CN110010784B

CN110010784B - Panchromatic organic electroluminescent device containing multi-channel carrier transmission material

Info

Publication number: CN110010784B
Application number: CN201910282074.1A
Authority: CN
Inventors: 赵鑫栋; 李崇; 张兆超
Original assignee: Jiangsu Sunera Technology Co Ltd
Current assignee: Jiangsu Sunera Technology Co Ltd
Priority date: 2019-04-09
Filing date: 2019-04-09
Publication date: 2021-07-13
Anticipated expiration: 2039-04-09
Also published as: CN110010784A

Abstract

The invention relates to a full-color organic electroluminescent device which sequentially comprises a substrate, a first electrode, an organic functional material layer and a second electrode from bottom to topThe organic functional material layer sequentially comprises a hole transmission area, a light-emitting layer and an electron transmission area from bottom to top, wherein the hole transmission area contains a multi-channel carrier transmission material with a general formula (1),

wherein the multichannel carrier transport material comprises more than two carrier conduction channels, wherein the absolute value difference of HOMO energy levels of the two carrier conduction channels is between 0.01-0.8 eV.

Description

Panchromatic organic electroluminescent device containing multi-channel carrier transmission material

Technical Field

The invention relates to the technical field of semiconductors. In particular, the invention relates to a full-color organic electroluminescent device containing a multi-channel carrier transport material.

Background

The Organic Light Emitting Diode (OLED) device technology can be used for manufacturing novel display products and novel illumination products, is expected to replace the existing liquid crystal display and fluorescent lamp illumination, and has wide application prospect. In general, an organic electroluminescent device composed of several layers includes an anode, a cathode, a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer. When a voltage is applied to electrodes at both ends of the organic electroluminescent device as a current device, holes from the anode and electrons from the cathode are recombined in the organic light-emitting layer by the action of an electric field to form excitons, and the excitons relax to the ground state to release energy, thereby generating organic electroluminescence.

The current performance studies of organic electroluminescent devices include: the driving voltage of the device is reduced, the luminous efficiency of the device is improved, the service life of the device is prolonged, and the like. In order to realize the continuous improvement of the performance of the organic electroluminescent device, not only the innovation of the structure and the preparation process of the organic electroluminescent device is required, but also the continuous research and innovation of the organic electroluminescent functional material are required to manufacture the organic electroluminescent device with higher performance.

The carriers (holes and electrons) in the organic electroluminescent device are respectively injected into the device from two electrodes of the device under the drive of an electric field, and meet and emit light in the organic light-emitting layer in a composite mode. High performance organic electroluminescent devices require various organic functional materials to have good optoelectronic properties, for example, as charge transport materials, good carrier mobility. The hole injection layer and the hole transport layer used in the existing organic electroluminescent device have relatively weak injection and transport characteristics, and the hole injection and transport rate is not matched with the electron injection and transport rate, so that the composite region has large deviation, and the stability of the device is not facilitated. In addition, reasonable energy level matching of the hole injection layer material and the hole transport layer material is an important factor for improving the efficiency and the service life of the device, so that the improvement of the injection and the transport of the holes has important significance for reducing the driving voltage of the device, improving the luminous efficiency and the service life of the device.

Currently, commonly used hole transport materials include single triphenylamine materials, carbazole materials, double triphenylamine materials, tri triphenylamine materials, and polyaniline conductive materials. For example, conventional β -TTA is typical of single triphenylamine materials, α -NPD and TAPC are typical of double triphenylamine materials, TDATA is typical of three triphenylamine materials, and TCTA is typical of single triphenylamine combined tricarbazole materials. All of these typical hole transport materials are of a fully symmetric structure. The full-symmetrical structure has the same molecular fragment structure and only has a single carrier transmission channel, so that the carrier transmission efficiency is low. Therefore, there is a need to develop materials having more excellent hole injection and transport rates for organic electroluminescent devices.

Disclosure of Invention

In order to solve the above problems, the inventors of the present invention have found through research that, in the same carrier conducting film layer constituting an organic electroluminescent device, if a carrier transport material has different multiple carrier conducting channels, the carrier transport material is helpful for improving injection and transport effects of carriers, is more helpful for stability of film phase of the material and stability of interfaces between different carrier conducting film layers, and is further helpful for improving overall performance of the organic electroluminescent device including light emitting efficiency, driving voltage, and driving lifetime.

A single molecule of the multi-channel carrier transport material has more than two carrier conduction channels, namely, a HOMO energy level of one channel is different from that of the other channel, so that the difference causes carriers to be different from the existing fully-symmetrical hole transport material in the injection and conduction processes, and the improvement of the device performance is facilitated.

Therefore, the present invention aims to provide a high performance organic electroluminescent device, in which the injection and conduction of carriers are facilitated due to the existence of a multi-channel carrier transport material, which is more advantageous to be performed in a tunneling mode, the injection and conduction efficiency of hole carriers is easily improved, and the low voltage driving effect is achieved, and meanwhile, the hole carriers can be more easily conducted to a light emitting layer, which is advantageous to the balance of carriers and the improvement of device performance.

The invention aims to provide a full-color organic electroluminescent device with improved luminous efficiency and service life, which sequentially comprises a substrate, a first electrode, an organic functional material layer and a second electrode from bottom to top, wherein the organic functional material layer comprises:

a hole transport region over the first electrode;

a light emitting layer on the hole transport region, the light emitting layer having a red light emitting layer, a green light emitting layer and a blue light emitting layer patterned in a red pixel region, a green pixel region and a blue pixel region, respectively;

an electron transport region over the light emitting layer;

wherein the hole transmission region sequentially comprises a hole injection layer, a hole transmission layer and a hole transmission auxiliary layer from bottom to top, the hole injection layer comprises a P-type doping material,

wherein the red pixel unit, the green pixel unit and the blue pixel unit have a common hole injection layer and a hole transport layer, and have respective hole transport auxiliary layers,

wherein the hole transport region comprises a multi-channel carrier transport material of formula (1),

comprising two or more carrier conduction channels composed of a carrier conduction fragment represented by general formula (A1) or general formula (A2),

the absolute difference in HOMO levels between the carrier conducting segment represented by the general formula (A1) and the carrier conducting segment represented by the general formula (A2) is 0.01-0.8eV,

wherein the content of the first and second substances,

Ar₁、Ar₂、Ar₃、Ar₄、Ar₅and Ar₆Each independently represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted benzophenanthrenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted pyrimidyl group, a substituted or unsubstituted azapyrenyl group, a substituted or unsubstituted azaphenanthrenyl group, or a structure of general formula (a 3):

