as the emission source, and then excites this blue light into a light color conversion film. In order to obtain the three primary colors of red, green and blue (RGB) visible light, and hope to use it to achieve the purpose of full color or project a white light source; Wang Wei, in this technology, not only the light color purity and luminous efficiency of the light color conversion film is not very good Satisfactory, and because the color conversion material will absorb the blue light (or ultraviolet light) of the environment, it will cause potential contrast and pixel problems. F 2 · Color Filter Method: Use white organic electro-active material as the backlight. Use color filters that have been used in lc D to achieve full-color effects; however, the key point of this technology is how to obtain a white light source, and whether the white light source is a full-band continuous light source and how to improve luminous efficiency. , Are the technologies that must be broken before the product is mass-produced 3. Red, blue and green three-color independent light-emitting method: "" The main three colors of RGB are emitted alone, # 月 望 achieved full color effect Or, it can be matched to become a white light source. The color must be independently emitted, and its color balance is poor. Second: The requirement of fine J also increases the independent emission of organic substances of different colors in the manufacturing process. There are also differences ^ You Zhenghan, the use of insulting Zhao Honghong's production is only okay, for example, the red light source is difficult to reach ,,,,,,,,,,,, ... Also short. 1229569

1229569 V. Description of the invention (5) [Embodiment] In order to make your reviewing members have a better understanding and understanding of the structural features and effects achieved by the present invention, I would like to provide a better description of the embodiment and the detailed description, The explanation is as follows: ^ First, please refer to FIG. 3, which is a structural cross-sectional view of a preferred embodiment of the present invention; as shown in the figure, the organic electro-optical excitation device 30 of the present invention is mainly a light-transmitting substrate 31. The upper side is formed by a method such as evaporation or sputtering to form a second 'layer 3 3 (e.g., ytterbium electrode)', and a hole transport layer 35 (HTL; first carrier transport) is sequentially formed on the upper side of the anode 3 3. Layer) and an electron blocking layer 47 (electron blocking layer) that blocks the second carrier (electrons) from advancing. A first host material layer 41 (Host 1), a first The host material layer 42 (Host 2) and the third host material layer 43 (Host 3) are on top of the third host material layer 43; a hole blocking layer 45 (h 〇le mnLuyer), electron transport layer 37 (etl; second carrier transport layer ^, and cathode 3 9 With the electron blocking layer 47, it can come from the upper side of the cathode 39 hole transport layer 35, in other words, the electron limit 3 (43) and Host 2 are reduced to within (41); The hole on the anode 33 is blocked on the bottom side of the battery 42. In other words, the hole is also limited to η〇 ^ ^

Host 2 (42) and Host 3 (43). Since most of the holes and holes will be guided and confined to the host, H0, and nost3, the electron hole pair will have a greater chance of being in each main material layer.

Page 9 1229569 V. Description of the invention (6) Inner shape recombination action, in order to effectively improve the luminous efficiency of each main material layer. A first guest luminous substance is mixed (m 丨 xi ng) in the first host material layer 41, and a corresponding first luminous substance (Guest 2) is also mixed in the second host material layer 42, and A corresponding third guest luminous substance (Guest 3) is also mixed in the third host material layer 43. These guest luminous substances can be selected as a corresponding fluorescent substance, phosphorescent substance, or both. A mixture that can project a different color light source when the electron hole pair is recombined and is released by the energy of the excimer molecule. For example, in this embodiment, Guest 1 can project red light (R), and Guest 2 Projects blue light (B), and Guest 3 projects green light (G), so you can produce RGB two-band three primary colors, and combine a white light source or full-color product with a full-band continuous spectrum. Not only is the process relatively simple, but Can effectively increase luminous efficiency. Of course, for the ideal c 丨 E chromaticity diagram system specification of white light or full color, the concentration of green light is slightly increased relative to red light and blue light. Therefore, in this embodiment, a guest who can project green light The concentration of 3 is relative to that of Guest 1 and Guest 2. It should also be relatively high, and the number of electron hole pairs in H0st 3 can also be designed to be larger than H0st 1 & H0st 2 and The positional arrangement of H0st 1, Host 2 and Host 3 all depends on the relative matching of their energy levels. Also, please refer to FIG. 4, which is a structural cross-sectional view of another embodiment of the present invention; In this embodiment, it is mainly formed on a light-transmitting substrate 3 made of glass, quartz, or plastic by evaporation or sputtering.

