CN107316886B

CN107316886B - White light emitting element

Info

Publication number: CN107316886B
Application number: CN201710580788.1A
Authority: CN
Inventors: 吴忻蕙; 陈重嘉; 李孟庭
Original assignee: AU Optronics Corp
Current assignee: AU Optronics Corp
Priority date: 2017-05-26
Filing date: 2017-07-17
Publication date: 2020-02-14
Anticipated expiration: 2037-07-17
Also published as: TW201901921A; CN107316886A; TWI627728B

Abstract

A white light emitting element has a first light emitting region and a second light emitting region. The white light emitting element comprises a first light emitting unit, a second light emitting unit and a connecting layer. The first light-emitting unit includes a first electrode layer and a first light-emitting layer, wherein the first light-emitting layer is disposed on the first electrode layer and located in the first light-emitting region and the second light-emitting region. The second light emitting unit comprises a second light emitting layer positioned in the first light emitting area and the second light emitting area and a second electrode layer configured on the second light emitting layer. The connection layer is located between the first light emitting unit and the second light emitting unit so as to connect the first light emitting unit and the second light emitting unit in series, wherein at least one of the first light emitting unit and the second light emitting unit comprises at least one patterned light emitting layer, and the at least one patterned light emitting layer is located in the first light emitting area or the second light emitting area.

Description

White light emitting element

Technical Field

The present invention relates to a light emitting device, and more particularly, to a white light emitting device.

Background

White light emitting diodes are widely used in display and lighting applications. There is a stacked white light device, in which a blue light emitting diode device and a red-green light emitting diode device are stacked together to mix the emitted color light into white light. However, at the current material development level, the blue light emitting material has a significant difference in light emitting efficiency and lifetime compared to the red and green light emitting materials; in terms of the overall optical design, the efficiency of the red-green led cannot be directly optimized for the blue led because of the consideration of the efficiency of the red-green led, so the light emitting efficiency of the stacked white light device is still limited at present, and the blue light intensity is significantly reduced after long-term operation. Therefore, the stacked white light device has problems of light color change and poor reliability after long-term operation in lighting or display applications.

Disclosure of Invention

The invention provides a white light emitting element, which can effectively optimize specific color light emitted by the white light emitting element so as to improve the luminous efficiency of the color light.

The white light emitting element of the invention has a first light emitting region and a second light emitting region, and includes a first light emitting unit, a second light emitting unit and a connection layer. The first light-emitting unit includes a first electrode layer and a first light-emitting layer. The first light emitting layer is disposed on the first electrode layer and located in the first light emitting region and the second light emitting region. The second light emitting unit includes a second light emitting layer and a second electrode layer. The second light emitting layer is located in the first light emitting region and the second light emitting region. The second electrode layer is configured on the second light-emitting layer. The connection layer is located between the first light emitting unit and the second light emitting unit so as to connect the first light emitting unit and the second light emitting unit in series, wherein at least one of the first light emitting unit and the second light emitting unit comprises at least one patterned light emitting layer, and the at least one patterned light emitting layer is located in the first light emitting area or the second light emitting area.

In view of the above, the white light emitting device of the invention includes a first light emitting unit, a second light emitting unit, and a connecting layer connecting the first light emitting unit and the second light emitting unit, wherein the first light emitting unit includes a first light emitting layer located in a first light emitting region and a second light emitting region, the second light emitting unit includes a second light emitting layer located in the first light emitting region and the second light emitting region, and at least one of the first light emitting unit and the second light emitting unit includes at least one patterned light emitting layer located in the first light emitting region or the second light emitting region, so that the light emitting efficiency of the patterned light emitting layer is not considered when the first light emitting layer and the second light emitting layer are designed, and further, the color lights emitted by the first light emitting layer and the second light emitting layer are effectively optimized, so as to improve the light emitting efficiency of the color lights. Therefore, the white light emitting device can solve the problems of light color change and poor reliability of the existing stacked white light emitting device after long-term operation.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic cross-sectional view of a white light emitting device according to a first embodiment of the present invention.

Fig. 2 is a graph showing the relationship between the wavelength and the intensity of light emitted by the white light emitting device of fig. 1 and the light emitted by the conventional stacked white light emitting device.

Fig. 3 is a schematic cross-sectional view of a white light emitting device according to a second embodiment of the present invention.

Fig. 4 is a graph showing the relationship between the wavelength and the intensity of light emitted by the white light emitting device of fig. 3 and the light emitted by the conventional stacked white light emitting device.

Fig. 5 is a schematic cross-sectional view of a white light emitting device according to a third embodiment of the present invention.

Fig. 6 is a graph showing the relationship between the wavelength and the intensity of light emitted by the white light emitting device of fig. 5 and the light emitted by the conventional stacked white light emitting device.

[ notation ] to show

10. 30, 50: white light emitting element

100. 300, 500: substrate

110. 310, 510: element layer

120. 320, 520: a first electrode layer

120a, 120b, 320a, 320b, 520a, 520b, 520 c: electrode pattern

130. 230, 330, 430, 530, 630: hole injection layer

140. 150, 240, 250, 340, 350, 440, 540, 550, 552, 640: hole transport layer

160. 360 and 560: a first light-emitting layer

162. 362, 562: a first patterned light-emitting layer

260. 460, 660: second luminescent layer

262. 364, 564: second patterned light-emitting layer

170. 270, 370, 470, 570, 670: electron transport layer

180. 280, 380, 480, 580, 680: electron injection layer

290. 490 and 690: a second electrode layer

A: a first light-emitting region

B: the second light-emitting region

C: third light emitting region

R: connecting layer

IA. 3IA, 5 IA: the first color light

IB. 3IB, 5 IB: second color light

5 IC: light of the third color

U1: first light emitting unit

U2: second light emitting unit

Detailed Description

Fig. 1 is a schematic cross-sectional view of a white light emitting device according to a first embodiment of the present invention. Referring to fig. 1, the white light emitting device 10 includes a first light emitting unit U1, a second light emitting unit U2 and a connection layer R, wherein the first light emitting unit U1 includes a first electrode layer 120, a first light emitting layer 160 and a first patterned light emitting layer 162, and the second light emitting unit U2 includes a second electrode layer 290, a second light emitting layer 260 and a second patterned light emitting layer 262. In addition, in the present embodiment, the white light emitting device 10 may further include a substrate 100, a device layer 110, a Hole Injection Layer (HIL) 130, a Hole Transport Layer (HTL) 140, a hole transport layer 150, an Electron Transport Layer (ETL) 170, an Electron Injection Layer (EIL) 180, a hole injection layer 230, a hole transport layer 240, a hole transport layer 250, an electron transport layer 270, and an electron injection layer 280, wherein the first light emitting unit U1 includes the hole injection layer 130, the hole transport layer 140, the hole transport layer 150, the electron transport layer 170, and the electron injection layer 180, and the second light emitting unit U2 includes the hole injection layer 230, the hole transport layer 240, the hole transport layer 250, the electron transport layer 270, and the electron injection layer 280. Hereinafter, each of the above-described members will be described in detail.

The substrate 100 has a first light-emitting region a and a second light-emitting region B. In the present embodiment, the first light-emitting region a and the second light-emitting region B are used to display color light of different colors, respectively. In the present embodiment, the first light emitting region a and the second light emitting region B may be arranged in a side by side (side by side) manner, that is, the first light emitting region a and the second light emitting region B are disposed adjacent to each other, but not limited thereto. In this embodiment, the substrate 100 is made of glass, quartz, an organic polymer, a metal, or the like.

