Organic electroluminescent device and display device including the same

Abstract

The present application provides an organic electroluminescent device and a display device including the organic electroluminescent device. The organic electroluminescent device comprises a polycyclic compound represented by Formula 1 in a hole blocking layer and in at least one of a first light emitting layer and an electron transport layer, wherein Y 1 To Y 5 and Y 11 To Y 15 Each of which is independently CH or N, Y 1 To Y 5 At least four of them are CH, Y 11 To Y 15 At least four of them are CH, and R 1 , R 2 and R 3 As disclosed in the specification. [Formula 1] #imgabs0#

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of Korean Patent Application No. 10-2019-0002844, filed on January 9, 2019, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure relates to an organic electroluminescent device and a display device including the organic electroluminescent device. Background Art

[0004] As an image display device, an organic electroluminescent device has been actively developed. The organic electroluminescent device is different from a liquid crystal display device and the like in that it is a so-called self-luminous display device that realizes display by causing holes and electrons injected from a first electrode and a second electrode to recombine in a light emitting layer to emit light from a light emitting material, which is an organic compound contained in the light emitting layer.

[0005] For example, an organic device consisting of a first electrode, a hole transport layer disposed on the first electrode, a light emission layer disposed on the hole transport layer, an electron transport layer disposed on the light emission layer, and a second electrode disposed on the electron transport layer is referred to as an organic electroluminescent device. Holes are injected from the first electrode, and the injected holes move through the hole transport layer and are injected into the light emission layer. At the same time, electrons are injected from the second electrode, and the injected electrons move through the electron transport layer and are injected into the light emission layer. Holes and electrons injected into the light emission layer are combined to generate excitons in the light emission layer. The organic electroluminescent device emits light using the light generated when the excitons drop to the ground state again.

[0006] In recent years, in order to realize efficient organic electroluminescent devices, technologies for phosphorescent light emission using triplet energy or delayed fluorescent light emission using triplet-triplet annihilation (TTA), in which singlet excitons are generated by collision of triplet excitons, have been developed.

[0007] In addition, in order to improve the service life of the organic electroluminescent device, research on materials for the organic electroluminescent device has been actively conducted. Summary of the invention

[0008] The present disclosure provides an organic electroluminescent device including a polycyclic compound and a display device including the organic electroluminescent device.

[0009] Embodiments of the inventive concept provide an organic electroluminescent device including a first electrode, a second electrode and a first light emitting unit. In an embodiment, the second electrode may be disposed on the first electrode. In an embodiment, the first light emitting unit may be disposed between the first electrode and the second electrode.

[0010] In an embodiment, the first light emission unit may include a first hole transport region, a first light emission layer and a first electron transport region. In an embodiment, the first hole transport region may be disposed on the first electrode. In an embodiment, the first light emission layer may be disposed on the first hole transport region and include a host and a dopant. In an embodiment, the first electron transport region may be disposed on the first light emission layer and include a hole blocking layer and an electron transport layer disposed on the hole blocking layer.

[0011] In an embodiment, the hole blocking layer, and at least one of the first light emitting layer and the electron transport layer may include a polycyclic compound represented by Formula 1 below.

[0012] [Formula 1]

[0013]

[0014] In formula 1, Y 1 To Y 5 and Y 11 To Y 15 Each of may independently be CH or N. In an embodiment, Y 1 To Y 5 At least four of may be CH. In an embodiment, Y 11 To Y 15 At least four of may be CH. In an embodiment, R 1 To R 3 It can be each independently a substituted or unsubstituted alkyl group with 2 to 20 carbon atoms, a substituted silyl group, a substituted boron group, a substituted or unsubstituted aryl group with 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group with 3 to 30 ring-forming carbon atoms, or a ring can be formed by being connected to an adjacent group. In an embodiment, each of p and q can be independently an integer from 1 to 5, and r can be an integer from 0 to 8.

[0015] In an embodiment, the host may include the polycyclic compound. In an embodiment, the hole blocking layer may only include the polycyclic compound. In an embodiment, the first light emitting layer, the hole blocking layer and the electron transport layer may include the polycyclic compound. In an embodiment, the difference in the highest occupied molecular orbital (HOMO) energy level and the difference in the lowest unoccupied molecular orbital (LUMO) energy level between the host and the polycyclic compound may each be 0eV to 0.1eV.

[0016] In an embodiment, the hole mobility of the polycyclic compound may be 0 cm 2 / Vs to 10 -6 cm 2 / Vs. In an embodiment, the triplet energy level of the polycyclic compound may be 1.6 eV to 1.8 eV. In an embodiment, the difference in triplet energy level between the host and the polycyclic compound may be 0 eV to 0.2 eV.

[0017] In an embodiment, in Formula 1, R 1 To R 3 At least one of the groups may be a substituted or unsubstituted pyridine group, a substituted or unsubstituted bipyridine group, a substituted or unsubstituted pyrimidine group, a substituted or unsubstituted triazine group, a substituted or unsubstituted quinoline group, a substituted or unsubstituted quinazoline group, a substituted or unsubstituted quinoxaline group, a substituted or unsubstituted phthalazine group, a substituted or unsubstituted indole group, a substituted or unsubstituted pyrazine group, a substituted or unsubstituted pyridazine group, a substituted or unsubstituted thiophene group, a substituted or unsubstituted oxazole group, a substituted or unsubstituted thiazole group, or a substituted or unsubstituted pyrazole group.

[0018] In an embodiment, the light emitting layer may emit light having a wavelength region of 440 nm to 490 nm.

[0019] In an embodiment, the organic electroluminescent device may further include at least one light emission unit disposed on the first light emission unit. In an embodiment, the at least one light emission unit may include a second hole transport region, a second light emission layer, and a second electron transport region. In an embodiment, the second hole transport region may be disposed on the first light emission unit. In an embodiment, the second light emission layer may be disposed on the second hole transport region. In an embodiment, the second electron transport region may be disposed between the second light emission layer and the second electrode. In an embodiment, the first light emission unit and the at least one light emission unit may emit blue light.

[0020] In an embodiment, the polycyclic compound may include at least one of the compounds represented by the following Compound Group 1.

[0021] [Compound Group 1]

[0022]

[0023] In an embodiment of the present inventive concept, an organic electroluminescent device includes a first electrode, a hole transport region, a light emitting layer, an electron transport region, and a second electrode.

[0024] In an embodiment, the hole transport region may be disposed on the first electrode. In an embodiment, the light emitting layer may be disposed on the hole transport region. In an embodiment, the electron transport region may be disposed on the light emitting layer. In an embodiment, the electron transport region may include a hole blocking layer and an electron transport layer disposed on the hole blocking layer. In an embodiment, the second electrode may be disposed on the electron transport region.

[0025] In an embodiment, the hole blocking layer and the electron transport layer may include a polycyclic compound represented by Formula 1.

[0026] In an embodiment, the light emitting layer may include a host and a dopant. In an embodiment, a difference in HOMO energy level and a difference in LUMO energy level between the host and the polycyclic compound may each be 0 eV to 0.1 eV.

[0027] In an embodiment, the hole blocking layer may include only the polycyclic compound, and the electron transport layer may further include the polycyclic compound and at least one electron transport material.

[0028] In an embodiment of the present inventive concept, a display device includes a light emitting element layer. The light emitting element layer may include a plurality of organic electroluminescent devices.

[0029] In an embodiment, the organic electroluminescent device may include a first electrode, a second electrode and a plurality of organic layers. In an embodiment, the second electrode may be disposed on the first electrode. In an embodiment, the plurality of organic layers may be disposed between the first electrode and the second electrode.

[0030] In an embodiment, the plurality of organic layers may include a hole transport region, a first light emission layer, and an electron transport region. In an embodiment, the hole transport region may be disposed on the first electrode. In an embodiment, the first light emission layer may be disposed on the hole transport region. In an embodiment, the electron transport region may be disposed on the first light emission layer and include a hole blocking layer and an electron transport layer. In an embodiment, the electron transport layer may be disposed on the hole blocking layer. In an embodiment, the hole blocking layer and the electron transport layer may include a polycyclic compound represented by Formula 1.

[0031] In an embodiment, the organic layer further includes at least one light emitting layer disposed between the electron transport region and the second electrode.

[0032] In an embodiment, a light conversion layer disposed on the light emitting element layer may be further included. In an embodiment, the light emitting element layer may emit blue light. In an embodiment, the light conversion layer may include a first light conversion component, a second light conversion component, and a third light conversion component. In an embodiment, the first light conversion component may absorb the blue light and emit green light. In an embodiment, the second light conversion component may absorb blue light and emit red light. In an embodiment, the third light conversion component may transmit blue light. In an embodiment, the first light conversion component may include a first quantum dot light emitter, which absorbs blue light and emits red light. In an embodiment, the second light conversion component may include a second quantum dot light emitter, which changes the wavelength of blue light and emits red light. In an embodiment, the third light conversion component may include a matrix resin and a scatterer dispersed in the matrix resin.