in the general formula (A3), R₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Any one of them represents a single bond to N in the general formula (1), and the remaining Rn's each independently represents a hydrogen atom, a deuterium atom, or C₁-C₁₀Alkoxy, adamantyl, cyano, C₁-C₁₀Alkyl radical, C₃-C₁₀Cycloalkyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted naphthyridinyl, substituted or unsubstituted pyridyl, substituted or unsubstituted biphenylyl, substituted or unsubstituted terphenyl, n represents an integer of 1 to 8;

x represents O, S, -C (R)₉)(R₁₀) -or-N (R)₁₁)-；

R₉、R₁₀And R₁₁Each independently represents C₁-C₁₀Substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted naphthyridinyl, substituted or unsubstituted pyridyl, substituted or unsubstituted biphenylyl, substituted or unsubstituted terphenylyl, wherein R is₉And R₁₀Can be connected with each other to form a ring;

wherein in said substituted groups said substituents are independently from each other selected from deuterium atom, halogen atom, C₁-C₁₀Alkoxy, adamantyl, cyano, C₁-C₁₀Alkyl radical, C₃-C₂₀Cycloalkyl radical, C₆-C₃₀Aryl, 5-30 membered heteroaryl containing one or more heteroatoms, wherein the heteroatoms are optionally selected from one or more of oxygen atoms, sulfur atoms or nitrogen atoms.

The core of the invention is to provide a selection mode and an advanced design concept of a hole transport material for preparing a high-performance organic electroluminescent device. Based on the design concept provided by the invention, the hole transport material conforming to the theoretical basis of the invention can be used for preparing a high-performance organic electroluminescent device, and the concept provided by the invention can be further used for research and development of the hole transport material so as to discover the hole transport material with more excellent performance.

Compared with the prior art, the invention has the beneficial effects that:

in any film layer for injecting and transmitting carriers, materials with more than two carrier conduction channels are used, namely the absolute value difference of the HOMO energy level of one channel and the HOMO energy level of the other channel is 0.01-0.8eV, and the carriers can be transmitted on the channels respectively in the injecting and transmitting processes, so that the injection and transmission efficiency of the carriers is improved, and the device performance is improved.

The full-color organic electroluminescent device made of the multi-channel carrier transmission material can keep high hole carrier injection and transmission characteristics, and effectively improves the photoelectric performance of the organic electroluminescent device and the service life of the organic electroluminescent device.

Drawings

Fig. 1 schematically shows a cross-sectional view of a full-color organic electroluminescent device of the present invention.

In fig. 1, a substrate; 2. a first electrode; 3. a hole injection layer; 4. a hole transport layer; 5. a hole transport auxiliary layer; 6. a light emitting layer; 7. a hole blocking layer; 8. an electron transport layer; 9. an electron injection layer; 10. a second electrode; A. an electron transport region; B. a hole transport region.

Fig. 2 schematically shows a light emitting layer composite structure of the present invention.

In fig. 2, G represents light, L represents a light emitting layer, and EM1, EM2, and EM3 represent different light emitting layer materials.

Detailed Description

The invention will be described in more detail hereinafter with reference to the accompanying drawings, without intending to limit the invention thereto.

In the present invention, unless otherwise specified, all operations are carried out under ambient temperature and pressure conditions.

In the present invention, unless otherwise specified, HOMO means the highest occupied orbital of a molecule, and LUMO means the lowest unoccupied orbital of a molecule. In addition, the "difference in HOMO energy levels" and "difference in LUMO energy levels" referred to in the present specification mean a difference in absolute value of each energy value. Further, in the present invention, HOMO and LUMO energy levels are expressed in absolute values, and the comparison between the energy levels is also a comparison of the magnitude of the absolute values thereof, and those skilled in the art know that the larger the absolute value of an energy level is, the lower the energy of the energy level is.

Any numerical range recited herein is intended to include all sub-ranges subsumed within the range with the same numerical precision. For example, "1.0 to 10.0" is intended to include all sub-ranges between (and including 1.0 and 10.0) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, all sub-ranges having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0. Any maximum numerical limitation recited herein is intended to include all smaller numerical limitations subsumed therein, and any minimum numerical limitation recited herein is intended to include all larger numerical limitations subsumed therein. Accordingly, applicants reserve the right to modify the specification, including the claims, to specifically describe any sub-ranges that fall within the ranges specifically described herein.

In the drawings, the size of layers and regions may be exaggerated for clarity. It will also be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. In addition, it will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. Like reference numerals refer to like elements throughout.

In the present invention, when describing electrodes and organic electroluminescent devices, and other structures, "upper", "lower", "top", and "bottom" and the like used to indicate orientation only indicate orientation in a certain specific state, and do not mean that the related structures can exist only in the orientation; conversely, if the structure is repositioned, e.g., inverted, the orientation of the structure is changed accordingly. Specifically, in the present invention, the "bottom" side of the electrode refers to the side of the electrode that is closer to the substrate during fabrication, while the opposite side that is further from the substrate is the "top" side.

The invention provides a full-color organic electroluminescent device with improved luminous efficiency and service life, which sequentially comprises a substrate, a first electrode, an organic functional material layer and a second electrode from bottom to top, wherein the organic functional material layer comprises:

a hole transport region over the first electrode;

an electron transport region over the light emitting layer;

wherein the content of the first and second substances,

Ar₁、Ar₂、Ar₃、Ar₄、Ar₅and Ar₆Each independently represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted benzophenanthrenyl group, a substituted or unsubstituted phenanthrenyl groupA pyrenyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted azapyrenyl group, a substituted or unsubstituted azaphenanthrenyl group, or a structure of the general formula (a 3):

x represents O, S, -C (R)₉)(R₁₀) -or-N (R)₁₁)-；

In a preferred embodiment of the present invention, the absolute value difference of the HOMO levels of the carrier conducting fragment represented by the general formula (a1) and the carrier conducting fragment represented by the general formula (a2) is between 0.02 and 0.5eV, more preferably between 0.02 and 0.2 eV.

In one embodiment of the present invention, in the carrier conducting segment represented by the general formula (A1), the group Ar₁And a group Ar₂The same is true. In another embodiment of the present invention, in the carrier conducting segment represented by the general formula (A1), the group Ar₁And a group Ar₂Different.

In one embodiment of the present invention, in the carrier conducting segment represented by the general formula (A2), the group-NAr₃Ar₄And the group-NAr₅Ar₆The same is true. In another embodiment of the present invention, in the carrier conducting segment represented by the general formula (A2), the group-NAr₃Ar₄And the group-NAr₅Ar₆Different.

