Organic light emitting diode and organic light emitting device comprising the same

Abstract

The present disclosure relates to an organic light emitting diode and an organic light emitting device including the same. The organic light emitting diode (OLED) includes a plurality of light emitting parts disposed between two facing electrodes and at least one charge generation layer disposed between the plurality of light emitting parts. At least one of the plurality of light emitting parts includes a green light emitting material layer, and a band gap between a HOMO energy level of a host and a LUMO energy level of a dopant in a P-type charge generation layer is controlled. The OLED and the organic light emitting device can improve light emitting efficiency thereof by controlling charge injection in a light emitting layer, and can effectively improve white balance by appropriate color compensation.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0153583, filed in Korea on November 17, 2020, the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] This disclosure relates to organic light-emitting diodes, and more specifically, to organic light-emitting diodes in which charge can be injected in a balanced manner to achieve effective color compensation, and to organic light-emitting devices including diodes. Background Technology

[0004] Organic light-emitting diodes (OLEDs) in widely used flat panel displays have become a focal point as a rapid replacement for liquid crystal displays (LCDs). OLEDs can be formed into sizes smaller than... OLEDs are thin organic films that can be used to create unidirectional or bidirectional images through electrode configuration. Furthermore, OLEDs can even be formed on flexible transparent substrates such as plastic substrates, making it easy to realize flexible or foldable display devices. In addition, compared to LCDs, OLEDs can be driven at lower voltages and have excellent color purity. Summary of the Invention

[0005] The inventors of this disclosure have recognized and understood that in related technologies, fluorescent materials exhibit low luminous efficiency because they utilize only singlet exciton energy during luminescence. In contrast, phosphorescent materials can exhibit high luminous efficiency because they utilize both triplet and singlet exciton energies during luminescence. However, the inventors have also recognized that representative phosphorescent metal complexes have short luminous lifetimes suitable for commercial use. Furthermore, when using multiple luminescent materials with different emission peaks in multiple luminescent material layers to achieve white light emission, the white balance within the luminescent materials is disrupted. Therefore, the inventors have determined the need to develop organic light-emitting diodes (OLEDs) that can improve both their luminous efficiency and luminous lifetime and effectively achieve the desired emission color.

[0006] Therefore, embodiments of this disclosure relate to organic light-emitting diodes (OLEDs) and organic light-emitting devices including diodes, said OLEDs substantially eliminating one or more problems caused by the limitations and disadvantages of related technologies. Embodiments of this disclosure provide solutions to the aforementioned problems and other technical problems in related technologies.

[0007] One or more embodiments of the present disclosure are to provide an organic light emitting diode and an organic light emitting device in which color compensation can be effectively implemented to maintain white balance.

[0008] One or more embodiments of the present disclosure are to provide an organic light emitting diode and an organic light emitting device in which charges can be injected in balance.

[0009] Additional features and aspects will be set forth in the description below, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the inventive concepts presented herein. Other features and aspects of the present inventive concepts will become apparent from consideration of the description and drawings, and from the claims and the description herein.

[0010] To achieve these and other aspects of the present inventive concepts, as presented and broadly described, in one aspect of the present disclosure, there is provided an organic light emitting diode comprising: a first electrode; a second electrode facing the first electrode; a plurality of light emitting portions between the first electrode and the second electrode; and at least one charge generation layer disposed between the plurality of light emitting portions, wherein the plurality of light emitting portions comprises at least one light emitting portion comprising a layer of green light emitting material, wherein the at least one charge generation layer comprises a P-type charge generation layer providing holes into the layer of green light emitting material, wherein the P-type charge generation layer comprises a P-type host and a P-type dopant, and wherein a band gap between a highest occupied molecular orbital (HOMO) level of the P-type host and a lowest unoccupied molecular orbital (LUMO) level of the P-type dopant satisfies a relationship of Formula A:

[0011] Formula A: 0.35 eV ≤ LUMO D - HOMO H ≤ 0.5 eV;

[0012] wherein LUMO D represents a LUMO level of the P-type dopant, and HOMO H represents a HOMO level of the P-type host.

[0013] In another aspect, the present disclosure provides an organic light emitting diode comprising: a first electrode; a second electrode facing the first electrode; and an emission layer disposed between the first electrode and the second electrode, wherein the emission layer comprises a first emission part disposed between the first electrode and the second electrode, a second emission part disposed between the first emission part and the second electrode, a third emission part disposed between the second emission part and the second electrode, a first charge generation layer disposed between the first emission part and the second emission part, and a second charge generation layer disposed between the second emission part and the third emission part, wherein the second emission part comprises a green emission material layer and a red emission material layer, wherein the first charge generation layer comprises a first P-type charge generation layer providing holes to the second emission part and a first N-type charge generation layer providing electrons to the first emission part, wherein the second charge generation layer comprises a second P-type charge generation layer providing holes to the third emission part and a second N-type charge generation layer providing electrons to the second emission part, wherein the first P-type charge generation layer comprises a first P-type host and a first P-type dopant, wherein the second P-type charge generation layer comprises a second P-type host and a second P-type dopant, and wherein an energy band gap between a highest occupied molecular orbital (HOMO) level of the first P-type host and a lowest unoccupied molecular orbital (LUMO) level of the first P-type dopant is different from an energy band gap between a HOMO level of the second P-type host and a LUMO level of the second P-type dopant.

[0014] In yet another aspect, the present disclosure provides an organic light emitting device comprising an organic light emitting diode over a substrate.

[0015] It is to be understood that both the foregoing general description and the following detailed description are illustrative and are intended to provide further explanation of the principles of the application concept as claimed. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure.

[0017] Figure 1 is a schematic circuit diagram illustrating an organic light emitting display device according to the present disclosure.

[0018] Figure 2 is a cross-sectional view illustrating an organic light emitting display device as an example of an organic light emitting device according to an aspect of the present disclosure.

[0019] Figure 3 is a cross-sectional view illustrating an organic light emitting diode having two emission parts according to an aspect of the present disclosure.

[0020] Figure 4is a graph showing relative charge mobility according to current density.

[0021] Figure 5 is a schematic diagram showing relative energy levels and bandgaps between a host and a dopant in one P-type charge generation layer that provides holes to a green light-emitting material layer.

[0022] Figure 6 is a cross-sectional view showing an organic light-emitting diode having two light-emitting parts according to another aspect of the present disclosure.

[0023] Figure 7 is a cross-sectional view showing an organic light-emitting diode having three light-emitting parts according to yet another aspect of the present disclosure.

[0024] Figure 8 is a schematic diagram showing relative energy levels and bandgaps between a host and a dopant in another P-type charge generation layer that provides holes to a blue light-emitting material layer.

[0025] Figure 9 is a cross-sectional view showing an organic light-emitting diode having three light-emitting parts according to yet another aspect of the present disclosure.

[0026] Figure 10 is a cross-sectional view showing an organic light-emitting display device according to another aspect of the present disclosure.

[0027] Figure 11 is a graph showing luminous efficiency of green light according to current density in OLEDs manufactured in Reference Examples and Examples.

[0028] Figures 12 to 14 is a graph showing color coordinates of white light emitted by OLEDs manufactured in Reference Examples and Examples.

[0029] Figure 15 is a graph showing current density measured according to voltage change in OLEDs manufactured in Reference Examples and Examples. DETAILED DESCRIPTION

[0030] Reference will now be made in detail to aspects of the present disclosure, examples of which are illustrated in the accompanying drawings.

[0031] The bandgap between a host and a dopant in a charge generation layer that provides charges into a light-emitting part can be controlled in an organic light-emitting diode (OLED) having a series structure. Charges can be injected into the light-emitting part in balance, so that charge generation and charge conductivity can be adjusted. Accordingly, the OLED can improve its luminous efficiency and reduce or minimize color variation caused by different gradations. The OLED can be applied to an organic light-emitting device, such as an organic light-emitting display device or an organic light-emitting illumination device.

[0032] Figure 1 is a schematic circuit diagram illustrating an organic light emitting display apparatus of the present disclosure. As shown in Figure 1 the organic light emitting display apparatus, gate lines GL, data lines DL, and power lines PL each cross each other to define a pixel area P. Within the pixel area P, a switching thin film transistor Ts, a driving thin film transistor Td, a storage capacitor Cst, and an organic light emitting diode D are formed. The pixel area P can include a red (R) pixel area RP, a green (G) pixel area GP, and a blue (B) pixel area BP.

[0033] The switching thin film transistor Ts is connected to the gate line GL and the data line DL, and the driving thin film transistor Td and the storage capacitor Cst are connected between the switching thin film transistor Ts and the power line PL. The organic light emitting diode D is connected to the driving thin film transistor Td. When the switching thin film transistor Ts is turned on by a gate signal applied to the gate line GL, a data signal applied to the data line DL is applied to a gate electrode of the driving thin film transistor Td and one electrode of the storage capacitor Cst through the switching thin film transistor Ts.

[0034] The driving thin film transistor Td is turned on by the data signal applied to the gate electrode, so that a current proportional to the data signal is supplied to the organic light emitting diode D from the power line PL through the driving thin film transistor Td. Then, the organic light emitting diode D emits light having a luminance proportional to the current flowing through the driving thin film transistor Td. In this case, the storage capacitor Cst is charged with a voltage proportional to the data signal, so that the voltage of the gate electrode in the driving thin film transistor Td is maintained constant during one frame. Accordingly, the organic light emitting display apparatus can display a desired image.

[0035] Figure 2 is a schematic cross-sectional view illustrating an organic light emitting display apparatus according to an aspect of the present disclosure. As shown in Figure 2 the organic light emitting display apparatus 100 includes a first substrate 102, a second substrate 104 facing the first substrate 102, a thin film transistor Tr above the first substrate 102, an organic light emitting diode D disposed between the first substrate 102 and the second substrate 104 and connected to the thin film transistor Tr and emitting white (W) light, and a color filter layer 180 disposed between the organic light emitting diode D and the second substrate 104.

[0036] As an example, the first substrate 102 defines a red pixel area RP, a green pixel area GP, and a blue pixel area BP, and the organic light emitting diode D is located in each of the pixel areas. In other words, the organic light emitting diode D each emitting white (W) light is correspondingly located in the red pixel area RP, the green pixel area GP, and the blue pixel area BP.

[0037] The first substrate 102 and the second substrate 104 can each include glass, a thin flexible material, and / or a polymer plastic, but are not limited thereto. For example, the flexible material can be selected from polyimide (PI), polyether sulfone (PES), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), and combinations thereof, but is not limited thereto. The first substrate 102, on which the thin film transistor Tr and the organic light emitting diode D are disposed, forms an array substrate.

[0038] A buffer layer 106 can be provided over the first substrate 102, and the thin film transistor Tr is provided over the buffer layer 106, corresponding to each of the red pixel region RP, the green pixel region GP, and the blue pixel region BP. The buffer layer 106 can be omitted.

[0039] A semiconductor layer 110 is provided over the buffer layer 106. In one aspect, the semiconductor layer 110 can include an oxide semiconductor material, but is not limited thereto. In this case, a light-blocking pattern can be provided under the semiconductor layer 110, which can prevent light from being incident toward the semiconductor layer 110, thereby preventing the semiconductor layer 110 from being deteriorated due to light. Alternatively, the semiconductor layer 110 can include polysilicon. In this case, opposite edges of the semiconductor layer 110 can be doped with impurities.