[0033] In an embodiment, each of the hole transport region, the first light emitting layer, and the electron transport region may be a layer in the light emitting element layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are included to provide a further understanding of the inventive concept and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate exemplary embodiments of the inventive concept and together with the description serve to explain the principles of the inventive concept. In the drawings:

[0035] Figure 1 is a perspective view of a display device according to an embodiment of the inventive concept;

[0036] Figure 2 Shown along Figure 1 A portion of a cross section taken along line II';

[0037] Figure 3 , Figure 4 , Figure 5 and Figure 6 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present inventive concept;

[0038] Figure 7 , Figure 8 , Fig. 9 and Fig.10 is a cross-sectional view of an embodiment according to the inventive concept;

[0039] Fig.11A is a graph showing the amount of brightness reduction over time in the embodiment and the comparative example;

[0040] Fig. 11B is a graph showing the amount of brightness reduction over time in the embodiment and the comparative example;

[0041] Fig. 12A shows enlarged images of thin films formed according to Examples and Comparative Examples; and

[0042] Fig. 12B is a graph showing current density values ​​according to driving voltage in Examples and Comparative Examples. DETAILED DESCRIPTION

[0043] In the present disclosure, when an element (or region, layer, part, etc.) is referred to as being "on", "connected to" or "coupled to" another element, it means that the element can be directly disposed on / connected to / coupled to the other element, or a third element can be disposed therebetween.

[0044] The same reference numerals refer to the same elements. In addition, in the drawings, the thickness, ratio and size of the elements are exaggerated for effective description of the technical contents.

[0045] The term "and / or" includes all combinations of one or more than one of the items that the associated configurations may define.

[0046] It should be understood that although the terms "first", "second", etc. can be used to describe various elements in this article, these elements are limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments of the present invention, the first element can be referred to as the second element, and similarly, the second element can be referred to as the first element. Unless the context clearly indicates otherwise, the terms in the singular may include plural forms.

[0047] In addition, terms such as "under", "lower", "over", "upper", etc. are used to describe the relationship of the configurations shown in the drawings. The terms are used as relative concepts and are described with reference to the directions indicated in the drawings.

[0048] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the inventive concept belongs. It should also be understood that terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are clearly defined herein unless they are interpreted in an ideal or overly formal sense.

[0049] It should be understood that the terms “comprising” or “having” are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof in the disclosure, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0050] Hereinafter, an organic electroluminescent device OLED according to an embodiment of the inventive concept will be described with reference to the accompanying drawings.

[0051] Figure 1 is a perspective view of a display device DD according to an embodiment of the inventive concept. Figure 1 As shown in , the display device DD can display an image IM through a display surface IS. The display surface IS is parallel to a plane defined by a first direction axis DR1 and a second direction axis DR2. A direction perpendicular to the display surface IS, that is, a thickness direction of the display device DD, is represented by a third direction axis DR3. The display surface IS may include a display area DA and a non-display area NDA. The display area DA may be an area on which an image IM is displayed. The non-display area NDA may be an area on which an image IM is not displayed. In an embodiment, the non-display area NDA may be omitted.

[0052] Figure 2 Shown along Figure 1 In order to describe the configuration relationship between the components constituting the display device DD, a simple diagram is shown. Figure 2 .

[0053] The display device DD may include a first base substrate BS1, a circuit layer CL, and a light emitting element layer ODL. The light emitting element layer ODL may include a plurality of organic electroluminescent devices OLED, a plurality of pixel defining layers PDL, and a thin film encapsulation layer TEF. On the first base substrate BS1, the circuit layer CL is provided, and on the circuit layer CL, the light emitting element layer ODL may be provided. On the circuit layer CL, a plurality of organic electroluminescent devices OLED may be provided, and on the organic electroluminescent device OLED, a thin film encapsulation layer TFE may be provided. Although not shown, the display device DD may further include other components. For example, a glass substrate (not shown) or a cover substrate (not shown) may be further provided on the thin film encapsulation layer TFE.

[0054] The first base substrate BS1 may be a silicon substrate, a plastic substrate, a glass substrate, an insulating film, or a structure including an arrangement of a plurality of insulating layers.

[0055] The circuit layer CL may include a plurality of transistors (not shown). Each of the organic electroluminescent devices OLED may be connected to each of the plurality of transistors (not shown) to receive a signal.

[0056] The respective organic electroluminescent devices OLED may be separated by a plurality of pixel defining layers PDL and may be spaced apart from each other on a plane. In the present specification, “on a plane” may mean observing the display device DD in a third direction DR3 (thickness direction).

[0057] Each of the organic electroluminescent devices OLED may include a first electrode EL1, a second electrode EL2 disposed on the first electrode EL1, and a plurality of organic layers OEL disposed between the first electrode EL1 and the second electrode EL2. The plurality of organic layers OEL may include a hole transport region HTR, a light emission layer EML disposed on the hole transport region HTR, and an electron transport region ETR disposed on the light emission layer EML.

[0058] The hole transport region HTR and the electron transport region ETR are exemplified as a common layer (i.e., one layer) provided in a plurality of organic electroluminescent devices. However, the embodiments of the present inventive concept are not limited thereto. For example, at least one of the hole transport region HTR and the electron transport region ETR may be provided to be separated by a pixel defining layer PDL, respectively.

[0059] The light emission layer EML is illustrated as being respectively provided in each of the organic electroluminescent devices. However, embodiments of the inventive concept are not limited thereto. The light emission layer EML may be provided as a common layer (ie, one layer) in the organic electroluminescent device OLED.

[0060] The pixel defining layer PDL is disposed between the first electrodes EL1 and may overlap at least a portion of the first electrode EL1. The pixel defining layer PDL may be formed of a polymer resin or an inorganic material. In addition, the pixel defining layer PDL may be formed by further including an inorganic material other than the polymer resin. Meanwhile, the pixel defining layer PDL may be formed by including a light absorbing material, or may be formed by including a black pigment or a black dye.

[0061] The thin film encapsulation layer TFE may directly cover the second electrode EL2. The thin film encapsulation layer TFE may include an organic material layer containing an organic material and an inorganic material layer containing an inorganic material. In an embodiment, a capping layer (not shown) for covering the second electrode EL2 may be further provided. At this time, the thin film encapsulation layer TFE may directly cover the capping layer.

[0062] Figures 3 to 6 2 is a cross-sectional view schematically illustrating organic electroluminescent devices OLED and OLED-1 according to an embodiment of the inventive concept.

[0063] refer to Figure 3 The hole transport region HTR may include a hole injection layer HIL and a hole transport layer HTL. The electron transport region ETR may include a hole blocking layer HBL, an electron transport layer ETL and an electron injection layer EIL.

[0064] In the organic electroluminescent device OLED of the embodiment, the hole blocking layer HBL, and at least one of the light emitting layer EML and the electron transport layer ETL may include the polycyclic compound of the embodiment to be described later. That is, in the embodiment, the hole blocking layer HBL may include the polycyclic compound of the embodiment, and at least one of the light emitting layer EML and the electron transport layer ETL may include the polycyclic compound of the embodiment.

[0065] When with Figure 3 When compared, Figure 4 A cross section of an organic electroluminescent device OLED is shown, wherein the hole transport region HTR further includes an electron blocking layer EBL disposed between the hole transport layer HTL and the light emitting layer EML.

[0066] refer to Figure 5 and Figure 6 , the organic electroluminescent device OLED-1 may include a first electrode EL1, an organic layer OEL-1, and a second electrode EL2 sequentially disposed. The organic electroluminescent device OLED-1 may include a plurality of light emission units EM1, EM2, and EM3, and a plurality of charge generation layers CGL1 and CGL2 disposed between the light emission units EM1, EM2, and EM3.

[0067] The first light emission unit EM1 may include a first hole transport region HTR1, a first light emission layer EML1, and a first electron transport region ETR1 that are sequentially disposed. The second light emission unit EM2 may include a second hole transport region HTR2, a second light emission layer EML2, and a second electron transport region ETR2 that are sequentially disposed. The third light emission unit EM3 may include a third hole transport region HTR3, a third light emission layer EML3, and a third electron transport region ETR3 that are sequentially disposed.

[0068] exist Figure 5 and Figure 6 In the present invention, unless otherwise described, substantially the same contents as those described above or to be described for the hole transport region HTR, the light emission layer EML, and the electron transport region ETR may be applied to each of the hole transport regions HTR1, HTR2, and HTR3, the light emission layers EML1, EML2, and EML3, and the electron transport regions ETR1, ETR2, and ETR3.

[0069] The first hole transport region HTR1 may include a hole injection layer HIL and a hole transport layer HTL disposed sequentially, and the first electron transport region ETR1 may include a hole blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL disposed sequentially. However, the embodiments of the present inventive concept are not limited thereto. At least one selected from the first to third hole transport regions (HTR1, HTR2, and HTR3) may include a hole injection layer HIL and a hole transport layer HTL, and at least one selected from the first to third electron transport regions (ETR1, ETR2, and ETR3) may include a hole blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL.

[0070] For example, Figure 6 As shown in the figure, all of the first hole transport region to the third hole transport region (HTR1, HTR2 and HTR3) may include a hole injection layer HIL and a hole transport layer HTL, and all of the first electron transport region to the third electron transport region (ETR1, ETR2 and ETR3) may include a hole blocking layer HBL, an electron transport layer ETL and an electron injection layer EIL.

[0071] When a voltage is applied to each of the charge generation layers CGL1 and CGL2, charges are generated. The charge generation layers CGL1 and CGL2 are disposed between the light emission units EM1, EM2, and EM3, and control the charge balance between the light emission units EM1, EM2, and EM3. For example, the first charge generation layer CGL1 can be used to help electron injection into the first light emission unit EM1 and help hole injection into the second light emission unit EM2.

[0072] The charge generation layers CGL1 and CGL2 may be composed of one layer in which an electron injection material and a hole injection material are mixed. Alternatively, the charge generation layers CGL1 and CGL2 may be composed of two or more layers. For example, each of the charge generation layers CGL1 and CGL2 may include an n-type charge generation layer doped with an n-type dopant and a p-type charge generation layer doped with a p-type dopant. The n-type charge generation layer may be a layer directly disposed on or adjacent to the electron transport region ETR to assist in electron injection, and the p-type charge generation layer may be a layer directly disposed on or adjacent to the hole transport region HTR to assist in hole injection.