In one embodiment of the present invention, the multichannel carrier transport material of general formula (1) may represent any one of the structures represented by general formulae (2) to (11) below:

wherein A, B, C, D, E and F each independently represent a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted anthryl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted benzophenanthryl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted pyrimidyl group, a substituted or unsubstituted azapyrenyl group, a substituted or unsubstituted azaphenanthrenyl group, or a structure of the general formula (A4)

In the general formula (A4), R₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Any one of them represents a single bond to N in the general formula (1), and the remaining Rn's each independently represents a hydrogen atom, a deuterium atom, or C₁-C₁₀Alkoxy, adamantyl, cyano, C₁-C₁₀Alkyl radical, C₃-C₁₀Cycloalkyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted naphthyridinyl, substituted or unsubstituted pyridyl, substituted or unsubstituted biphenylyl, substituted or unsubstituted terphenyl, n represents an integer of 1 to 8;

x represents O, S, -C (R)₉)(R₁₀) -or-N (R)₁₁)-；

In a preferred embodiment of the present invention, the multichannel carrier transport material of general formula (1) may be selected from any one of the following compounds:

the compounds of formulae (I-1) to (I-310) described above can be synthesized according to methods known to the person skilled in the art, for example the method described in patent application CN 1458141A, JP 2010-280635A.

In a more preferred embodiment of the present invention, the multichannel carrier transport material of general formula (1) may be selected from any one of the following compounds:

the multi-channel carrier transport material can obviously improve the injection and transport rate of holes. Herein, hole carrier conducting groups that may be cited include carbazole groups, aniline groups, carbazolo-ring groups, and the like. Based on the principle of the present invention, in order to realize multi-level carrier conduction, the carrier conduction group constituting the hole transport material is not necessarily one, but there are a plurality of hole-like groups, such as molecular structural features of two anilines, molecular structural features of one aniline and one carbazole, molecular structural features of three anilines, molecular structural features of two anilines and one carbazole, and the like. Meanwhile, the hole conducting material is not in a full-symmetric structure, and the difference of HOMO energy levels of all hole conducting segments can be caused only by the non-full-symmetric structure, so that the hole conducting material has good performance.

An essential feature of the hole transport material of the present invention is that there are two or more energy levels in the hole carrier conducting segment constituting the hole transport material, and the difference between these various energy levels is between 0.01 and 0.8eV, preferably between 0.02 and 0.5 eV.

The hole type carrier conduction material is divided into two characteristics of asymmetry and full symmetry, the full symmetry material is divided based on a molecular structure and can be divided into structural fragments with one characteristic, and the asymmetric structure, namely the multi-carrier conduction channel material is characterized in that a plurality of structural fragments with different characteristics can be divided based on the molecular structure division.

All symmetric structural materials that we can list here include, all single triphenylamine structural materials, α -NPD, etc., and specific molecular structural formulas can be listed as follows:

however, the materials of the

structures

1 and 2 are single triphenylamine materials and cannot be further disassembled, while the structure 3 is a double triphenylamine structure, but the conduction fragment thereof can only be disassembled into

A feature, the molecular structure is still a hole carrier conducting material of a fully symmetric character.

As an example, a hole-conducting material of the formula

Based on the principles of the present invention, it is not necessary for their structural features that R1-R6 are identical groups; if the groups are completely the same, the whole molecule becomes a full-symmetric structure, and the carrier conduction channel of the molecule with the configuration characteristic is only one type and has one characteristic, but does not accord with the principle explained by the invention, so that the performance of the prepared organic electroluminescent device is difficult to have a larger breakthrough. Based on the above principle, the hole-conducting material of the above general structure can be further decomposed into materials characterized by the following general formula

Specifically, the hole-conducting material can be enumerated as follows:

based on the principle of the invention, the method for judging whether a molecule has hole conduction channels with various energy levels is to disassemble the molecular structure at different hole conduction segments, actually measure or calculate the HOMO energy level of the disassembled molecular structure, and judge the difference and the similarity of the hole carrier conduction channels of the disassembled material, thereby judging the quality and the physical property quality of the molecule. An exemplary way of resolving molecules is as follows:

can be disassembled into

Two structures;

can be disassembled into

Two structures;

can be disassembled into

Two structures are provided.

Direct test methods for the HOMO level of the organic electroluminescent material include, for example, CV method, UPS method, IPS method, AC method, and the like. In addition, the HOMO level of the organic electroluminescent material can be predicted by means of quantization calculation. Among the various testing methods, the CV method is greatly influenced by solvents and operation methods, and the measured values are often different; when the AC method is used for measurement, a sample needs to be placed in an environment of dry air, when high-energy ultraviolet monochromatic light acts on the surface of the sample, emitted electrons need to be combined with oxygen in the air, and a detector can obtain a signal, so that the sample material is greatly influenced by oxygen elements in the environment, and the measurement of the HOMO energy level of some materials with deep HOMO energy level (such as P-doped materials) is inaccurate. However, both the UPS method and the IPS method can test the photoelectron spectrum of the organic electroluminescent material in a high vacuum environment, so that the influence of adverse environment can be eliminated to the maximum, which is close to the preparation environment atmosphere of the organic electroluminescent device, and the concept of in-situ measurement to the maximum. Therefore, the UPS method and the IPS method have higher numerical accuracy in terms of measurement methods than other measurement methods. Even so, it needs to be emphasized that the testing of HOMO energy levels of different materials only achieves the consistency of equipment and the consistency of a method, and meanwhile avoids the influence of a testing environment, and the HOMO energy levels between the materials have the significance of absolute comparison.

In the present invention, after the multi-channel carrier transport material of the general formula (1) is disassembled into the carrier conducting fragment of the general formula (a1) and the carrier conducting fragment of the general formula (a2), the HOMO levels of the carrier conducting fragments of the general formula (a1) and the general formula (a2), respectively, may be measured by the IPS measurement method, and the absolute value difference of the HOMO levels may be calculated, wherein specific measurement conditions are known to those skilled in the art.

The invention does not deny the substrate collocation principle of the traditional hole materials, but further superposes the physical parameters screened by the traditional materials, namely, the influence effects of HOMO energy level, carrier mobility, film phase stability, heat resistance stability of the materials and the like on the hole injection efficiency of the organic electroluminescent device are acknowledged. On the basis, the material screening conditions are further increased, and the material selection accuracy for preparing the high-performance organic electroluminescent device is improved by selecting more excellent organic electroluminescent materials for matching the device.

The device of the invention can achieve better performance, and the advanced physical model can be described as follows:

1. the hole transport materials are matched with each other based on proper HOMO energy level selection, and carriers are transported between different hole conducting film layers under the action of an electric field.

2. The carriers enter the hole conducting film layer with the characteristics of the invention and are based on the following physical characteristics in the process of forming conduction:

2.1 when carriers are introduced into the conductive film layer from the adjacent organic electroluminescent material film layer strip, the carriers enter the hole conductive film layer along a relatively lower channel among a plurality of carrier conduction channels.

2.2 in the hole conducting film layer, the carriers form electron exchange in different conducting channels, and flow out of the hole conducting film layer along multiple carrier conducting channels and enter the next adjacent organic electroluminescent material film layer along relatively higher channels.

