# US 10,319,290 B2 · Electroluminescent device, manufacturing method and driving method thereof, and display device

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- Number: US 10,319,290 B2
- Document ID: US10319290B2
- Status: Granted
- Kind: B2
- Application number: 15/321,892
- Filed: 2016-04-14
- Published: 2017-07-06
- Granted: 2019-06-11
- Earliest claimed: 2015-06-26
- Assignees: Boe Technology Group Co., Ltd.; Ordos Yuansheng Optoelectronics Co., Ltd.
- Applicants: Boe Technology Group Co., Ltd.; Ordos Yuansheng Optoelectronics Co., Ltd.
- Inventors: Xiaojin Zhang; Xiang Feng; Dini Xie
- Web page: https://patentgrep.com/patent/US10319290B2

## CPC

- G09G 3/14: Semiconductor devices, e.g. diodes
- G09G 3/3208: organic, e.g. using organic light-emitting diodes [OLED]
- H10K 59/128: comprising two independent displays, e.g. for emitting information from two major sides of the display
- H10K 59/30: Devices specially adapted for multicolour light emission
- H10K 59/32: Stacked devices having two or more layers, each emitting at different wavelengths
- H10K 59/8052: {Cathodes}
- H10K 77/10: Substrates, e.g. flexible substrates
- G09G 2320/0233: Improving the luminance or brightness uniformity across the screen
- G09G 2320/0666: for control of colour parameters, e.g. colour temperature
- H10K 50/15: Hole transporting layers
- H10K 50/16: Electron transporting layers
- H10K 50/17: Carrier injection layers
- H10K 50/171: {Electron injection layers}
- H10K 85/311: {Phthalocyanine}
- H10K 85/324: {comprising aluminium, e.g. Alq3}
- H10K 85/342: {comprising iridium}
- H10K 85/60: Organic compounds having low molecular weight (H10K85/10 - H10K85/50 take precedence)
- H10K 85/624: {containing six or more rings}
- H10K 85/626: {containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene}
- H10K 85/633: {comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom}
- H10K 85/6572: {comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole}
- H10K 2102/00: Constructional details relating to the organic devices covered by this subclass
- H10K 2102/103: {comprising indium oxides, e.g. ITO}
- H10K 2102/3023: {Direction of light emission}
- H10K 2102/3026: {Top emission}
- H10K 2102/351: {Thickness}
- Y02E 10/549: Organic PV cells
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

The present invention provides an electroluminescent device, a manufacturing method and driving method thereof, and a display device. The electroluminescent device comprises a transparent substrate, and a first light emitting unit and a second light emitting unit disposed at both sides of the transparent substrate respectively, wherein the first light emitting unit and the second light emitting unit have the same light output direction and are connected to two control circuit respectively. In the present invention, a parallel device structure is adopted to achieve independent control of two light emitting units in a single electroluminescent device, not only the color temperature is adjustable, but also the light emitting efficiency of the device can be increased. Also the transparent substrate can be fabricated using polymers having a refractive index adapted to the light emitting material, thereby reducing the optical waveguide loss in the device and realizing display of flexible device.

## Claims

### Claim 1

An electroluminescent device, comprising:
a transparent substrate;
a first light emitting unit and a second light emitting unit disposed at both sides of the transparent substrate, respectively, wherein the first light emitting unit and the second light emitting unit have a same light output direction and are connected to two control circuits, respectively, and the transparent substrate has a refractive index adapted to light emitting materials of the first light emitting unit and the second light emitting unit,
the first light emitting unit is a bottom emitting type light emitting unit, and the second light emitting unit is a top emitting type light emitting unit;
the first light emitting unit comprises a first transparent anode, a first light emitting layer and a total reflection cathode sequentially arranged from one side close to the transparent substrate to the other side away from the transparent substrate; the second light emitting unit comprises a second transparent anode, a second light emitting layer and a transparent cathode sequentially arranged from one side close to the transparent substrate to the other side away from the transparent substrate; and
the first transparent anode and the second transparent anode are directly electrically connected to each other.

### Claim 2 (depends on 1)

The electroluminescent device according to claim 1, wherein the refractive index of the transparent substrate ranges from 1.7 to 2.

### Claim 3 (depends on 1)

The electroluminescent device according to claim 1, wherein the first light emitting layer is a long wavelength organic light emitting material layer, which is capable of emitting light with a wavelength of 561-760 nm; and the second light emitting layer is a short wavelength organic light emitting material layer, which is capable of emitting light with a wavelength of 380-560 nm.

### Claim 4 (depends on 3)

The electroluminescent device according to claim 3, wherein the first light emitting layer is a yellow organic light emitting material layer, and the second light emitting layer is a blue organic light emitting material layer.