[0073] The material of the charge generation layers CGL1 and CGL2 is not particularly limited, and any material known to those skilled in the art may be used without limitation.

[0074] Although not illustrated, in the organic electroluminescent device OLED-1 of the embodiment, the charge generation layers CGL1 and CGL2 may be omitted.

[0075] The first light emitting layer EML1 may emit a first color light, the second light emitting layer EML2 may emit a second color light, and the third light emitting layer EML3 may emit a third color light. The first color light to the third color light may be the same color light having the same wavelength region or different color lights having different wavelength regions. For example, the first color light to the third color light may be blue light having the same wavelength region, specifically, blue light having a wavelength region of 430nm to 500nm, or 440nm to 490nm. In another example, the first color light may be blue light, the second color light may be green light, and the third color light may be red light. Alternatively, the first color light to the third color light may be blue light having different central wavelength regions. However, the embodiments of the present inventive concept are not limited thereto. Each of the light emitting layers EML1, EML2, and EML3 may emit light having various wavelength regions.

[0076] Since a plurality of light emitting layers EML1 , EML2 , and EML3 are provided in the organic electroluminescent device OLED1 of the embodiment, current efficiency may be improved and a long life of the device may be achieved.

[0077] Figure 5 and Figure 6 Three light emission units are illustrated. However, embodiments of the inventive concept are not limited thereto. Another embodiment may include one, two, or four or more light emission units. The charge generation layer may be disposed between the light emission units. Therefore, as the number of light emission units increases or decreases, the number of charge generation layers may increase or decrease.

[0078] The first electrode EL1 is conductive. The first electrode EL1 may be formed of a metal alloy or a conductive compound. The first electrode EL1 may be an anode. The first electrode EL1 may be a transmissive electrode, a semi-transmissive reflective electrode or a reflective electrode. When the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include a transparent metal oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. When the first electrode EL1 is a semi-transmissive reflective electrode or a reflective electrode, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof (e.g., a mixture of Ag and Mg). Alternatively, the first electrode EL1 may have a multilayer structure including a reflective film or a semi-transmissive reflective film (both of which are formed of the materials exemplified above) and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but is not limited thereto. The thickness of the first electrode EL1 may be about 1000 Å. to about For example, about to about about to about or about to about

[0079] The hole transport region HTR is provided on the first electrode EL1. As described above, the hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer (not shown), and an electron blocking layer EBL.

[0080] The hole transport region HTR may have a single-layer structure having a single layer formed of a single material, a single-layer structure having a single layer formed of a plurality of different materials, or a multi-layer structure having a plurality of layers formed of a plurality of different materials.

[0081] For example, the hole transport region HTR may have a single-layer structure having a single layer of a hole injection layer HIL or a hole transport layer HTL, or a single-layer structure having a single layer formed of a hole injection material and a hole transport material. In addition, the hole transport region HTR may have a single-layer structure containing a single layer formed of a plurality of different materials, or a structure having a hole injection layer HIL / hole transport layer HTL, a hole injection layer HIL / hole transport layer HTL / hole buffer layer (not shown), a hole injection layer HIL / hole buffer layer (not shown), a hole transport layer HTL / hole buffer layer (not shown), or a hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL sequentially disposed on the first electrode EL1, but the embodiments of the inventive concept are not limited thereto.

[0082] The hole transport region HTR may be formed by various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB), inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0083] The hole injection layer HIL may include, for example, a phthalocyanine compound, such as copper phthalocyanine; N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine (DNTPD), 4,4',4"-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tris{N,N-(2-naphthyl)-N-phenylamino}triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-phenylene)triphenylamine. Sulfonate) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphorsulfonic acid (PANI / CSA), (polyaniline) / poly(4-styrenesulfonate) (PANI / PSS), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPD), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), etc.

[0084] The hole transport layer HTL may further include, for example, carbazole-based derivatives (e.g., N-phenylcarbazole and polyvinylcarbazole), fluorene-based derivatives, triphenylamine-based derivatives (e.g., N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD) and 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA)), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB), 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-methylphenyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP), and the like.

[0085] The thickness of the hole transport region HTR may be about to about For example, about to about The thickness of the hole injection layer HIL can be about to about And the thickness of the hole transport layer HTL can be about to about For example, the thickness of the electron blocking layer EBL may be about to about When the thicknesses of the hole transport region HTR, the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL satisfy the above-described ranges, satisfactory hole transport properties may be obtained without a significant increase in driving voltage.

[0086] In addition to the materials mentioned above, the hole transport region HTR may further include a charge generating material to improve conductivity. The charge generating material may be uniformly or non-uniformly dispersed in the hole transport region HTR. The charge generating material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, or a compound containing a cyano group, but is not limited thereto. For example, non-limiting examples of p-dopants may include quinone derivatives (e.g., tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ)) and metal oxides (e.g., tungsten oxide and molybdenum oxide), but are not limited thereto.

[0087] As described above, in addition to the hole injection layer HIL and the hole transport layer HTL, the hole transport region HTR may further include at least one of a hole buffer layer (not shown) and an electron blocking layer EBL. The hole buffer layer (not shown) may increase the light emission efficiency by compensating the resonance distance according to the wavelength of the light emitted from the light emission layer EML. Regarding the material that may be included in the hole buffer layer, the material that may be included in the hole transport region HTR may be used. The electron blocking layer EBL is a layer for preventing electron injection from the electron transport region ETR to the hole transport region HTR.

[0088] A light emitting layer EML is provided on the hole transport region HTR. The thickness of the light emitting layer EML may be, for example, about 100 Å. to about or about to about The light emitting layer EML may have a single-layer structure having a single layer formed of a single material, a single-layer structure having a single layer formed of a plurality of different materials, or a multi-layer structure having a plurality of layers formed of a plurality of different materials.

[0089] In the organic electroluminescent devices OLED and OLED-1 of the embodiments, the light emitting layer EML may include anthracene derivatives, pyrene derivatives, fluoranthene derivatives, derivatives, dihydrobenzanthracene derivatives or triphenylene derivatives.

[0090] exist Figures 3 to 6 In the organic electroluminescent devices OLED and OLED-1 of the embodiment shown in , the light emitting layer EML may include a host and a dopant. The host may include a polycyclic compound according to the embodiment to be described later.

[0091] The light emitting layer EML may further include a general material known in the art as a host material. For example, the light emitting layer EML may include at least one of bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), 4,4'-bis(carbazol-9-yl)biphenyl (CBP), 1,3-bis(carbazol-9-yl)benzene (mCP), 2,8-bis(diphenylphosphino)dibenzo[b,d]furan (PPF), 4,4',4"-tri(carbazol-9-yl)-triphenylamine (TCTA), and 1,3,5-tri(N-phenylbenzimidazol-2-yl)benzene (TPBi) as a host material. However, embodiments of the inventive concept are not limited thereto. For example, tris(8-hydroxyquinolinato)aluminum (Alq3), 4,4'-bis(N-carbazol-9-yl)-1,1'-biphenyl (CBP), poly(N-vinylcarbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN) may be used. , 4,4',4"-tri(carbazole-9-yl)-triphenylamine (TCTA), 1,3,5-tri(N-phenylbenzimidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-di(naphthalene-2-yl)anthracene (TBADN), distyrylene arylide (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (CDBP), 2-methyl-9,10-bis(naphthalene-2-yl)anthracene (MADN), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetrasiloxane (DPSiO4), 2,8-bis(diphenylphosphino)dibenzofuran (PPF), etc. are used as the main materials.

[0092] In an embodiment, the light emitting layer EML may include styrene derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styrene]diphenylethylene (DPAVB), and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styrene)naphthalene-2-yl)vinyl)phenyl)-N-phenylaniline (N-BDAVBi)), perylene and its derivatives (e.g., 2,5,5,8,11-tetra-tert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, and 1,4-bis(N,N-diphenylamino)pyrene), and the like as dopant materials known in the art.

[0093] The electron transport region ETR may have a single-layer structure having a single layer formed of a single material, a single-layer structure having a single layer formed of a plurality of different materials, or a multilayer structure having a layer or a combination of more than one layer composed of a plurality of different materials. Alternatively, the electron transport region ETR may have a multilayer structure having a plurality of layers formed of a plurality of different materials.

[0094] The thickness of the electron transport region ETR may be, for example, about to about

[0095] The electron transport region ETR may be formed by various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB), inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0096] The electron transport region ETR includes an electron transport layer ETL, and the electron transport region ETR may include a polycyclic compound according to an embodiment to be described later. In addition, the electron transport layer ETR may further include a known electron transport material. For example, the electron transport region ETR may include Alq3 (tris (8-hydroxyquinolinolato) aluminum), 1,3,5-tris [(3-pyridyl) -phenyl-3-yl] benzene, 2,4,6-tris (3'- (pyridyl-3-yl) biphenyl-3-yl) -1,3,5-triazine, 2- (4- (N-phenylbenzimidazol-1-yl) phenyl) -9,10-dinaphthyl anthracene, TPBi (1,3,5-tris (1-phenyl-1H-benzo [d] imidazole-2-yl) benzene), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen (4,7-diphenyl-1,1 0-phenanthroline), TAZ (3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ (4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-ato)aluminum), Bebq2 (bis(benzoquinolin-10-ato)beryllium), ADN (9,10-di(naphthalene-2-yl)anthracene) and compounds thereof. The thickness of the electron transport layer ETL may be about 500 Å. to about For example, about to about When the thickness of the electron transport layer ETL satisfies the above-described range, satisfactory electron transport properties may be obtained without a significant increase in driving voltage.