[0040] A gate insulating layer 120 including an insulating material is provided over the semiconductor layer 110. The gate insulating layer 120 can include an inorganic insulating material, such as silicon oxide (SiO x ) or silicon nitride (SiN x ), but is not limited thereto.

[0041] A gate electrode 130 made of a conductive material, such as metal, is provided over the gate insulating layer 120, corresponding to the center of the semiconductor layer 110. Although the gate insulating layer 120 is provided over the entire region of the first substrate 102 in Figure 2 , the gate insulating layer 120 can be patterned the same as the gate electrode 130.

[0042] An interlayer insulating layer 140 including an insulating material is provided over the gate electrode 130, covering over the entire surface of the substrate 102. The interlayer insulating layer 140 can include an inorganic insulating material, such as silicon oxide (SiO x ) or silicon nitride (SiN x ); or an organic insulating material, such as benzocyclobutene or photo-acryl.

[0043] The interlayer insulating layer 140 has a first semiconductor layer contact hole 142 and a second semiconductor layer contact hole 144 that expose both sides of the semiconductor layer 110. The first semiconductor layer contact hole 142 and the second semiconductor layer contact hole 144 are provided above opposite sides of the gate electrode 130, spaced apart from the gate electrode 130. In Figure 2 the first semiconductor layer contact hole 142 and the second semiconductor layer contact hole 144 are formed within the gate insulating layer 120. Alternatively, when the gate insulating layer 120 is patterned identically to the gate electrode 130, the first semiconductor layer contact hole 142 and the second semiconductor layer contact hole 144 are formed only within the interlayer insulating layer 140.

[0044] The source electrode 152 and the drain electrode 154, made of a conductive material such as metal, are provided on the interlayer insulating layer 140. The source electrode 152 and the drain electrode 154 are spaced apart from each other with respect to the gate electrode 130, and contact both sides of the semiconductor layer 110 through the first semiconductor layer contact hole 142 and the second semiconductor layer contact hole 144, respectively.

[0045] The semiconductor layer 110, the gate electrode 130, the source electrode 152, and the drain electrode 154 constitute a thin film transistor Tr that functions as a drive element. Figure 2 The thin film transistor Tr in may have a coplanar structure in which the gate electrode 130, the source electrode 152, and the drain electrode 154 are provided above the semiconductor layer 110. Alternatively, the thin film transistor Tr can have an inverted staggered structure in which the gate electrode is provided below the semiconductor layer, and the source electrode and the drain electrode are provided above the semiconductor layer. In this case, the semiconductor layer can include amorphous silicon.

[0046] Figure 2 Although not shown in the gate line and the data line that cross each other to define the pixel region, and a switching element connected to the gate line and the data line. The switching element is connected to the thin film transistor Tr that functions as a drive element. Further, a power supply line is spaced apart in parallel with the gate line or the data line, and the thin film transistor Tr can further include a storage capacitor configured to constantly hold a voltage of the gate electrode for one frame.

[0047] The passivation layer 160 is provided on the source electrode 152 and the drain electrode 154 over the entire substrate 102, covering the thin film transistor Tr. The passivation layer 160 has a flat top surface and a drain contact hole 162 that exposes the drain electrode 154 of the thin film transistor Tr. Although the drain contact hole 162 is provided on the second semiconductor layer contact hole 144, it can be spaced apart from the second semiconductor layer contact hole 144.

[0048] An organic light emitting diode (OLED) D includes a first electrode 210 disposed on the passivation layer 160 and connected to the drain electrode 154 of the thin film transistor Tr. The organic light emitting diode D further includes an emission layer 230 and a second electrode 220 each sequentially disposed on the first electrode 210.

[0049] The first electrode 210 is disposed in each pixel region. The first electrode 210 can be an anode and include a conductive material having a relatively high work function value. For example, the first electrode 210 can include a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), SnO, ZnO, indium cerium oxide (ICO), zinc oxide doped with aluminum (AZO), etc., but is not limited thereto.

[0050] In one aspect, when the organic light emitting display device 100 is a top emission type, a reflective electrode or a reflective layer can be disposed under the first electrode 210. For example, the reflective electrode or the reflective layer can include silver or an aluminum-palladium-copper (APC) alloy, but is not limited thereto.

[0051] Further, a bank layer 164 is disposed on the passivation layer 160 to cover edges of the first electrode 210. The bank layer 164 exposes a center of the first electrode 210. The bank layer 164 can be omitted.

[0052] The emission layer 230 is disposed on the first electrode 210. In one embodiment, the emission layer 230 can have a plurality of emission parts 300, 400, 400A, 500, 600, 600A, and 700 and at least one charge generation layer 370, 570, and 670 Figure 3 、 Figures 5 to 6 and Figure 8 ). The emission parts 300, 400, 400A, 500, 600, 600A, and 700 each include at least one emission material layer (EML), and can further include at least one of a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a hole blocking layer (HBL), an electron transport layer (ETL), and / or an electron injection layer (EIL).

[0053] The second electrode 220 is disposed above the substrate 102 on which the light-emitting layer 230 is disposed. The second electrode 220 can be disposed over the entire display area, and can include a conductive material having a relatively low work function value compared to the first electrode 210, and can be a cathode. For example, the second electrode 220 can include aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), an alloy thereof, or a combination thereof, such as an aluminum-magnesium alloy (Al-Mg), but is not limited thereto. As an example, since light emitted from the light-emitting layer 230 in the organic light-emitting display device 100 is incident on the color filter layer 180 through the second electrode 220, the second electrode 220 has a thin thickness so that light can be transmitted.

[0054] Further, an encapsulation film can be disposed above the OLED D to prevent external moisture from penetrating into the OLED D. The encapsulation film 170 can have a laminate structure of a first inorganic insulating film, an organic insulating film, and a second inorganic insulating film, but is not limited thereto. The encapsulation film can be omitted.

[0055] A polarizing plate can be attached to the second substrate 104 to reduce reflection of external light. For example, the polarizing plate can be a circular polarizing plate. Further, a cover window can be attached to the second substrate 104 or the polarizing plate. In this case, the first substrate 102 and the second substrate 104, and the cover window have a flexible property, so that a flexible display device can be configured.

[0056] The color filter layer 180 is disposed above the OLED D, and includes a red color filter 182, a green color filter 184, and a blue color filter 186 each disposed to respectively correspond to the red pixel area RP, the green pixel area GP, and the blue pixel area BP. Although not shown in Figure 2 The color filter layer 180 can be attached to the OLED D by an adhesive layer. Alternatively, the color filter layer 180 can be directly disposed on the OLED D.

[0057] In Figure 2 In

[0058] As described above, the white (W) color light emitted from the OLED D is transmitted through the red color filter 182, the green color filter 184, and the blue color filter 186 respectively disposed to respectively correspond to the red pixel region RP, the green pixel region GP, and the blue pixel region BP, so that red light, green light, and blue light are displayed in the red pixel region RP, the green pixel region GP, and the blue pixel region BP.

[0059] Now, we will describe the OLED in more detail. Figure 3 is a cross-sectional view illustrating an organic light emitting diode having two light emitting parts to form a series structure according to one aspect of the disclosure.

[0060] As Figure 3 illustrated, the organic light emitting diode (OLED) D1 includes a first electrode 210 and a second electrode 220 facing each other, and a light emitting layer 230 disposed between the first electrode 210 and the second electrode 220. The light emitting layer 230 includes a first light emitting part 300 disposed between the first electrode 210 and the second electrode 220, a second light emitting part 400 disposed between the first light emitting part 300 and the second electrode 220, and a charge generation layer (CGL) 370 disposed between the first light emitting part 300 and the second light emitting part 400.

[0061] The first light emitting part 300 includes a first light emitting material layer (EML1) 340. The first light emitting part 300 can further include at least one of a HIL 310 and a first HTL (HTL1) 320 sequentially disposed between the first electrode and the EML1 340, and a first ETL (ETL1) 360 disposed between the EML1 340 and the CGL 370. Alternatively, the first light emitting part 300 can further include at least one of a first EBL (EBL1) 330 disposed between the HTL1 320 and the EML1 340, and a first HBL (HBL1) 350 disposed between the EML1 340 and the ETL1 360.

[0062] The second light emitting part 400 includes a second light emitting material layer (EML2) 440. The second light emitting part 400 can further include a second HTL (HTL2) 420 disposed between the CGL 370 and the EML2 440, and at least one of a second ETL (ETL2) 460 and an EIL 470 sequentially disposed between the EML2 440 and the second electrode 220. Alternatively, the second light emitting part 400 can further include at least one of a second EBL (EBL2) 430 disposed between the HTL2 420 and the EML2 440, and a second HBL (HBL2) 450 disposed between the EML2 440 and the ETL2 460.

[0063] As an example, EML1 340 can be a blue light-emitting material layer, and EML2 440 can be a light-emitting material layer that emits light having a longer wavelength peak than light emitted from the blue light-emitting material layer, such that OLED D1 can emit white (W) light. EML1 340 and EML2 440 can each include a host and a dopant, respectively. The content of the dopant in the EML can be about 1 wt% to about 50 wt%, for example, about 1 wt% to about 30 wt%, but is not limited thereto.

[0064] HIL 310 is disposed between the first electrode 210 and HTL1 320 and improves the interface properties between the inorganic first electrode 210 and the organic HTL1 320. In one aspect, HIL 310 can include 4,4’4”-tris(3-methylphenylamino)triphenylamine (MTDATA), 4,4’,4”-tris(N,N-diphenyl-amino)triphenylamine (NATA), 4,4’,4”-tris(N-(naphthalene-1-yl)-N-phenyl-amino)triphenylamine (1T-NATA), 4,4’,4”-tris(N-(naphthalene-2-yl)-N-phenyl-amino)triphenylamine (2T-NATA), copper phthalocyanine (CuPc), tris(4-carbazoyl-9-yl-phenyl)amine (TCTA), N,N’-diphenyl-N,N’-bis(1-naphthyl)-1,1’-biphenyl-4,4”-diamine (NPB; NPD), 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (dipyrazino[2,3-f:2’3’-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile; HAT-CN), 1,3,5-tris[4-(diphenylamino)phenyl]benzene (TDAPB), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT / PSS), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine, and combinations thereof, but is not limited thereto. HIL 310 can be omitted depending on the properties of OLED D1.

[0065] HTL1 320 is configured to be adjacent to EML1 340, and HTL2 420 is configured to be adjacent to EML2 440. In one embodiment, HTL1 320 and HTL2 320 are... Each of 420 may contain N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), NPB (NPD), N,N'-bis[4-[bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (DNTPD), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] (poly-TPD), poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), 1,1-bis[4-(N,N'-di(p-tolyl)amino] 3,5-Bis(9H-carbazol-9-yl)-N,N-diphenylaniline (DCDPA), N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine, N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)) (Phenyl)biphenyl-4-amine, N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine, N4,N4,N4',N4'-tetra([1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, and combinations thereof, but not limited thereto.

[0066] ETL1 360 and ETL2 460 each comprise materials with high electron mobility to stably provide electrons to each of ETL1 340 and ETL2 440 via rapid electron transport. In one aspect, ETL1 360 and ETL2 460 may each comprise either of the following: based on Compounds based on diazoles, compounds based on triazoles, compounds based on phenanthroline, compounds based on benzo[a] Compounds based on azoles, benzothiazoles, benzimidazoles, triazines, etc., but not limited to these.

