Structure of white OLED device

Abstract

The present invention provides a structure of a white OLED device that includes a plurality of emissive layers, of which at least one emissive layer is made of a quantum dot and at least one emissive layer is made of an organic light emission material so as to combine the advantages of the quantum dot and the organic light emission material, where the manufacturing cost is low, the utilization of material is high, and the light emission efficiency is high thereby increasing the brightness of a display device and providing excellent performance for use in flat panel display devices, televisions, and other fields of display.

Claims

1. A structure of a white organic light-emitting (OLED) device, comprising two or more emissive layers, in which at least one of the emissive layers is made of a quantum dot and at least one of the emissive layers is made of an organic light emission material, wherein a charge generation layer is arranged between the emissive layer of quantum dot and the emissive layer of organic light emission material to generate first and second electric charges that are respectively fed into the quantum dot and the organic light emission material such that the quantum dot and the organic light emission material are respectively excited by the first and second electric charges to individually emit first light and second light according to the electric charges fed thereto, the first light and the second light being of complementary colors for formation of white light; and wherein the quantum dot, the organic light emission material, and the charge generation layer are collectively enclosed in a sealed package; wherein the first electric charges are electrons and the second electric charges are holes, the white OLED device further comprising a substrate, an anode formed on the substrate, a first hole injection layer formed on the anode, a first hole transporting layer formed on the first hole injection layer, a first emissive layer formed on the first hole transporting layer, a first electron transporting layer formed on the first emissive layer, a first electron injection layer formed on the first electron transporting layer, the charge generation layer formed on the first electron injection layer, a second hole injection layer formed on the charge generation layer, a second hole transporting layer formed on the second hole injection layer, a second emissive layer formed on the second hole transporting layer, a second electron transporting layer formed on the second emissive layer, a second electron injection layer formed on the second electron transporting layer, a cathode formed on the second electron injection layer, a package cover plate arranged above the cathode, and a sealing enclosure resin arranged between the substrate and the package cover plate to bond the substrate and the package cover plate together, wherein the substrate, the package cover plate, and the sealing enclosure resin collectively form the sealed package.

2. The structure of the white OLED device as claimed in claim 1, wherein the first emissive layer is the emissive layer of quantum dot and the second emissive layer is the emissive layer of organic light emission material.

3. The structure of the white OLED device as claimed in claim 2, wherein the quantum dot comprises one or more of a blue quantum dot, a yellow quantum dot, a green quantum dot, a red quantum dot, and a white quantum dot that emits the first light and the second light emitting from the organic light emission material of the second emissive layer is combinable with the first light emitting from the quantum dot of the first emissive layer to form white light.

4. The structure of the white OLED device as claimed in claim 1, wherein the first electron transporting layer and the second hole transporting layer that are arranged between the first emissive layer and the second emissive layer respectively transport the electrons and the holes generated by the charge generation layer under an electric field to the first emissive layer and the second emissive layer to be respectively re-combined with holes and electrons injected from the anode and the cathode into the first emissive layer and the second emissive layer so as to generate the first light and the second light o be combined to form white light.

5. The structure of the white OLED device as claimed in claim 1, wherein the charge generation layer comprises a first charge generation layer formed on the first electron injection layer and a second charge generation layer formed on the first charge generation layer, the first charge generation layer showing property of transporting electrons, the second charge generation layer showing property of transporting holes.

6. The structure of the white OLED device as claimed in claim 1, wherein the charge generation layer is formed by mixing a p-type organic semiconductor and an n-type organic semiconductor.

7. The structure of the white OLED device as claimed in claim 1, wherein the first emissive layer is the emissive layer of organic light emission material and the second emissive layer is the emissive layer of quantum dot.

8. The structure of the white OLED device as claimed in claim 7, wherein the quantum dot comprises one or more of a blue quantum dot, a yellow quantum dot, a green quantum dot, a red quantum dot, and a white quantum dot that emits the first light and the second light emitting from the organic light emission material of the first emissive layer is combinable with the first light emitting from the quantum dot of the second emissive layer to form white light.