[0097] When the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR may be formed of LiF, lithium quinolate (LiQ), Li 2 O, BaO, NaCl, CsF, lanthanide metals (e.g., Yb) and / or metal halides (e.g., RbCl and / or RbI), but are not limited thereto. The electron injection layer EIL may be composed of a mixture of an electron injection material and an insulating organic metal salt. The organic metal salt may be a material having an energy band gap of about 4 eV or greater than 4 eV. In particular, for example, the organic metal salt may include a metal acetate, a metal benzoate, a metal acetoacetate, a metal acetylacetonate, or a metal stearate. The thickness of the electron injection layer EIL may be about 1000 nm. to about or about to about When the thickness of the electron injection layer EIL satisfies the above-described range, satisfactory electron injection properties may be obtained without a significant increase in driving voltage.

[0098] The electron transport region ETR may include a hole blocking layer HBL as described above. The hole blocking layer HBL includes a polycyclic compound of an embodiment to be described later. The hole blocking layer HBL may further include a known hole blocking material. For example, the hole blocking layer HBL may include at least one of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and Bphen (4,7-diphenyl-1,10-phenanthroline), but is not limited thereto. The thickness of the hole blocking layer HBL may be about 1000 Å. to about or about to about or about to about

[0099] In the organic electroluminescent device OLED of the embodiment, the hole blocking layer HBL may include the polycyclic compound of the embodiment, and at least one layer of the light emitting layer EML and the electron transport layer ETL may include the polycyclic compound of the embodiment.

[0100] For example, the hole blocking layer HBL and the light emitting layer EML, or the hole blocking layer HBL and the electron transport layer ETL may include the polycyclic compound of the embodiment, and the hole blocking layer HBL, the light emitting layer EML and the electron transport layer ETL may all include the polycyclic compound of the embodiment. The light emitting layer EML may include the polycyclic compound of the embodiment as a material of the main body of the light emitting layer EML.

[0101] The hole blocking layer HBL may include only the polycyclic compound of the embodiment, and the electron transport layer ETL may include the polycyclic compound of the embodiment, or may further include at least one electron transport material. The light emitting layer EML may include the polycyclic compound of the embodiment as a host material, or may further include at least one host material.

[0102] For example, the hole blocking layer HBL may include only the polycyclic compound of the embodiment, and the electron transport layer ETL may include the polycyclic compound of the embodiment and at least one electron transport material.

[0103] The polycyclic compound of the embodiment may be represented by Formula 1 below.

[0104] [Formula 1]

[0105]

[0106] In this specification, "substituted or unsubstituted" may mean substituted or unsubstituted by one or more than one substituent selected from the group consisting of deuterium atoms, halogen atoms, cyano groups, nitro groups, amino groups, silyl groups, oxy groups, sulfenyl groups, sulfonyl groups, carbonyl groups, boron groups, phosphine oxide groups, phosphine sulfide groups, alkyl groups, alkenyl groups, alkoxy groups, hydrocarbon ring groups, aryl groups and heterocyclic groups. In addition, each of the substituents exemplified above may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group, and may be interpreted as a phenyl group substituted by a phenyl group.

[0107] In the present specification, "forming a ring by connecting to an adjacent group" may mean forming a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle by connecting to an adjacent group. The hydrocarbon ring includes an aliphatic hydrocarbon ring and an aromatic hydrocarbon ring. The heterocycle includes an aliphatic heterocycle and an aromatic heterocycle. The hydrocarbon ring and the heterocycle may be monocyclic or polycyclic. In addition, the ring formed by connecting to each other may be connected to another ring to form a spiro structure.

[0108] In the present specification, "adjacent groups" may mean a substituent substituted by an atom directly connected to the atom substituted with the substituent, another substituent substituted by the atom substituted with the substituent, or a substituent most adjacent to the corresponding substituent in a three-dimensional structure. For example, in 1,2-dimethylbenzene, two methyl groups may be interpreted as "adjacent groups" to each other, and in 1,2-diethylcyclopentene, two ethyl groups may be interpreted as "adjacent groups" to each other.

[0109] In the present specification, the alkyl group may be linear, branched or cyclic. The number of carbon atoms of the alkyl group is 1 to 30, 1 to 20, 1 to 10 or 1 to 6. Examples of the alkyl group may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, a 2-ethylbutyl group, a 3,3-dimethylbutyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, a 1-methylpentyl group, a 3-methylpentyl group, a 2-ethylpentyl group, a 4-methyl-2-pentyl group, an n-hexyl group, a 1-methylhexyl group, a 2-ethylhexyl group group, 2-butylhexyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-tert-butylcyclohexyl group, n-heptyl group, 1-methylheptyl group, 2,2-dimethylheptyl group, 2-ethylheptyl group, 2-butylheptyl group, n-octyl group, tert-octyl group, 2-ethyloctyl group, 2-butyloctyl group, 2-hexyloctyl group, 3,7-dimethyloctyl group, cyclooctyl group, n-nonyl group, n-decyl group, adamantyl group, 2-ethyldecyl group , a 2-butyldecyl group, a 2-hexyldecyl group, a 2-octyldecyl group, an n-undecyl group, an n-dodecyl group, a 2-ethyldodecyl group, a 2-butyldodecyl group, a 2-hexyldodecyl group, a 2-octyldodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, a 2-ethylhexadecyl group, a 2-butylhexadecyl group, a 2-hexylhexadecyl group, a 2-octylhexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, an n-eicosyl group, a 2-ethyleicosyl group, a 2-butyleicosyl group, a 2-hexyleicosyl group, a 2-octyleicosyl group, an n-heneicosyl group, an n-docosyl group, an n-tricosyl group, an n-tetracosyl group, an n-pentacosyl group, an n-hexacosyl group, an n-heptacosyl group, an n-octacosyl group, an n-nonacosyl group and an n-triacontyl group, etc., but are not limited thereto.

[0110] In the present specification, the hydrocarbon ring group means any functional group or substituent derived from an aliphatic hydrocarbon ring. The hydrocarbon ring group may be a saturated hydrocarbon ring group having 5 to 20 ring-forming carbon atoms.

[0111] In this specification, aryl group means any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group can be a monocyclic aryl group or a polycyclic aryl group. The number of ring carbon atoms of the aryl group can be 6 to 60, 6 to 30, 6 to 20 or 6 to 15. Examples of aryl groups can include phenyl groups, naphthyl groups, fluorenyl groups, anthracenyl groups, phenanthrenyl groups, biphenyl groups, terphenyl groups, quaterphenyl groups, pentaphenyl groups, hexaphenyl groups, biphenylene groups, triphenylenyl groups, pyrenyl groups, benzofluoranthenyl groups, group, etc., but are not limited thereto.

[0112] In this specification, the heteroaryl group can be a heteroaryl group containing one or more than one of B, O, N, P, Si and S as a heteroatom. When the heteroaryl group contains two or more heteroatoms, the two or more heteroatoms can be the same or different from each other. The heteroaryl group can be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The number of ring carbon atoms of the heteroaryl group can be 3 to 30, 3 to 20 or 3 to 10, and the number of ring heteroatoms can be 1 to 6, or 1 to 3, such as 1, 2, 3, 4, 5 or 6. Examples of the heteroaryl group may include a thienyl group, a furanyl group, a pyrrolyl group, an imidazolyl group, a thiazolyl group, an oxazolyl group, an oxadiazolyl group, a triazolyl group, a pyridyl group, a bipyridyl group, a pyrimidyl group, a triazinyl group, an acridinyl group, a pyridazinyl group, a pyrazinyl group, a quinolyl group, a quinazolinyl group, a quinoxalinyl group, a phenothiazinyl group, a phthalazinyl group, a pyridopyrimidinyl group, a pyridopyrazinyl group, a pyrazinopyrazinyl group, Isoquinolyl group, indolyl group, carbazolyl group, N-arylcarbazolyl group, N-heteroarylcarbazolyl group, N-alkylcarbazolyl group, benzoxazolyl group, benzimidazolyl group, benzothiazolyl group, benzocarbazolyl group, benzothiophenyl group, dibenzothiophenyl group, thienothiphenyl group, benzofuranyl group, phenanthroline group, isoxazolyl group, thiadiazolyl group, dibenzosilyl group, dibenzofuranyl group and the like, but are not limited thereto.

[0113] In the present specification, the silyl group includes an alkylsilyl group and an arylsilyl group. Examples of the silyl group may include a trimethylsilyl group, a triethylsilyl group, a tert-butyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, etc., but are not limited thereto.

[0114] In the present specification, the boron group includes an alkyl boron group and an aryl boron group. Examples of the boron group may include a trimethyl boron group, a triethyl boron group, a tert-butyl dimethyl boron group, a triphenyl boron group, a diphenyl boron group, a phenyl boron group, etc., but are not limited thereto.

[0115] In formula 1, Y 1 To Y 5 and Y 11 To Y 15 Y may each independently be CH or N. 1 To Y 5 At least four of them may be CH, and Y 11 To Y 15 At least four of them may be CH. That is, each of the aromatic six-membered rings substituted by the anthracene nucleus may be a substituted phenyl group or a substituted pyrimidinyl group.

[0116] R 1 To R 3 Each may independently be an alkyl group, a silyl group, a boron group, an aryl group or a heteroaryl group.

[0117] The alkyl group can be a substituted or unsubstituted alkyl group with 2 to 20 carbon atoms. The silyl group can be a substituted silyl group, and the boron group can be a substituted boron group. The aryl group can be a substituted or unsubstituted aryl group with 6 to 30 ring-forming carbon atoms. The heteroaryl group can be a substituted or unsubstituted heteroaryl group with 3 to 30 ring-forming carbon atoms, or can form a ring by being connected to an adjacent group.