The device layer 110 is disposed on the substrate 100. In this embodiment, the element layer 110 can be any active element layer known to those of ordinary skill in the art. Specifically, in the present embodiment, the device layer 110 may include a plurality of driving devices such as Thin Film Transistors (TFTs) and capacitors, but the invention is not limited thereto.

The first electrode layer 120 is disposed on the substrate 100. In detail, in the present embodiment, the first electrode layer 120 includes an electrode pattern 120a and an electrode pattern 120B separated from each other, wherein the electrode pattern 120a is located in the first light emitting region a, and the electrode pattern 120B is located in the second light emitting region B. That is, in the present embodiment, the first electrode layer 120 is a patterned electrode layer, and the first electrode layer 120 is located in the first light-emitting region a and the second light-emitting region B.

In this embodiment, the first electrode layer 120 can be formed by any method known to those skilled in the art for manufacturing an electrode layer. For example, in one embodiment, the method of forming the first electrode layer 120 includes the following steps: a Chemical Vapor Deposition (CVD) process or a Physical Vapor Deposition (PVD) process is used to form an electrode material layer on the substrate 100, and then a photolithography (lithography) process is used to pattern the electrode material layer. For another example, in one embodiment, the method of forming the first electrode layer 120 includes performing an object printing process.

In addition, in the present embodiment, the material of the first electrode layer 120 may include a reflective material, such as a conductive material of metal, alloy, metal oxide, or the like, or a stacked layer of metal and a transparent metal oxide conductive material, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indium germanium zinc oxide, or other suitable oxides. That is, in the present embodiment, the first electrode layer 120 is a reflective electrode layer, whereby the white light emitting element 10 is of a top emission type (top emission type) design.

The hole injection layer 130 and the hole transport layer 140 are sequentially disposed on the first electrode layer 120. In detail, in the present embodiment, the hole injection layer 130 and the hole transport layer 140 are both located in the first light emitting region a and the second light emitting region B. In addition, the forming methods of the hole injection layer 130 and the hole transport layer 140 include, for example, performing an evaporation process or an inkjet process. The hole injection layer 130 may be made of copper phthalocyanine, star-like arylamine, polyaniline, polyethylene dioxythiophene, or other suitable materials. The material of the hole transport layer 140 includes, for example, triarylamines, cross-structure diaminobiphenyl, diaminobiphenyl derivatives, or other suitable materials. It should be noted that, in the present embodiment, the white light emitting device 10 includes the hole injection layer 130 and the hole transport layer 140, but the invention is not limited thereto. In other embodiments, the white light emitting device 10 may only include the hole injection layer 130 or the hole transport layer 140, or the white light emitting device 10 may not include the hole injection layer 130 and the hole transport layer 140. That is, the configuration of the hole injection layer 130 and the hole transport layer 140 is optional.

The hole transport layer 150 is disposed between the first electrode layer 120 and the first patterned light emitting layer 162, and is used to satisfy the optical thickness of the light emitted by the first patterned light emitting layer 162. In detail, in the present embodiment, the hole transport layer 150 is located in the first light-emitting region a. That is, the hole transport layer 150 is a patterned hole transport layer. The hole transport layer 150 is formed by an evaporation process with a Fine Metal Mask (FMM) or an inkjet process. The material of the hole transport layer 150 includes, for example, triarylamines, cross-linked diamine biphenyl, diamine biphenyl derivatives, or other suitable materials, and may be the same as or different from the hole transport layer 140.

The first patterned light emitting layer 162 is disposed between the first electrode layer 120 and the first light emitting layer 160. In detail, in the present embodiment, the first patterned light emitting layer 162 is located in the first light emitting region a and is not located in the second light emitting region B. In the present embodiment, the first patterned light emitting layer 162 is formed by an evaporation process and a corresponding FMM process or an inkjet process. In addition, in this embodiment, the first patterned light emitting layer 162 is a red light emitting layer. That is, in the present embodiment, the first patterned light emitting layer 162 includes a red light emitting material.

The first light-emitting layer 160 is disposed on the first electrode layer 120. Specifically, in the present embodiment, the first light-emitting layer 160 is located in the first light-emitting region a and the second light-emitting region B. More specifically, in the present embodiment, in the first light-emitting region a, the first light-emitting layer 160 covers the first patterned light-emitting layer 162. From another perspective, in the present embodiment, the first patterned light-emitting layer 162 is only located in the first light-emitting region a, and the first light-emitting layer 160 is a continuous structure layer and is continuously distributed in the first light-emitting region a and the second light-emitting region B. It should be noted that, in the present embodiment, since the first light emitting layer 160 is a continuous structure layer, the first light emitting layer 160 does not need to be formed by using an FMM. In detail, in the present embodiment, the first light emitting layer 160 is formed by using, for example, an evaporation process or an inkjet process in combination with a general metal mask.

In this embodiment, the first light-emitting layer 160 is a blue light-emitting layer. That is, in the present embodiment, the first light emitting layer 160 includes a blue light emitting material. From another point of view, in the present embodiment, the first light emitting layer 160 is a Blue Common Layer (BCL). It should be noted that in this embodiment, the first light emitting layer 160 is preferably made of a material with a relatively high electron mobility (mobility), so that electrons and holes can be easily combined in the first patterned light emitting layer 162 to emit light in the first light emitting region a where the first light emitting layer 160 covers the first patterned light emitting layer 162. That is, in the present embodiment, the first light-emitting layer 160 located in the first light-emitting region a functions as an electron transport layer. On the other hand, in the present embodiment, the light emitted from the first light-emitting layer 160 in the second light-emitting region B can be optimized by the micro-resonant cavity effect.

The electron transport layer 170 and the electron injection layer 180 are sequentially disposed on the first light emitting layer 160. In detail, in the present embodiment, the electron injection layer 170 and the electron transport layer 180 are both located in the first light emitting region a and the second light emitting region B. In addition, the electron transport layer 170 and the electron injection layer 180 may be formed by performing an evaporation process or an inkjet process. The material of the electron transport layer 170 includes, for example, oxazole derivatives and dendrimers thereof, metal chelates, azole compounds, diazaanthracene derivatives, silicon-containing heterocyclic compounds, or other suitable materials. The material of the electron injection layer 180 includes, for example, lithium oxide, lithium boron oxide, potassium silicon oxide, cesium carbonate, sodium acetate, lithium fluoride base, or other suitable materials. It should be noted that, in the present embodiment, the white light emitting device 10 includes the electron transport layer 170 and the electron injection layer 180, but the invention is not limited thereto. In other embodiments, the white light emitting device 10 may only include the electron transport layer 170 or the electron injection layer 180, or the white light emitting device 10 may not include the electron transport layer 170 and the electron injection layer 180. That is, the configuration of the electron transport layer 170 and the electron injection layer 180 is optional.

The connection layer R is disposed between the first light emitting unit U1 and the second light emitting unit U2, so that the first light emitting unit U1 and the second light emitting unit U2 are connected in series. In this embodiment, the connection layer R comprises a conductive material, which is for example Molybdenum oxide (MoO 3), Tungsten oxide (Tungsten trioxide, WO3), lithium or cesium.

The hole injection layer 230 and the hole transport layer 240 are sequentially disposed on the connection layer R. In detail, in the present embodiment, the hole injection layer 230 and the hole transport layer 240 are both located in the first light emitting region a and the second light emitting region B. In addition, the forming methods of the hole injection layer 230 and the hole transport layer 240 include, for example, performing an evaporation process or an inkjet process. The hole injection layer 230 may be made of copper phthalocyanine, star-like arylamine, polyaniline, polyethylene dioxythiophene, or other suitable materials. The material of the hole transport layer 240 includes, for example, triarylamines, cross-structure diaminobiphenyl, diaminobiphenyl derivatives, or other suitable materials. It should be noted that, in the present embodiment, the white light emitting device 10 includes the hole injection layer 230 and the hole transport layer 240, but the invention is not limited thereto. In other embodiments, the white light emitting device 10 may only include the hole injection layer 230 or the hole transport layer 240, or the white light emitting device 10 may not include the hole injection layer 230 and the hole transport layer 240. That is, the configuration of the hole injection layer 230 and the hole transport layer 240 is optional.

