WO2014019295A1

WO2014019295A1 - White organic electroluminescent device and manufacturing method thereof

Info

Publication number: WO2014019295A1
Application number: PCT/CN2012/083736
Authority: WO
Inventors: 朱儒晖; 于军胜
Original assignee: 京东方科技集团股份有限公司
Priority date: 2012-07-31
Filing date: 2012-10-30
Publication date: 2014-02-06
Also published as: CN102779948B; CN102779948A

Abstract

A white organic electroluminescent device and a manufacturing method thereof. The device comprises a cathode layer (8), an anode conducting layer (2) and an organic layer which is clamped between the cathode layer (8) and the anode conducting layer (2). The organic layer comprises a phosphorescent luminous layer (4) and a fluorescent luminous layer (6); the luminous color of the phosphorescent luminous layer (4) is different from that of the fluorescent luminous layer (6); and a composite inner connecting layer (5) is arranged between the phosphorescent luminous layer (4) and the fluorescent luminous layer (6). By means of the device and the manufacturing method thereof, the luminous efficiency can be improved and the color stability can be ensured.

Description

White organic electroluminescent device and method of manufacturing the same

Embodiments of the present invention relate to a white organic electroluminescent device and a method of fabricating the same. Background technique

White organic electroluminescent devices (WOLEDs) have become one of the hot research directions in the field of organic light-emitting due to their broad application potential in the field of illumination and display.

After nearly 20 years of development, the performance and theoretical research of white organic electroluminescent devices have made great progress. However, fluorescent devices have been used in most devices in the past, and only 25% of the excitons (single-line) in the fluorescent materials are involved in light emission, thereby limiting the efficiency of the entire device. In order to overcome this limitation, it is common to introduce phosphorescent materials in which singlet and triplet are involved in luminescence. Due to the heavy atom coupling effect, the theoretical value of the internal quantum efficiency of the monumental material can reach 100%. Due to the large energy gap of the Blu-ray monument material, it is more difficult to select a suitable wide-gap main body material, which further increases the difficulty of obtaining high-efficiency blue phosphorescence emission. So far, blue phosphorescent materials have not been put to practical use due to their relatively low color purity and poor lifetime stability. In contrast, the application of blue fluorescent materials is more common, and the use of blue fluorescent materials in part to make white light devices has become a possible solution.

The existing white organic electroluminescent device with blue fluorescence and green and red phosphorescence can achieve an external quantum efficiency of 18.7% by designing a single inner connecting layer and using the triplet excitons. The disadvantage is that the color coordinates are obvious. Yellowish, and the device structure is relatively complex. In general, the fluorescence is relatively weak relative to phosphorescence. How to match the structure of phosphorescence and fluorescence to achieve the balance between the energy point CIE (0.33, 0.33) and high efficiency is still a difficult point. Summary of the invention

Embodiments of the present invention provide a white organic electroluminescent device and a method of fabricating the same to improve luminous efficiency and ensure color stability.

One aspect of the present invention provides a white organic electroluminescent device comprising a cathode layer, a positive electrode including a barrier light emitting layer, and a fluorescent emitting layer; an emitting color of the phosphorescent emitting layer and the fluorescent emitting layer The luminescent color is different; a composite interconnecting layer is disposed between the phosphorescent luminescent layer and the fluorescent luminescent layer. In the white organic electroluminescent device, for example, the monumental light emitting layer is a yellow phosphorescent emitting layer disposed under the composite interconnecting layer; the fluorescent emitting layer is a blue fluorescent emitting layer, disposed in the Above the composite interconnect layer.

In the white organic electroluminescent device, for example, the yellow phosphorescent emitting layer may be composed of a combination of a red phosphor layer and a green phosphor layer.

In the white organic electroluminescent device, for example, the organic layer may further include a hole transport layer and an electron transport layer; the hole transport layer is disposed on the anode conductive layer and the yellow light-emitting layer The electron transport layer is disposed between the blue fluorescent light emitting layer and the cathode layer.