Page 10 V. Description of the invention (7) Formation of indium tin oxide (IT〇), polyaniline (pANI), zinc oxide (ZnOx), molybdenum oxide (MOZO), vanadium oxide (ν〇χ) ), Ruthenium oxide (Ru0x), Au, CuI, Sn02, or ZnO and other anodes 33 composed of metals, alloys, compounds or mixtures with light transmission conductivity. Subsequently, a hole injection layer (hil) 53 made of M-MTDATA, a hole transport layer (htl) 35 made of NPB, and an electron barrier made of UF were sequentially formed on the upper surface of IT03. Layer 47, a first host material layer 41 made of NPB, a second host material layer 42 made of DpvBi, a third host material layer 43 made of Alq3, a hole barrier layer 45 made of BCP, Electron Transport Layer (ETL) 37 made of Alq, Electron Injection Layer (EIL) 57 made of LiF, and one made of Au, Al, Mg, Pt, Ag, MgAg, AlLi, AlLiO, AIL ΐ F or Ca And other cathodes made of conductive material 39. Among them, the NPB of the first host material layer 41 is mixed with at least one DCM2 substance that can emit red light, and the DPVBi of the second host material layer 42 is mixed with at least one DSA substance that can project blue light. The three main material layers 4 3 A1 q 3 are mixed with at least one c 6 substance capable of projecting green light. By the arrangement of the energy level positions of the host material layers (Hosts), the hole blocking layer 4 5 Electron hole pairs in the range of NpB 41, DPVBi 42, Alq3 43 and the blocking effect of the electron blocking layer 47 can be generally divided into each of the main material layers 41 to 43. When an external bias is applied, the three primary color light sources of red, blue, and green can be projected through each guest luminous substance (Guest) to form a complete three-wavelength projection light source system. White light source or full color product.

In order to integrate the light source, such as white light, it is more in line with the ideal C i E 1229569 V. Description of the invention (8) Chromaticity chart system specifications, the concentration of C6 is comparable to that of DSA, DCM2, or the thickness of Alq3 43 is comparable to DPVBi 42 The thickness of NPB 41. Of course, in the above embodiments of the present invention, the materials used for each layer can have various changes. The materials and materials disclosed in the following patents can also be applied for reference: For example, the materials of the ETL layer or HTL layer can be Reference to U.S. Patent No. 5 29 4, 8 70 'HTL layer material can refer to U.S. Patent No. 5, 〇61,569, No. 5,256,945 1 several layers of material can refer to U.S. Patent No. 4 5391 > 507 No. 5, 886, 464. For the material of the HIL layer, please refer to US Patent Nos. 3,9 35, 031 and 4, 356, 429. For the anode, please refer to US Patent No. & 7 73, 929, EIL. For layer material, refer to US Patent No. 4,539,507. In summary, the present invention relates to a light-emitting device, especially two organic electro-excitation light devices having three-wavelength white light emitting characteristics: by this means, a continuous light source having three-wavelength characteristics can be directly obtained. Therefore, the present invention is really a novel, progressive and available for industrial users, should comply with the patent application of China's patent law, the application of the invention patent application method, pray to fishermen and sisters. The τ month research fishing bureau has granted a quasi-patent earlier, but the above is just a prayer. It is only a respectful BΗ + _ L 1 Real Madrid. This is a preferred embodiment, and is not intended to limit the practicality of the present invention. The range of Xi Zhitu R D, Shi-Xi j, for example, the shape, structure, and sacrifice according to the scope of the patent application of the present invention ^, S々 红 士士 ⑺ 4 inch quilt and spiritual behavior equal changes and Modifications should be included in the scope of patent application of the present invention. Page 12 1229569

Page 13 V. Description of the invention (9) [Illustration of drawing number] • 10 OLED 11 Transparent substrate 13 Anode 15 Hole transfer layer 17 Light emitting layer 19 Cathode 22 Anode 23 Hole transfer layer 24 Electron transfer layer 25 Cathode 30 OLED 31 substrate 33 first conductive layer 35 first carrier barrier layer 37 second carrier transport layer 39 second conductive layer 41 first host material layer 42 first host material layer 43 third host material layer 45 first Sub-blocking layer 47 Second carrier-blocking layer 53 First carrier-injecting layer 57 Second carrier-injecting layer 1229569 Brief description of the diagram Figure 1: A cross-sectional view of the structure of a conventional light-emitting device; Figure 2 ... is another conventional Schematic diagram of the energy levels of each element of the light-emitting device; FIG. 3 is a structural cross-sectional view of a preferred embodiment of the light-emitting device of the present invention; and FIG. 4 is a structural cross-sectional view of yet another embodiment of the present invention.