The hole transport layer 250 is disposed between the connection layer R and the second patterned light-emitting layer 262 to satisfy the optical thickness of the light emitted by the second patterned light-emitting layer 262. In detail, in the present embodiment, the hole transport layer 250 is located in the first light-emitting region a. That is, the hole transport layer 250 is a patterned hole transport layer. The hole transport layer 250 is formed by an evaporation process with FMM or an inkjet process. The material of the hole transport layer 250 includes, for example, triarylamines, cross-linked diamine biphenyl, diamine biphenyl derivatives, or other suitable materials, and may be the same as or different from the hole transport layer 240.

The second patterned light emitting layer 262 is disposed between the connection layer R and the second light emitting layer 260. In detail, in the present embodiment, the second patterned light emitting layer 262 is located in the first light emitting region a and is not located in the second light emitting region B. In the present embodiment, the second patterned light emitting layer 262 is formed by an evaporation process and a corresponding FMM process or an inkjet process. In addition, in this embodiment, the second patterned light emitting layer 262 is a green light emitting layer. That is, in the present embodiment, the second patterned emission layer 262 includes a green emission material.

The second light emitting layer 260 is disposed on the connection layer R. In detail, in the present embodiment, the second light emitting layer 260 is located in the first light emitting region a and the second light emitting region B. More specifically, in the present embodiment, the second light emitting layer 260 covers the second patterned light emitting layer 262 in the first light emitting region a. From another perspective, in the present embodiment, the second patterned light emitting layer 262 is only located in the first light emitting region a, and the second light emitting layer 260 is a continuous structure layer and is continuously distributed in the first light emitting region a and the second light emitting region B. It should be noted that, in the present embodiment, since the second light emitting layer 260 is a continuous structural layer, the second light emitting layer 260 is not formed by using FMM. In detail, in the present embodiment, the second light emitting layer 260 is formed by using an evaporation process or an inkjet process with a general metal mask.

In this embodiment mode, the second light-emitting layer 260 is a blue light-emitting layer. That is, in this embodiment mode, the second light emitting layer 260 includes a blue light emitting material. From another point of view, in this embodiment, the second light emitting layer 260 is a blue light common layer. In another aspect, in this embodiment, the first light-emitting layer 160 and the second light-emitting layer 260 can emit light of the same color. It should be noted that in this embodiment, the second light emitting layer 260 is made of a material with a relatively high electron mobility, so that in the first light emitting region a where the second light emitting layer 260 covers the second patterned light emitting layer 262, electrons and holes are easily combined in the second patterned light emitting layer 262 to emit light. That is, in this embodiment, the second light emitting layer 260 located in the first light emitting region a functions as an electron transporting layer. On the other hand, in the present embodiment, the light emitted from the second light-emitting layer 260 in the second light-emitting region B can be optimized by the micro-resonant cavity effect.

The electron transport layer 270 and the electron injection layer 280 are sequentially disposed on the second light emitting layer 260. In detail, in the present embodiment, the electron injection layer 270 and the electron transport layer 280 are both located in the first light emitting region a and the second light emitting region B. In addition, the electron transport layer 270 and the electron injection layer 280 are formed by performing an evaporation process or an inkjet process. The material of the electron transport layer 270 includes, for example, oxazole derivatives and dendrimers thereof, metal chelates, azole compounds, diazaanthracene derivatives, silicon-containing heterocyclic compounds, or other suitable materials. The material of the electron injection layer 280 includes, for example, lithium oxide, lithium boron oxide, potassium silicon oxide, cesium carbonate, sodium acetate, lithium fluoride base, or other suitable materials. It should be noted that, in the present embodiment, the white light emitting device 10 includes the electron transport layer 270 and the electron injection layer 280, but the invention is not limited thereto. In other embodiments, the white light emitting device 10 may only include the electron transport layer 270 or the electron injection layer 280, or the white light emitting device 10 may not include the electron transport layer 270 and the electron injection layer 280. That is, the configuration of the electron transport layer 270 and the electron injection layer 280 is optional.

The second electrode layer 290 is disposed on the second light emitting layer 260. In detail, in the present embodiment, the second electrode layer 290 is located in the first light emitting region a and the second light emitting region B. In this embodiment, the material of the second electrode layer 290 includes, for example, a transparent metal oxide conductive material, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indium germanium zinc oxide, or other suitable oxide; a metal; or a stack of at least two of the foregoing. That is, in this embodiment mode, the second electrode layer 290 may be a transparent electrode layer or a transflective electrode layer.

In addition, in this embodiment, the first electrode layer 120 serves as an anode, and the second electrode layer 290 serves as a cathode. It should be noted that, for design reasons, the first electrode layer 120 may also serve as a cathode, and the second electrode layer 290 may serve as an anode. Further, the white light emitting device 10 drives the first light emitting layer 160, the first patterned light emitting layer 162, the second light emitting layer 260 and the second patterned light emitting layer 262 to emit light by generating a voltage difference between the first electrode layer 120 and the second electrode layer 290.

It should be noted that in the white light emitting device 10, micro-cavities (micro-cavities) may be respectively formed between the first electrode layer 120 and the second electrode layer 290 in the first light emitting region a and between the first electrode layer 120 and the second electrode layer 290 in the second light emitting region B, so that the color lights respectively emitted by the first light emitting layer 160, the first patterned light emitting layer 162, the second light emitting layer 260, and the second patterned light emitting layer 262 may generate a micro-cavity effect in the corresponding micro-cavities, and the first light emitting region a and the second light emitting region B respectively display the first color light IA and the second color light IB.

Specifically, the color lights emitted by the first patterned light-emitting layer 162 and the second patterned light-emitting layer 262 are mixed into the first color light IA and emitted from the first light-emitting region a, and the color lights emitted by the first light-emitting layer 160 and the second light-emitting layer 260 are mixed into the second color light IB and emitted from the second light-emitting region B. Specifically, in the present embodiment, the first color light IA is yellow light, and the second color light IB is blue light. In this way, when the white light emitting device 10 is applied to illumination, the first color light IA and the second color light IB are mixed into white light; when the white light emitting device 10 is applied to a display, a red filter layer and a green filter layer may be disposed in the first light emitting area a to obtain red light and green light without disposing any blue filter layer.

From another point of view, in the present embodiment, the first patterned light-emitting layer 162 and the second patterned light-emitting layer 262 are located in the first light-emitting region a, so that the first light-emitting layer 160 and the second light-emitting layer 260 continuously distributed in the first light-emitting region a and the second light-emitting region B can be designed without considering the light-emitting efficiency of the first patterned light-emitting layer 162 and the first patterned light-emitting layer 262, and the second color light IB formed by mixing the color lights emitted by the first light-emitting layer 160 and the second light-emitting layer 260 located in the second light-emitting region B can be effectively optimized, so as to improve the light-emitting efficiency of the second color light IB.