[0067] As examples, ETL1 360 and ETL2 460 can each independently contain tris-(8-hydroxyquinoline aluminum (Alq3), 2-biphenyl-4-yl-5-(4-tert-butylphenyl)-1,3,4- Diazole (PBD), Spiro-PBD, Lithium Quinoline (Liq), 1,3,5-Tris(N-phenylbenzimidazol-2-yl)benzene (TPBi), Bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), 4,7-Diphenyl-1,10-phenanthroline (Bphen), 2,9-Bis(naphthyl-2-yl)4,7-diphenyl-1,10-phenanthroline (NBphen), 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthyl-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTA) Z), 1,3,5-tris(p-pyridin-3-yl-phenyl)benzene (TpPyPB), 1,3,5-tris(m-pyridin-3-yl-phenyl)benzene (TmPyPB), 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)1,3,5-triazine (TmPPPyTz), poly[9,9-bis(3'-(N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene]-alternating-2,7-(9,9-dioctylfluorene)] (PFNBr), tris(phenylquinoxaline) (TPQ), TSPO1, 2-[4-(9,10-di-2-naphth-2-yl-2-anthracene-2-yl)phenyl]-1-phenyl-1H-benzimidazole (ZADN), and combinations thereof, but not limited thereto.

[0068] EIL470 is disposed between ETL2 460 and the second electrode 220 and can improve the physical properties of the second electrode 220, thus enhancing the luminous lifetime of OLED D1. In one aspect, EIL470 may comprise alkali metal halides or alkaline earth metal halides, such as LiF, CsF, NaF, BaF2, etc.; and / or organometallic compounds, such as Liq, lithium benzoate, sodium stearate, etc., but is not limited thereto. EIL470 may be omitted depending on the OLED D1 structure.

[0069] When holes are transferred to the second electrode 220 and / or electrons are transferred to the first electrode 210, the OLED D1 may have a short lifetime and reduced luminous efficiency. The first light-emitting portion 300 and the second light-emitting portion 400 may each have at least one exciton blocking layer disposed adjacent to each of EML1 340 and EML2 440.

[0070] EBL1 330 and EBL2 430 are each disposed between HTL1 320 and EML1 340, or HTL2 420 and EML2 440, to control and prevent electron transport between these layers. As examples, EBL1 330 and EBL2 430 can each independently include TCTA, tris[4-(diethylamino)phenyl]amine, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H- fluorene-2-amine, TAPC, MTDATA, 1,3-bis(carbazol-9-yl)benzene (mCP), 3,3-di(9H-carbazol-9-yl)-biphenyl (mCBP), CuPc, N,N'-bis[4-(bis(3-methylphenyl)amino)phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (DNTPD), TDAPB, DCDPA, 2,8-bis(9-phenyl-9H-carbazol-3-yl)dibenzo[b,d]thiophene, and combinations thereof, but are not limited thereto.

[0071] Further, HBL1 350 and HBL2 450 are each disposed between EML1 340 and ETL1 360, or EML2 440 and ETL2 460, to control and prevent hole transport between these layers. In one aspect, HBL1 350 and HBL2 450 can each independently include any of the following: oxadiazole-based compounds, triazole-based compounds, phenanthroline-based compounds, benzoxazole-based compounds, benzothiazole-based compounds, benzimidazole-based compounds, triazine-based compounds, and the like, but are not limited thereto. Further, HBL1 350 and HBL2 450 are each disposed between EML1 340 and ETL1 360, or EML2 440 and ETL2 460, to control and prevent hole transport between these layers. In one aspect, HBL1 350 and HBL2 450 can each independently include any of the following: oxadiazole-based compounds, triazole-based compounds, phenanthroline-based compounds, benzoxazole-based compounds, benzothiazole-based compounds, benzimidazole-based compounds, triazine-based compounds, and the like, but are not limited thereto.

[0072] As examples, HBL1 350 and HBL2 450 can each include a compound having a relatively low highest occupied molecular orbital (HOMO) energy level compared to the HOMO energy level of the light-emitting material in each of EML1 340 and EML2 440. For example, HBL1 350 and HBL2 450 can each include Alq3, BAlq, Liq, PBD, spiro-PBD, BCP, TSPO1, bis-4,5-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine (B3PYMPM), DPEPO, 9-(6-(9H-carbazol-9-yl)pyridin-3-yl)-9H-3,9'-bicarbazole, and combinations thereof, but are not limited thereto.

[0073] ​As described above, the EML1 340 can be a blue light emitting material layer. For example, the EML1 340 can include one of a blue light emitting material layer, a deep blue light emitting material layer, and a sky blue light emitting material layer. In this case, the EML1 340 can emit light having a photoluminescence peak of about 440 nm to about 480 nm.

[0074] The EML1 can include a blue host and a blue dopant. For example, the blue host can include mCP, 9-(3-(9H-carbazol-9-yl)phenyl)-9H-carbazole-3-carbonitrile (mCP-CN), mCBP, CBP-CN, 9-(3-(9H-carbazol-9-yl)phenyl)-3-(diphenylphosphoryl)-9H-carbazole (mCPPO1), 3,5-di(9H-carbazol-9-yl)biphenyl (Ph-mCP), TSPO1, 9-(3’-(9H-carbazol-9-yl)-[1,1’-biphenyl]-3-yl)-9H-pyrido[2,3-b]indole (CzBPCb), bis(2-methylphenyl)diphenylsilane (UGH-1), 1,4-bis(triphenylsilyl)benzene (UGH-2), 1,3-bis(triphenylsilyl)benzene (UGH-3), 9,9-spirobilogermane-2-yl-diphenylphosphine oxide (SPPO1), 9,9’-(5-(triphenylsilyl)-1,3-phenylene)bis(9H-carbazole) (SimCP), 9,10-bis(naphthalen-2-yl)anthracene (2-ADN), and combinations thereof, but are not limited thereto.

[0075] The blue dopant can include at least one of a blue phosphorescent material, a blue fluorescent material, and a blue delayed fluorescent material. For example, the blue (B) dopant can include perylene, 4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi), 4-(di-p-tolylamino)-4'-[di-p-tolylamino)styryl]styrene (DPAB), 4,4'-bis[4-(diphenylamino)styryl]biphenyl (BDAVBi), 2,7-bis(4-diphenylamino)styryl)-9,9-spirobifluorene (Spiro-DPVBi), [1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl]vinyl]benzene (DSB), 1-4-di-[4-(N,N-diphenyl)amino]styrylbenzene (DSA), 2,5,8,11-tetra-tert-butylperylene (TBPe), bis(2-hydroxyphenyl)pyridinato)beryllium (Bepp2), 9-(9-phenylcarbazol-3-yl)-10-(naphthalen-1-yl)anthracene (PCAN), 1,6-bis(diphenylamino)pyrene, mer-tris(1-phenyl-3-methylimidazolin-2-ylidene-C,C(2)'iridium(III) (mer-Ir(pmi)3), fac-tris(1,3-diphenyl-benzimidazolin-2-ylidene-C,C(2)'iridium(III) (fac-Ir(dpbic)3), bis(3,4,5-trifluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III) (Ir(tfpd)2pic), tris(2-(4,6-difluorophenyl)pyridine)iridium(III) (Ir(Fppy)3), bis[2-(4,6-difluorophenyl)pyridine-C2,N](picolinato)iridium(III) (FIrpic), and combinations thereof, but are not limited thereto.

[0076] EML2 440 emits light having a longer photo luminescence peak than light emitted from EML1 340, and can include a green (G) light emitting material layer. For example, EML2 440 includes a red (R) light emitting material layer 442 disposed between EBL2 430 and HBL2 450, and a green (G) light emitting material layer 444, such that EML2 440 can emit red-green light. When EML2 440 emits red-green light, EML2 440 can emit light having a wavelength of about 510 nm to about 650 nm.

[0077] The red (R) light emitting material layer 442 can include a red (R) host and a red (R) dopant. For example, the red (R) host can include 9,9'-biphenyl-9H,9'H-3,3'-bicarbazole (BCzPh), CBP, 1,3,5-tris(carbazol-9-yl)benzene (TCP), TCTA, 4,4'-bis(carbazol-9-yl)-2,2'-dimethylbiphenyl (CDBP), 2,7-bis(carbazol-9-yl)-9,9-dimethylfluorene (DMFL-CBP), 2,2',7,7'-tetrakis(carbazol-9-yl)-9,9-spirofluorene (spiro-CBP), DPEPO, 4'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile (PCzB-2CN), 3'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile (mCzB-2CN), 3,6-bis(carbazol-9-yl)-9-(2-ethyl-hexyl)-9H-carbazole (TCz1), Bepp2, bis(10-hydroxybenzo[h]quinolino)beryllium (Bebq2), 1,3,5-tris(1-pyrenyl)benzene (TPB3), and combinations thereof, but are not limited thereto.

[0078] The red (R) dopant can include at least one of a red phosphorescent material, a red fluorescent material, and a red delayed fluorescent material. For example, the red (R) dopant can include tris(1-phenylisoquinoline)iridium(III) (Ir(piq)3), [bis(2-(4,6-dimethyl)phenylquinoline)](2,2,6,6-tetramethylheptane-3,5-dione acid)iridium(III), bis[2-(4-n-hexylphenyl)quinoline](acetylacetone)iridium(III) (Hex-Ir(phq)2(acac)), tris[2-(4-n-hexylphenyl)quinoline]iridium(III) (Hex-Ir(phq)3), tris[2-phenyl-4-methylquinoline]iridium(III) (Ir(Mphq)3), bis(2-phenylquinoline)(2,2,6,6-tetramethylheptane-3,5-dione acid)iridium(III) (Ir(dpm)PQ2), bis(phenylisoquinoline)(2,2,6,6-tetramethylheptane-3,5-dione acid)iridium(III) (Ir(dpm)(piq)2), bis[(4-n-hexylphenyl)isoquinoline](acetylacetone)iridium(III) (Hex-Ir(piq)2(acac)), tris[2-(4-n-hexylphenyl)quinoline]iridium(III) (Hex-Ir(piq)3), tris(2-(3-methylphenyl)-7-methyl-quinolyl)iridium (Ir(dmpq)3), bis[2-(2-methylphenyl)-7-methyl-quinoline](acetylacetone)iridium(III) (Ir(dmpq)2(acac)), bis[2-(3,5-dimethylphenyl)-4-methyl-quinoline(acetylacetone)iridium(III)) (Ir(mphmq)2(acac)), tris(dibenzoylmethane)mono(1,10-phenanthroline)europium(III) (Eu(dbm)3(phen)), and combinations thereof, but are not limited thereto.