It should be noted that the HOMO energy level of the hole conducting material constituting the feature of the present invention has a certain relationship with various carrier conduction channels owned by the material itself, and it is generally considered that the value of the HOMO energy level of the material measured based on the existing evaluation means is between the intermediate values of the deep HOMO energy level conduction segment and the shallow HOMO energy level conduction segment, and meanwhile, the shallow carrier conduction channel in the various carrier conduction channels is different from the value of the shallow HOMO energy level segment, and a single molecule constituted by different HOMO energy level conduction segments must have mutual influence between two different HOMO segments.

As an organic semiconductor element, carriers are conducted from an electrode to a light emitting layer and need to go over a certain energy level, and this energy level difference adversely affects the driving voltage of the organic electroluminescent device. The specific influence factors are many, and firstly, the process of injecting carriers from an electrode interface into an organic electroluminescent material film layer exists, and the process has two modes of thermal current injection and tunneling injection. In the so-called hot current injection, carriers need to jump over the energy level difference between the electrode and the organic material, and the carriers can be injected into the organic material film layer only when a certain electric field strength is reached, so that the transmission of the carriers is formed. By tunneling injection, it is understood that ohmic contact is formed between the organic material and the electrode, and the injection of carriers does not depend on the electric field strength. The two modes of the hole-type material constituting the organic electroluminescent device exist simultaneously, but the ratio of the two modes is different according to the characteristics of the material. Tunneling injection is favored if the HOMO level of the organic electroluminescent material is very close to the work function of the electrode, and needless to say, the larger the proportion of thermal current injection, the greater the adverse effect on the drive voltage of the device. Further, the flow of carriers between organic electroluminescent materials of different energy levels also has a problem of mutual injection, and if the injection effect is not good, the driving voltage of the device is too high. In general, the largest factor affecting the injection barrier between organic materials of different energy levels is also the difference in conduction energy levels of the different materials. As for the hole-type material, that is, the HOMO level difference, the larger the level difference is, the larger the adverse effect on the driving voltage of the device is. The organic electroluminescent material with the characteristics of the invention has two carrier conduction channels with different energy level levels, and when the carriers are conducted in the material film layer, the low-level conduction channel and the high-level conduction channel are switched, because the action of field energy is not needed, the adverse effect on driving voltage does not exist, the organic electroluminescent material is completely the electronic exchange in the molecular structure, and can be understood as a complete tunneling conduction mode. Meanwhile, if the low-level conduction channel (molecular structure segment) is close to the HOMO level of the adjacent organic electroluminescent material at the low electric field side, and the high-level conduction channel (molecular structure segment) is close to the HOMO level of the adjacent organic electroluminescent material at the high electric field side, under the action of an electric field, carriers are conducted to the material film layer from the shallow HOMO level film layer, and then conducted to the adjacent material film layer at the deep HOMO level, the injection and conduction of the carriers can be carried out in a tunneling mode, so that the injection conduction efficiency of hole carriers is easily improved, the effect of low-voltage driving is achieved, and meanwhile, the hole carriers can be conducted to the light-emitting layer more easily, so that the balance of the carriers is facilitated, and the improvement of the device performance is facilitated.

The organic electroluminescent device of the present invention may be a bottom emission organic electroluminescent device, a top emission organic electroluminescent device, and a stacked organic electroluminescent device, which is not particularly limited.

As the substrate of the organic electroluminescent device of the present invention, any substrate commonly used for organic electroluminescent devices can be used. Examples are transparent substrates, such as glass or transparent plastic substrates; opaque substrates, such as silicon substrates; flexible PI film substrate. Different substrates have different mechanical strength, thermal stability, transparency, surface smoothness, water resistance. The direction of use varies depending on the nature of the substrate. In the present invention, a transparent substrate is preferably used. The thickness of the substrate is not particularly limited.

A first electrode is formed on the substrate, and the first electrode and the second electrode may be opposite to each other. The first electrode may be an anode. The first electrode may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the first electrode is a transmissive electrode, it may be formed using a transparent metal oxide, such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), zinc oxide (ZnO), Indium Tin Zinc Oxide (ITZO), or the like. When the first electrode is a semi-transmissive electrode or a reflective electrode, it may include Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a metal mixture. The thickness of the first electrode layer depends on the material used and is typically 50-500nm, preferably 70-300nm and more preferably 100-200 nm.

The organic functional material layer arranged between the first electrode and the second electrode sequentially comprises a hole transmission area, a light emitting layer and an electron transmission area from bottom to top.

The hole transport region may be disposed between the first electrode and the light emitting layer. The hole transport region may include a hole injection layer, a hole transport layer, and a hole transport auxiliary layer. For example, referring to fig. 1, the hole transport region may include a hole injection layer, a hole transport layer, and a hole transport auxiliary layer sequentially disposed on the first electrode from bottom to top.

Herein, the hole carrier conducting film layer constituting the organic electroluminescent device may be exemplified by a hole injection layer, a hole transport layer, an electron blocking layer, and the like. Recently, in the AMOLED light emitting display, a hole injection layer adjacent to an anode is named an anode buffer layer or a P-doped hole injection layer, a hole conduction film layer adjacent to the anode buffer layer is named a hole transport layer, and a hole conduction film layer adjacent to a light emitting layer is named a hole transport auxiliary layer, an electron blocking layer, or a Prime layer. Furthermore, according to the matching requirements of the devices, the hole transport film layer between the hole transport auxiliary layer and the hole injection layer of the organic electroluminescent device can be a single film layer or a superposition structure of a plurality of hole transport materials. In this context, the film thickness of the hole carrier conducting film layer having the above-described various functions is not particularly limited.

Here, as for the organic electroluminescent device characterized by the present invention, there is no particular limitation in the material and structure of the electron-conducting film layer. Meanwhile, the material of the luminescent layer can be selected from various monochromatic luminescent materials such as red, green and blue, and the like, and can also be a combination of mixed color luminescent materials with multispectral characteristics. The core technology of the invention is to select a material with a multi-carrier conduction channel and use the material for a hole conduction film layer of an organic electroluminescent device, wherein the hole conduction film layer comprises the hole injection layer, the hole transport layer and the hole transport auxiliary layer.

In the full-color organic electroluminescent device, the hole injection layer and the hole transport layer comprise the multi-channel carrier transport material shown in the general formula (1), namely the absolute value difference of the HOMO energy level of one channel and the HOMO energy level of the other channel is 0.01-0.8eV, so that hole carriers can be respectively and jointly transported on the channels, the injection and transport efficiency of the carriers is improved, and the performance of the device is improved.