In the white organic electroluminescent device, for example, the composite interconnect layer comprises an auxiliary transition layer composed of at least a bipolar organic transport material doped with a single polarity transport type material.

In the white organic electroluminescent device, for example, the composite interconnect layer further comprises an auxiliary transition layer composed of a bipolar organic transport material or a single polar transport material.

In the white organic electroluminescent device, for example, the composite interconnect layer has a single-layer structure in which a bipolar transport type material is doped with a single polarity transport type material.

In the white organic electroluminescent device, for example, the structure of the composite interconnect layer is a two-layer structure including a bipolar type connection layer and a bipolar type doped connection layer arranged from bottom to top; The bipolar type connection layer is composed of a bipolar transmission type material; the bipolar type doped connection layer is composed of a bipolar transmission type material doped single polarity transmission type material.

In the white organic electroluminescent device, for example, the structure of the composite interconnect layer is a two-layer structure including a bipolar type doped connection layer and a bipolar type connection layer arranged from bottom to top; The bipolar type connection layer is composed of a bipolar transmission type material; the bipolar type doped connection layer is composed of a bipolar transmission type material doped single polarity transmission type material.

In the white organic electroluminescent device, for example, the composite interconnect layer is structured to include a bipolar type connection layer, a bipolar type doped connection layer, and a bipolar type connection layer arranged from bottom to top. The bilayer structure is composed of a bipolar transmission type material; and the bipolar type doping connection layer is composed of a bipolar transmission type material doped single polarity transmission type material.

In the white organic electroluminescent device, for example, the composite interconnect layer is structured to include a bipolar type connection layer, a bipolar type doped connection layer, and a single polarity transfer layer arranged from bottom to top. a three-layer structure; the bipolar connection layer is composed of a bipolar transmission type material; The hybrid layer is composed of a bipolar transmission type material doped with a single polarity transmission type material.

Another aspect of the present invention provides a method of fabricating a white organic electroluminescent device, comprising: forming an anode conductive layer, an organic layer, and a cathode layer in order from bottom to top on a substrate; the organic layer including a barrier light emitting layer And a fluorescent light-emitting layer; the light-emitting color of the phosphorescent light-emitting layer is different from the light-emitting color of the fluorescent light-emitting layer; and a composite inner connecting layer is disposed between the phosphorescent light-emitting layer and the fluorescent light-emitting layer.

In the method, for example, the monument light emitting layer is a yellow phosphorescent emitting layer, the fluorescent emitting layer is a blue fluorescent emitting layer; and the step of providing a composite interconnecting layer between the phosphorescent emitting layer and the fluorescent emitting layer comprises A yellow phosphorescent emitting layer, a composite interconnecting layer, and a blue fluorescent emitting layer are sequentially formed between the cathode layer and the anode conductive layer from bottom to top.

In the method, for example, the organic layer further includes a hole transport layer and an electron transport layer; for example, the manufacturing method may further include: providing a hole transport layer between the yellow phosphorescent layer and the anode conductive layer; An electron transport layer is disposed between the fluorescent light emitting layer and the cathode layer.

A white organic electroluminescent device and a method of fabricating the same according to embodiments of the present invention, wherein an organic layer is provided between a cathode layer and an anode conductive layer arranged from top to bottom, the organic layer comprising a phosphorescent emitting layer having different luminescent colors and a fluorescent light emitting layer, and a composite interconnecting layer is disposed between the phosphorescent emitting layer and the fluorescent emitting layer, and the composite interconnecting layer can effectively modulate carrier and singlet and triplet exciton transmission, and balance The distribution of carriers and singlet and triplet excitons in different luminescent layers adjusts the efficiency of the white organic electroluminescent device and ensures the color stability of the white organic electroluminescent device. DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below. It is obvious that the drawings in the following description relate only to some embodiments of the present invention, and are not intended to limit the present invention. .