[0079] The green (G) light emitting material layer 444 can include a green (G) host and a green (G) dopant. For example, the green (G) host can include BCzPh, CBP, TCP, TCTA, CDBP, DMFL-CBP, Spiro-CBP, DPEPO, PCzB-2CN, mCzB-2CN, TCz1, and combinations thereof, but is not limited thereto. The green (G) dopant can include at least one of a green phosphorescent material, a green fluorescent material, and a green delayed fluorescent material. For example, the green (G) dopant can include [bis(2-phenylpyridine)](pyridyl-2-benzofuran[2,3-b]pyridine)iridium, tris(2-phenylpyridine)iridium(III) (Ir(ppy)3), fac-tris(2-phenylpyridine)iridium(III) (fac-Ir(ppy)3), bis(2-phenylpyridine)(acetylacetonate)iridium(III) (Ir(ppy)2(acac)), tris[2-(p-tolyl)pyridine]iridium(III) (Ir(mppy)3), bis(2-(naphthalene-2-yl)pyridine)(acetylacetonate)iridium(III) (Ir(npy)2acac), tris(2-phenyl-3-methyl-pyridine)iridium (Ir(3mppy)3), fac-tris(2-(3-p-tolyl)phenyl)pyridine iridium(III) (TEG), Alq3, and combinations thereof, but is not limited thereto.

[0080] The CGL 370 is disposed between the first light emitting part 300 and the second light emitting part 400. The CGL 370 generates charges and controls charge injection balance between the first light emitting part 300 and the second light emitting part 400.

[0081] The CGL 370 includes an N-type CGL (N-CGL) 380 disposed adjacent to the first light emitting part 300 and a P-type CGL (P-CGL) 390 disposed adjacent to the second light emitting part 400. The N-CGL 380 provides electrons into the first light emitting part 300, and the P-CGL 390 provides holes into the second light emitting part 400. The N-CGL 380 can include an N-type host 382 and an N-type dopant 384, and the P-CGL 390 can include a P-type host 392 and a P-type dopant 394. The N-type host 382 and the P-type host 392 can each form a medium or matrix for each of the N-CGL 380 and the P-CGL 390, respectively.

[0082] The P-type host 392 in the P-CGL 390 injects holes generated in the P-CGL 390 through its own HOMO energy level into the EML2 440. For example, the P-type dopant 394 can generally have a strong electron-withdrawing group within its molecule. Thus, the P-type dopant 394 receives electrons at its own lowest unoccupied molecular orbital (LUMO) energy level from the HOMO energy level of the holes from the P-type host 392 or a hole transport material in the HTL2 disposed adjacent to the P-CGL 390, so that the P-type dopant 394 can form a path for transporting holes from the P-CGL 390 to the EML2 440.

[0083] As shown in FIG. 6, there is a large difference in charge mobility depending on the color tone or current density, particularly in the light-emitting material layer including the green light-emitting material layer 444. The difference between the hole mobility and the electron mobility is relatively large in the low color tone period (low current density period), while the difference between the hole mobility and the electron mobility is relatively small in the high color tone period (high current density period). Particularly, when shifting to the high color tone period, the electron mobility relatively significantly increases compared to the hole mobility. Figure 4

[0084] Since, in the EML2 440 including the green light-emitting material layer 444, the electron mobility increases close to the hole mobility in the high color tone period, in the EML2 440, a light-emitting region is uniformly formed over the entire red light-emitting material layer 442 and the green light-emitting material layer 444. However, the amount of green light emitted from the EML2 440 is relatively reduced in the high color tone portion. In other words, since the green component in the white light emitted from the OLED D1 is relatively small in the high color tone portion, the chromaticity value of the X axis is relatively larger than that of the Y axis in the CIE chromaticity distribution of the white light.

[0085] On the other hand, in the low color tone period, the holes excessively injected into the green light-emitting material layer 444 are quenched without forming excitons, which results in an efficiency roll-off rapidly reducing the light-emitting efficiency thereof in high luminance. Further, as described above, in the low color tone portion, the holes are very rapidly injected into the EML2 440 compared to the electrons. In the low color tone period, the light-emitting region of the EML2 440 is mainly formed on the green light-emitting material layer 444 disposed relatively adjacent to the second electrode 220, and the EML2 440 emits light close to green. In other words, in the high color tone period, the white light emitted from the OLED D1 has a relatively small amount of green component, i.e., the chromaticity value of the X axis of the white light is relatively larger than that of the Y axis in the CIE chromaticity distribution. In contrast, in the low color tone period, the white light emitted from the OLED D1 has a relatively large amount of green component, i.e., the chromaticity value of the Y axis of the white light is relatively larger than that of the X axis in the CIE chromaticity distribution by color conversion.​

[0086] In other words, in the EML2 440 including the green light-emitting material layer 444, the amount of green component of the white light emitted from the OLED D1 is relatively large in the low color locus portion, and the amount of green component of the white light is relatively small in the high color locus portion.

[0087] Therefore, when the chromaticity of the X-axis of the white light is compensated to achieve white balance by controlling the relatively large green light emitted in the low color locus portion where color conversion occurs, the chromaticity of the X-axis of the white light in the high color locus portion is over-compensated. In contrast, when the chromaticity of the Y-axis of the white light is compensated to achieve white balance by increasing the relatively small green color in the high color locus portion, the chromaticity of the Y-axis of the white light in the low color locus where color conversion occurs is over-compensated. When optical compensation is made, since color compensation cannot be properly made according to the color-converted color locus portion, panel defects can occur.

[0088] Considering hole generation as well as hole mobility and hole injection into the EML2 440, in the general P-CGL 390 constituting an OLED having a tandem structure, the P-type host 392 is designed such that its HOMO energy level HOMO H The LUMO energy level LUMO D of the P-type dopant 394 is lower than the HOMO energy level HOMO H of the P-type host 392. D In other words, the P-type host 392 and the P-type dopant 394 are selected such that, within the general P-CGL 390, the energy band gap between the HOMO energy level HOMO H of the P-type host 392 and the LUMO energy level LUMO D of the P-type dopant 394 is at least 0.01 eV to 0.1 eV.

[0089] When the energy band gap between the HOMO energy level HOMO H of the P-type host 392 and the LUMO energy level LUMO D of the P-type dopant 394 is minimized, since the hole mobility is significantly higher than the electron mobility in the low color locus period, the EML 440 emits a relatively large amount of light close to green light. In addition, in the low color locus period, the holes excessively injected into the green light-emitting material layer 444 are quenched without forming excitons, which results in efficiency roll-off of green light in high brightness. Such efficiency roll-off results in that the EML 440 emits a relatively large amount of light close to red light in the high color locus period. Therefore, the white light emitted from the OLED D1 in the low color locus period contains a relatively large amount of green light, and the light emitted from the OLED D1 in the high color locus period contains a relatively large amount of red light.

[0090] Therefore, in an organic light emitting diode having a general P-type CGL, it is very difficult to effectively perform color compensation according to a color tone or a current density. For example, in the case of compensating for a deficiency in the chromaticity of the Y-axis in the CIE chromaticity distribution of white light in a high color tone period, white light in a low color tone period in which green light has been excessively emitted through color conversion is further shifted toward green light. In the low color tone period, since color compensation is performed in a manner of further enhancing green light that has been excessively emitted, white balance is distorted, thereby causing panel failure.

[0091] In contrast, the P-type host 392 in the P-CGL 390 is designed to have a deeper HOMO energy level HOMO H , the P-type dopant 394 in the P-CGL 390 is designed to have a shallower LUMO energy level LUMO D than a general P-type dopant. H For example, the energy band gap ΔE1 between the HOMO energy level HOMO D of the P-type host 392 and the LUMO energy level LUMO D of the P-type dopant 394 satisfies the following relation of Equation A:

[0092] Equation A: 0.35 eV ≤ LUMO D - HOMO H ≤ 0.5 eV.

[0093] When the energy band gap ΔE1 between the HOMO energy level HOMO H of the P-type host 392 and the LUMO energy level LUMO D of the P-type dopant 394 satisfies the relation of Equation A, hole generation in the P-CGL 390 and hole mobility and hole conductivity to the EML2 440 are reduced. Since the amount of holes injected into the green light emitting material layer 444 in the EML 440 is reduced, holes and electrons can be balancedly injected into the green light emitting material layer 444. Since holes and electrons are balancedly injected into the green light emitting material layer 444, the amount of charges that do not form excitons is reduced, and thus, roll-off in the green light emitting material layer 444 can be reduced or minimized.

[0094] Therefore, in the case where the P-type host 392 and the P-type dopant 394 satisfying the relation of Equation A are introduced into the P-CGL 390, the amount of green light in light emitted from the EML2 440 can be constantly maintained regardless of a color tone or a current density, and thus, white light emitted from the OLED D1 can maintain a constant value, for example, the chromaticity of the Y-axis is greater than the chromaticity of the X-axis in the CIE chromaticity distribution regardless of a color tone or a current density.

[0095] If X-axis chromaticity compensation is performed only for white light having constant chromaticity without considering hue, effective white balance can be achieved in both the low-hue portion and the high-hue portion. In other words, since white light having constant chromaticity is emitted from the OLED D1 without chromaticity conversion by hue or current density, effective optical compensation can be performed.

[0096] In contrast, when the energy band gap ΔE1 between the HOMO level HOMO H of the P-type host 392 and the LUMO level LUMO D of the P-type dopant 394 is less than the relationship of Equation A, charges can not be injected into the EML2 440 in balance, and color conversion can occur, such that optical conversion can be insufficient. In addition, when the energy band gap ΔE1 between the HOMO level HOMO H of the P-type host 392 and the LUMO level LUMO D of the P-type dopant 394 exceeds the range in the relationship of Equation A, holes can not be sufficiently injected into the EML2 440, which causes the OLED D1 to increase its driving voltage and reduce its luminous efficiency.

[0097] The P-type host 392 satisfying the relationship of Equation A can include an organic compound having a HOMO level of about -5.0 eV to about -6.0 eV, for example, about -5.2 eV to -5.5 eV. As an example, the P-type host 392 can include an anthracene-based compound having the following structure of Formula 1 and / or a spirofluorene-based compound having the following structure of Formula 3, but is not limited thereto:

[0098] [Formula 1]

[0099]

[0100] wherein R1 to R4 are each independently C6-C 30 aryl or C3-C 30 heteroaryl, each of the aryl and heteroaryl can be unsubstituted or substituted with at least one C1-C 10 alkyl;

[0101] [Formula 3]

[0102]

[0103] wherein R5 and R6 are each independently protium, deuterium, carbazolyl, or at least one of R5 and R6 is carbazolyl or wherein R7 and R8 are each independently C6-C 30 aryl or C3-C 30 heteroaryl, and wherein each of the carbazolyl, aryl, and heteroaryl can be independently unsubstituted or substituted with at least one C1-C10 Alkyl substitution, and at least one of R7 and R8 can be a polycyclic aryl or a polycyclic heteroaryl.

[0104] For example, R1 to R4 in Equation 1 can each independently include components that are either unsubstituted or modified by C1-C2. 10 Alkyl-substituted aryl groups, such as phenyl, naphthyl, and phenanthrene, but not limited thereto. As examples, anthracene-based compounds having the structure of Formula 1 can be selected from, but are not limited to, the following organic compounds of Formula 2:

[0105] [Equation 2]

[0106]

[0107] Furthermore, one of R7 and R8 in Formula 3 can be phenyl, biphenyl, naphthyl, or anthracene, and the other of R7 and R8 in Formula 3 can be unsubstituted or via at least one C1-C junction. 10 Alkyl-substituted fluorene groups, but not limited to these. As examples, spirofluorene-based compounds having the structure of Formula 3 can be selected from, but are not limited to, the following organic compounds of Formula 4:

[0108] [Formula 4]

[0109]

[0110] The p-type dopant 394 satisfying the relationship of Formula A may include organic compounds with LUMO levels of about -4.0 eV to about -5.0 eV, for example, about -4.5 eV to about -5.0 eV. In one aspect, the p-type dopant 394 may include, but is not limited to, an organic compound having an axial alkene core, a quinone core, or an inductor core. As an example, the p-type dopant 394 having an inductor core may include an organic compound having the following structure of Formula 5:

[0111] [Formula 5]

[0112]

[0113] Where R 11 It is a group having an exocyclic double bond with the following structure of Formula 6; R 12 and R 13 One of them and R 11 Same, and R 12 and R 13 The other one in R 14 Same; R 14 To R 16 Each of the C1-C atoms is independently a halogen atom, substituted by at least one halogen atom. 10 Alkyl groups, C1-C atoms substituted with at least one halogen atom 10halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 30 halogen atom, C1-C4alkyl or C1-C4alkoxy; 30 halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 17 halogen atom, C1-C4alkyl or C1-C4alkoxy; 18 each independently hydrogen, deuterium, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy.