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Claims (1)

1229569 6. Scope of patent application 1. A light-emitting device whose main structure includes at least: a first conductive layer having first-type conductivity; a first main material layer provided on the upper side of the first conductive layer; A hybrid object is provided with a first guest luminous substance, which can project a light source of a first color under an external bias; a second host material layer is provided on the upper side of the first host material layer, and a second host material is provided in the hybrid The guest luminous substance can project a second-color light source under the external bias; a third host material layer provided on the upper side of the second host material layer, and a third guest luminous substance is mixed therein, A third color light source is projected under the external bias; and a second conductive layer having a second type of conductivity is disposed on the upper side of the third body material layer. A light emitting device whose main structure includes at least: a first conductive layer having a first conductivity; a second carrier blocking layer provided on an upper side of the first conductive layer; and a second carrier blocking layer provided on the first conductive layer; A first host material layer on the upper side of the sub-barrier layer is mixed with a first guest luminous substance, which can project a first-color light source under an external bias; a is on the upper side of the first host material layer. A second host material layer is mixed with a second guest luminous substance, and a second color light source can be projected under the applied bias; a third host material layer provided on the upper side of the second host material layer, inside A third guest luminous substance is mixed, which can be applied at the external bias voltage. 1229569 6. Scope of patent application A third-color light source is projected under use; and a second conductive layer having a second-type conductivity is provided on the upper side of the third host material layer. 3. A light-emitting device whose main structure includes at least: a first conductive layer having first-type conductivity; a first body material layer provided on the upper side of the first conductive layer, and a first The guest luminous substance can project a light source of a first color under an external bias; a second host material layer disposed on the upper side of the first host material layer, and a second guest luminous substance is mixed therein, A second color light source can be projected under the external bias; a third host material layer provided on the upper side of the second host material layer, and a third guest luminous substance is mixed therein, which can be applied to the external bias A third color light source is projected under the action; a first carrier blocking layer provided on the upper side of the third host material layer; and a second conductive layer having a second type of conductivity provided on the first carrier blocking layer. Layer above. 4. A light-emitting device whose main structure includes at least: a first conductive layer having first-type conductivity; a second carrier blocking layer provided on an upper side of the first conductive layer; A first host material layer above the carrier barrier layer is mixed with a first guest luminous substance, which can project a first-color light source under an external bias; a first light source is provided on the first host material layer Second body material layer, inside Page / i6 1229569 6. The scope of the patent application is mixed with a second color light source and a luminous substance which can be used to project a third light source material on the upper side of the 5 6 main material layer. The luminous material can be a third-color light source at the external bias voltage; a first carrier blocking layer on the upper side of the host material layer; and a conductive second conductive layer provided on the first carrier side. The light-emitting device according to item 4, wherein the first main body is an NPB layer, and the second main body material layer is an illuminant layer, and the Alq3 layer is an Alq3 layer. The light-emitting device according to item 4, wherein the first is an NPB layer, and the first guest luminous substance is 7. One is provided in the second and second is provided with a projection and one is provided in the third. The second type barrier layer is a DPVBi layer, and the second layer is the DPVBi layer. The second layer is the DCM2. The light-emitting device according to item 4 of the scope of the patent application, wherein the second host material layer is a DPVBi layer, and the second guest light-emitting substance is a light-emitting device described in item 4 of DSA 0, wherein the The third is an Alq3 layer, and the third guest light substance is 8. If the main material layer of the patent application is 9 10 The light-emitting device described in item 4 of the patent application scope, wherein the third guest light The concentration is greater than the respective concentrations of the one guest luminous body and the second guest luminous body. The light-emitting device according to item 4 of the scope of patent application, wherein the first Page 17 1229569 6. Scope of patent application Guest luminous substance is one of fluorescent substance, phosphorescent substance, and combinations thereof. 11 · The light-emitting device according to item 4 of the scope of patent application, wherein the second guest light-emitting substance is one of a fluorescent substance, a phosphorescent substance, and a combination. 1 2 The light-emitting device according to item 4 of the scope of patent application, wherein the third guest light-emitting substance is one of a fluorescent substance, a phosphorescent substance, and / or a combination thereof. 