1 is a structural view of a white organic electroluminescent device according to the present invention;

Figure 2 is a structural view of Embodiment 1 of the white organic electroluminescent device of the present invention; Figure 3 is a structural view of Embodiment 2 of the white organic electroluminescent device of the present invention; Figure 3 is a structural view of a white organic electroluminescent device of the present invention; Figure 5 is a structural view of a white organic electroluminescent device of the present invention; Figure 6 is a white organic electro-optic according to the present invention. A structural diagram of Embodiment 5 of the light emitting device. detailed description

The technical solutions of the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings of the embodiments of the present invention. It is apparent that the described embodiments are part of the embodiments of the invention, rather than all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the described embodiments of the present invention without departing from the scope of the invention are within the scope of the invention.

Unless otherwise defined, technical terms or scientific terms used herein shall be of the ordinary meaning understood by those of ordinary skill in the art to which the invention pertains. The words "first", "second" and similar terms used in the specification and claims of the present invention do not denote any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the words "a" or "an" do not denote a quantity limitation, but rather mean that there is at least one. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "Down", "Left", "Right", etc. are only used to indicate the relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship is also changed accordingly.

As shown in FIG. 1 , an embodiment of the white organic electroluminescent device of the present invention includes a transparent substrate 1 , an anode conductive layer 2 , a hole transport layer 3 , and a yellow phosphorescent light emitting layer 4 arranged in this order from bottom to top. The composite inner connecting layer 5, the blue fluorescent light emitting layer 6, the electron transport layer 7, and the cathode layer 8.

The transparent substrate 1 may be, for example, a glass or a flexible substrate, and the flexible substrate may be made of one of a polyester or a polyimide compound; an indium tin oxide (ITO), an aluminum-doped oxide A metal oxide such as ruthenium, preferably ruthenium, is preferably one of poly(3,4-ethylenedioxythiophene)/polystyrenesulfonic acid (PEDOT/PSS) and polyaniline (PANI).

The hole transport layer 3 may be a P-type organic semiconductor having a strong hole transporting ability, and is generally a triphenylamine compound such as fluorene, Ν'-diphenyl-N, N'-(1-naphthyl). - Ι, Γ-biphenyl-4,4'-diamine (NPB), hydrazine, Ν'-diphenyl-fluorene, Ν'-bis(3-mercaptophenyl)-fluorene, fluorene-biphenyl One of materials such as -4,4'-diamine (TPD), 4,4',4"-tris(indol-3-phenylphenyl)-phenyl-triphenylamine (MTDATA), preferably hydrazine .

The yellow phosphorescent light-emitting layer 4 can be used as a resistive dopant such as bis[2-(4-triamine-butylphenyl)benzothiazolato-N, C2'] oxime (acetylacetonate compound) (t -bt)2Ir ( acac ) , two ( 2-(2- One of materials such as fluorophenyl)-1,3-benzothiazole-N, C2'] fluorene (acetylacetonate compound) (f-bt) 2Ir (acac), preferably (t-bt) 2Ir ( acac ) The doping concentration is 2%~10%, preferably 7%. The main body may be an electron transport type main body such as 4,7-diphenyl-1,10-phenanthroline (Bphen), or a hole transport type body may be selected. For example, PB, electron-hole mixed type main body such as hole type 4,4',4"-tris(carbazol-9-yl)triphenylamine (TCTA)-doped electron type 1,3-double (optional) The triphenylsilyl)benzene (UGH3) mixed host or the like is preferably NPB in the embodiment of the present invention, and the film layer has a thickness of 10 to 30 nm, and the embodiment of the present invention preferably has 15 nm.

The composite inner connecting layer 5 may be doped with an electron transporting type material such as CBP (4,4'-bis(9-carbazole)biphenyl) (such as 1, 3, 5 - 3) (1-Phenyl-1H-benzimidazol-2-yl)benzene (TPBI), Bphen).