[0118] When R 1 To R 3 When it is a substituent having a small volume (for example, an alkyl group having 1 carbon atom (i.e., a methyl group), an unsubstituted silyl group, or an unsubstituted boron group), the film-forming property is poor, so that the formation of a uniform thin film may be difficult. Therefore, the driving voltage may be increased.

[0119] The polycyclic compound of the embodiment is formed into a thin film by using a material substituted with a relatively bulky substituent (e.g., an alkyl group having 2 or more carbon atoms, a substituted silyl group, or a substituted boron group). Therefore, a uniform thin film can be formed, so that a low driving voltage can be achieved.

[0120] When R 1 , R 2 and R 3When each of R is a heteroaryl group, the heteroaryl group may be an electron withdrawing group. For example, the heteroaryl group may be a substituted or unsubstituted pyridine group, a substituted or unsubstituted bipyridine group, a substituted or unsubstituted pyrimidine group, a substituted or unsubstituted triazine group, a substituted or unsubstituted quinoline group, a substituted or unsubstituted quinazoline group, a substituted or unsubstituted quinoxaline group, a substituted or unsubstituted phthalazine group, a substituted or unsubstituted indole group, a substituted or unsubstituted pyrazine group, a substituted or unsubstituted pyridazine group, a substituted or unsubstituted thiophene group, a substituted or unsubstituted oxazole group, a substituted or unsubstituted thiazole group, or a substituted or unsubstituted pyrazole group. In an embodiment, when R 1 , R 2 and R 3 When each of R is an electron-withdrawing group, the hole-blocking property is better than that when R 1 , R 2 and R 3 It is better when each of them is an electron donating group.

[0121] Each of p and q may independently be an integer of 1 to 5. For example, each of p and q may independently be 1 or 2. When p or q is 2 or more, a plurality of substituents may be the same as or different from each other.

[0122] r may be an integer of 1 to 8. When r is 2 or more, a plurality of substituents may be the same as or different from each other.

[0123] Formula 1 can be represented by, for example, the following Formula 2-1 to Formula 2-3.

[0124]

[0125] [Formula 2-3]

[0126]

[0127] Formula 2-1 to Formula 2-3 are respectively 1 To R 2 The number and substitution position of Y 1 To Y 5 and Y 11 To Y 15 The atoms in the compound are specified. 1 , R 2 , R 11 , R 12 , R 21 , R 22 , R 31 and R 32 It can be compared with R defined in Formula 1 1 To R 3 same.

[0128] The polycyclic compound of the embodiment may include at least one of the compounds represented by the following Compound Group 1.

[0129] [Compound Group 1]

[0130]

[0131] The difference in the highest occupied molecular orbital (HOMO) energy level between the light emission layer EML host and the polycyclic compound of the embodiment can be 0 eV to 0.1 eV. In the embodiment, when the light emission layer EML host and the polycyclic compound both have an anthracene nucleus, the HOMO energy level can be similarly formed. Therefore, since the residual holes in the host after the exciton generation are released, the residual holes in the light emission layer EML can be reduced. Therefore, the degradation caused by the exciton-polaron (electron or hole) annihilation phenomenon (triplet-polaron quenching, TPQ; or singlet-polaron quenching, SPQ) in the light emission layer EML can be prevented.

[0132] The difference between the lowest occupied molecular orbital (LOMO) energy level of the light emission layer EML host and the LOMO energy level of the polycyclic compound of the embodiment can be 0eV to 0.1eV. Therefore, due to the small difference in LUMO energy level between the light emission layer EML and the hole blocking layer HBL, electrons can be smoothly injected into the light emission layer EML and the light emission efficiency can be improved. Since the polycyclic compound of the embodiment has a substituted substituent having a large volume, the hole mobility of the polycyclic compound can be 0cm 2 / Vs to 10 -6 cm 2 / Vs. Since the polycyclic compound according to the embodiment has 10 -6 cm 2 / Vs or less than 10 - 6 cm 2 The hole mobility value of 100 nm / Vs is small, and even when the energy difference between the HOMO energy level and the LUMO energy level of the polycyclic compound of the embodiment and the main material of the light emitting layer EML is small, excellent hole blocking properties are exhibited. In particular, when the polycyclic compound of the embodiment is used as a material for the hole blocking layer HBL, the hole blocking layer HBL can be formed to be thin, so that excellent hole blocking properties can be exhibited while achieving a low driving voltage.

[0133] The triplet energy level of the polycyclic compound of the embodiment may be 1.6eV to 1.8eV. In this specification, unless otherwise noted, the triplet energy level may refer to the lowest triplet energy level. The difference in triplet energy level between the polycyclic compound and the main body of the light emitting layer EML may be small, and the triplet energy level of the polycyclic compound may be less than the triplet energy level of the main body of the light emitting layer EML. For example, the difference in triplet energy level between the polycyclic compound and the main body of the light emitting layer EML may be about 0eV to about 0.2eV. Therefore, even if some holes are injected into the hole blocking layer HBL, the energy generated by triplet-triplet fusion (TTF) in the hole blocking layer HBL can be easily moved to the light emitting layer EML, so that triplet leakage is reduced to prevent the device efficiency from being degraded.

[0134] Generally, since the triplet energy level difference between the main body of the light emitting layer EML and the hole blocking layer EBL material is designed to be large, the excitons with a long service life in the triplet state are retained at the interface between the light emitting layer EML and the hole blocking layer HBL, and continue to cause damage. In the case of the organic electroluminescent device OLED of the embodiment, the triplet energy level difference between the main body of the light emitting layer EML and the polycyclic compound of the embodiment contained in the hole blocking layer EBL is designed to be small, so that such damage can be alleviated. Therefore, the long service life of the element can be preserved. In addition, the efficiency degradation caused by the reduction of the triplet concentration in the light emitting layer EML can be compensated by the triplet-triplet fusion (TTF) generated in the hole blocking layer HBL.

[0135] At the same time, the polycyclic compound of the embodiment has excellent durability against holes, so that even when in continuous contact with holes, the degradation rate is low. In the organic electroluminescent device OLED of the embodiment, the hole blocking layer HBL includes the polycyclic compound of the embodiment, and at least one layer of the light emitting layer EML and the electron transport layer ETL includes the polycyclic compound of the embodiment, so that the durability against holes can be further improved to prevent degradation of the device, and thus a long service life of the device can be achieved.

[0136] A second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 may be a common electrode or a cathode. The second electrode EL2 may be a transmissive electrode, a semi-transmissive reflective electrode or a reflective electrode. When the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be formed of a transparent metal oxide (e.g., indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc.).

[0137] When the second electrode EL2 is a semi-transmissive reflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof (e.g., a mixture of Ag and Mg). Alternatively, the second electrode EL2 may have a multilayer structure including a reflective film or a semi-transmissive reflective film (both of which are formed of the materials exemplified above) and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), or the like.

[0138] Although not illustrated, the second electrode EL2 may be connected to the auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0139] Meanwhile, although not shown in the drawings, a capping layer (not shown) may be further provided on the second electrode EL2 of the organic electroluminescent device OLED of the embodiment. The capping layer (not shown) may include, for example, α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc, TPD15 (N4, N4, N4', N4'-tetrakis(biphenyl-4-yl)biphenyl-4,4'-diamine), TCTA (4,4', 4"-tris(carbazole-9-yl)triphenylamine), and the like.

[0140] Figures 7 to 10 are cross-sectional views of display devices DD-1, DD-2, DD-3, and DD-4 according to embodiments of the inventive concept. Figures 7 to 10 The display devices DD-1, DD-2, DD-3 and DD-4 may have a corresponding Figure 2 0047] The configuration of a cross section of a display device DD is shown in FIG.

[0141] refer to Figure 7 The display device DD-1 of the embodiment includes an organic electroluminescent device OLED-1. The organic electroluminescent device OLED-1 includes a first electrode EL1, an organic layer OEL-1, and a second electrode EL2. The organic electroluminescent device OLED-1 may include a plurality of light emitting units EM1, EM2, and EM3, and charge generation layers CGL1 and CGL2 disposed between the light emitting units EM1, EM2, and EM3. Figure 7 Unless otherwise noted, the same Figure 2 , Figure 5 and Figure 6 Substantially the same contents as those described above apply to the Figure 2 , Figure 5 and Figure 6Components of the components, and therefore their detailed description will be omitted.

[0142] refer to Figure 8 , the display device DD-2 of the embodiment may include a first base substrate BS1, a circuit layer CL, a light emitting element layer ODL, an adhesive member ADH, a light conversion layer WCL, and a second base substrate BS2. Unless otherwise noted, substantially the same contents as those described above may be applied to the first base substrate BS1, the circuit layer CL, and the light emitting element layer ODL. Although not illustrated, the light emitting element layer ODL may include an organic electroluminescent device including a plurality of light emitting units.

[0143] The adhesive member ADH may bond the light emitting element layer ODL and the light conversion layer WCL. The adhesive member ADH may be an optically transparent adhesive.

[0144] On the bonding member ADH, a second base substrate BS2 may be disposed The second base substrate BS2 may be a silicon substrate, a plastic substrate, a glass substrate, an insulating film, or a structure including an arrangement of a plurality of insulating layers.