In one embodiment of the present invention, in the hole injection layer and the hole transport layer, the multi-channel carrier transport material of the general formula (1) is selected from at least one of the following formulae: formula (I-1), formula (I-32), formula (I-58), formula (I-61), formula (I-114), formula (I-129), formula (I-134), formula (I-146), formula (I-242), and formula (I-265). In another embodiment of the present invention, the HOMO level of the multi-channel carrier-transporting material of formula (1) is between 5.40-5.60eV, preferably 5.43-5.55eV, more preferably 5.47-5.52eV in the hole injecting layer and the hole transporting layer.

Herein, the hole conducting film layer covering the surface of the anode can be referred to as an anode interface buffer layer, a hole injection layer, or a hole transport layer containing P doping. In either case, the film material has a basic feature of including a host organic material that conducts holes, and a P-type dopant material with a deep HOMO level (and correspondingly a deep LUMO level). Based on empirical summary, in order to achieve smooth injection of holes from the anode to the organic film layer, the HOMO level of the host organic material for conducting holes used in the anode interface buffer layer must have certain characteristics with the P-doped material, so that the generation of a charge transfer state between the host material and the doped material is expected to be achieved, ohmic contact between the buffer layer and the anode is achieved, and efficient injection of holes from the electrode to the injection conduction is achieved, which is summarized as: the HOMO energy level of the host material-the LUMO energy level of the P doping material is less than or equal to 0.4 eV.

In view of the above empirical summary, for the hole-type host materials with different HOMO levels, different P-doped materials need to be selected and matched to realize ohmic contact at the interface, so as to improve the hole injection effect.

Thus, in one embodiment of the present invention, for better hole injection, the hole injection layer further comprises a P-type dopant material having charge conductivity selected from the group consisting of: quinone derivatives such as Tetracyanoquinodimethane (TCNQ) and 2,3,5, 6-tetrafluoro-tetracyano-1, 4-benzoquinodimethane (F4-TCNQ); or hexaazatriphenylene derivatives, such as 2,3,6,7,10, 11-hexacyano-1, 4,5,8,9, 12-hexaazatriphenylene (HAT-CN); or a cyclopropane derivative, such as 4,4',4 "- ((1E,1' E, 1" E) -cyclopropane-1, 2, 3-trimethylenetri (cyanoformylidene)) tris (2,3,5, 6-tetrafluorobenzyl); or metal oxides such as tungsten oxide and molybdenum oxide, but not limited thereto. Preferred P-type dopant materials are selected from at least one of the following P1-P10:

in the hole injection layer of the present invention, the ratio of the hole transporting host material to the P-type dopant material used is 99:1 to 95:5, preferably 99:1 to 97:3, on a mass basis.

In the present invention, after a hole injection layer and a hole transport layer common to red, green and blue pixels are formed over a first electrode, a hole transport auxiliary layer is formed over the hole transport layer for each pixel. The hole transport auxiliary layer may be composed of a single compound or may be composed of two different compounds from the bottom up, which are hole transport materials that are conventional in the art. In one embodiment of the invention, at least one hole transport assisting layer of the pixel unit comprises the multi-channel carrier transport material of the general formula (1) described in the invention. In one embodiment of the invention, at least one hole transport assist layer of a pixel cell comprises at least one multichannel carrier transport material of the formula: formula (I-2), formula (I-15), formula (I-156), formula (I-292) and formula (I-310). In another embodiment of the invention the HOMO level of the hole transport assist layer of at least one pixel cell is between 5.50-5.75eV, preferably between 5.55-5.65eV, more preferably between 5.55-5.57eV, and the triplet level (T1) ≧ 2.4 eV.

In another embodiment of the invention, the absolute difference between the HOMO level of the hole transport assist layer and the HOMO level of the hole transport layer of at least one pixel cell is less than or equal to 0.3 eV.

The thickness of the hole injection layer of the present invention may be 5 to 100nm, preferably 5 to 50nm and more preferably 5 to 20nm, but the thickness is not limited to this range.

The thickness of the hole transport layer of the present invention may be 5 to 200nm, preferably 10 to 150nm and more preferably 20 to 100nm, but the thickness is not limited to this range.

The thickness of the hole transport assist layer of the present invention may be 1 to 200nm, preferably 10 to 100nm, but the thickness is not limited to this range.

After the hole injection layer, the hole transport layer, and the hole transport auxiliary layer are formed, respective light emitting layers are formed on the respective red, green, and blue pixel regions by patterning. For example, referring to fig. 2, three pixel light emitting cells are arranged in a lateral direction. The light emitting layer may include a host material and a guest material. As the host material and the guest material of the light emitting layer of the organic electroluminescent device of the present invention, a light emitting layer material for organic electroluminescent devices, which is well known in the art, may be used, and the host material may be, for example, a thiazole derivative, a benzimidazole derivative, a polydialkylfluorene derivative, or 4,4' -bis (9-Carbazolyl) Biphenyl (CBP); the guest material may be, for example, quinacridone, coumarin, rubrene, perylene and derivatives thereof, benzopyran derivatives, rhodamine derivatives or aminostyrene derivatives. In a preferred embodiment of the present invention, the host material of the light-emitting layer used is selected from one or more of the following combinations of EMH-1 to EMH-22:

in addition, the light emitting material may further include a phosphorescent or fluorescent material in order to improve fluorescent or phosphorescent characteristics. Specific examples of the phosphorescent material include metal complexes of iridium, platinum, and the like. For example, Ir (ppy)₃[ fac-tris (2-phenylpyridine) iridium]And the like, blue phosphorescent materials such as FIrpic and FIr6, and red phosphorescent materials such as Btp2Ir (acac). For the fluorescent material, those generally used in the art can be used. In a preferred embodiment of the present invention, the guest material of the light-emitting layer used is selected from one of the following EMD-1 to EMD-25:

in the light-emitting layer of the present invention, the ratio of the host material to the guest material used is 99:1 to 70:30, preferably 99:1 to 85:15 and more preferably 97:3 to 87:13 on a mass basis.

When a vacuum deposition process is used, the R, G, B layer is finely patterned using a shadow mask, but when a spin-on process or a laser induced thermal imaging process is used, patterning by means of a shadow mask is not necessary.

The thicknesses of the red, green, and blue light emitting layers may be adjusted to optimize light emitting efficiency and driving voltage. The preferred thickness range is 5nm to 50nm, but the thickness is not limited to this range.

In the present invention, the electron transport region may include, from bottom to top, a hole blocking layer, an electron transport layer, and an electron injection layer disposed over the light emitting layer, in this order, but is not limited thereto.