The composite inner connecting layer 5 may also be composed of a bipolar transmission type material doped single polarity transmission type material and an auxiliary transition layer; the auxiliary transition layer may be a bipolar transmission type material or a single polarity transmission type Material composition.

The main body of the blue fluorescent light emitting layer 6 may be an electron transporting type material such as 9-(2-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene (BH), and the film layer has a thickness of, for example, 20 ~40匪, preferably 30nm, the doped dye of the blue fluorescent light-emitting layer 6 may be selected from 4,4'-bis(9-ethyl-3-carbazolevinyl)-fluorene, fluorene-biphenyl (BczVBi) , 4,4'-bis[4-(di-p-phenylamino)styrene]biphenyl (DPAVBi), 4,4'-bis[4-(diphenylamino)styryl]biphenyl ( BDAVBi ) or Ν,Ν'-diphenyl-fluorene, Ν'-bis(2-naphthyl)-2,2'-dinaphthylvinyl-6,6,-diamine (BD), preferably BD The doping concentration is, for example, 2% to 7%, preferably 4%; the blue fluorescent emitting layer 6 may also be selected as an undoped single layer, such as 4,4'-bis(2,2-diphenylethyl). Women's base) -1,1'-biphenyl DPVBi.

The electron transport layer 7 is, for example, a metal organic complex such as Alq3 (8-hydroxyquinoline aluminum), BAlq (bis(2-mercapto-8-hydroxyquinoline-Ν1,08)-(1, Γ-linked Benzene-4-hydroxy)aluminum), Gaq3 (8-hydroxyquinolate) or Bebq2 (bis(10-hydroxybenzo[h]quinoline)indole), phenanthroline or oxadiazole Materials, the present invention selects Bebq2 as an electron transport layer, and has a thickness of, for example, 15 nm.

The cathode layer 8 may, for example, be a metal having a lower work function such as lithium, magnesium, calcium, aluminum or indium or an alloy thereof with copper, gold or silver, and an organic or inorganic material which enhances electron injecting ability, and the present invention In the examples, a lithium fluoride (LiF) layer and an A1 layer which were sequentially laminated were used as a metal cathode layer. For example, the LiF layer has a thickness of 0.5 nm and the A1 layer has a thickness of 200 Å.

Example 1 As shown in FIG. 2, the laminated structure of the organic electro white light device of Example 1 is as follows: Glass substrate / ITO / NPB / NPB: (t - bt) 2 Ir ( acac ) / CBP / CBP: TPBi / BH: BD /Bebq2/LiF/AL

In Embodiment 1, the composite interconnection layer includes a bipolar type connection layer 51 and a bipolar type doping connection layer 52 which are arranged from bottom to top.

According to an example, the preparation method of the white organic electroluminescent device of the present embodiment is as follows. Ultrasonic cleaning of a glass substrate coated with an ITO film as a transparent conductive substrate, for example, sequentially coating a transparent conductive substrate with an ethanol solution, an acetone solution, and deionized water, respectively.

The glass substrate of the ITO film was ultrasonically cleaned, washed, and dried by high-purity dry nitrogen. The ITO film on the surface of the glass substrate serves as the anode conductive layer of the device. For example, the ITO film has a sheet resistance of 10 Ω - 50 Ω and a film thickness of 100 nm - 200 nm.

The dried glass substrate is transferred to a pretreatment chamber, for example, by oxygen plasma treatment for 5 minutes at an oxygen partial pressure of 25 Pa, and the power is 100 W.

The above cleaned and pretreated glass substrate is placed in a vacuum chamber, evacuated to 5 χ 10" ⁴ Pa, and then a hole transporting material NPB is evaporated on the ITO film. For example, the evaporation rate of the material may be It is selected to be 0.1 to 0.2 nm/s, and the film thickness is preferably 40 nm.