[0114] [Formula 6]

[0115]

[0116] wherein R 21 and R 22 each independently a halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 30 halogen atom, C1-C4alkyl or C1-C4alkoxy; 30 halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy; 10 halogen atom, C1-C4alkyl or C1-C4alkoxy.

[0117] In one aspect, the organic compound having an indacen core of Formula 5 can be selected from the following organic compounds of Formula 7, but is not limited thereto:

[0118] [Formula 7]

[0119]

[0120] In one aspect, the content of the P-type dopant 394 in the P-CGL 390 can be about 3 wt% to about 30 wt%, for example, about 5 wt% to about 20 wt%. When the content of the P-type dopant 394 in the P-CGL 390 is less than about 3 wt%, hole generation in the P-CGL 390 and hole injection and hole transport from the P-CGL 390 into the EML2 440 can be insufficient. In contrast, when the content of the P-type dopant 394 in the P-CGL 390 is greater than about 30 wt%, the P-CGL 390 generates too many holes, which results in the EML2 440 reducing its light-emitting efficiency (roll-off) because too many holes are injected into the EML2 440 without recombining with electrons. For example, the content of the P-type dopant 394 in the P-CGL 390 can be about 5 times to about 60 times, for example, about 5 times to about 20 times, the content of the N-type dopant 384 in the N-CGL 380.

[0121] The N-CGL 380 can be an organic layer including an N-type host 382 and an N-type dopant 384. For example, the N-type host 382 can include an organic metal compound having a hydroxyquinoline ligand such as Alq3, a triazine-based compound, a benzoxazole-based compound, a xanthene-based compound, Bphen, and MTDATA, but is not limited thereto.

[0122] In an aspect, the N-type dopant 384 can include alkali metals, such as Li, Na, K, and Cs; and / or alkaline earth metals, such as Mg, Sr, Ba, and Ra. Alternatively, the N-type dopant 384 can include a compound including an anion of 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hpp) (e.g., Cr2hpp4, Fe2hpp4, Mnr2hpp4, Co2hpp4, Mo2hpp4, W2hpp4, Ni2hpp4, Cu2hpp4, Zn2hpp4, W(hpp)4); and / or an imidazole-based compound, such as 4,4',5,5'-tetrahexyl-1,1',2,2',3,3'-hexamethyl-2,2',3,3'-tetrahydro-1H,1'H-2,2'-biimidazole, 2,2'-diisopropyl-1,1',3,3'-tetramethyl-2,2',3,3',4,4',5,5',6,6',7,7'-dodecyl-1H,1'H-2,2'-bi-benzo[d]imidazole, 2,2'-diisopropyl-4,4',5,5'-tetra(4-methoxyphenyl)-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-1H,1'H-2,2'-biimidazole, 2,2'-diisopropyl-4,5-bis(2-methoxyphenyl)-4',5'-bis(4-methoxyphenyl)-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-1H,1'H-2,2'-biimidazole, 2,2'-diisopropyl-4,5-bis(2-methoxyphenyl)-4',5'-bis(3-methoxyphenyl)-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-1H,1'H-2,2'-biimidazole, but not limited thereto.

[0123] In an aspect, the content of the N-type dopant 384 in the N-CGL 380 can be about 0.1 wt% to about 5 wt%, for example, about 0.5 wt% to about 3 wt%. When the content of the N-type dopant 384 in the N-CGL 380 is less than about 0.1 wt%, electron generation in the N-CGL 380 and electron injection and electron transport from the N-CGL 380 into the first light-emitting part 300 can be insufficient. In contrast, when the content of the N-type dopant 384 in the N-CGL 380 is greater than about 5 wt%, excessive electrons are injected into the first light-emitting part 300, so that current leakage can occur or the driving voltage of the OLED D1 can increase.

[0124] In the above, although the EML2 440 emits green light and red light, the EML2 440 can further include other light-emitting material layers. Figure 6 is a cross-sectional view illustrating an organic light-emitting diode having two light-emitting parts according to another aspect of the disclosure.

[0125] like Figure 6 As shown, the organic light-emitting diode (OLED) D2 according to a second aspect of this disclosure includes a first electrode 210 and a second electrode 220 facing each other, and a light-emitting layer 230A disposed between the first electrode 210 and the second electrode 220. The light-emitting layer 230A includes a first light-emitting portion 300 disposed between the first electrode 210 and the second electrode 220, a second light-emitting portion 400A disposed between the first light-emitting portion 300 and the second electrode 220, and a CGL 370 disposed between the first light-emitting portion 300 and the second light-emitting portion 400A.

[0126] The first light-emitting part 300 includes EML1 340. The first light-emitting part 300 may further include at least one of HIL 310 and HTL1 320 sequentially disposed between the first electrode and EML1 340, and ETL1 360 disposed between EML1 340 and CGL 370. Alternatively, the first light-emitting part 300 may further include EBL1 330 disposed between HTL1 320 and EML1 340 and / or HBL1 350 disposed between EML1 340 and ETL1 360.

[0127] The second light-emitting portion 400A includes EML2 440A. The second light-emitting portion 400A may further include HTL2 420 disposed between CGL 370 and EML2 440A, and at least one of ETL2 460 and EIL 470 sequentially disposed between EML2 440A and the second electrode 220. Alternatively, the second light-emitting portion 400A may further include EBL2 430 disposed between HTL2 420 and EML2 440A and / or HBL2 450 disposed between EML2 440A and ETL2 460. The configuration of the light-emitting layer 230A, excluding EML2 440A, can be substantially the same as the configuration in the light-emitting layer 230 as described above.

[0128] In this respect, EML1 340 can emit blue light and may contain a blue (B) body and a blue (B) dopant. EML2 440A may include a red (R) emitting material layer 442, a yellow-green (YG) or yellow (Y) emitting material layer 446, and a green emitting material layer 444, each sequentially disposed between EBL2 430 and HBL2 450. The red (R) emitting material layer 442 contains a red (R) body and a red (R) dopant, and the green (G) emitting material layer 444 contains a green body and a green dopant. The blue (B) / red (R) / green (G) body and the blue (B) / red (R) / green (G) dopant may each be the same as described above.

[0129] The yellow-green (YG) or yellow (Y) light-emitting material layer 446 can include a yellow-green (YG) or yellow (Y) host and a yellow-green (YG) or yellow (Y) dopant. The yellow-green (YG) or yellow (Y) host can include BCzPh, CBP, TCP, TCTA, CDBP, DMFL-CBP, Spiro-CBP, DPEPO, PCzB-2CN, mCzB-2CN, TCz1, Bebq2, TPB3, BAlq, and combinations thereof, but is not limited thereto, and the yellow-green (YG) or yellow (Y) dopant can include at least one of a yellow-green (YG) or yellow (Y) phosphorescent material, a yellow-green (YG) or yellow (Y) fluorescent material, and a yellow-green (YG) or yellow (Y) delayed fluorescent material. For example, the yellow-green (YG) or yellow (Y) dopant can include 5,6,11,12-tetraphenylnaphthalene (Rubrene), 2,8-di-tert-butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenylbenzo[2,1,2]thiophorine (TBRb), bis(2-phenylbenzothiazole)(acetylacetonate)iridium(III) (Ir(BT)2(acac)), bis(2-(9,9-diethoxy-fluoren-2-yl)-1-phenyl-1H-benzo[d]imidazole)(acetylacetonate)iridium(III) (Ir(fbi)2(acac)), bis(2-phenylpyridine)(3-(pyridin-2-yl)-2H-chromen-2-one)iridium(III) (fac-Ir(ppy)2Pc), bis(2-(2,4-difluorophenyl)quinoline)(picolinic acid)iridium(III) (FPQIrpic), and combinations thereof, but is not limited thereto.

[0130] In this aspect, the HOMO energy level HOMO H of the P-type host 392 in the P-CGL 390 can satisfy a relationship of Formula A (see D of the P-type dopant 394. Figure 5 For example, the P-type host 392 can include anthracene-based compounds having Formulas 1 and 2 and / or spirofluorene-based compounds having Formulas 3 and 4, but is not limited thereto. Also, the P-type dopant 394 can include organic compounds having at least one exocyclic double bond at an indacene core having structures of Formulas 5 to 6, but is not limited thereto.

[0131] The P-CGL controls the HOMO energy level HOMO H of the P-type host 392 to be higher than the LUMO energy level LUMO Dthe band gap DE1 between the HOMO of the EML2 440A and the LUMO of the ETL2 460A is such that the content of green light emitted from the EML2 440A can be maintained regardless of the hue and the current density. Thus, the white light emitted from the OLED D1 has a constant value, for example, in the CIE chromaticity diagram, the chromaticity of the Y axis is greater than that of the X axis regardless of the hue. In other words, since white light having a constant chromaticity is emitted from the OLED D1 without the need for chromaticity conversion by the hue or the current density, effective optical compensation can be performed.

[0132] In the above first and second aspects, the OLED has two light emitting parts to form a series structure. Differently, the organic light emitting diode can have three or more light emitting parts to form a series structure. Figure 7 is a cross-sectional view illustrating an organic light emitting diode having three light emitting parts according to still another aspect of the disclosure.

[0133] As shown in Figure 7 , the organic light emitting diode (OLED) D3 according to this aspect includes a first electrode 210 and a second electrode 220 facing each other, and a light emitting layer 230B disposed between the first electrode 210 and the second electrode 220. The light emitting layer 230B includes a first light emitting part 500 disposed between the first electrode 210 and the second electrode 220, a second light emitting part 600 disposed between the first light emitting part 500 and the second electrode 220, a third light emitting part 700 disposed between the second light emitting part 600 and the second electrode, a first charge generation layer (CGL1) 570 disposed between the first light emitting part 500 and the second light emitting part 600, and a second charge generation layer (CGL2) 670 disposed between the second light emitting part 600 and the third light emitting part 700.

[0134] The first light emitting part 500 includes an EML1 540. The first light emitting part 500 can further include at least one of a HIL 510 and a HTL1 520 sequentially disposed between the first electrode and the EML1 540, and an ETL1 560 disposed between the EML1 540 and the CGL1 570. Alternatively, the first light emitting part 500 can further include at least one of an EBL1 530 disposed between the HTL1 520 and the EML1 540, and a HBL1 550 disposed between the EML1 540 and the ETL1 560.