[0145] Between the bonding member ADH and the second base substrate BS2, a light conversion layer WCL may be provided. The light conversion layer WCL may include a first light conversion component WCL1, a second light conversion component WCL2, and a third light conversion component WCL3. The light conversion layer WCL may transmit or absorb the first color light emitted from the light emitting element layer ODL to emit the second color light, or may absorb the first color light to emit the third color light. Specifically, the first light conversion component WCL1 absorbs the first color light to emit the second color light, the second light conversion component WCL2 absorbs the first color light to emit the third color light, and the third light conversion component WCL3 may transmit the first color light. The first color light may be blue light, the second color light may be green light, and the third color light may be red light.

[0146] Each of the first to third light conversion members ( WCL1 , WCL2 , and WCL3 ) may overlap the light emission layer EML on a plane, and may overlap a portion of the pixel defining layer PDL.

[0147] The first light conversion part WCL1 may include a matrix resin RS, scattering particles SC dispersed in the matrix resin RS, and a first quantum dot light emitter QD2. The first quantum dot light emitter QD2 may absorb the first color light to emit the second color light.

[0148] The second light conversion part WCL2 may include a matrix resin RS, scattering particles SC dispersed in the matrix resin RS, and a second quantum dot light emitter QD1. The second quantum dot light emitter QD1 may absorb the first color light to emit a third color light.

[0149] The third light conversion part WCL3 may include a matrix resin RS and scattering particles SC dispersed in the matrix resin RS. The scattering particles SC may be TiO 2 Or silica-based nanoparticles. The scattering particles SC may scatter light. Since the third light conversion component WCL3 does not include a quantum dot light emitter, the amount of scattering particles SC per unit area included in the third light conversion component WCL may be greater than the amount of scattering particles SC per unit area included in each of the first light conversion component WCL1 and the second light conversion component WCL2.

[0150] Each of the quantum dot light emitters QD1 and QD2 may include a material selected from a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element, a group IV compound, and a combination thereof. Each of the quantum dot light emitters QD1 and QD2 may be a binary compound, a ternary compound, or a quaternary compound, and may be present as particles having a uniform concentration distribution, or may be present as the same particles having partially different concentrations. Each of the quantum dot light emitters QD1 and QD2 may have a core-shell structure comprising a core and a shell surrounding the core. In addition, each of the quantum dot light emitters QD1 and QD2 may have a core-shell structure in which one quantum dot light emitter surrounds another quantum dot light emitter. The interface between the core and the shell may have a concentration gradient in which the concentration of the element present in the shell decreases toward the center.

[0151] Each of the quantum dot light emitters QD1 and QD2 may be a particle having a nanometer size. Each of the quantum dot light emitters QD1 and QD2 may have a full width at half maximum (FWHM) of a light emission wavelength spectrum of about 45 nm or less, preferably about 40 nm or less, more preferably about 30 nm or less, and color purity or color reproducibility may be improved within the above range. In addition, light emitted by such quantum dot light emitters QD1 and QD2 is emitted in all directions, so that a wide viewing angle may be improved.

[0152] In addition, although the form of each of the quantum dot light emitters QD1 and QD2 is not particularly limited as long as it is a form commonly used in the art, more specifically, quantum dot light emitters in the form of spherical, conical, multi-armed or cubic nanoparticles, nanotubes, nanowires, nanofibers, etc. can be used.

[0153] refer to Fig. 9 In the light emitting element layer ODL-2, the light emitting layer EML-1 can be set as a common layer (i.e., one layer) in the organic electroluminescent device OLED. At this time, since a separate mask for depositing the light emitting layer EML-1 is not required, the manufacturing process of the display device DD-3 can be simplified.

[0154] refer to Fig.10 , the display device DD-4 may include first to third color filters (CF1, CF2, and CF3). The first color filter CF1 is disposed on the first light conversion component WCL1 and may overlap with the first light conversion component WCL1 on a plane. The second color filter CF2 is disposed on the second light conversion component WCL2 and may overlap with the second light conversion component WCL2 on a plane. The third color filter CF3 is disposed on the third light conversion component WCL3 and may overlap with the third light conversion component WCL3 on a plane.

[0155] Each of the first to third color filters (CF1, CF2, and CF3) can transmit light of different wavelengths. For example, the first color filter CF1 can transmit the second color light and absorb other light. The second color filter CF2 can transmit the third color light and absorb other light. The third color filter CF3 can transmit the first color light and absorb other light.

[0156] Each of the first to third color filters (CF1, CF2, and CF3) may transmit color light corresponding to light emitted from the first to third light conversion layers (WCL1, WCL2, and WCL3), and absorb other light. The first color filter CF1 may be a green color filter for transmitting green light. The second color filter CF2 may be a red color filter for transmitting red light. The third color filter CF3 may be a blue color filter for transmitting blue light.

[0157] Each of the first to third color filters (CF1, CF2, and CF3) includes a matrix resin and may include at least one pigment or dye dispersed in the matrix resin. Each of the first to third color filters (CF1, CF2, and CF3) includes a matrix resin and may include at least one dye or pigment dispersed in the matrix resin. For example, the first color filter CF1 may include at least one green dye or green pigment. The second color filter CF2 may include at least one red dye or red pigment. The third color filter CF3 may include at least one blue dye or blue pigment.

[0158] By setting the first to third color filters (CF1, CF2 and CF3), only light in the target wavelength region is emitted, so that the color reproducibility of the display device DD-4 can be improved. In addition, since the light incident from the outside is absorbed and the external light reflection is reduced, the visibility of the display device DD-4 can be improved.

[0159] Between each of the first to third color filters (CF1, CF2, and CF3), a light blocking layer BM may be provided. The light blocking layer BM may be provided directly under the second base substrate. The light blocking layer BM may overlap with the non-light emitting area on a plane. The light blocking layer BM may include carbon black particles. By providing the light blocking layer BM, light emitted from adjacent pixel areas may be prevented from mixing with each other. In the embodiment, the light blocking layer BM may be omitted.

[0160] In the following, refer to FIG. 11A to FIG. 12B , specific embodiments and comparative examples will describe the present inventive concept in more detail.

[0161] Fig.11A : is a graph showing the amount of decrease in brightness over time in the example and the comparative example. Fig. 11B : is a graph showing the amount of decrease in brightness over time in the example and the comparative example. Fig. 12A Enlarged images of thin films formed according to Examples and Comparative Examples are shown. Fig. 12B is a graph showing current density values ​​according to driving voltage in Examples and Comparative Examples.

[0162] The following embodiments are only for illustrative purposes to facilitate understanding of the present inventive concept, and thus, the scope of the present inventive concept is not limited thereto.

[0163] 1. Synthesis example

[0164] The polycyclic compound of the embodiment can be synthesized, for example, as follows. However, the synthesis method of the polycyclic compound of the embodiment is not limited thereto.

[0165] 1-1 Synthesis of Compound 1

[0166] The polycyclic compound of the embodiment can be synthesized, for example, by the following Reaction Formula 1.

[0167] [Reaction 1]

[0168]

[0169] 3 g (0.0089 mol) of 9,10-dibromoanthracene and 5.38 g (0.01869 mol) of 2-(3,5-diisopropylphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane were placed in a three-necked flask (100 ml), and 3 ml of 2N Na 2CO 3 and a toluene / ethanol mixed solution, and then stirred to remove oxygen. Thereafter, 0.1 g of Pd (pph) was added thereto in a nitrogen atmosphere. 3 ) 4 as a catalyst, and then the mixture was refluxed at 110° C. for 8 hours. The reaction was terminated with water, and dichloromethane (CH 2 Cl 2 ) was subjected to extraction of the product three times. The solvent was removed. The resulting product thus obtained was subjected to column chromatography using a mixed solvent in which ethyl acetate and hexane were mixed at a ratio of 1:10, and 3.91 g (yield 88%) of Compound 1 was obtained. 1 H NMR (CDCl 3 )The measurement results are as follows.

[0170] δ8.23(4H,d), δ7.80(4H,s), δ7.50(2H,s), δ7.37-7.35(4H,d), δ2.87(4H,m), δ1.30-1.28(24H,t).

[0171] 1-2 Synthesis of Compound 2

[0172] [Reaction 2]

[0173]

[0174] 3 g (0.0089 mol) of 9,10-dibromoanthracene and 4.86 g (0.01869 mol) of 2-(4-(tert-butyl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane were placed in a three-necked flask (100 ml), and 3 ml of 2N Na 2 CO 3 and a mixed solution of toluene / ethanol, and then stirred to remove oxygen. Thereafter, 0.1 g of Pd (pph) was added thereto in a nitrogen atmosphere. 3 ) 4 as a catalyst, and then the mixture was refluxed at 110° C. for 8 hours. The reaction was terminated with water, and dichloromethane (CH 2 Cl 2 ) was subjected to extraction of the product three times. The solvent was removed. The resulting product thus obtained was subjected to column chromatography using a mixed solvent in which ethyl acetate and hexane were mixed at a ratio of 1:10, and 3.91 g (yield 88%) of Compound 2 was obtained. 1 H NMR (CDCl 3 )The measurement results are as follows.

[0175] δ8.21(4H,d), δ7.40-7.30(12H,m), δ1.30-1.28(18H,t).

[0176] 1-3 Synthesis of Compound 3

[0177] [Reaction 3]

[0178]

[0179] 3 g (0.0089 mol) of 9,10-dibromoanthracene and 4.88 g (0.01869 mol) of 4-(tert-butyl)-2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine were placed in a three-necked flask (100 ml), and 3 ml of 2N Na 2 CO 3 and a mixed solution of toluene / ethanol, and then stirred to remove oxygen. Thereafter, 0.1 g of Pd (pph) was added thereto in a nitrogen atmosphere. 3 ) 4 as a catalyst, and then the mixture was refluxed at 110° C. for 8 hours. The reaction was terminated with water, and dichloromethane (CH 2 Cl 2 ) was subjected to extraction of the product three times. The solvent was removed. The resulting product thus obtained was subjected to column chromatography using a mixed solvent in which ethyl acetate and hexane were mixed at a ratio of 1:10, and 2.97 g (yield 75%) of Compound 3 was obtained. 1 H NMR (CDCl 3 )The measurement results are as follows.