On the above hole transport layer, the yellow phosphorescent light-emitting layer is further evaporated, and doping is performed by a dual-source co-evaporation method. For example, the evaporation rate of NPB is preferably 0.1 nm/s, and the doping rate is controlled by (t-bt). The 2Ir (acac) doping ratio is preferably maintained at 6%, and the film layer thickness is, for example, 15 nm.

CBP is evaporated on the yellow phosphorescent layer, the evaporation rate is, for example, 0.01-0.05 nm/s, and the film thickness of CBP is, for example, 1 nm; then the ratio of 1:1 is used to co-evaporate CBP and TPBI, CBP at a ratio of 1:1. The total film thickness of TPBI and the TPBI is, for example, 3.2 nm.

The blue fluorescent light-emitting layer is evaporated on the composite inner connecting layer, and the double-source co-steaming method is used. For example, the evaporation rate of BH is preferably 0.1 nm/s, and the thickness of the BH film layer is preferably 25 nm. The proportion of impurities is preferably controlled at 4%.

The pressure in the vacuum chamber is kept constant, and Bebq ₂ is continuously evaporated on the organic light-emitting layer as an electron transport layer. For example, the evaporation rate is preferably 0.1 to 0.2 nm/s, and the film thickness is preferably 15 nm.

A metal fluoride LiF layer and a metal A1 layer are sequentially deposited on the electron transport layer as a cathode layer of the device. For example, the thickness of the LiF layer is 0.5 nm, and the thickness of the A1 layer is 200 nm.

Comparative example 1

The stack structure of the device is as follows: Glass substrate / ITO / NPB / NPB: (t-bt) 2Ir ( acac ) / CBP / BH: BD / Bebq2 / LiF / Al Comparative Example 1 The preparation method of the device is similar to that of Example 1, except that the internal connection The layer is a single tie layer composed of a bipolar transport material such as CBP having a film thickness of 4.2 nm.

Comparative example 2

The stack structure of the device is as follows:

Glass substrate / ITO / NPB / NPB: (t-bt) 2Ir ( acac ) / BH: BD / Bebq2 / LiF / Al Comparative Example 1 The preparation method of the device is similar to that of Example 1, except that there is no design connection Floor.

The efficiency of Example 1 was 9.9 cd/A at a current density of 100 mA/cm ² , while the efficiency of Comparative Example 1 was 3.4 cd/A, while the efficiency of Comparative Example 2 was 2.3 cd/A. It can be seen that the efficiency of the device with the composite interconnect layer is significantly higher than that of the single tie layer. In Comparative Example 1, the white light was bluish, the light in Comparative Example 2 was blue, and the light in Example 1 was white, which was closer to the energy point such as white light. This can be understood as the following reasons.

(1) Excitons form singlet excitons and triplet excitons in the blue body; singlet excitons are transmitted to the blue fluorescent dye object by Forster energy transfer, and the non-radiative triplet exciton energy can neither pass

Forster energy transfer, because it is low concentration doping, can not be effectively transmitted to the fluorescent dye through Dexter energy transfer, and the propagation distance of triplet excitons is closer to 100 nm, so when a layer of CBP is inserted between the two light-emitting layers of the device, : TPBi and CBP with auxiliary transition layer: When TPBi is used, as long as its thickness is larger than the radius of Forster energy transfer and less than the propagation distance of the triplet state, the singlet energy can be all confined to the blue light-emitting layer, so that the fluorescent dye Fully utilized, it is also possible to propagate part of the triplet energy to the yellow luminescent layer to illuminate the lithographic dye.

(2) Due to the addition of the auxiliary transition layer, it is possible to effectively isolate the fluorescent or phosphorescent luminescent dye from contaminating CBP: TPBi to prevent quenching of triplet excitons.

(3) Another reason is that TPBi is an effective carrier block material and an excellent electron transport material, which can block some holes between the two light-emitting layers, thereby making the electron and hole devices. Performance and the device color coordinates remain substantially constant with voltage changes and are within the white field.