Further, in the present embodiment, since the second color light IB formed by mixing the color lights emitted from the two light emitting layers (i.e., the first light emitting layer 160 and the second light emitting layer 260) in the second light emitting region B can be optimized and the first light emitting layer 160 and the second light emitting layer 260 are both blue light emitting layers, the white light emitting device 10 has higher blue light efficiency compared to the conventional stacked white light emitting device in which a blue light emitting diode device and a red-green light emitting diode device are stacked together. Accordingly, compared to the conventional stacked white light emitting device, the white light emitting device 10 can obtain blue light with a relatively low operating current, so as to effectively prolong the service life of the first light emitting layer 160 and the second light emitting layer 260, and solve the problems of light color change and poor reliability after long-term operation of the conventional stacked white light emitting device. On the other hand, as mentioned above, when the white light emitting device 10 is applied to a display, there is no need to provide any blue color filter layer, so that the blue light efficiency of the white light emitting device 10 can be maintained.

Further, it can be confirmed through a simulated light emitting experiment that the white light emitting device 10 of the present invention has good blue light efficiency. Fig. 2 is a graph showing the relationship between the wavelength and the intensity of light emitted by the white light emitting device of fig. 1 and the light emitted by the conventional stacked white light emitting device. In detail, the existing stacked white light emitting device used in the simulation experiment is a stacked white light emitting device in which a blue light emitting diode device and a red-green light emitting diode device are stacked together. As can be seen from fig. 2, the white light emitting device 10 of the present invention can emit blue light with a stronger intensity than the conventional stacked white light emitting device.

Based on the first embodiment, the first light-emitting unit U1 includes the first light-emitting layer 160 in the first light-emitting region a and the second light-emitting region B and the first patterned light-emitting layer 162 in the first light-emitting region a, and the second light-emitting unit U2 includes the second light-emitting layer 260 in the first light-emitting region a and the second light-emitting region B and the second patterned light-emitting layer 262 in the first light-emitting region a, so that the light-emitting efficiencies of the first patterned light-emitting layer 162 and the second patterned light-emitting layer 262 are not considered when designing the first light-emitting layer 160 and the second light-emitting layer 260, and the second color light IB is further optimized effectively to improve the light-emitting efficiency of the second color light IB. Thus, the white light emitting device 10 can solve the problems of the conventional stacked white light emitting device such as the color change and poor reliability after long-term operation.

In addition, although the first light emitting unit U1 includes the first patterned light emitting layer 162 in the first light emitting area a and the second light emitting unit U2 includes the second patterned light emitting layer 262 in the first light emitting area a in the first embodiment, the present invention is not limited thereto. In detail, it falls within the scope of the present invention as long as at least one of the first and second light-emitting units U1 and U2 includes at least one patterned light-emitting layer in the first or second light-emitting area a or B. That is, in other embodiments, the first light emitting unit U1 may include two patterned light emitting layers in the first light emitting area a; or in other embodiments, the first light-emitting unit U1 may include one patterned light-emitting layer in the first light-emitting area a, and the second light-emitting unit U2 may include one patterned light-emitting layer in the second light-emitting area B.

In the first embodiment, the white light emitting element 10 includes only the first light emitting region a and the second light emitting region B, but the present invention is not limited thereto. In another embodiment, the white light emitting element may include at least a first light emitting region a and a second light emitting region B.

Other embodiments will be described below with reference to fig. 3 to 6. It should be noted that the following embodiments follow the reference numerals and some contents of the foregoing embodiments, wherein the same or similar reference numerals are used to indicate the same or similar elements, and the description of the same technical contents is omitted. For the description of the omitted portions, reference may be made to the foregoing embodiments, and the following embodiments will not be described in detail.

Fig. 3 is a schematic cross-sectional view of a white light emitting device according to a second embodiment of the present invention. Referring to fig. 3 and fig. 1, the white light emitting device 30 of the second embodiment is similar to the white light emitting device 10 of the first embodiment, and the difference is mainly: in the white light emitting element 30, the first light emitting unit U1 includes two patterned light emitting layers, and the second light emitting unit U2 does not include any patterned light emitting layers and patterned hole transport layers; in the white light emitting device 10, the first light emitting unit U1 and the second light emitting unit U2 each include a patterned light emitting layer, and the second light emitting unit U2 includes a patterned hole transporting layer. In view of this, in the second embodiment, the substrate 300, the device layer 310, the first electrode layer 320, the electrode patterns 320a to 320b, the hole injection layer 330, the hole transport layer 340, the first patterned light emitting layer 362, the electron transport layer 370, the electron injection layer 380, the hole injection layer 430, the hole transport layer 440, the electron transport layer 470, the electron injection layer 480, and the second electrode layer 490 may be the same as or similar to those in the first embodiment, and therefore, the description thereof will not be repeated. Hereinafter, the difference between the two will be explained.

Referring to fig. 3, in the present embodiment, the first light emitting unit U1 includes a second patterned light emitting layer 364. In detail, in this embodiment, the second patterned light emitting layer 364 is disposed between the first electrode layer 320 and the first light emitting layer 360, and the first patterned light emitting layer 362 is disposed between the first electrode layer 320 and the second patterned light emitting layer 364. That is, the first patterned light emitting layer 362, the second patterned light emitting layer 364, and the first light emitting layer 360 are sequentially disposed on the first electrode layer 320. On the other hand, in the present embodiment, the second patterned light emitting layer 364 is located in the first light emitting region a and is not located in the second light emitting region B. That is, in the present embodiment, the first patterned luminescent layer 362 and the second patterned luminescent layer 364 are sequentially disposed on the electrode pattern 320 a. The second patterned light emitting layer 364 is formed by an evaporation process with a corresponding FMM or an inkjet process, for example. In addition, in this embodiment mode, the second patterned light emitting layer 364 is a green light emitting layer. That is, in the present embodiment, the second patterned light emitting layer 364 includes a green light emitting material.

In this embodiment, the first light emitting unit U1 includes a hole transporting layer 350 disposed between the first electrode layer 320 and the first patterned light emitting layer 362 to satisfy the optical thickness of the light emitted from the first patterned light emitting layer 362 and the second patterned light emitting layer 364. In detail, in the present embodiment, the hole transport layer 350 is located in the first light-emitting region a. That is, the hole transport layer 350 is a patterned hole transport layer. The hole transport layer 350 is formed by an evaporation process with FMM or an inkjet process. The material of the hole transport layer 350 includes, for example, triarylamines, cross-linked diamine biphenyl, diamine biphenyl derivatives, or other suitable materials, and may be the same as or different from the hole transport layer 340.

In this embodiment mode, the first light-emitting unit U1 includes a first light-emitting layer 360 disposed on the first electrode layer 320. In detail, in the present embodiment, the first light-emitting layer 360 is located in the first light-emitting region a and the second light-emitting region B. More specifically, in the present embodiment, in the first light-emitting region a, the first light-emitting layer 360 covers the first patterned light-emitting layer 362 and the second patterned light-emitting layer 364. From another perspective, in the present embodiment, the first patterned light emitting layer 362 and the second patterned light emitting layer 364 are both located only in the first light emitting region a, and the first light emitting layer 360 is a continuous structure layer and is continuously distributed in the first light emitting region a and the second light emitting region B. It should be noted that, in the present embodiment, since the first light emitting layer 360 is a continuous structure layer, the first light emitting layer 360 does not need to be formed by using an FMM. In detail, in the present embodiment, the first light emitting layer 360 is formed by using an evaporation process or an inkjet process, for example, and a general metal mask.