The hole blocking layer is a layer that blocks holes injected from the anode from passing through the light emitting layer to the cathode, thereby extending the lifetime of the device and improving the performance of the device. The hole blocking layer of the present invention may be disposed over the light emitting layer. As the hole-blocking layer material of the organic electroluminescent device of the present invention, compounds having a hole-blocking effect known in the art can be used, for example, phenanthroline derivatives such as bathocuproine (referred to as BCP), metal complexes of hydroxyquinoline derivatives such as aluminum (III) bis (2-methyl-8-quinoline) -4-phenylphenolate (BAlq), various rare earth complexes, oxazole derivatives, triazole derivatives, triazine derivatives, pyrimidine derivatives such as 9,9'- (5- (6- ([1,1' -biphenyl ] -4-yl) -2-phenylpyrimidin-4-yl) -1, 3-phenylene) bis (9H-carbazole) (CAS No. 1345338-69-3), and the like. The hole blocking layer of the present invention may have a thickness of 2 to 200nm, preferably 5 to 150nm, and more preferably 10 to 100nm, but the thickness is not limited to this range.

The electron transport layer may be disposed over the light-emitting layer or, if present, the hole blocking layer. The electron transport layer material is a material that easily receives electrons of the cathode and transfers the received electrons to the light emitting layer. Materials with high electron mobility are preferred. As the electron transport layer of the organic electroluminescent device of the present invention, an electron transport layer material for organic electroluminescent devices known in the art, for example, in Alq, can be used₃Metal complexes of hydroxyquinoline derivatives represented by BAlq and Liq, various rare earth metal complexes, triazole derivatives, triazine derivatives such as 2, 4-bis (9, 9-dimethyl-9H-fluoren-2-yl) -6- (naphthalen-2-yl) -1,3, 5-triazine (CAS number: 1459162-51-6), 2- (4- (9, 10-di (naphthalen-2-yl) anthracen-2-yl) phenyl) -1-phenyl-1H-benzo [ d]Imidazole derivatives such as imidazole (CAS number: 561064-11-7, commonly known as LG201), oxadiazole derivatives, thiadiazole derivatives, carbodiimide derivatives, quinoxaline derivatives, phenanthroline derivatives, silicon-based compound derivatives, and the like. The thickness of the electron transport layer of the present invention may be 10 to 80nm, preferably 20 to 60nm, and more preferably 25 to 45nm, but the thickness is not limited to this range.

The electron injection layer may be disposed over the electron transport layer. The electron injection layer material is generally a material preferably having a low work function so that electrons are easily injected into the organic functional material layer. As the electron injection layer material of the organic electroluminescent device of the present invention, electron injection layer materials for organic electroluminescent devices known in the art, for example, lithium; lithium salts such as lithium 8-hydroxyquinoline, lithium fluoride, lithium carbonate or lithium azide; or cesium salts, cesium fluoride, cesium carbonate or cesium azide. The thickness of the electron injection layer of the present invention may be 0.1 to 5nm, preferably 0.5 to 3nm, and more preferably 0.8 to 1.5nm, but the thickness is not limited to this range.

The second electrode may be disposed over the electron transport region. The second electrode may be a cathode. The second electrode may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the second electrode is a transmissive electrode, the second electrode may comprise, for example, Li, Yb, Ca, LiF/Al, Mg, BaF, Ba, Ag, or compounds or mixtures thereof; when the second electrode is a semi-transmissive electrode or a reflective electrode, the second electrode may include Ag, Mg, Yb, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF/Al, Mo, Ti, or a compound or mixture thereof.

The full-color organic electroluminescent device of the present invention may be of a top emission type, a bottom emission type, or a dual emission type depending on the materials used.

In the case where the organic electroluminescent device is of a top emission type, the first electrode may be a reflective electrode, and the second electrode may be a transmissive electrode or a semi-transmissive electrode. In the case where the organic electroluminescent device is of a bottom emission type, the first electrode may be a transmissive electrode or a semi-transmissive electrode, and the second electrode may be a reflective electrode.

In the process of producing a full-color organic electroluminescent device, the organic electroluminescent device of the present invention may be produced, for example, by sequentially laminating a first electrode, an organic functional material layer, and a second electrode on a substrate. In this regard, a physical vapor deposition method such as a sputtering method or an electron beam vapor method, or a vacuum evaporation method may be used, but is not limited thereto. Also, the above-mentioned compound can be used to form the organic functional material layer by, for example, a vacuum deposition method, a vacuum evaporation method, or a solution coating method. In this regard, the solution coating method means spin coating, dip coating, jet printing, screen printing, spraying, and roll coating, but is not limited thereto. Vacuum evaporation means that a material is heated and plated onto a substrate in a vacuum environment. In the present invention, it is preferable that the respective layers are formed by a vacuum evaporation method.

The material for forming each layer according to the present invention may be used as a single layer by forming a film alone, may be used as a single layer by forming a film in admixture with another material, or may be used as a laminated structure of layers formed alone, layers formed in admixture with each other, or a laminated structure of layers formed alone and layers formed in admixture with each other.

It is to be understood that there have been disclosed herein exemplary embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation. Unless otherwise indicated, the features, characteristics and/or elements described in connection with a particular embodiment may be used alone or in combination with the features, characteristics and/or elements described in connection with other embodiments.

Examples

The following examples are intended to better illustrate the invention, but the scope of the invention is not limited thereto.

For a clearer understanding of the present invention, the embodiments of the present invention only describe each pixel light emitting unit, but those skilled in the art should understand that each pixel light emitting unit may use the same hole injection layer and hole transport layer when forming a full-color organic electroluminescent device.

The various materials used in the examples and comparative examples are commercially available or can be obtained by methods known to those skilled in the art.

Preparation of a Compound of the formula (1)

Example 1: synthesis of Compound I-6

A250 ml three-necked flask was charged with 0.01mol of the raw material A-1, 0.012mol of the raw material B-1, 0.03mol of t-butanol under a nitrogen gas atmospherePotassium, 1X 10^-4molPd₂(dba)₃，1×10^-4Heating and refluxing tri-tert-butylphosphine and 150ml toluene for 12 hr, sampling the sample, and reacting completely; naturally cooling, filtering, rotatably steaming the filtrate, and passing through a silica gel column to obtain an intermediate D-1; elemental analysis Structure (molecular formula C)₄₂H₃₁BrN₂): theoretical value C, 78.38; h, 4.85; n, 4.35; br, 12.41; test values are: c, 78.36; h, 4.86; n, 4.34; br, 12.43. ESI-MS (M/z) (M)⁺): theoretical value is 642.17, found 642.23.

A250 ml three-necked flask was charged with 0.01mol of intermediate B-1, 0.012mol of raw material C-1, 0.03mol of potassium tert-butoxide, 1X 10 in a nitrogen-purged atmosphere^-4molPd₂(dba)₃，1×10^-4Heating and refluxing tri-tert-butylphosphine and 150ml toluene for 12 hr, sampling the sample, and reacting completely; naturally cooling, filtering, rotatably steaming the filtrate, and passing through a silica gel column to obtain a target compound I-6; elemental analysis Structure (molecular formula C)₅₄H₄₁N₃): theoretical value C, 88.61; h, 5.65; n, 5.74; test values are: c, 88.62; h, 5.65; n, 5.73. ESI-MS (M/z) (M)⁺): theoretical value is 731.33, found 731.66.