(4) CBP can easily crystallize and crystallize in the vapor deposited film state, which affects the life and stability of the device. Doping TPBi can improve the film formation of CBP and reduce the charge trap.

Example 2 As shown in FIG. 3, the organic electro white light device of Example 2 has a laminated structure of the following structural formula: Glass substrate / ITO / NPB / NPB: (t - bt) 2 Ir ( acac ) / CBP : TPBi / CBP / BH :BD/Bebq2/LiF/Al In Embodiment 2, the composite interconnect layer includes a bipolar type doped connection layer 52 and a bipolar type connection layer 51 which are arranged from bottom to top.

The structure of the composite connection layer of Embodiment 2 is a two-layer structure, and the bipolar type doped connection layer 52 is composed of a bipolar transmission type material CBP doped with a single polarity transmission type material TPBi, and is adjacent to the yellow light layer. The bipolar type connection layer 51 is an auxiliary transition layer composed of CBP, which is close to the blue side.

The fabrication method of the device of Example 2 was similar to that of Example 1, except that the bipolar type connection layer 51 and the bipolar type doping connection layer 52 were arranged from top to bottom. For example, the ratio of CBP to TPBi of the bipolar type doped connection layer 52 in the composite interconnect layer may be 3:2, the total film thickness may be 3 nm, and the film thickness of the bipolar type connection layer 51 may be 1 nm. The structure can also balance the distribution of carriers and singlet and triplet excitons in different luminescent layers to achieve a balance between efficiency and color coordinates.

Example 3

As shown in FIG. 4, the laminated structure of the organic electroluminescent device of Example 3 is as follows: Glass substrate

/ITO/NPB/NPB: (t-bt)2Ir ( acac ) /CBP/CBP: TPBi/CBP/BH: BD/Bebq2/LiF/Al In Example 3, the composite interconnect layer includes bottom to top The bipolar type connection layer 51, the bipolar type doping connection layer 52, and the bipolar type connection layer 51 are arranged.

The composite connecting layer of Embodiment 3 has a three-layer structure, the bipolar connecting layer 51 is an auxiliary transition layer composed of CBP, and is adjacent to the side of the yellow light-emitting layer; and the other bipolar connecting layer 51 is also composed of CBP. The auxiliary transition layer is adjacent to the blue fluorescent light emitting side; the bipolar type doped connection layer 52 is composed of a bipolar transmission material CBP doped electron transport type material TPBi, and the two bipolar type connection layers 51 are interposed therebetween. between.

The preparation method of the device of Embodiment 3 is similar to that of Embodiment 1, except that the ratio of CBP to TPBi of the bipolar type doped connection layer in the interconnect layer can be, for example, 2:3, and the total film thickness can be, for example, 4 nm. The film thickness of the two double polarity connection layers 51 may be, for example, 1 nm. Since the auxiliary transition layer is added on both sides of the inner connecting layer, the fluorescent or phosphorescent luminescent dye can be more effectively isolated from contaminating CBP: TPBi to prevent quenching of triplet excitons.

Example 4

As shown in FIG. 5, the laminated structure of the organic electro white light device of Example 4 is as follows: Glass substrate /ITO/NPB/NPB: (t-bt)2Ir ( acac ) /CBP/CBP: TPBi/TPBi/BH: BD/Bebq2/LiF/Al In Example 4, the composite interconnect layer includes The bipolar type connection layer 51, the bipolar type doping connection layer 52, and the single polarity transmission layer 53 are arranged above.

The composite connection layer of Embodiment 4 is a three-layer structure, the bipolar connection layer 51 is an auxiliary transition layer composed of CBP, and is adjacent to the side of the yellow light-emitting layer; the single-polarity transmission layer 53 is made of electrons. Another auxiliary transition layer composed of the transport material TPBi is adjacent to the side of the blue fluorescent light emitting layer; the bipolar type doped connection layer 52 is composed of a bipolar transport material CBP doped electron transport type material TPBi layer, The bipolar type connection layer 51 is between the single polarity transmission layer 53.