In this embodiment mode, the first light-emitting layer 360 is a blue light-emitting layer. That is, in this embodiment mode, the first light-emitting layer 360 includes a blue light-emitting material. From another viewpoint, in this embodiment mode, the first light-emitting layer 360 is a blue light-common layer. It should be noted that in this embodiment, the first light emitting layer 360 is made of a material with a relatively high electron mobility, so that in the first light emitting region a where the first light emitting layer 360 covers the first patterned light emitting layer 362 and the second patterned light emitting layer 364, electrons and holes can be easily combined in the first patterned light emitting layer 362 and the second patterned light emitting layer 364 to emit light. That is, in this embodiment mode, the first light-emitting layer 360 located in the first light-emitting region a functions as an electron-transporting layer. On the other hand, in the present embodiment, the light emitted from the first light-emitting layer 360 in the second light-emitting region B can be optimized by the micro-resonant cavity effect.

In this embodiment, the second light-emitting unit U2 includes a second light-emitting layer 460 disposed on the connection layer R. In detail, in the present embodiment, the second light emitting layer 460 is located in the first light emitting region a and the second light emitting region B. That is, in the present embodiment, the second light emitting layer 460 is a continuous structure layer and is continuously distributed in the first light emitting region a and the second light emitting region B. It should be noted that, in the present embodiment, since the second light emitting layer 460 is a continuous structural layer, the second light emitting layer 460 is not formed by using FMM. In detail, in the present embodiment, the second light emitting layer 460 is formed by using an evaporation process or an inkjet process with a general metal mask.

In this embodiment, the second light-emitting layer 460 is a blue light-emitting layer. That is, in this embodiment mode, the second light emitting layer 460 includes a blue light emitting material. From another point of view, in the present embodiment, the second light emitting layer 460 is a blue light common layer. In another aspect, in this embodiment, the first light-emitting layer 360 and the second light-emitting layer 460 can emit color lights of the same color. It should be noted that, in the present embodiment, through the micro-resonant cavity effect, the light emitted by the second light-emitting layer 460 can be emitted to the outside from the first light-emitting region a and the second light-emitting region B.

As can be seen from the first embodiment, in the present embodiment, the white light emitting device 30 drives the first light emitting layer 360, the first patterned light emitting layer 362, the second patterned light emitting layer 364 and the second light emitting layer 460 to emit light by generating a voltage difference between the first electrode layer 320 and the second electrode layer 490. It should be noted that in the present embodiment, micro-resonant cavities can be formed between the first electrode layer 320 and the second electrode layer 490 in the first light-emitting region a and between the first electrode layer 320 and the second electrode layer 490 in the second light-emitting region B, so that the color lights respectively emitted by the first light-emitting layer 360, the first patterned light-emitting layer 362, the second patterned light-emitting layer 364, and the second light-emitting layer 460 can generate a micro-resonant cavity effect in the corresponding micro-resonant cavities, and the first light-emitting region a and the second light-emitting region B can respectively display the first color light 3IA and the second color light 3 IB.

In detail, as described above, in the white light emitting device 30, the light emitted by the first light emitting layer 360 and the light emitted by the second light emitting layer 460 in the second light emitting region B can be optimized through the microcavity effect, so that the color lights emitted by the first patterned light emitting layer 362, the second patterned light emitting layer 364 and the second light emitting layer 460 are mixed into the first color light 3IA and emitted from the first light emitting region a, and the color lights emitted by the first light emitting layer 360 and the second light emitting layer 460 are mixed into the second color light 3IB and emitted from the second light emitting region B. Specifically, in the present embodiment, the first color light 3IA is a mixed color light of yellow light and blue light, and the second color light IB is blue light. In this way, when the white light emitting device 30 is applied to illumination, the first color light 3IA and the second color light 3IB are mixed into white light; when the white light emitting device 30 is applied to a display, a red filter layer and a green filter layer or a red filter layer, a green filter layer and a wavelength conversion layer may be disposed in the first light emitting area a to obtain red light and green light without disposing any blue filter layer.

From another point of view, in the present embodiment, the first patterned light-emitting layer 362 and the second patterned light-emitting layer 364 are located in the first light-emitting region a, so that the first light-emitting layer 360 and the second light-emitting layer 460 continuously distributed in the first light-emitting region a and the second light-emitting region B can be designed without considering the light-emitting efficiency of the first patterned light-emitting layer 362 and the second patterned light-emitting layer 364, and the second color light 3IB formed by mixing the color lights emitted by the first light-emitting layer 360 and the second light-emitting layer 460 located in the second light-emitting region B can be effectively optimized, so as to improve the light-emitting efficiency of the second color light 3 IB.

Further, in the present embodiment, since the second color light 3IB formed by mixing the color lights emitted from the two light emitting layers (i.e., the first light emitting layer 360 and the second light emitting layer 460) in the second light emitting region B can be optimized, the light emitted from the second light emitting layer 460 in the first light emitting region a can be emitted to the outside, and the first light emitting layer 360 and the second light emitting layer 460 are both blue light emitting layers, the blue light efficiency of the white light emitting device 30 is higher than that of the conventional stacked white light emitting device in which a blue light emitting diode device and a red-green light emitting diode device are stacked. Accordingly, compared to the conventional stacked white light device, the white light emitting device 30 can obtain blue light with a relatively low operating current, so as to effectively prolong the service life of the first light emitting layer 360 and the second light emitting layer 460, and solve the problems of light color change and poor reliability after long-term operation of the conventional stacked white light device. On the other hand, as mentioned above, when the white light emitting device 30 is applied to a display, there is no need to provide any blue color filter layer, so that the blue light efficiency of the white light emitting device 30 can be maintained.

Further, it can be confirmed by a simulation luminescence experiment that the white light emitting device 30 of the present invention has a good blue light efficiency. Fig. 4 is a graph showing the relationship between the wavelength and the intensity of light emitted by the white light emitting device of fig. 3 and the light emitted by the conventional stacked white light emitting device. In detail, the existing stacked white light emitting device used in the simulation experiment is a stacked white light emitting device in which a blue light emitting diode device and a red-green light emitting diode device are stacked together. As can be seen from fig. 4, the white light emitting device 30 of the present invention can emit blue light with a stronger intensity than the conventional stacked white light emitting device.

Based on the first and second embodiments, the first light-emitting unit U1 includes the first light-emitting layer 360 in the first light-emitting region a and the second light-emitting region B and the first patterned light-emitting layer 362 and the second patterned light-emitting layer 364 in the first light-emitting region a, and the second light-emitting unit U2 includes the second light-emitting layer 460 in the first light-emitting region a and the second light-emitting region B, so that the light-emitting efficiency of the first patterned light-emitting layer 362 and the second patterned light-emitting layer 364 is not considered when designing the first light-emitting layer 360 and the second light-emitting layer 460, and the second color light 3IB is further optimized effectively, so as to improve the light-emitting efficiency of the second color light 3 IB. Thus, the white light emitting device 30 can solve the problems of the conventional stacked white light emitting device such as the color change and poor reliability after long-term operation.

Fig. 5 is a schematic cross-sectional view of a white light emitting device according to a third embodiment of the present invention. Referring to fig. 5, the white light emitting device 50 includes a first light emitting unit U1, a second light emitting unit U2 and a connection layer R, wherein the first light emitting unit U1 includes a first electrode layer 520, a first light emitting layer 560, a first patterned light emitting layer 562 and a second patterned light emitting layer 564, and the second light emitting unit U2 includes a second electrode layer 690 and a second light emitting layer 660. In addition, in this embodiment, the white light emitting device 50 further includes a substrate 500, a device layer 510, a hole injection layer 530, a hole transport layer 540, a hole transport layer 550, a hole transport layer 552, an electron transport layer 570, an electron injection layer 580, a hole injection layer 630, a hole transport layer 640, an electron transport layer 670, and an electron injection layer 680, wherein the first light emitting unit U1 includes the hole injection layer 530, the hole transport layer 540, the hole transport layer 550, the hole transport layer 552, the electron transport layer 570, and the electron injection layer 580, and the second light emitting unit U2 includes the hole injection layer 630, the hole transport layer 640, the electron transport layer 670, and the electron injection layer 680. Hereinafter, each of the above-described members will be described in detail.