[0135] The second light emitting part 600 includes an EML2 640. The second light emitting part 600 can further include at least one of an HTL2 620 disposed between the CGL1 570 and the EML2 640 and an ETL2 660 disposed between the EML2 640 and the CGL2 670. Alternatively, the second light emitting part 600 can further include at least one of an EBL2 630 disposed between the HTL2 620 and the EML2 640 and an HBL2 650 disposed between the EML2 640 and the ETL2 660.

[0136] The third light emitting part 700 includes a third light emitting material layer (EML3) 740. The third light emitting part 700 can further include a third hole transport layer (HTL3) 720 disposed between the CGL2 670 and the EML3 740, and a third electron transport layer (ETL3) 760 and an EIL 770 sequentially disposed between the EML3 740 and the second electrode 220. Alternatively, the third light emitting part 700 can further include a third electron blocking layer (EBL3) 730 disposed between the HTL3 720 and the EML3 740 and / or a third hole blocking layer (HBL3) 750 disposed between the EML3 740 and the ETL3 760.

[0137] In one aspect, the EML1 540 and the EML3 740 can each be a blue (B) light emitting material layer, respectively, and the EML2 640 can be any light emitting material layer that emits light having a photo luminescence wavelength longer than light emitted from the blue light emitting material layer, such that the OLED D3 can achieve white light. The EML1 540, the EML2 640, and the EML3 740 can each include a host and a dopant, respectively. As an example, the content of the dopant in each of the EML1 540, the EML2 640, and the EML3 740 can be about 1 wt% to about 50 wt%, for example, about 1 wt% to about 30 wt%, but is not limited thereto.

[0138] The HIL 510 is disposed between the first electrode 210 and the HTL1 520 and improves the interface characteristics between the inorganic first electrode 210 and the organic HTL1 520. As an example, the HIL 510 can include MTDATA, NTA, 1T-NATA, 2T-NATA, CuPc, TCTA, NPB (NPD), HAT-CN, TDAPB, PEDOT / PSS, F4-TCNQ, N-(Biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine, and combinations thereof, but is not limited thereto. The HIL 510 can be omitted according to the characteristics of the OLED D3.

[0139] The HTL1 520 is disposed between the HIL 510 and the EML1 540, the HTL2 620 is disposed between the CGL1 570 and the EML2 640, and the HTL3 720 is disposed between the CGL2 670 and the EML3 740. As an example, the HTL1 520, the HTL2 620, and the HTL3 720 can each independently include TPD, NPB (NPB), DNTPD, CBP, poly-TPD, TFB, TAPC, DCDPA, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, N-(biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl-4-amine, N-([[1,1’-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-1H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, N4,N4,N4’,N4’-tetra([[1,1’-biphenyl]-4-yl)-[1,1’-biphenyl]-4,4’-diamine, and combinations thereof, but are not limited thereto.

[0140] The ETL1 560, the ETL2 660, and the ETL3 760 each provide an electron to each of the EML1 540, the EML2 640, and the EML3 740, respectively. For example, the ETL1 560, the ETL2 660, and the ETL3 760 can each independently include any one of a compound based on an oxadiazole, a compound based on a triazole, a compound based on a phenanthroline, a compound based on a benz oxazole, a compound based on a benzothiazole, a compound based on a benzimidazole, a compound based on a triazine, and the like, but are not limited thereto. More specifically, the ETL1 560, the ETL2 660, and the ETL3 760 can each independently include Alq3, PBD, Spiro-PBD, Liq, TPBi, BAlq, Bphen, NBphen, BCP, TAZ, NTAZ, TpPyPB, TmPyPB, TmPPPyTz, PFNBr, TPQ, TSPO1, ZADN, and combinations thereof, but are not limited thereto.

[0141] The EIL 770 is disposed between the ETL3 760 and the second electrode 220, and can improve physical properties of the second electrode 220, and thus can enhance the light emitting lifetime of the OLED D3. In one aspect, the EIL 770 can include an alkali metal halide or an alkaline earth metal halide, such as LiF, CsF, NaF, BaF2, and the like; and / or an organic metal compound, such as Liq, lithium benzoate, sodium stearate, and the like, but is not limited thereto. The EIL 770 can be omitted according to the OLED D3 structure.​

[0142] EBL1 530, EBL2 630, and EBL3 730 each control electron transport between HTL1 520 and EML1 540, between HTL2 620 and EML2 640, and between HTL3 720 and EML3 740, respectively. As examples, EBL1 530, EBL2 630, and EBL3 730 may each independently contain TCTA, tris[4-(diethylamino)phenyl]amine, N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluorene-2-amine, TAPC, MTDATA, mCP, mCBP, CuPc, DNTPD, TDAPB, 2,8-bis(9-phenyl-9H-carbazole-3-yl)dibenzo[b,d]thiophene, and combinations thereof, but are not limited thereto.

[0143] HBL1 550, HBL2 650, and HBL3 750 each control hole transmission between EML1 540 and ETL1 560, between EML2 640 and ETL2 660, and between EML3 740 and ETL3 760, respectively. HBL1 550 and HBL2 650 can each independently include any of the following: each can be used for hole transmission in each of ETL1 560, ETL2 660, and ETL3 760 based on... Compounds based on diazoles, compounds based on triazoles, compounds based on phenanthroline, compounds based on benzo[a] Compounds based on azoles, benzothiazoles, benzimidazoles, triazines, etc., but not limited to these.

[0144] For example, HBL1 550, HBL2 650 and HBL3 750 may each independently contain Alq3, BAlq, Liq, PBD, spiro-PBD, BCP, TSPO1, bis-4,5-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine (B3PYMPM), DPEPO, 9-(6-(9H-carbazole-9-yl)pyridin-3-yl)-9H-3,9'-bicarbazole, and combinations thereof, but are not limited thereto.

[0145] As described above, EML1 540 and EML3 740 can each be a blue (B) luminescent material layer. For example, EML1 540 and EML3 740 can each independently include one of a blue luminescent material layer, a dark blue luminescent material layer, and a sky blue luminescent material layer. In this case, EML1 540 and EML3 740 can each emit light having a photoluminescence peak of about 440 nm to about 480 nm.

[0146] EML1 540 and EML3 740 can each include a blue (B) host and a blue (B) dopant, respectively. As an example, the blue (B) host can include mCP, mCP-CN, mCBP, CBP-CN, mCPPO1, Ph-mCP, TSPO1, CzBPCb, UGH-1, UGH-2, UGH-3, SPPO1, SimCP, 2-AND, and combinations thereof, but is not limited thereto. The blue (B) dopant can include at least one of a blue phosphorescent material, a blue fluorescent material, and a blue delayed fluorescent material. For example, the blue (B) dopant can include perylene, DPAVBi, DPAVB, BDAVBi, Spiro-DPVBi, DSB, DSA, TBPe, Beep2, PCAN, 1,6-bis(diphenylamino)pyrene, mer-Ir(pmi)3), fac-Ir(dpbic)3, Ir(tfpd)2pic, Ir(Fppy)3, FIrpic, and combinations thereof, but is not limited thereto.

[0147] EML2 640 can emit light of a longer photo luminescence peak than blue light emitted from each of the first EML 540 and the third EML 740, and can include a green (G) light emitting material layer. As an example, the EML2 640 includes a red (R) light emitting material layer 642 and a green (G) light emitting material layer 644 disposed between the EBL2 630 and the HBL2 650, such that the EML2 640 can emit red-green light. When the EML2 640 emits the red-green light, the EML2 640 can emit light having a wavelength of about 510 nm to about 650 nm.

[0148] The red (R) light emitting material layer 642 can include a red (R) host and a red (R) dopant. For example, the red (R) host can include BCzPH, CBP, TCP, TCTA, CDBP, DMFL-CBP, Spiro-CBP, DPEPO, PCzB-2CN, mCzB-2CN, TCz1, Bepp2, Bebq2, TBP3, and combinations thereof, but is not limited thereto.

[0149] The red (R) dopant can include at least one of a red phosphorescent material, a red fluorescent material, and a red delayed fluorescent material. For example, the red (R) dopant can include Ir((piq)3, [bis(2-(4,6-dimethyl)phenylquinoline)](2,2,6,6-tetramethylheptane-3,5-diiodo)iridium(III), Hex-Ir(phq)2(acac), Hex-Ir(phq)3, Ir(Mphq)3, Ir(dpm)PQ2, Ir(dpm)(piq)2, Hex-Ir(piq)2(acac), Hex-Ir(piq)3, Ir(dmpq)3, Ir(dmpq)2(acac), Ir(mphmq)2(acac), Eu(dbm)3(phen), and combinations thereof, but is not limited thereto.

[0150] The green (G) light-emitting material layer 644 can include a green (G) host and a green (G) dopant. For example, the green (G) host can include BCzPh, CBP, TCP, TCTA, CDBP, DMFL-CBP, Spiro-CBP, DPEPO, PCzB-2CN, mCzB-2CN, TCz1, and combinations thereof, but is not limited thereto. The green (G) dopant can include at least one of a green phosphorescent material, a green fluorescent material, and a green delayed fluorescent material. For example, the green (G) dopant can include [bis(2-phenylpyridine)](pyridyl-2-benzofuran[2,3-b]pyridine)iridium, Ir(ppy)3, fac-Ir(ppy)3, Ir(ppy)2(acac), Ir(mppy)3, Ir(npy)2acac, Ir(3mppy)3, TEG, Alq3, and combinations thereof, but is not limited thereto.

[0151] The CGL1 570 is disposed between the first light-emitting part 500 and the second light-emitting part 600, and the CGL2 670 is disposed between the second light-emitting part 600 and the third light-emitting part 700. The CGL1 570 and the CGL2 670 each generate charges and control charge injection balance between the first light-emitting part 500 and the second light-emitting part 600 and between the second light-emitting part 600 and the third light-emitting part 700, respectively.

[0152] The CGL1 570 includes a first N-type CGL (N-CGL1) 580 disposed adjacent to the first light-emitting part 500 and a first P-type CGL (P-CGL1) 590 disposed adjacent to the second light-emitting part 600. The CGL2 670 includes a second N-type CGL (N-CGL2) 680 disposed adjacent to the second light-emitting part 600 and a second P-type CGL (P-CGL2) 690 disposed adjacent to the third light-emitting part 700.

[0153] The N-CGL1 580 and the N-CGL2 680 each separately supply electrons into the first light emitting part 500 and the second light emitting part 600, and the P-CGL1 590 and the P-CGL2 690 each separately supply holes into the second light emitting part 600 and the third light emitting part 700. The N-CGL1 580 can include a first N-type host 582 and a first N-type dopant 584, and the N-CGL2 680 can include a second N-type host 682 and a second N-type dopant 684. The P-CGL1 590 can include a first P-type host 592 and a first P-type dopant 594, and the P-CGL2 690 can include a second P-type host 692 and a second P-type dopant 694.

[0154] The first P-type host 592 in the P-CGL1 590 is designed to have a deep HOMO energy level, and the first P-type dopant 594 in the P-CGL1 590 is designed to have a shallow LUMO energy level. For example, the HOMO energy level HOMO H and the LUMO energy level LUMO D of the first P-type dopant 594 can satisfy the relationship of the above Equation A (see Figure 5

[0155] As described above, when the energy band gap ΔE1 between the HOMO energy level HOMO H and the LUMO energy level LUMO D of the first P-type dopant 594 satisfies the relationship of Equation A, holes and electrons can be injected into the green (G) light emitting material layer 644 in balance, and roll-off in the green light emitting material layer 644 can be reduced or minimized.