[0180] δ8.36(2H,d), δ8.20(4H,d), δ7.80(2H,s), δ7.40(4H,m), δ7.02(2H,d), δ1.30-1.28(18H,s).

[0181] 1-4 Synthesis of Compound 4

[0182] [Reaction 4]

[0183]

[0184] 3 g (0.0089 mol) of 9,10-dibromoanthracene and 4.75 g (0.01869 mol) of 4,4,5,5-tetramethyl-2-(naphthalen-2-yl)-1,3,2-dioxaborolane were placed in a three-necked flask (100 ml), and 3 ml of 2N Na 2 CO 3and a mixed solution of toluene / ethanol, and then stirred to remove oxygen. Thereafter, 0.1 g of Pd (pph) was added thereto in a nitrogen atmosphere. 3 ) 4 as a catalyst, and then the mixture was refluxed at 110° C. for 8 hours. The reaction was terminated with water, and dichloromethane (CH 2 Cl 2 ) was subjected to extraction of the product three times. The solvent was removed. The resulting product thus obtained was subjected to column chromatography using a mixed solvent in which ethyl acetate and hexane were mixed at a ratio of 1:10, and 3.64 g (yield 95%) of compound 4 was obtained. 1 H NMR (CDCl 3 )The measurement results are as follows.

[0185] δ8.21(4H,d), δ8.08-7.95(6H,m), δ7.66-7.55(6H,m), δ7.40-7.37(6H,m).

[0186] 2. Preparation and evaluation of polycyclic compounds and organic electroluminescent devices containing polycyclic compounds

[0187] 2-1. Energy levels of polycyclic compounds

[0188] The HOMO level, LUMO level, TI level and S1 level of Example Compounds 1 to 4 and Comparative Example Compounds X1, X2 and X3 were measured by the non-empirical molecular orbital method. Specifically, Gaussian 09 (Gaussian09), a product of Gaussian Co., was used, B3LYP was used for the general function, and 6-31G (d) was used for the basis function to perform the calculation.

[0189] (Example Compound)

[0190]

[0191] (Comparative Example Compound)

[0192]

[0193] [Table 1]

[0194] Compound HOMO(eV) LUMO(eV) T1(eV) S1(eV) Example Compound 1 -5.61 -2.49 1.665 3.1 Example Compound 2 -5.63 -2.51 1.67 3.1 Example Compound 3 -5.58 -2.53 1.75 3.1 Example Compound 4 -5.6 -2.49 1.77 3.07 Comparative Example Compound X1 -6.05 -2.58 2.7 3.2 Comparative Example Compound X2 -5.91 -2.70 2.8 3.3

[0195] Table 1 shows the HOMO level, LUMO level, TI level, and S1 level of Example Compounds 1 to 4 and Comparative Example Compounds X1 and X2.

[0196] 2-2 Fabrication and property evaluation of organic electroluminescent devices

[0197] (Manufacturing of organic electroluminescent device)

[0198] In the organic electroluminescent devices of Examples 1 to 3 and Comparative Example 1, the first electrode EL1 having a thickness of 30 nm was formed using ITO. The hole injection layer HIL having a thickness of 10 nm was formed by HAT-CN, and the hole transport layer HTL having a thickness of 60 nm was formed using TCTA. By using Example Compound 4, a light emitting layer EML doped with 3% TBP and having a thickness of 20 nm was formed.

[0199]

[0200] Thereafter, the electron injection layer EIL was formed with a thickness of 1 nm using LiQ. The second electrode EL2 was formed with a thickness of 100 nm using Al. Each layer was formed by vacuum deposition.

[0201] In each of Examples 1 to 3, a hole blocking layer HBL having a thickness of 5 nm was formed using Example Compounds 1 to 3, respectively, and an electron transport layer ETL having a thickness of 30 nm was formed by mixing each of Example Compounds 1 to 3 with LiQ at a ratio of 1:1.

[0202] In each of Examples 7 to 9, a device was manufactured in the same manner as in Examples 1 to 3, except that Comparative Example Compound X2 was used instead of Example Compounds 1 to 3 to form the electron transport layer ETL.

[0203] In Comparative Example 1, a device was manufactured in the same manner as in Example 1, except that Comparative Example Compound X1 was used instead of Example Compound 1 to form the hole blocking layer HBL and Comparative Example Compound X2 was used instead of Example Compound 1 to form the electron transport layer ETL.

[0204] The material compositions of the light emitting layer, the hole blocking layer, and the electron transport layer of each of Examples 1 to 3, Examples 7 to 9, and Comparative Example 1 are shown in Table 2.

[0205] [Table 2]

[0206]

[0207] (Manufacture of an organic electroluminescent device having multiple light emitting units)

[0208] In the organic electroluminescent device of Example 10, a first electrode EL1 having a thickness of 30 nm was formed using ITO. HAT-CN was deposited to a thickness of 5 nm, and then a hole injection layer (HIL) having a thickness of 10 nm was formed using NPB. A hole transport layer HTL having a thickness of 20 nm was formed using TCTA. By using Example Compound 4, a first light emitting layer EML1 doped with 3% TBP and having a thickness of 20 nm was formed.

[0209] Thereafter, a hole blocking layer HBL was formed having a thickness of 5 nm using Example Compound 1, and an electron transport layer ETL was formed having a thickness of 25 nm by mixing Example Compound 1 with LiQ at a ratio of 1:1 to form a first light emission unit EM1.

[0210] Thereafter, BCP and Li were co-deposited at a weight ratio of 97:3 to a thickness of 15 nm as an n-type charge generation layer, and HAT-CN was deposited to a thickness of 5 nm as a p-type charge generation layer.

[0211]

[0212] Thereafter, a hole injection layer HIL was formed with NPB having a thickness of 10 nm, and a hole transport layer HTL was formed with TCTA having a thickness of 20 nm. By using Example Compound 4, the following second light emitting layer EML2 doped with 3% TBP and having a thickness of 20 nm was formed.

[0213] Thereafter, a hole blocking layer HBL was formed having a thickness of 5 nm using Example Compound 1, and an electron transport layer ETL was formed having a thickness of 25 nm by mixing Example Compound 1 with LiQ at a ratio of 1:1 to form a second light emission unit EM2.

[0214] Thereafter, BCP and Li were co-deposited to a thickness of 15 nm as an n-type charge generation layer at a weight ratio of 97:3, and HAT-CN was deposited to a thickness of 5 nm as a p-type charge generation layer to form a second charge generation layer CGL2.

[0215] Thereafter, a hole injection layer HIL was formed with NPB to have a thickness of 10 nm, and a hole transport layer HTL was formed with a thickness of 20 nm using TCTA. By using Example Compound 4, a third light emitting layer EML3 doped with 3% TBP and having a thickness of 20 nm was formed.

[0216] Thereafter, a hole blocking layer HBL having a thickness of 5 nm was formed using Example Compound 1, Example Compound 1 and LiQ were deposited to a thickness of 35 nm at a ratio of 1:1, and an electron injection layer EIL having a thickness of 1 nm was formed by using LiQ to form a third light emission unit EM3. Thereafter, a second electrode EL2 having a thickness of 100 nm was formed using Al. Each layer was formed by vacuum deposition.

[0217] The organic electroluminescent device of Example 11 was manufactured in the same manner as in Example 10, except that Example Compound 2 was used instead of Example Compound 1 as the material of the hole blocking layer HBL and the electron transport layer ETL.

[0218] The organic electroluminescent device of Example 12 was manufactured in the same manner as in Example 10, except that Example Compound 3 was used instead of Example Compound 1 as the material of the hole blocking layer HBL and the electron transport layer ETL.

[0219] The organic electroluminescent device of Comparative Example 2 was manufactured in the same manner as in Example 10, but the hole blocking layer HBL of each of the first to third light emission units (EM1, EM2, and EM3) was formed using Comparative Example Compound X3 instead of Example Compound 1.

[0220] (Evaluation of properties of organic electroluminescent devices)

[0221] 1) Evaluation of service life

[0222] In order to evaluate the properties of the organic electroluminescent devices according to the examples and comparative examples, the service life of each device was measured.

[0223] Fig.11A The degree of decrease in luminance over time of the organic electroluminescent devices of Examples 1 to 3, Examples 7 to 9, and Comparative Example 1 is shown. Fig. 11B The degree of decrease in luminance over time of the organic electroluminescent devices of Examples 10 to 12 and Comparative Example 2 is shown.

[0224] Table 3 selectively shows the evaluation values ​​of the organic electroluminescent devices of Examples 1 to 3, Examples 7 to 12, and Comparative Examples 1 and 2. The service life of each device is represented by T 2 Indicates that T 2 It is the time required for the brightness to decrease from 1000 nits to 2% of that.

[0225] [Table 3]

[0226]

[0227]

[0228] refer to Fig.11A , Fig. 11B From Table 3, it can be confirmed that the organic electroluminescent device according to the embodiment can achieve a long service life.

[0229] Specifically, Examples 1 to 3 and Examples 7 to 9 exhibited excellent T values ​​of 102 to 163 hours. 2 However, Comparative Example 1 showed a low T 2 The values ​​of Examples 10 to 12 having the plurality of light emitting units EM1, EM2, and EM3 exhibited excellent T values ​​of 248 to 252 hours. 2 However, Comparative Example 2 showed a low T 2 value, which is 200 hours.