The substrate 500 has a first light-emitting region a, a second light-emitting region B, and a third light-emitting region C. In the present embodiment, the first light-emitting region a, the second light-emitting region B, and the third light-emitting region C are used to display color light of different colors. In this embodiment, the first light-emitting area a, the second light-emitting area B and the third light-emitting area C may be arranged in parallel, that is, the first light-emitting area a and the second light-emitting area B are disposed adjacent to each other, and the second light-emitting area B and the third light-emitting area C are disposed adjacent to each other, but not limited thereto. In this embodiment, the substrate 500 is made of glass, quartz, an organic polymer, a metal, or the like.

The device layer 510 is disposed on the substrate 500. In this embodiment, the element layer 510 can be any active element layer known to those of ordinary skill in the art. Specifically, in the present embodiment, the element layer 510 may include a plurality of driving elements such as TFTs and capacitors, but the invention is not limited thereto.

The first electrode layer 520 is disposed on the substrate 500. In detail, in the present embodiment, the first electrode layer 520 includes an electrode pattern 520a, an electrode pattern 520B, and an electrode pattern 520C that are separated from each other, wherein the electrode pattern 520a is located in the first light-emitting area a, the electrode pattern 520B is located in the second light-emitting area B, and the electrode pattern 520C is located in the third light-emitting area C. That is, in the present embodiment, the first electrode layer 520 is a patterned electrode layer, and the first electrode layer 520 is located in the first light-emitting region a, the second light-emitting region B, and the third light-emitting region C.

In this embodiment, the first electrode layer 520 can be formed by any method known to those skilled in the art for manufacturing an electrode layer. For example, in one embodiment, the method of forming the first electrode layer 520 includes the steps of: an electrode material layer is formed on the substrate 500 using a CVD process or a PVD process, and then patterned using a photolithography process. For another example, in one embodiment, the method of forming the first electrode layer 520 includes performing a printing and spraying process.

In addition, in the present embodiment, the material of the first electrode layer 520 may include a reflective material, such as a conductive material of metal, alloy, metal oxide, or the like, or a stacked layer of metal and a transparent metal oxide conductive material, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indium germanium zinc oxide, or other suitable oxides. That is, in the present embodiment, the first electrode layer 520 is a reflective electrode layer, so that the white light emitting device 50 is of a top emission type design.

The hole injection layer 530 and the hole transport layer 540 are sequentially disposed on the first electrode layer 520. In detail, in the present embodiment, the hole injection layer 530 and the hole transport layer 540 are located in the first light-emitting region a, the second light-emitting region B, and the third light-emitting region C. In addition, the forming methods of the hole injection layer 530 and the hole transport layer 540 include, for example, performing an evaporation process or an inkjet process. The hole injection layer 530 may be made of copper phthalocyanine, star-like arylamine, polyaniline, polyethylene dioxythiophene, or other suitable materials. The material of the hole transport layer 540 includes, for example, triarylamines, cross-linked diaminobiphenyl, diaminobiphenyl derivatives, or other suitable materials. It should be noted that, in the present embodiment, the white light emitting device 50 includes the hole injection layer 530 and the hole transport layer 540, but the invention is not limited thereto. In other embodiments, the white light emitting device 50 may only include the hole injection layer 530 or the hole transport layer 540, or the white light emitting device 50 may not include the hole injection layer 530 and the hole transport layer 540. That is, the configuration of the hole injection layer 530 and the hole transport layer 540 is optional.

The hole transport layer 550 is disposed between the first electrode layer 520 and the first patterned light-emitting layer 562, and is used to satisfy the optical thickness of the light emitted from the first patterned light-emitting layer 562. In detail, in the present embodiment, the hole transport layer 550 is located in the first light-emitting region a. That is, the hole transport layer 550 is a patterned hole transport layer. The hole transport layer 550 is formed by an evaporation process with FMM or an inkjet process. The material of the hole transport layer 550 includes, for example, triarylamines, cross-linked diamine biphenyl, diamine biphenyl derivatives, or other suitable materials, and may be the same as or different from the hole transport layer 540.

The hole transport layer 552 is disposed between the first electrode layer 520 and the second patterned light emitting layer 564 to satisfy the optical thickness of the light emitted from the second patterned light emitting layer 564. In detail, in this embodiment mode, the thickness of the hole transport layer 552 is smaller than that of the hole transport layer 550. In addition, in this embodiment mode, the hole transport layer 552 is located in the second light emitting region B. That is, the hole transport layer 552 is a patterned hole transport layer. The hole transport layer 552 is formed by an evaporation process with FMM or an inkjet process. The material of the hole transport layer 552 includes, for example, triarylamines, cross-linked diamine biphenyl, diamine biphenyl derivatives, or other suitable materials, and may be the same as or different from the hole transport layer 540, and may be the same as or different from the hole transport layer 550.

The first patterned light emitting layer 562 is disposed between the first electrode layer 520 and the first light emitting layer 560. In detail, in this embodiment, the first patterned light emitting layer 562 is disposed on the hole transport layer 550 on the side opposite to the first electrode layer 520. In addition, in the present embodiment, the first patterned light emitting layer 562 is located in the first light emitting region a and is not located in the second light emitting region B. The first patterned light emitting layer 562 is formed by an evaporation process and a corresponding FMM or an inkjet process. In this embodiment, the first patterned light-emitting layer 562 is a red light-emitting layer. That is, in this embodiment mode, the first patterned light emitting layer 562 includes a red light emitting material.

The second patterned light emitting layer 564 is disposed between the first electrode layer 520 and the first light emitting layer 560. In detail, in this embodiment, the second patterned light emitting layer 564 is disposed on a side of the hole transport layer 552 opposite to the first electrode layer 520. In addition, in the present embodiment, the second patterned light emitting layer 564 is located in the second light emitting region B and is not located in the first light emitting region a. The second patterned light emitting layer 564 is formed by an evaporation process with a corresponding FMM or an inkjet process. In addition, in this embodiment mode, the second patterned light emitting layer 564 is a green light emitting layer. That is, in the present embodiment, the second patterned light emitting layer 564 includes a green light emitting material.

The first light-emitting layer 560 is disposed on the first electrode layer 520. In detail, in the present embodiment, the first light-emitting layer 560 is positioned in the first light-emitting region a, the second light-emitting region B, and the third light-emitting region C. In more detail, in this embodiment, in the first light-emitting region a, the first light-emitting layer 560 covers the first patterned light-emitting layer 562; and in the second light emitting region B, the first light emitting layer 560 covers the second patterned light emitting layer 564. From another perspective, in this embodiment, the first patterned light-emitting layer 562 is only located in the first light-emitting region a, the second patterned light-emitting layer 564 is only located in the second light-emitting region B, and the first light-emitting layer 560 is a continuous structure layer and is continuously distributed in the first light-emitting region a, the second light-emitting region B, and the third light-emitting region C. It should be noted that, in the present embodiment, since the first light emitting layer 560 is a continuous structure layer, the first light emitting layer 560 is not formed by using FMM. In detail, in the present embodiment, the first light emitting layer 560 is formed by using, for example, an evaporation process or an inkjet process in combination with a general metal mask.