[0156] Therefore, in the case where the first P-type host 592 and the first P-type dopant 594 satisfying the relationship of Equation A are introduced into the P-CGL1 590, the amount of green light in light emitted from the EML2 640 can be constantly maintained regardless of the color tone or the current density, and thus white light emitted from the OLED D3 can maintain a constant value, for example, in the CIE chromaticity distribution, the chromaticity of the Y axis is greater than that of the X axis, regardless of the color tone or the current density.

[0157] If the color tone is not considered and only white light having a constant chromaticity is compensated for the X axis chromaticity, effective white balance can be achieved in both the low color tone part and the high color tone part. Since white light having a constant chromaticity is emitted from the OLED D3 without chromaticity conversion by the color tone or the current density, effective optical compensation can be made.

[0158] ​For example, the first P-type host 592 satisfying the relationship of Equation A can include an organic compound having a HOMO energy level of about -5.0 eV to about -6.0 eV, for example, about -5.2 eV to about -5.5 eV. As an example, the first P-type host 592 can include an anthracene-based compound having a structure of Formulae 1 to 2 and / or a spirofluorene-based compound having a structure of Formulae 3 to 4, but is not limited thereto.

[0159] The first P-type dopant 594 satisfying the relationship of Equation A can include an organic compound having a LUMO energy level of about -4.0 eV to about -5.0 eV, for example, about -4.5 eV to about -5.0 eV. As an example, the first P-type dopant 594 can include an organic compound having at least one exocyclic double bond at an indacene core having a structure of Formulae 5 to 6, but is not limited thereto.

[0160] In one aspect, the content of the first P-type dopant 594 in the P-CGL1 590 can be about 3 wt% to about 30 wt%, for example, about 5 wt% to about 20 wt%. For example, the content of the first P-type dopant 594 in the P-CGL1 590 can be about 5 times to about 60 times, for example, about 5 times to about 20 times, of the content of the first N-type dopant 584 in the N-CGL1 580.

[0161] Unlike the P-CGL1 590, in some embodiments, the P-CGL2 690 is required to efficiently generate holes and rapidly inject the holes into the EML3 740 of the blue (B) light-emitting material layer. Referring to Equation B, the second P-type host 692 of the P-CGL2 690 can have a HOMO energy level HOMO Figure 8 The HOMO energy level HOMO H2 The LUMO energy level LUMO D2 The LUMO energy level LUMO

[0162] In other words, the HOMO energy level HOMO H The LUMO energy level LUMO D The LUMO energy level LUMO Figure 5 Unlike the HOMO energy level HOMO H2 The LUMO energy level LUMO D2the LUMO energy level LUMO of the second P-type dopant 694. For example, the HOMO energy level HOMO of the second P-type host 692 in the P-CGL2 690 H the LUMO energy level LUMO of the first P-type dopant 594. For example, the HOMO energy level HOMO of the first P-type host 592 in the P-CGL1 590 D the LUMO energy level LUMO of the second P-type dopant 694. For example, the HOMO energy level HOMO of the second P-type host 692 in the P-CGL2 690 H2 the LUMO energy level LUMO of the first P-type dopant 594. For example, the HOMO energy level HOMO of the first P-type host 592 in the P-CGL1 590 D2 the LUMO energy level LUMO of the second P-type dopant 694. For example, the HOMO energy level HOMO of the second P-type host 692 in the P-CGL2 690 H2 the LUMO energy level LUMO of the first P-type dopant 594. For example, the HOMO energy level HOMO of the first P-type host 592 in the P-CGL1 590 D2 the LUMO energy level LUMO of the second P-type dopant 694. For example, the HOMO energy level HOMO of the second P-type host 692 in the P-CGL2 690

[0163] Formula B: 0.35 eV < LUMO D2 -HOMO H2 < 0.5 eV.

[0164] In one aspect, the HOMO energy level HOMO of the second P-type host 692 in the P-CGL2 690 H2 the LUMO energy level LUMO of the first P-type dopant 594. For example, the HOMO energy level HOMO of the first P-type host 592 in the P-CGL1 590 D2 the LUMO energy level LUMO of the second P-type dopant 694. For example, the HOMO energy level HOMO of the second P-type host 692 in the P-CGL2 690

[0165] [Formula 8]

[0166]

[0167] wherein R 31 and R 32 are each independently protium, deuterium, carbazolyl, or wherein R 31 and R 32 are at least one of carbazolyl or R 33 and R 34 are each independently C6-C 30 aryl or C3-C 30 heteroaryl, wherein the carbazolyl, aryl, and heteroaryl can each independently be unsubstituted or substituted with at least one C1-C 10 alkyl, and R 33 and R 34At least one of them can be a polycyclic aryl or a polycyclic heteroaryl.

[0168] For example, R in Equation 8 33 and R 34 One of them may include phenyl, biphenyl, naphthyl, and anthracene, as well as R 33 and R 34 The other one may include unsubstituted or C1-C 10 Alkyl-substituted fluorene groups, but not limited to these. As examples, spirofluorene-based compounds having the structure of Formula 8 can be selected from, but are not limited to, the following organic compounds of Formula 9:

[0169] [Formula 9]

[0170]

[0171] The second p-type dopant 694, satisfying the relationship of formula B, may comprise an organic compound with a LUMO level of about -5.0 eV to about -5.5 eV, for example, about -5.0 eV to about -5.2 eV. For example, the second p-type dopant 694 may have an axial ene structure or comprise aromatic and heteroaromatic compounds, each having at least one strongly electron-withdrawing group such as a cyano group, a halogen atom (e.g., F, Cl, and / or Br), or a C1-C2 group. 10 Halogenated alkyl groups, such as CF3, and / or nitro-substituted.

[0172] For example, the second P-type dopant 694 may include HAT-CN, F4-TCNQ, 7,7,8,8-tetracyanoquinolinedimethyl (F6-TCNQ), hexacyano-trimethylene-cyclopropane (CN6-CP), 2,2-(perfluoronaphthalene-2,6-dialkylene)-dimethylnitrile (F6-TCNNQ), 2,2'-(2,5-dibromo-3,6-difluorocyclohexane-2,5-diene-1,4-dialkylene)dinitrile, (2E,2'E,2”E)-2,2',2”-(cyclopropane-1,2,3-trimethylene)tris(2-(perfluorophenyl)acetonitrile), (2E,2'E,2”E)-2,2',2”-(cyclopropane-1,2... (2,3-Trimethylene)tris(2-(perfluoropyridin-4-yl)acetonitrile), (2E,2'E,2”E)-2,2',2”-(cyclopropane-1,2,3-trimethylene)tris(2-(4-cyanofluorophenyl)acetonitrile), (2E,2'E,2”E)-2,2',2”-(cyclopropane-1,2,3-trimethylene)tris(2-(2,3,5,6-tetrafluoro-4-(trifluoromethyl)phenyl)acetonitrile), (2E,2'E,2”E)-2,2',2”-(cyclopropane-1,2,3-trimethylene)tris(2-(2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)phenyl))acetonitrile), and combinations thereof, but not limited thereto.

[0173] As an example, the second P-type dopant 694 having an acene structure can be selected from the following organic compounds of Formula 10, but is not limited thereto:

[0174] [Formula 10]

[0175]

[0176] In one aspect, the content of the second P-type dopant 694 in the P-CGL2 690 can be about 3 wt% to about 30 wt%, for example, about 5 wt% to about 20 wt%.

[0177] When the content of the second P-type dopant 694 in the P-CGL2 690 is less than about 3 wt%, hole generation in the P-CGL2 690 and hole injection and hole transport from the P-CGL2 690 into the EML2 640 can be insufficient. In contrast, when the content of the second P-type dopant 694 in the P-CGL2 690 is greater than about 30 wt%, the P-CGL2 690 generates too many holes, which results in the EML3 740 reducing its light emission efficiency (roll-off) because too many holes are injected into the EML3 740 without recombining with electrons. For example, the content of the second P-type dopant 694 in the P-CGL2 690 can be about 5 times to about 60 times, for example, about 5 times to about 20 times, the content of the second N-type dopant 684 in the N-CGL2 680.

[0178] The N-CGL1 580 and the N-CGL2 680 can each be an organic layer including a first N-type host 582 and a first N-type dopant 584, a second N-type host 682 and a second N-type dopant 684, respectively. For example, the first N-type host 582 and the second N-type host 682 can each independently include an organic metal compound having a hydroxyquinoline ligand such as Alq3, a triazine-based compound, a benzoxazole-based compound, a xylene-based compound, Bphen, and MTDATA, but is not limited thereto.

[0179] The first N-type dopant 584 and the second N-type dopant 684 can each independently include alkali metals, for example, Li, Na, K, and Cs; and / or alkaline earth metals, for example, Mg, Sr, Ba, and Ra. Alternatively, the first N-type dopant 584 and the second N-type dopant 684 can each independently include a compound including hpp (e.g., Cr2hpp4, Fe2hpp4, Mn2hpp4, Co2hpp4, Mo2hpp4, W2hpp4, Ni2hpp4, Cu2hpp4, Zn2hpp4, W(hpp)4); and / or an imidazole-based compound, for example, 4,4',5,5'-tetrahexyl-1,1',2,2',3,3'-hexamethyl-2,2',3,3'-tetrahydro-1H,1'H-2,2'-biimidazole, 2,2'-diisopropyl-1,1',3,3'-tetramethyl-2,2',3,3',4,4',5,5',6,6',7,7'-dodecyl-1H,1'H-2,2'-biimidazole, 2,2'-diisopropyl-4,4',5,5'-tetra(4-methoxyphenyl)-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-1H,1'H-2,2'-biimidazole, 2,2'-diisopropyl-4,5-bis(2-methoxyphenyl)-4',5'-bis(4-methoxyphenyl)-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-1H,1'H-2,2'-biimidazole, 2,2'-diisopropyl-4,5-bis(2-methoxyphenyl)-4',5'-bis(3-methoxyphenyl)-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-1H,1'H-2,2'-biimidazole, but are not limited thereto.

[0180] In one aspect, the content of the first N-type dopant 584 and the second N-type dopant 684 in the N-CGL1 580 and the N-CGL2 680 can be about 0.1% by weight to about 5% by weight, for example, about 0.5% by weight to about 3% by weight, respectively. When the content of the first N-type dopant 584 and the second N-type dopant 684 in the N-CGL1 580 and the N-CGL2 680 is less than about 0.1% by weight, electron generation in the N-CGL1 580 and the N-CGL2 680 and electron injection and electron transport from the N-CGL1 580 and the N-CGL2 680 to the first light emitting part 500 and the second light emitting part 600 can be insufficient. In contrast, when the content of the first N-type dopant 584 and the second N-type dopant 684 in the N-CGL1 580 and the N-CGL2 680 is greater than about 5% by weight, too many electrons are injected into the first light emitting part 500 and the second light emitting part 600, so that current leakage can occur or the driving voltage of the OLED D3 can increase.

[0181] Similarly to the second aspect, the second light-emitting material layer in the OLED having three light-emitting parts can further include another light-emitting material layer in addition to the red (R) and green (G) light-emitting material layers. Figure 9 is a cross-sectional view illustrating an organic light-emitting diode having three light-emitting parts according to still another aspect of the disclosure.