9. A structure of a white organic light-emitting (OLED) device, comprising two or more emissive layers, in which at least one of the emissive layers is made of a quantum dot and at least one of the emissive layers is made of an organic light emission material, wherein a charge generation layer is arranged between the emissive layer of quantum dot and the emissive layer of organic light emission material to generate first and second electric charges that are respectively fed into the quantum dot and the organic light emission material such that the quantum dot and the organic light emission material are respectively excited by the first and second electric charges to individually emit first light and second light according to the electric charges fed thereto, the first light and the second light being of complementary colors for formation of white light; and wherein the quantum dot, the organic light emission material, and the charge generation layer are collectively enclosed in a sealed package; wherein the first electric charges are electrons and the second electric charges are holes, the white OLED device further comprising a substrate, an anode formed on the substrate, a first hole injection layer formed on the anode, a first hole transporting layer formed on the first hole injection layer, a first emissive layer formed on the first hole transporting layer, a first electron transporting layer 61 formed on the first emissive layer, a first electron injection layer formed on the first electron transporting layer, the charge generation layer formed on the first electron injection layer, a second hole injection layer formed on the charge generation layer, a second hole transporting layer formed on the second hole injection layer, a second emissive layer formed on the second hole transporting layer, a second electron transporting layer formed on the second emissive layer, a second electron injection layer formed on the second electron transporting layer, a cathode formed on the second electron injection layer, a package cover plate arranged above the cathode, and a sealing enclosure resin arranged between the substrate and the package cover plate to bond the substrate and the package cover plate together, wherein the substrate, the package cover plate, and the sealing enclosure resin collectively form the sealed package; wherein the first emissive layer is the emissive layer of quantum dot and the second emissive layer is the emissive layer of organic light emission material; wherein the quantum dot comprises one or more of a blue quantum dot, a yellow quantum dot, a green quantum dot, a red quantum dot, and a white quantum dot that emits the first light and the second light emitting from the organic light emission material of the second emissive layer is combinable with the first light emitting from the quantum dot of the first emissive layer to form white light; wherein the first electron transporting layer and the second hole transporting layer that are arranged between the first emissive layer and the second emissive layer respectively transport the electrons and the holes generated by the charge generation layer under an electric field to the first emissive layer and the second emissive layer to be respectively re-combined with holes and electrons injected from the anode and the cathode into the first emissive layer and the second emissive layer so as to generate the first light and the second light to be combined to form white light; wherein the charge generation layer comprises a first charge generation layer formed on the first electron injection layer and a second charge generation layer formed on the first charge generation layer, the first charge generation layer showing property of transporting electrons, the second charge generation layer showing property of transporting holes; and wherein the charge generation layer is formed by mixing a p-type organic semiconductor and an n-type organic semiconductor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The technical solution, as well as other beneficial advantages, of the present invention will become apparent from the following detailed description of an embodiment of the present invention, with reference to the attached drawings.

(2) In the drawings:

(3) FIG. 1 is cross-sectional view showing a structure of a white OLED (Organic Light-Emitting Diode) device according to the present invention; and

(4) FIG. 2 is a cross-sectional view showing another structure of a white OLED device according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) To further expound the technical solution adopted in the present invention and the advantages thereof, a detailed description is given to a preferred embodiment of the present invention and the attached drawings.

(6) The present invention provides a structure of a white OLED (Organic Light-Emitting Diode) device, which comprises two or more than two emissive layers, of which at least one emissive layer is made of a quantum dot and at least one emissive layer is made of an organic light emission material.

(7) FIG. 1 illustrates a preferred embodiment of the structure of the white OLED device according to the present invention. In the embodiment, the number of emissive layers used is two, which are respectively a first emissive layer and a second emissive layer. Specifically, the structure of the white OLED device comprises a substrate 1, an anode 21 formed on the substrate 1, a first hole injection layer 31 formed on the anode 21, a first hole transporting layer 41 formed on the first hole injection layer 31, a first emissive layer 51 formed on the first hole transporting layer 41, a first electron transporting layer 61 formed on the first emissive layer 51, a first electron injection layer 71 formed on the first electron transporting layer 61, a charge generation layer 8 formed on the first electron injection layer 71, a second hole injection layer 32 formed on the charge generation layer 8, a second hole transporting layer 42 formed on the second hole injection layer 32, a second emissive layer 52 formed on the second hole transporting layer 42, a second electron transporting layer 62 formed on the second emissive layer 52, a second electron injection layer 72 formed on the second electron transporting layer 62, a cathode 22 formed on the second electron injection layer 72, a package cover plate 2 arranged above the cathode 22, and a sealing enclosure resin 3 arranged between the substrate 1 and the package cover plate 2 to bond the substrate 1 and the package cover plate 2 together.