### Claim 5 (depends on 1)

The electroluminescent device according to claim 1, wherein the first light emitting unit further comprises a first hole injection layer and a first hole transport layer arranged between the first transparent anode and the first light emitting layer, and a first electron injection layer and a first electron transport layer arranged between the total reflection cathode and the first light emitting layer; and
the second light emitting unit further comprises a second hole injection layer and a second hole transport layer arranged between the second transparent anode and the second light emitting layer, and a second electron injection layer and a second electron transport layer arranged between the transparent cathode and the second light emitting layer.

### Claim 6

A manufacturing method of an electroluminescent device comprising:
providing a transparent substrate;
fabricating a first light emitting unit and a second light emitting unit on both sides of the transparent substrate, respectively, wherein the first light emitting unit and the second light emitting unit have a same light output direction and are connected to two control circuits, respectively, and the transparent substrate has a refractive index adapted to light emitting materials of the first light emitting unit and the second light emitting unit,
wherein the first light emitting unit is a bottom emitting type light emitting unit, and the step of fabricating the first light emitting unit includes: forming a first transparent anode, a first light emitting layer and a total reflection cathode sequentially on one side of the transparent substrate;
the second light emitting unit is a top emitting type light emitting unit, and the step of forming the second light emitting unit comprises: forming a second transparent anode, a second light emitting layer and a transparent cathode sequentially on the other side of the transparent substrate; and
the first transparent anode and the second transparent anode are directly electrically connected to each other.

### Claim 7 (depends on 6)

The manufacturing method according to claim 6, wherein a material of the first transparent anode includes indium tin oxide, and a thickness of the first transparent anode is 80-160 nm.

### Claim 8 (depends on 6)

The manufacturing method according to claim 6, wherein the first light emitting layer is a yellow organic light emitting material layer made of a yellow fluorescent material or a yellow phosphorescent material, and a thickness of the first light emitting layer ranges from 20 to 50 nm.

### Claim 9 (depends on 6)

The manufacturing method according to claim 6, wherein the total reflection cathode is a metal cathode made of any one or arbitrary alloy of magnesium, silver and aluminum, and a thickness of the total reflection cathode ranges from 80 to 200 nm.

### Claim 10 (depends on 6)

The manufacturing method according to claim 6, wherein the manufacturing method further comprises:
a step between forming the first transparent anode and forming the first light emitting layer:
forming a first hole injection layer and a first hole transport layer; and
a step between forming the first light emitting layer and forming the total reflection cathode:
forming a first electron transport layer and a first electron injection layer.

### Claim 11 (depends on 10)

The manufacturing method according to claim 10, wherein a material for forming the first hole injection layer includes any one of copper phthalocyanine, zinc phthalocyanine, 2,3,6,7,10,11-Hexacyano-1,4,5,8,9,12-hexaazatriphenylene and 2,3,5,6-Tetrafluoro-7,7′,8,8′-tetracyanoquinodimethane, and a thickness of the first hole injection layer ranges from 5 to 40 nm.

### Claim 12 (depends on 10)

The manufacturing method according to claim 10, wherein a material for forming the first hole transport layer includes N,N′-di(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine or 2,2′,7,7′-Tetrakis(diphenylamino)-9,9′-spirobifluorene, and a thickness of the first hole transport layer ranges from 10 to 100 nm.

### Claim 13 (depends on 10)

The manufacturing method according to claim 10, wherein the first electron injection layer and the first electron transport layer together form a first electronic auxiliary layer, a material from which the first electronic auxiliary layer is made includes: Alq3:Li or BPhen:Cs, and a thickness of the first electronic auxiliary layer ranges from 10 to 100 nm.

### Claim 14 (depends on 6)

The manufacturing method according to claim 6, wherein the transparent cathode is made of any one of lithium fluoride, aluminum, indium tin oxide and lithium, or a composite material of lithium/indium tin oxide;
when the transparent cathode is made of lithium fluoride, a thickness of the transparent cathode ranges from 0.5 to 1 nm;
when the transparent cathode is made of aluminum, the thickness of the transparent cathode ranges from 1 to 3 nm;
when the transparent cathode is made of lithium, the thickness of the transparent cathode ranges from 0.5 to 1.5 nm; and
when the transparent cathode is made of indium tin oxide or the composite material of lithium/indium tin oxide, the thickness of the transparent cathode ranges from 20 to 50 nm.

### Claim 15 (depends on 1)

A driving method of the electroluminescent device according to claim 1, comprising:
driving the first light emitting device to emit light through a first control circuit;
driving the second light emitting device to emit light through a second control circuit;
wherein the first control circuit and the second control circuit are independent to each other.

### Claim 16 (depends on 15)

The driving method according to claim 15, wherein
a voltage output to the first transparent anode from the first control circuit is equal to a voltage output to the second transparent anode from the second control circuit, so that the first transparent anode and the second transparent anode have the same potential.