In this embodiment mode, the first light-emitting layer 560 is a blue light-emitting layer. That is, in the present embodiment, the first light emitting layer 560 includes a blue light emitting material. From another viewpoint, in this embodiment mode, the first light-emitting layer 560 is a blue light-common layer. It should be noted that in this embodiment, the first light emitting layer 560 is made of a material with a relatively high electron mobility, so that in the first light emitting region a where the first light emitting layer 560 covers the first patterned light emitting layer 562, electrons and holes can be easily combined in the first patterned light emitting layer 562 to emit light, and in the second light emitting region B where the first light emitting layer 560 covers the second patterned light emitting layer 564, electrons and holes can be easily combined in the second patterned light emitting layer 564 to emit light. That is, in this embodiment, the first light-emitting layer 560 located in the first light-emitting region a and the second light-emitting region B functions as an electron-transporting layer. On the other hand, in the present embodiment, the light emitted from the first light-emitting layer 560 in the third light-emitting region C can be optimized by the micro-resonant cavity effect.

The electron transport layer 570 and the electron injection layer 580 are sequentially disposed on the first light emitting layer 560. In detail, in the present embodiment, the electron injection layer 570 and the electron transport layer 580 are located in the first light emitting region a, the second light emitting region B, and the third light emitting region C. In addition, the electron transport layer 570 and the electron injection layer 580 are formed by an evaporation process or an inkjet process. The material of the electron transport layer 570 includes, for example, oxazole derivatives and dendrimers thereof, metal chelates, azole compounds, diazaanthracene derivatives, silicon-containing heterocyclic compounds, or other suitable materials. The material of the electron injection layer 580 includes, for example, lithium oxide, lithium boron oxide, potassium silicon oxide, cesium carbonate, sodium acetate, lithium fluoride base, or other suitable materials. It should be noted that, in the present embodiment, the white light emitting device 50 includes the electron transport layer 570 and the electron injection layer 580, but the invention is not limited thereto. In other embodiments, the white light emitting device 50 may include only the electron transport layer 570 or the electron injection layer 580, or the white light emitting device 50 may not include the electron transport layer 570 and the electron injection layer 580. That is, the configuration of the electron transport layer 570 and the electron injection layer 580 is optional.

The hole injection layer 630 and the hole transport layer 640 are sequentially disposed on the connection layer R. In detail, in the present embodiment, the hole injection layer 630 and the hole transport layer 640 are located in the first light emitting region a, the second light emitting region B and the third light emitting region C. In addition, the forming methods of the hole injection layer 630 and the hole transport layer 640 include, for example, performing an evaporation process or an inkjet process. The hole injection layer 630 may be made of copper phthalocyanine, star-like arylamine, polyaniline, polyethylene dioxythiophene, or other suitable materials. The material of the hole transport layer 640 includes, for example, triarylamines, cross-structure diaminobiphenyl, diaminobiphenyl derivatives, or other suitable materials. It should be noted that, in the present embodiment, the white light emitting element 50 includes the hole injection layer 630 and the hole transport layer 640, but the invention is not limited thereto. In other embodiments, the white light emitting device 50 may include only the hole injection layer 630 or the hole transport layer 640, or the white light emitting device 50 may not include the hole injection layer 630 and the hole transport layer 640. That is, the configuration of the hole injection layer 630 and the hole transport layer 640 is optional.

The second light emitting layer 660 is disposed on the connection layer R. In detail, in the present embodiment, the second light emitting layer 660 is located in the first light emitting region a, the second light emitting region B, and the third light emitting region C. That is, the second light emitting layer 660 is a continuous structure layer and is continuously distributed in the first light emitting region a, the second light emitting region B and the third light emitting region C. It should be noted that, in the present embodiment, since the second light emitting layer 660 is a continuous structure layer, the second light emitting layer 660 does not need to be formed by using FMM. In detail, in the present embodiment, the second light emitting layer 660 is formed by using an evaporation process or an inkjet process with a general metal mask.

In this embodiment mode, the second light-emitting layer 660 is a blue light-emitting layer. That is, in this embodiment mode, the second light emitting layer 660 includes a blue light emitting material. In another aspect, in this embodiment, the second light emitting layer 660 is a blue light common layer. In this embodiment, the first light-emitting layer 560 and the second light-emitting layer 660 can emit light of the same color. It should be noted that, in the present embodiment, through the micro-resonant cavity effect, the light emitted by the second light-emitting layer 660 can be emitted to the outside from the first light-emitting region a, the second light-emitting region B and the third light-emitting region C.

The electron transport layer 670 and the electron injection layer 680 are sequentially disposed on the second light emitting layer 660. In detail, in the present embodiment, the electron injection layer 670 and the electron transport layer 680 are located in the first light emitting area a, the second light emitting area B and the third light emitting area C. In addition, the electron transport layer 670 and the electron injection layer 680 are formed by performing an evaporation process or an inkjet process. The material of the electron transport layer 670 includes, for example, oxazole derivatives and dendrimers thereof, metal chelates, azole compounds, diazaanthracene derivatives, silicon-containing heterocyclic compounds, or other suitable materials. The material of the electron injection layer 680 includes, for example, lithium oxide, lithium boron oxide, potassium silicon oxide, cesium carbonate, sodium acetate, lithium fluoride base, or other suitable materials. It should be noted that, in the present embodiment, the white light emitting device 50 includes the electron transport layer 670 and the electron injection layer 680, but the invention is not limited thereto. In other embodiments, the white light emitting device 50 may include only the electron transport layer 670 or the electron injection layer 680, or the white light emitting device 50 may not include the electron transport layer 670 and the electron injection layer 680. That is, the configuration of the electron transport layer 670 and the electron injection layer 680 is optional.

The second electrode layer 690 is disposed on the second light emitting layer 660. In detail, in this embodiment, the second electrode layer 690 is positioned in the first light-emitting region a, the second light-emitting region B, and the third light-emitting region C. In this embodiment, the material of the second electrode layer 690 includes, for example, a transparent metal oxide conductive material, such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indium germanium zinc oxide, or other suitable oxide; a metal; or a stack of at least two of the foregoing. That is, in this embodiment mode, the second electrode layer 690 may be a transparent electrode layer or a transflective electrode layer.

In addition, in this embodiment, the first electrode layer 520 serves as an anode, and the second electrode layer 690 serves as a cathode. It should be noted that the first electrode layer 520 may also serve as a cathode and the second electrode layer 690 may serve as an anode for design reasons. In addition, the white light emitting device 50 drives the first light emitting layer 560, the first patterned light emitting layer 562, the second patterned light emitting layer 564 and the second light emitting layer 660 to emit light by generating a voltage difference between the first electrode layer 520 and the second electrode layer 690.

It should be noted that in the white light emitting device 50, micro-resonant cavities may be formed between the first electrode layer 520 and the second electrode layer 690 in the first light emitting region a, between the first electrode layer 520 and the second electrode layer 690 in the second light emitting region B, and between the first electrode layer 520 and the second electrode layer 690 in the third light emitting region C, so that the color lights emitted by the first light emitting layer 560, the first patterned light emitting layer 562, the second patterned light emitting layer 564, and the second light emitting layer 660 can generate a micro-resonant cavity effect in the corresponding micro-resonant cavities, and the first light emitting region a, the second light emitting region B, and the third light emitting region C respectively display the first color light emitting region 5IA, the second color light 5IB, and the third color light 5 IC.