[0230] In the case of the organic electroluminescent devices of Examples 1 to 3 and Examples 7 to 12, it is believed that the service life of the devices has been improved, due to the use of the polycyclic compound of the embodiment showing excellent durability against holes as the material of the hole blocking layer HBL, and the material of at least one of the light emitting layers EML, EML1, EML2 and EML3 and the electron transport layer ETL. In addition, in the case of Examples 1 to 3 and Example 7, it is believed that the service life of the devices has been improved, due to the fact that the difference in triplet energy level between the host material of the light emitting layers EML, EML1, EML2 and EML3 and the material of the hole blocking layer material HBL is small, which reduces the damage of the excitons to the hole blocking layer.

[0231] Referring to Table 1, in Example 1, the difference in HOMO energy level and the difference in LUMO energy level between Example Compound 4, which is the main material of the light emission layer EML, and Example Compound 1, which is the material of the hole blocking layer HBL, are 0.01 eV and 0 eV, respectively, and the difference in T1 energy level between them is 0.105 eV. In Example 2, the difference in HOMO energy level and the difference in LUMO energy level between Example Compound 4, which is the main material of the light emission layer EML, and Example Compound 2, which is the material of the hole blocking layer HBL, are 0.03 eV and 0.02 eV, respectively, and the difference in T1 energy level between them is 0.1 eV. In Example 3, the difference in HOMO energy level and the difference in LUMO energy level between Example Compound 4, which is the main material of the light emission layer EML, and Example Compound 3, which is the material of the hole blocking layer HBL, are 0.02 eV and 0.04 eV, respectively, and the difference in T1 energy level between them is 0.2 eV.

[0232] In Examples 7 to 9, respective differences in HOMO level, LUMO level, and T1 level between the host material of the light emitting layer EML and the material of the hole blocking layer HBL are the same as those in Examples 1 to 3.

[0233] However, in the case of Comparative Example 1, each energy level difference is greater than the energy level difference in Examples 1 to 3 and Examples 7 to 9. Specifically, in Comparative Example 1, the difference in HOMO energy level and the difference in LUMO energy level between Example Compound 4 which is the host material of the light emitting layer EML and Comparative Example Compound X1 which is the material of the hole blocking layer HBL are 0.45 eV and 0.09 eV, respectively, and the difference in T1 energy level between them is 0.93 eV.

[0234] In the case of Examples 1 to 3 and Examples 7 to 9, since the difference in triplet energy level between the polycyclic compound contained in the hole blocking layer HBL and the host of the light emitting layer EML is small, even if some holes are injected into the hole blocking layer HBL, the energy generated by triplet-triplet fusion (TTF) in the hole blocking layer HBL can be easily moved to the light emitting layer EML, so it is considered that triplet leakage has been alleviated to prevent the device efficiency from being deteriorated.

[0235] 2) Evaluation of film stability

[0236] In Example 1 and Comparative Example 3, in order to evaluate the stability of the film, each of Example Compound 1 and Comparative Example Compound 3 was deposited to The film morphology was observed using an optical microscope. Fig. 12A 1-1 and Fig. 12A 1-2) and 50x magnification ( Fig. 12A 2-1 and Fig. 12A 2-2) Compare the film morphology.

[0237] refer to Fig. 12A , Image 1-1 and Image 2-1 respectively illustrate the hole blocking layers HBL formed according to Example 1 and Comparative Example 3, each magnified 50 times. Image 1-2 and Image 2-2 respectively illustrate the region AA and the region BB, each magnified 50 times.

[0238] refer to Fig. 12A When the hole blocking layer HBL was formed using Example Compound 1 substituted with an isopropyl group having a large volume, a uniform thin film was formed, whereas when the hole blocking layer HBL was formed using Comparative Example Compound X3 substituted with a methyl group having a small volume, a non-uniform thin film was formed.

[0239] refer to Fig. 12BIn the case of Example 1, the film stability is good, so that a low driving voltage can be achieved. However, in the case of Comparative Example 3, the film stability is poor, so that the driving voltage property is deteriorated.

[0240] In the organic electroluminescent device OLED of the embodiment, the hole blocking layer HBL and at least one of the light emitting layer EML and the electron transport layer ETL are formed using the polycyclic compound of the embodiment, and thus, a long lifetime of the device may be achieved.

[0241] An organic electroluminescent device according to an embodiment of the inventive concept and a display device including the same may achieve a long service life.

[0242] Although the present invention has been described with reference to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various changes may be made in form and detail without departing from the spirit and scope of the present invention. Therefore, it should be understood that the above embodiments are exemplary and non-restrictive in all respects.

Claims

1. An organic electroluminescent device, comprising: a first electrode; a second electrode disposed on the first electrode; as well as a first light emitting unit disposed between the first electrode and the second electrode, wherein the first light emitting unit comprises: a first hole transport region disposed on the first electrode; a first light emitting layer disposed on the first hole transporting zone and comprising a host and a dopant; and A first electron transport region disposed on the first light emitting layer and comprising a hole blocking layer and an electron transport layer disposed on the hole blocking layer, wherein the hole blocking layer and at least one of the first light emitting layer and the electron transport layer comprise a polycyclic compound represented by the following Formula 1: [Formula 1] In formula 1, Y1 to Y5 and Y 11 To Y 15 Each of is independently CH or N, At least four of Y1 to Y5 are CH, Y 11 To Y 15 At least four of them are CH, Each of R1, R2 and R3 is independently a substituted or unsubstituted alkyl group having 2 to 20 carbon atoms, or is connected to an adjacent group to form a ring, Each of p and q is independently 1 or 2, and r is 0, The hole mobility of the polycyclic compound is 0 cm 2 / Vs to 10 -6 cm 2 / Vs, and Herein, "substituted" means substituted with one or more than one substituent selected from the group consisting of a deuterium atom and an alkyl group having 1 to 10 carbon atoms. 2 . The organic electroluminescent device as claimed in claim 1 , wherein the host comprises the polycyclic compound. The organic electroluminescent device as claimed in claim 1 , wherein the hole blocking layer comprises only the polycyclic compound. 4 . The organic electroluminescent device as claimed in claim 1 , wherein the first light emitting layer, the hole blocking layer and the electron transport layer comprise the polycyclic compound. 5 . The organic electroluminescent device as claimed in claim 1 , wherein a difference in the highest occupied molecular orbital energy level and a difference in the lowest unoccupied molecular orbital energy level between the host and the polycyclic compound are each 0 eV to 0.1 eV. 6 . The organic electroluminescent device according to claim 1 , wherein the lowest triplet energy level of the polycyclic compound is 1.6 eV to 1.8 eV, and the difference in the lowest triplet energy level between the host and the polycyclic compound is 0 eV to 0.2 eV.

7. The organic electroluminescent device according to claim 1, further comprising at least one light emitting unit disposed on the first light emitting unit, in, The at least one light emitting unit comprises: a second hole transport region disposed on the first light emitting unit; a second light emitting layer disposed on the second hole transporting region; and A second electron transport region is disposed between the second light emitting layer and the second electrode. 8 . The organic electroluminescent device of claim 7 , wherein the first light emission unit and the at least one light emission unit emit blue light.

9. The organic electroluminescent device according to claim 1, wherein the polycyclic compound comprises at least one of the compounds represented by the following compound group 1: [Compound Group 1] 10. A display device comprising a light emitting element layer, wherein the light emitting element layer comprises a plurality of organic electroluminescent devices, Each of the organic electroluminescent devices comprises: a first electrode; a second electrode disposed on the first electrode; A plurality of organic layers disposed between the first electrode and the second electrode, wherein the plurality of organic layers comprises: a hole transport region disposed on the first electrode; a first light emitting layer disposed on the hole transport region; An electron transport region disposed on the first light emitting layer and comprising a hole blocking layer and an electron transport layer disposed on the hole blocking layer, wherein the hole blocking layer and the electron transport layer comprise a polycyclic compound represented by the following Formula 1: [Formula 1] In formula 1, Y1 to Y5 and Y 11 To Y 15 are each independently CH or N, At least four of Y1 to Y5 are CH, Y 11 To Y 15 At least four of them are CH, Each of R1, R2 and R3 is independently a substituted or unsubstituted alkyl group having 2 to 20 carbon atoms, or is connected to an adjacent group to form a ring, Each of p and q is independently 1 or 2, and r is 0, The hole mobility of the polycyclic compound is 0 cm 2 / Vs to 10 -6 cm 2 / Vs, and Herein, "substituted" means substituted with one or more than one substituent selected from the group consisting of a deuterium atom and an alkyl group having 1 to 10 carbon atoms. 11 . The display device of claim 10 , wherein the organic layer further comprises at least one light emitting layer disposed between the electron transport region and the second electrode.

12. The display device according to claim 10, further comprising a light conversion layer disposed on the light emitting element layer, in The light emitting element layer emits blue light, and The light conversion layer comprises: a first light conversion component that absorbs the blue light and emits green light; a second light conversion component that absorbs the blue light and emits red light; as well as A third light conversion member transmits the blue light.

13. The display device according to claim 12, wherein The first light conversion component includes a first quantum dot light emitter that absorbs the blue light and emits green light, the second light conversion component comprises a second quantum dot light emitter that absorbs the blue light and emits red light, and The third light conversion member includes a matrix resin and a scatterer dispersed in the matrix resin. 14 . The display device of claim 10 , wherein each of the hole transport region, the first light emitting layer, and the electron transport region is included in the light emitting element layer in the form of one layer.

Images