The following compounds (all starting materials provided by Zhongxiao Wan) were prepared in the same manner as in example 1, and the synthetic starting materials were as shown in Table 1 below.

TABLE 1

Detection method

HOMO energy level: the measurement was carried out by IPS measurement, the specific measurement procedure was as follows:

vacuum evaporation equipment is used, and the vacuum degree is 1.0E^-5The vapor deposition rate is controlled to be Pa

Evaporating a sample on an ITO substrate, wherein the film thickness is 60-80 nm; the HOMO level of the sample film was then measured using an IPS-3 measuring device under a measurement environment of 10^-2A vacuum environment below Pa.

Eg energy level: a tangent line is drawn based on the ultraviolet spectrophotometric (UV absorption) baseline of the sample single film and the rising side of the first absorption peak, and the numerical value of the intersection of the tangent line and the baseline is calculated.

LUMO energy level: and calculating based on the difference between the HOMO energy level and the Eg energy level.

Work function of electrode material: the test was carried out in an atmospheric environment using a surface work function tester developed by the university of shanghai.

Hole mobility: the material is made into a single-charge device, and the single-charge device is measured by a single-charge fitting method.

Table 2 shows the results of the energy level tests of the hole transport material, the P-type dopant material, the hole transport auxiliary layer material, and the light emitting host materials (EMH-1, EMH-7, and EMH-13) and guest materials (EMD-1, EMD-8, and EMD-13).

TABLE 2

As shown in table 2 above, the hole transport materials can each be divided into two different fragments, where each fragment has a different HOMO energy level, and the difference in HOMO energy levels is between 0.01-0.2 eV. The HOMO energy level of the hole transport layer material is 5.43-5.50 eV; the HOMO energy level of the material of the hole-transport auxiliary layer is between 5.55 and 5.57eV, and the triplet state energy level (T1) is not less than 2.62 eV.

Preparation of organic electroluminescent device

The molecular structural formula of the related material is shown as follows:

example 1

The organic electroluminescent device was prepared as follows:

a) using transparent glass as a substrate, coating ITO with the thickness of 150nm on the transparent glass as an anode layer, respectively ultrasonically cleaning the transparent glass with deionized water, acetone and ethanol for 15 minutes, and then treating the transparent glass in a plasma cleaner for 2 minutes;

b) on the anode layer washed, a hole transport material I-1 and a P-type dopant material P1 were placed in two evaporation sources, respectively, under a vacuum of 1.0E^-5The vapor deposition rate of I-1 is controlled to be Pa

The evaporation rate of the P-type doping material is

Co-evaporating to form a hole injection layer with the thickness of 10 nm;

c) evaporating a hole transport layer on the hole injection layer in a vacuum evaporation mode, wherein the hole transport layer is made of I-1 and has the thickness of 60 nm;

d) evaporating a hole transmission auxiliary layer I-2 on the hole transmission layer in a vacuum evaporation mode, wherein the thickness of the hole transmission auxiliary layer I-2 is 40 nm;

e) evaporating a luminescent layer material on the hole-transport auxiliary layer in a vacuum evaporation mode, wherein the host material is EMH-7 and EMH-9, the guest material is EMD-13, the mass ratio is 45:45:10, and the thickness is 40 nm;

f) evaporating LG201 and Liq on the luminescent layer in a vacuum evaporation mode, wherein the mass ratio of the LG201 to the Liq is 50:50, the thickness of the LG201 to the Liq is 40nm, and the layer serves as an electron transport layer;

g) evaporating LiF on the electron transport layer in a vacuum evaporation mode, wherein the thickness of the LiF is 1nm, and the LiF is an electron injection layer;

h) on the electron injection layer, Al was vacuum evaporated to a thickness of 80nm, which layer was a cathode layer.

Examples 2 to 20

The procedure of example 1 was followed except that in step b), the hole transporting material I-1 was replaced with any one of the hole transporting materials I-32, I-58, I-61, I-114, I-129, I-134, I-146, I-242, I-265; replacing in step c) the hole transporting material I-1 with any one of the hole transporting materials I-32, I-58, I-61, I-114, I-129, I-134, I-146, I-242, I-265; in step d), the hole transport auxiliary layer material I-2 is replaced by any one of the hole transport auxiliary layer materials I-15, I-156, I-292 and I-310 or the combination of the materials I-15 and EB-1, and the specific device structure is shown in Table 3.

Example 21

The procedure of example 1 was followed except that the host material in step e) was EMH-13, the guest material was EMD-8, and the mass ratio of EMH-13 to EMD-8 was 96:4 and the thickness was 40 nm.

Examples 22 to 40

The procedure of example 21 was followed except that in step b), the hole transporting material I-1 was replaced with any one of the hole transporting materials I-32, I-58, I-61, I-114, I-129, I-134, I-146, I-242, I-265; replacing in step c) the hole transporting material I-1 with any one of the hole transporting materials I-32, I-58, I-61, I-114, I-129, I-134, I-146, I-242, I-265; in step d), the hole transport auxiliary layer material I-2 is replaced by any one of the hole transport auxiliary layer materials I-15, I-156, I-292 and I-310 or the combination of the materials I-15 and EB-1, and the specific device structure is shown in the table 5.

EXAMPLE 41

The procedure of example 1 was followed except that the hole transport assistance layer had a thickness of 10nm in step d); in the step e), the host material is EMH-1, the guest material is EMD-1, the mass ratio of the EMH-1 to the EMD-1 is 95:5, and the thickness is 25 nm.

Examples 42 to 60

The procedure of example 41 was followed except that in step b), the hole transporting material I-1 was replaced with any one of the hole transporting materials I-32, I-58, I-61, I-114, I-129, I-134, I-146, I-242, and I-265; replacing in step c) the hole transporting material I-1 with any one of the hole transporting materials I-32, I-58, I-61, I-114, I-129, I-134, I-146, I-242, I-265; in step d), the hole transport auxiliary layer material I-2 is replaced by any one of the hole transport auxiliary layer materials I-15, I-156, I-292 and I-310 or the combination of the materials I-15 and EB-1, and the specific device structure is shown in the table 7.

Comparative examples 1 to 4

The procedure of example 1 was followed, except that the hole transport material used in step b) was HT-1; c) the middle hole transport layer is made of HT-1; d) wherein the hole transport auxiliary layer material I-2 is replaced by hole transport auxiliary layer materials EB-1, EB-2, I-15 or the combination of EB-1 and I-15, and the specific device structure is shown in Table 3.