The preparation method of the device of Embodiment 4 is similar to that of Embodiment 1, except that the ratio of CBP to TPBi of the bipolar type doped connection layer 52 in the composite interconnection layer may be, for example, 4:1, and the total film thickness is, for example, The film thickness of the bipolar connection layer 51 may be, for example, 1 nm, and the film thickness of the electron transport layer 53 may be, for example, 0.5 nm.

As a simplification in the manufacturing process, the present invention can also employ the following preferred embodiment 5:

Example 5

6, the laminated structure of the organic electro white light device of Example 5 has the following structural formula: Glass substrate / ITO / NPB / NPB: (t - bt) 2 Ir ( acac ) / CBP: TPBi / BH: BD / Bebq2 /LiF/Al;

In Embodiment 5, the composite interconnect layer comprises a bipolar doped connection layer 52;

Example 5 The preparation method of the device was similar to that of Example 1. The composite inner connecting layer was a single-layer doped structure, and the CBP:TPBi ratio may be, for example, 1:1, and the film thickness may be, for example, 4 Å. Wherein NPB:(t-bt)2Ir( acac ) may also preferably be mCP:(f-bt) 2Ir ( acac ) , and BH:BD may also preferably be 4,4′-bis(2,2-distyryl)- 1,1'-biphenyl DPVBi, or as an alternative, the yellow phosphor layer is interchanged with the blue phosphor layer, NPB: (t-bt) 2Ir ( acac ) is replaced by DPVBi, BH: BD by Bphen : ( T-bt)2Ir ( acac ) replacement „

The structure and properties of the devices of the above Examples 1, 2, 3, 4, 5 and Comparative Examples 1, 2 are shown in Table 1. The composite inner connecting layer structure of the device luminous efficiency color coordinates (x, y)

( cd /A )

Comparative Example 1 CBP (4.2 nm) 3.4 (0.26, 0.29) Comparative Example 2 No 2.3 (0.17, 0.20) Example 1 CBP (lnm) / CBP: 50% TPBi (3.2 匪) 9.9 (0.32, 0.34) Example 2 CBP: 40% TPBi (3 nm) / CBP (lnm) 10.5 (0.33, 0.35) Example 3 CBP (lnm) / CBP: 60% TPBi (4 nm) / CB 14.8 (0.32, 0.35)

P(lnm)

Embodiments of the present invention also provide a method of fabricating a white organic electroluminescent device, which may include the following steps:

Forming an anode conductive layer, an organic layer and a cathode layer in order from bottom to top on the substrate;

The organic layer includes a barrier light emitting layer and a fluorescent emitting layer;

The luminescent color of the phosphorescent luminescent layer is different from the luminescent color of the fluorescent luminescent layer;

A composite interconnect layer is provided between the phosphorescent layer and the fluorescent layer.

According to a specific embodiment, the monumental light emitting layer is a yellow phosphorescent emitting layer, and the fluorescent emitting layer is a blue fluorescent emitting layer.

For example, the step of providing a composite interconnect layer between the phosphorescent layer and the fluorescent layer comprises: a layer and a blue fluorescent layer.

According to a specific embodiment, the organic layer further includes a hole transport layer and an electron transport layer. According to a specific embodiment, the manufacturing method further comprises: providing a hole transport layer between the yellow phosphorescent layer and the anode conductive layer; and providing an electron transport layer between the blue phosphor layer and the cathode layer.

The white organic electroluminescent device according to an embodiment of the present invention can be used, for example, for an organic light emitting display device, a lighting device, or the like.

The above is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims.