In detail, as described above, in the white light emitting device 50, the light emitted by the first light emitting layer 560 and the light emitted by the second light emitting layer 660 in the third light emitting region C can be optimized through the microcavity effect, so that the color lights emitted by the first patterned light emitting layer 562 and the second light emitting layer 660 are mixed into the first color light 5IA and emitted from the first light emitting region a, the color lights emitted by the second patterned light emitting layer 564 and the second light emitting layer 660 are mixed into the second color light 5IB and emitted from the second light emitting region B, and the color lights emitted by the first light emitting layer 560 and the second light emitting layer 660 are mixed into the third color light 5IC and emitted from the third light emitting region C. Specifically, in the present embodiment, the first color light 5IA is a mixed color light of red light and blue light, the second color light 5IB is a mixed color light of green light and blue light, and the third color light 5IC is blue light. Thus, when the white light emitting device 50 is used for illumination, the first color light 5IA, the second color light 5IB and the third color light 5IC are mixed into white light; when the white light emitting device 50 is applied to a display, a red filter layer or a red wavelength conversion layer may be disposed in the first light emitting region a to obtain red light, and a green filter layer or a green wavelength conversion layer may be disposed in the second light emitting region B to obtain green light, without disposing any blue filter layer.

From another perspective, in the present embodiment, the first patterned light-emitting layer 562 is located in the first light-emitting region a and the second patterned light-emitting layer 564 is located in the second light-emitting region B, so that the first light-emitting layer 560 and the second light-emitting layer 660 continuously distributed in the first light-emitting region a, the second light-emitting region B and the third light-emitting region C can be designed without considering the light-emitting efficiency of the first patterned light-emitting layer 562 and the second patterned light-emitting layer 564, and the third color light 5IC formed by mixing the color lights emitted from the first light-emitting layer 560 and the second light-emitting layer 660 located in the third light-emitting region C can be effectively optimized, so as to improve the light-emitting efficiency of the third color light 5 IC.

Further, in the present embodiment, since the third color light 5IC formed by mixing the color lights emitted from the two light emitting layers (i.e., the first light emitting layer 560 and the second light emitting layer 660) in the third light emitting region C can be optimized, the light emitted from the second light emitting layer 660 in the first light emitting region a and the second light emitting region B can be emitted to the outside, and the first light emitting layer 560 and the second light emitting layer 660 are both blue light emitting layers, the blue light efficiency of the white light emitting device 50 is higher than that of the conventional stacked white light emitting device in which a blue light emitting diode device and a red-green light emitting diode device are stacked. Accordingly, compared to the conventional stacked white light emitting device, the white light emitting device 50 can obtain blue light with a relatively low operating current, so as to effectively prolong the service life of the first light emitting layer 560 and the second light emitting layer 660, and solve the problems of light color change and poor reliability after long-term operation of the conventional stacked white light emitting device. On the other hand, as mentioned above, when the white light emitting device 50 is applied to a display, there is no need to provide any blue color filter layer, so that the blue light efficiency of the white light emitting device 50 can be maintained.

Further, it can be confirmed by a simulated light emitting experiment that the white light emitting device 50 of the present invention has good blue light efficiency. Fig. 6 is a graph showing the relationship between the wavelength and the intensity of light emitted by the white light emitting device of fig. 5 and the light emitted by the conventional stacked white light emitting device. In detail, the existing stacked white light emitting device used in the simulation experiment is a stacked white light emitting device in which a blue light emitting diode device and a red-green light emitting diode device are stacked together. As can be seen from fig. 6, the white light emitting device 50 of the present invention can emit blue light with a stronger intensity than the conventional stacked white light emitting device.

Based on the first and third embodiments, the first light-emitting unit U1 includes the first light-emitting layer 560 located in the first light-emitting area a, the second light-emitting area B, and the third light-emitting area C, the first patterned light-emitting layer 562 located in the first light-emitting area a, and the second patterned light-emitting layer 564 located in the second light-emitting area B, and the second light-emitting unit U2 includes the second light-emitting layer 660 located in the first light-emitting area a, the second light-emitting area B, and the third light-emitting area C, so that the light-emitting efficiencies of the first patterned light-emitting layer 562 and the second patterned light-emitting layer 564 are not considered when the first light-emitting layer 560 and the second light-emitting layer 660 are designed, and the third light 5IC is further optimized effectively, so as to improve the light-emitting efficiency of the third light 5 IC. Thus, the white light emitting device 50 can solve the problems of the conventional stacked white light emitting device such as the color change and poor reliability after long-term operation.

In summary, the white light emitting device provided in the foregoing embodiments includes a first light emitting unit, a second light emitting unit, and a connection layer connecting the first light emitting unit and the second light emitting unit, wherein the first light emitting unit includes a first light emitting layer located in a first light emitting region and a second light emitting region, the second light emitting unit includes a second light emitting layer located in the first light emitting region and the second light emitting region, and at least one of the first light emitting unit and the second light emitting unit includes at least one patterned light emitting layer located in the first light emitting region or the second light emitting region, so that the light emitting efficiency of the patterned light emitting layer is not considered when designing the first light emitting layer and the second light emitting layer, and the color light emitted by the first light emitting layer and the second light emitting layer is further optimized effectively, so as to improve the light emitting efficiency of the color light. Therefore, the white light emitting device can solve the problems of light color change and poor reliability of the existing stacked white light emitting device after long-term operation.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A white light emitting device having a first light emitting region and a second light emitting region, the white light emitting device comprising:

a first light emitting unit comprising:

a first electrode layer; and

a first light emitting layer disposed on the first electrode layer and located in the first light emitting region and the second light emitting region;

a second light emitting unit including:

a second light emitting layer in the first light emitting region and the second light emitting region; and

a second electrode layer disposed on the second light emitting layer; and

a connection layer between the first light emitting unit and the second light emitting unit to connect the first light emitting unit and the second light emitting unit in series, wherein at least one of the first light emitting unit and the second light emitting unit comprises at least one patterned light emitting layer located in the first light emitting region or the second light emitting region;

the first light-emitting layer is a blue light-emitting layer, and the second light-emitting layer is a blue light-emitting layer.

2. The white light emitting device of claim 1, wherein the at least one patterned light emitting layer comprises a first patterned light emitting layer and a second patterned light emitting layer.

3. The white light emitting device of claim 2, wherein the first patterned light emitting layer is in the first light emitting region and not in the second light emitting region, and the second patterned light emitting layer is in the first light emitting region and not in the second light emitting region.

4. The white light emitting device of claim 3, wherein:

the first light-emitting unit comprises the first patterned light-emitting layer, wherein the first patterned light-emitting layer is arranged between the first electrode layer and the first light-emitting layer; and

the second light-emitting unit comprises a second patterned light-emitting layer, and the second patterned light-emitting layer is arranged between the connecting layer and the second light-emitting layer.

5. The white light emitting device of claim 3, wherein:

the first light-emitting unit comprises a first patterned light-emitting layer and a second patterned light-emitting layer, the first patterned light-emitting layer and the second patterned light-emitting layer are arranged between the first electrode layer and the first light-emitting layer, and the first patterned light-emitting layer is arranged between the first electrode layer and the second patterned light-emitting layer.

6. The white light emitting device of claim 2, wherein the white light emitting device further comprises a third light emitting region, the first light emitting layer is further located in the third light emitting region, and the second light emitting layer is further located in the third light emitting region.

7. The white light emitting device of claim 6, wherein the first patterned light emitting layer is in the first light emitting region and not in the second light emitting region, and the second patterned light emitting layer is in the second light emitting region and not in the first light emitting region.

8. The white light emitting device of claim 7, wherein:

the first light-emitting unit comprises a first patterned light-emitting layer and a second patterned light-emitting layer, and the first patterned light-emitting layer and the second patterned light-emitting layer are arranged between the first electrode layer and the first light-emitting layer.

9. The white light emitting device of claim 2, wherein the first patterned light emitting layer is a red light emitting layer and the second patterned light emitting layer is a green light emitting layer.