(8) In the structure of the white OLED device of the present invention, the substrate 1 and the package cover plate 2 are made of glass or flexible materials. At least one of the substrate 1 and the package cover plate 2 is light transmittable. Preferably, the substrate 1 and the package cover plate 2 are both glass sheets. The substrate 1 and the package cover plate 2 are bonded together by the sealing enclosure resin 3 to prevent invasion of external moisture and oxygen in order to achieve hermetic sealing for protection of internal electronic components.

(9) The first emissive layer 51 is made of a quantum dot and the second emissive layer 52 is made of an organic light emission material. Since the quantum dot possess an extremely high fluorescence efficiency, the composite emissive layer composed of the first emissive layer 51 that is made of a quantum dot and the second emissive layer 52 that is made of an organic light emission material has a luminous efficiency that is greatly enhanced thereby increasing the brightness of a display device.

(10) The quantum dot can be one or more of a blue quantum dot, a yellow quantum dot, a green quantum dot, a red quantum dot, and a white quantum dot. The light emitting from the organic light emission material of the second emissive layer 52 is combined with the light emitting from the quantum dot of the first emissive layer 51 to form white light.

(11) The first electron transporting layer 61 and the second hole transporting layer 42 that are arranged between the first emissive layer 51 and the second emissive layer 52 respectively transport the electrons and holes that are generated in the charge generation layer 8 as being effected by an electric field to the first emissive layer 51 and the second emissive layer 52 to be respectively re-combined with holes and electrons injected from the anode 21 and the cathode 22 into the first emissive layer 51 and the second emissive layer 52 so as to generate light of different colors to be combined to form white light.

(12) The charge generation layer 8 comprises a first charge generation layer 81 formed on the first electron injection layer 71 and a second charge generation layer 82 formed on the first charge generation layer 81. The first charge generation layer 81 shows the property of transporting electrons and the second charge generation layer 82 shows the property of transporting holes. Thus, the electrons generated by the charge generation layer 8 are transported through the first charge generation layer 81 to the first emissive layer 51, while the holes generated in the charge generation layer 8 are transported through the second charge generation layer 82 to the second emissive layer 52.

(13) It is noted that the charge generation layer 8 can alternatively be a single-layered charge generation layer that is formed by mixing a p-type organic semiconductor and an n-type organic semiconductor. The interior and interfaces of the charge generation layer exhibits interactions between the p-type organic semiconductor and the n-type organic semiconductor so that the electrons generated in the charge generation layer are accumulated in the n-type organic semiconductor portion, while holes are accumulated in the p-type organic semiconductor portion, wherein under a predetermined voltage, the electrons and the holes are respectively conducted to the anode 21 and the cathode 22.

(14) FIG. 2 shows another structure of a white OLED device according to the present invention, wherein a first emissive layer 51 is made of an organic light emission material and a second emissive layer 52 is made of a quantum dot.

(15) The quantum dot can be one or more of a blue quantum dot, a yellow quantum dot, a green quantum dot, a red quantum dot, and a white quantum dot. The light emitting from the organic light emission material of the first emissive layer 51 is combined with the light emitting from the quantum dot of the second emissive layer 52 to form white light.

(16) In summary, the present invention provides a structure of a white OLED device, which comprises a plurality of emissive layers, of which at least one of the emissive layers is made of a quantum dot and at least one of the emissive layers is made of an organic light emission material so as to combine the advantages of the quantum dot and the organic light emission material, wherein the manufacturing cost is low, the utilization of material is high, and the light emission efficiency is high thereby increasing the brightness of a display device and providing excellent performance for use in flat panel display devices, televisions, and other fields of display.

(17) Based on the description given above, those having ordinary skills of the art may easily contemplate various changes and modifications of the technical solution and technical ideas of the present invention and all these changes and modifications are considered within the protection scope of right for the present invention.