Claims

claims

1. A white organic electroluminescent device, including a cathode layer, an anode conductive layer, and an organic layer sandwiched between the cathode layer and the anode conductive layer;

The organic layer includes a light emitting layer and a fluorescent emitting layer;

A composite interconnect layer is disposed between the phosphorescent light-emitting layer and the fluorescent light-emitting layer.

2. The white organic electroluminescent device according to claim 1, wherein,

The monumental light-emitting layer is a yellow phosphorescent light-emitting layer, which is disposed under the composite interconnection layer; the fluorescent luminescence layer is a blue fluorescent luminescence layer, which is disposed above the composite interconnection layer.

3. The white organic electroluminescent device according to claim 2, wherein the yellow phosphorescent light-emitting layer is composed of a red phosphorescent layer and a green phosphorescent layer.

4. The white organic electroluminescent device according to claim 2, wherein the organic layer further includes a hole transport layer and an electron transport layer;

The hole transport layer is disposed between the anode conductive layer and the yellow light emitting layer; the electron transport layer is disposed between the blue fluorescent emitting layer and the cathode layer.

5. The white organic electroluminescent device according to any one of claims 1 to 4, wherein the composite interconnection layer is composed of at least a bipolar organic transmission material doped with a single polarity transmission material. Auxiliary transition layer.

6. The white organic electroluminescent device according to any one of claims 1 to 4, wherein the composite interconnection layer further includes an auxiliary transition composed of a bipolar organic transmission material or a single polarity transmission material. layer.

7. The white organic electroluminescent device according to any one of claims 1 to 4, wherein the structure of the composite inner connection layer is a bipolar transmission type material doped with a single polarity transmission type material. Single layer structure.

8. The white organic electroluminescent device according to any one of claims 1 to 4, wherein the structure of the composite inner connection layer includes a bipolar connection layer and a bipolar connection layer arranged from bottom to top. Double-layer structure of sexually doped connection layer;

The bipolar connection layer is composed of bipolar transmission material;

The bipolar doped connection layer is made of a bipolar transmission material doped with a single polarity transmission material. composition.

9. The white organic electroluminescent device according to any one of claims 1 to 4, wherein the structure of the composite inner connection layer includes a bipolar doped connection layer arranged from bottom to top and Double-layer structure of bipolar connection layer;

The bipolar connection layer is composed of bipolar transmission material;

The bipolar doped connection layer is composed of a bipolar transmission material doped with a single polarity transmission material.

10. The white organic electroluminescent device according to any one of claims 1 to 4, wherein the structure of the composite inner connection layer includes a bipolar connection layer arranged from bottom to top, a bipolar connection layer, and a bipolar connection layer. A three-layer structure of a linear doped connection layer and a bipolar connection layer;

The bipolar connection layer is composed of bipolar transmission material;

11. The white organic electroluminescent device according to any one of claims 1 to 4, wherein the structure of the composite inner connection layer includes a bipolar connection layer arranged from bottom to top, a bipolar connection layer, and a bipolar connection layer. A three-layer structure with a linearly doped connection layer and a single polarity transmission layer;

The bipolar connection layer is composed of bipolar transmission material;

12. A method for manufacturing a white organic electroluminescent device, including:

Form an anode conductive layer, an organic layer and a cathode layer on the substrate in sequence from bottom to top;

13. The method for manufacturing a white organic electroluminescent device according to claim 12, wherein the phosphorescent light-emitting layer is a yellow phosphorescent light-emitting layer, and the fluorescent light-emitting layer is a blue fluorescent light-emitting layer; in the phosphorescent light-emitting layer and The step of arranging a composite internal connection layer between the fluorescent light-emitting layers includes: a connection layer and a blue fluorescent light-emitting layer.

14. The method for manufacturing a white organic electroluminescent device according to claim 13, wherein: The organic layer also includes a hole transport layer and an electron transport layer. The manufacturing method further includes: setting a hole transport layer between the yellow phosphorescent emitting layer and the anode conductive layer; setting up electron transport between the blue fluorescent emitting layer and the cathode layer. layer.