13 · A light-emitting device whose main structure includes at least: a first conductive layer having first-type conductivity; a first carrier-transporting layer provided on the upper side of the first conductive layer; =: The second carrier barrier layer on the carrier transport layer; a first host material provided on the second and the carrier barrier layer ^, mixed with a -th-guest luminous substance, which can be used for an external use A first-color light source is projected downward; a second host material layer disposed on the upper side of the first body material layer is mixed with a second guest light substance, which can be projected under the external bias voltage; A second-color light source; a third host material layer provided on the upper side of the first body material layer, and a second guest luminous substance mixed therein, which can project a third-color light source under the external bias voltage A first carrier blocking layer provided on the upper side of the second host material layer; and a second conductive layer having a second type conductivity provided on the first carrier p and on the upper side of the barrier layer. Page 18, 1229569 VI. Scope of patent application 14 · A light emitting device whose main structure includes at least: an anode; a hole transmission layer provided on the upper side of the anode; and a hole transmission layer provided on the upper side of the hole transmission layer. An electronic barrier layer; a first host material layer provided on the upper side of the electronic barrier layer, a first guest luminous substance mixed therein, which can project a first color light source under an external bias; A second host material layer on the upper side of the first host material layer is mixed with a second guest luminous substance, and a second color light source can be projected under the applied bias; a second source material is provided on the second host material layer. A third host material layer on the upper side is mixed with a third guest luminous substance, and a third color light source can be projected under the external bias; a hole blocking layer provided on the upper side of the third host material layer. An electron transport layer provided on the upper side of the hole barrier layer; and a cathode provided on the upper side of the electron transport layer. · 15 · The light-emitting device according to item 14 of the scope of patent application, wherein a light-transmitting substrate may be further provided on the lower side of the anode. 16 · The light-emitting device according to item 14 of the scope of patent application, wherein the first host material layer is an NPB layer, the second host material layer is a DPVBi layer, and the third emitter layer is an Alq3 layer. . 17 · The light-emitting device according to item 14 of the scope of patent application, wherein the first color light source is red light, the second color light source is blue light 'and the third color light source is green light. Page 19, 1229569 VI. Patent application scope 1 8 · The light-emitting device according to item 14 of the patent application scope, wherein the first guest light-emitting substance, the second guest light-emitting substance, and the third guest light-emitting substance are acceptable. Individual selection is one of a fluorescent substance, a phosphorescent substance, and a combination thereof. 19 · The light-emitting device according to item 14 of the scope of patent application, wherein the hole blocking layer is a BCP layer. 2 0. The light-emitting device according to item 14 of the scope of patent application, wherein the electron blocking layer is composed of a L i F layer. 2 1 · A light-emitting device whose main structure includes at least a transparent substrate; an anode provided on the upper side of the transparent substrate; a hole injection layer provided on the upper side of the anode; An NPB layer on the upper side of the hole injection layer; a L i F layer provided on the upper side of the NPB layer; an NPB layer provided on the upper side of the L i F layer; a DC Μ 2 substance is mixed therein; A red light source is projected under the action; a DPVB i layer provided on the upper side of the NPB layer is mixed with a DSA substance, and a blue light source can be projected under the external bias; a DPVB i layer is provided A 1 q 3 layer on the upper side is mixed with a C 6 substance, which can project a green light source under the external bias; a BCP layer on the upper side of the DPVBi layer; and a BCP layer on the upper side of the BCP layer A 1 q layer; an electron injection layer provided on the upper side of the electron transport layer; and a cathode provided on the upper side of the electron injection layer. 1229569-^ 1 ^ 92130350 said VI. Patent application scope The following steps amend 27: ί: same as ^: a barrier layer is formed on the upper side of the third main body holding layer, and the cathode is formed on the upper side of the ^ barrier layer. • The production as described in the 24th item of the application of the patent No. 4 has the following steps ... No, it is still "28" The hole transfer layer is formed on the anode, and then formed on the hole transfer layer in order. The first host material layer, the second host material layer, and the second host material layer. • The manufacturing method described in item 24 of the scope of patent application, including the following steps: forming an electron transfer layer on the upper side of the third host material layer, and forming the cathode on the upper side of the electron transport layer. 29. The manufacturing method as described in item 24 of the scope of patent application, wherein the first guest luminous substance, the second guest luminous substance, and the third; the luminous substance can be individually selected as a fluorescent substance, a phosphorescent substance, and the like. One of the t of the combination. ΰ 30 The manufacturing method as described in item 24 of the scope of patent application, wherein the first host material layer is an NPβ layer, the first guest light emitting substance system is a DCM2, and the second host material layer is a _DpvBi layer The second guest material is a DSA, the third host material layer is an A1q3 layer, and the third guest material is a c6. Page 22