Comparative examples 5 to 8

The procedures of comparative examples 1 to 4 were respectively followed except that the host material in e) was EMH-13 and the guest material was EMD-8, and the mass ratio of EMH-13 to EMD-8 was 96:4 and the thickness was 40 nm. The specific device structure is shown in table 5.

Comparative examples 9 to 12

The steps of comparative examples 1 to 4 were respectively performed except that the hole transport auxiliary layer material in step d) was EB-1, EB-2, I-15 or I-156 and its thickness was 10 nm; e) the medium host material is EMH-1, the guest material is EMD-1, the mass ratio of the EMH-1 to the EMD-1 is 95:5, and the thickness is 25 nm. The specific device structure is shown in table 7.

TABLE 3

The results of measuring the performance of the devices of examples 1 to 20 and comparative examples 1 to 4 are shown in Table 4.

TABLE 4

Note: LT97 refers to the time it takes for the device brightness to decay to 97% of its original brightness;

the life test system is an organic electroluminescent device life tester which is researched by the owner of the invention together with Shanghai university.

The comments also apply to tables 6 and 8 below.

TABLE 5

The results of measuring properties of the devices of examples 21 to 40 and comparative examples 5 to 8 are shown in Table 6.

TABLE 6

TABLE 7

The results of measuring properties of the devices of examples 41 to 60 and comparative examples 9 to 12 are shown in Table 8.

TABLE 8

As can be seen from the results in table 4, the driving voltage of the devices prepared in examples 1 to 20 was significantly reduced, and the light emitting efficiency and the lifetime were significantly improved, using the organic substance with multiple channels of carriers as the hole transport layer, the hole injection layer, or as the hole transport auxiliary layer material.

As can be seen from the results of table 6, the driving voltage of the devices prepared in examples 21 to 40 was significantly reduced, and the light emitting efficiency and the lifetime were significantly improved, using the organic substance having multiple channels of carriers as the hole transport layer, the hole injection layer, or as the hole transport auxiliary layer material.

As can be seen from the results in table 8, the devices prepared using the organic substance with multiple channels for carriers as the hole transport layer, the hole injection layer, or as the hole transport auxiliary layer material have significantly reduced driving voltages and significantly improved luminous efficiencies and lifetimes.

As described above, the full-color organic electroluminescent device of the present invention using the multi-channel hole transport material can provide a full-color organic electroluminescent device having improved luminance, luminous efficiency, and lifespan.

Claims

1. A full-color organic electroluminescent device comprises a substrate, a first electrode, an organic functional material layer and a second electrode from bottom to top in sequence, wherein the organic functional material layer comprises:

a hole transport region over the first electrode;

an electron transport region over the light emitting layer;

the multi-channel carrier transport material comprises more than two carrier conduction channels, the carrier conduction channels are composed of carrier conduction segments shown in a general formula (A1) or a general formula (A2),

wherein the absolute difference in HOMO levels of the carrier conducting segment represented by the general formula (A1) and the carrier conducting segment represented by the general formula (A2) is between 0.01-0.8eV,

wherein the content of the first and second substances,

Ar₁、Ar₂、Ar₃、Ar₄、Ar₅and Ar₆Each independently represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenylyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted naphthyl groupSubstituted terphenyl, substituted or unsubstituted anthracyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted benzophenanthryl, substituted or unsubstituted pyrenyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted azapyrenyl, substituted or unsubstituted azaphenanthryl, or a structure of formula (a 3):

x represents O, S, -C (R)₉)(R₁₀) -or-N (R)₁₁)-；

wherein in the substituted groups, the substituents are independently of one another selected from deuterium atom, halogen atom, C₁-C₁₀Alkoxy, adamantyl, cyano, C₁-C₁₀Alkyl radical, C₃-C₂₀Cycloalkyl radical, C₆-C₃₀Aryl, 5-30 membered heteroaryl containing one or more heteroatoms, wherein the heteroatoms are optionally selected from proto-oxygensOne or more of a sulfur atom or a nitrogen atom,

wherein the hole injection layer and the hole transport layer comprise a multichannel carrier transport material of formula (1).

2. The full-color organic electroluminescent device according to claim 1, wherein: the absolute difference between the HOMO levels of the carrier conducting segment represented by the general formula (a1) and the carrier conducting segment represented by the general formula (a2) is 0.02 to 0.5 eV.

3. The full-color organic electroluminescent device according to claim 2, characterized in that: the absolute difference between the HOMO levels of the carrier conducting segment represented by the general formula (a1) and the carrier conducting segment represented by the general formula (a2) is 0.02 to 0.2 eV.

4. The full-color organic electroluminescent device according to any one of claims 1 to 3, characterized in that: the multichannel carrier transport material of the general formula (1) can represent any one of structures shown in general formulas (2) to (11):

x represents O, S, -C (R)₉)(R₁₀) -or-N (R)₁₁)-；

wherein in the substituted groups, the substituents are independently from each other selected from deuterium atom, halogen atom, C₁-C₁₀Alkoxy, adamantyl, cyano, C₁-C₁₀Alkyl radical, C₃-C₂₀Cycloalkyl radical, C₆-C₃₀Aryl, 5-30 membered heteroaryl containing one or more heteroatoms, wherein the heteroatoms are optionally selected from one or more of oxygen atoms, sulfur atoms or nitrogen atoms.

5. The full-color organic electroluminescent device according to any one of claims 1 to 3, characterized in that: the multichannel carrier transmission material with the general formula (1) is selected from any one of the following compounds:

6. the full-color organic electroluminescent device according to any one of claims 1 to 3, characterized in that: the HOMO energy level of the hole transport layer is between 5.40-5.60 eV.

7. The full-color organic electroluminescent device according to claim 6, wherein: the HOMO energy level of the hole transport layer is between 5.43-5.55 eV.

8. The full-color organic electroluminescent device according to claim 7, wherein: the HOMO energy level of the hole transport layer is between 5.47-5.52 eV.

9. The full-color organic electroluminescent device according to any one of claims 1 to 3, characterized in that: the hole-transport auxiliary layer comprises one or two hole-transport materials from bottom to top.

10. The full-color organic electroluminescent device according to claim 9, wherein: the hole transport auxiliary layer of at least one pixel cell comprises a multi-channel carrier transport material of formula (1).

11. The full-color organic electroluminescent device according to claim 10, wherein: the HOMO level of the hole transport assist layer of the pixel cell is between 5.50eV and 5.75 eV.

12. The full-color organic electroluminescent device according to claim 11, wherein: the triplet state energy level (T1) of the hole transport auxiliary layer of the pixel unit is more than or equal to 2.4 eV.

13. The full-color organic electroluminescent device according to claim 10, wherein: the absolute value difference between the HOMO energy level of the hole transmission auxiliary layer of the pixel unit and the HOMO energy level of the hole transmission layer is less than or equal to 0.3 eV.