[0182] As shown in Figure 9 , the organic light-emitting diode (OLED) D4 according to this aspect includes a first electrode 210 and a second electrode 220 facing each other, and a light-emitting layer 230C disposed between the first electrode 210 and the second electrode 220. The light-emitting layer 230C includes a first light-emitting part 500 disposed between the first electrode 210 and the second electrode 220, a second light-emitting part 600A disposed between the first light-emitting part 500 and the second electrode 220, a third light-emitting part 700 disposed between the second light-emitting part 600A and the second electrode, a first charge generation layer (CGL1) 570 disposed between the first light-emitting part 500 and the second light-emitting part 600A, and a second charge generation layer (CGL2) 670 disposed between the second light-emitting part 600A and the third light-emitting part 700.

[0183] The first light-emitting part 500 includes an EML1 540. The first light-emitting part 500 can further include at least one of a HIL 510 and a HTL1 520 sequentially disposed between the first electrode and the EML1 540, and an ETL1 560 disposed between the EML1 540 and the CGL1 570. Alternatively, the first light-emitting part 500 can further include at least one of an EBL1 530 disposed between the HTL1 520 and the EML1 540, and a HBL1 550 disposed between the EML1 540 and the ETL1 560.

[0184] The second light-emitting part 600A includes an EML2 640A. The second light-emitting part 600A can further include at least one of a HTL2 620 disposed between the CGL1 570 and the EML2 640A, and an ETL2 660 disposed between the EML2 640A and the CGL2 670. Alternatively, the second light-emitting part 600A can further include at least one of an EBL2 630 disposed between the HTL2 620 and the EML2 640A, and a HBL2 650 disposed between the EML2 640A and the ETL2 660.

[0185] The third light emitting part 700 includes the EML3 740. The third light emitting part 700 can further include the HTL3 720 disposed between the CGL2 670 and the EML3 740, and at least one of the ETL3 760 and the EIL 770 sequentially disposed between the EML3 740 and the second electrode 220. Alternatively, the third light emitting part 700 can further include the EBL3 730 disposed between the HTL3 720 and the EML3 740 and / or the HBL3 750 disposed between the EML3 740 and the ETL3 760. As described above, the configuration of the light emitting layer 230C except for the EML2 640A can be substantially the same as that in the light emitting layer 230B as described above.

[0186] For example, the EML1 540 and the EML3 740 can each be a blue (B) light emitting material layer, respectively, and can include a blue (B) host and a blue (B) dopant. The EML2 640A includes a red (R) light emitting material layer 642, a yellow-green (YG) or yellow (Y) light emitting material layer 646, and a green light emitting material layer 644 each sequentially disposed between the EBL2 630 and the HBL2 650. The red (R) light emitting material layer 642 includes a red (R) host and a red (R) dopant, and the green (G) light emitting material layer 644 includes a green host and a green dopant. The blue (B) / red (R) / green (G) host and the blue (B) / red (R) / green (G) dopant can each be the same as described above, respectively.

[0187] The yellow-green (YG) or yellow (Y) light emitting material layer 646 can include a yellow-green (YG) or yellow (Y) host and a yellow-green (YG) or yellow (Y) dopant. The yellow-green (YG) or yellow (Y) host can include BCzPh, CBP, TCP, TCTA, CDBP, DMFL-CBP, Spiro-CBP, DPEPO, PCzB-2CN, mCzB-2CN, TCz1, Bebq2, TPB3, Balq, and combinations thereof, but is not limited thereto, and the yellow-green (YG) or yellow (Y) dopant can include at least one of a yellow-green (YG) or yellow (Y) phosphorescent material, a yellow-green (YG) or yellow (Y) fluorescent material, and a yellow-green (YG) or yellow (Y) delayed fluorescent material. For example, the yellow-green (YG) or yellow (Y) dopant can include Rubrene, TBRb, Ir(BT)2(acac), Ir(fbi)2(acac), fac-Ir(ppy)2Pc, FPQIrpic, and combinations thereof, but is not limited thereto.

[0188] In this aspect, the HOMO energy level HOMO Hthe LUMO level LUMO of the first P-type dopant 594 D The relationship of Equation A (see Figure 5 ) can be satisfied. For example, the first P-type host 592 can include anthracene-based compounds having Equations 1 and 2 and / or spirofluorene-based compounds having Equations 3 and 4, but is not limited thereto. In addition, the first P-type dopant 594 can include organic compounds having at least one exocyclic double bond at an indacene core having the structures of Equations 5 to 6, but is not limited thereto.

[0189] The P-CGL1 controls the HOMO level HOMO of the first P-type host 592 H the LUMO level LUMO of the first P-type dopant 594 D such that the content of green light emitted from the EML2 640A can be maintained regardless of the color tone and the current density. Accordingly, the white light emitted from the OLED D4 has a constant value, for example, the chromaticity of the Y axis is greater than that of the X axis in the CIE chromaticity distribution regardless of the color tone. In other words, since the white light having a constant chromaticity is emitted from the OLED D4 without chromaticity conversion by the color tone or the current density, efficient optical compensation can be performed.

[0190] In addition, the HOMO level HOMO of the first P-type host 592 in the P-CGL1 590 H the LUMO level LUMO of the first P-type dopant 594 D (see Figure 5 ) is different from the HOMO level HOMO of the second P-type host 692 in the P-CGL2 690 H2 the LUMO level LUMO of the second P-type dopant 694 D2 (see Figure 8 ). The HOMO level HOMO of the first P-type host 592 in the P-CGL1 590 H the LUMO level LUMO of the first P-type dopant 594 D may be greater than the HOMO level HOMO of the second P-type host 692 in the P-CGL2 690 H2 the LUMO level LUMO of the second P-type dopant 694 D2 . For example, the HOMO level HOMO of the second P-type host 692 in the P-CGL2 690 H2 the LUMO level LUMO of the second P-type dopant 694 D2The band gap ΔE2 between the HOMO level of the second P-type dopant 694 and the LUMO level of the second P-type host 692 can satisfy the relationship of Equation B. Thus, the second P-type dopant 694 receives electrons from the HOMO level of the hole-transporting material in the second P-type host 692 or HTL3 720 to its LUMO level, so that a hole-transporting path for transporting holes from the P-CGL2 690 to the EML3 740 can be formed.

[0191] As examples, the second P-type host 692 can include a spirofluorene-based compound having a structure of Formulas 8 to 9. The second P-type dopant 694 can have an axiallyene structure or include aromatic compounds and heteroaromatic compounds, each of which is substituted with at least one strong electron-withdrawing group such as a cyano group, a halogen atom (e.g., F, Cl, and / or Br), a C1-C6 alkyl group substituted with at least one halogen atom (e.g., CF3), a nitro group, and / or a combination thereof. 10 halogen atoms (e.g., F, Cl, and / or Br), a C1-C6 alkyl group substituted with at least one halogen atom (e.g., CF3), a nitro group, and / or a combination thereof.

[0192] For example, the second P-type dopant 694 can include HAT-CN, F4-TCNQ, F6-TCNQ, CN6-CP, F6-TCNNQ, 2,2’-(2,5-dibromo-3,6-difluorocyclohexa-2,5-diene-1,4-diylidene)dicyanide, (2E,2’E,2″E)-2,2′,2″-(cyclopropane-1,2,3-trimethylidene)tris(2-(perfluorophenyl)-acetonitrile), (2E,2’E,2”E)-2,2’,2”-(cyclopropane-1,2,3-trimethylidene)tris(2-(perfluoropyridine-4-yl)-acetonitrile), (2E,2’E,2”E)-2,2’,2”-(cyclopropane-1,2,3-trimethylidene)tris(2-(4-cyanoperfluorophenyl)-acetonitrile), (2E,2’E,2”E)-2,2’,2”-(cyclopropane-1,2,3-trimethylidene)tris(2-(2,3,5,6-tetrafluoro-4-(trifluoromethyl)phenyl)-acetonitrile), (2E,2’E,2”E)-2,2’,2”-(cyclopropane-1,2,3-trimethylidene)tris(2-(2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)phenyl)-acetonitrile), and combinations thereof, but are not limited thereto.

[0193] In the above aspect, an OLED having three light-emitting portions and two charge generation layers between the light-emitting portions is described. Alternatively, the OLED can have a tandem structure of four or more, which includes one or more light-emitting portions between the third light-emitting portion and the second electrode and one or more charge generation layers over the third light-emitting portion.

[0194] In another aspect, the organic light emitting display device can further include a color conversion layer. Figure 10 FIG. 1 is a cross-sectional view illustrating an organic light emitting display device according to an aspect of the present disclosure.

[0195] As described above, the organic light emitting display device according to the present disclosure can include a first light-emitting portion, a second light-emitting portion, and a third light-emitting portion. Figure 10As shown, the organic light emitting display device 800 includes a first substrate 802 defining each of a red pixel region RP, a green pixel region GP, and a blue pixel region BP, a second substrate 804 facing the first substrate 802, thin film transistors Tr over the first substrate 802, organic light emitting diodes (OLEDs) D disposed between the first substrate 802 and the second substrate 804 and emitting white (W) light, and color conversion layers 880 disposed between the OLEDs D and the second substrate 804. Although Figure 10 A color filter layer can be disposed between the second substrate 804 and the color conversion layers 880, although not shown in FIG. 8.

[0196] The thin film transistors Tr are disposed over the first substrate 802 corresponding to each of the red pixel region RP, the green pixel region GP, and the blue pixel region BP. A passivation layer 860 is formed over the entire first substrate 802 covering the thin film transistors Tr, the passivation layer 860 having a drain contact hole exposing one electrode, e.g., a drain electrode, of the thin film transistors Tr.

[0197] The OLEDs D including a first electrode 910, a light emitting layer 930, and a second electrode 920 are disposed over the passivation layer 860. The first electrode 910 can be connected to the drain electrode of the thin film transistor Tr through the drain contact hole. Further, a bank layer 864 covering edges of the first electrode 910 is formed at boundaries between the red pixel region RP, the green pixel region GP, and the blue pixel region BP. In this case, the OLEDs D can have a structure of Figure 3 、 Figure 5 、 Figure 6 and Figure 8 and can emit white (W) light. The OLEDs D are disposed in each of the red pixel region RP, the green pixel region GP, and the blue pixel region BP to provide white (W) light.

[0198] The color conversion layers 880 can include a first color conversion layer 882 corresponding to the red pixel region RP, a second color conversion layer 884 corresponding to the green pixel region GP, and a third color conversion layer 886 corresponding to the blue pixel region BP. As an example, the color conversion layers 880 can include an inorganic light emitting material, e.g., quantum dots (QDs).

[0199] White (W) light emitted from the OLEDs D in the red pixel region RP is converted to red (R) color light by the first color conversion layer 882, white (W) light emitted from the OLEDs D in the green pixel region GP is converted to green (G) color light by the second color conversion layer 884, and white (W) light emitted from the OLEDs D in the blue pixel region BP is converted to blue (B) color light by the third color conversion layer 886. Accordingly, the organic light emitting display device 800 can implement a full color image.

[0200] Further, when light emitted from the OLED D is displayed through the first substrate 802, a color conversion layer 880 can be disposed between the OLED D and the first substrate 802.

[0201] Example 1 (Ex. 1): Manufacture of an OLED

[0202] An organic light emitting diode having a three-stack structure to realize white light, in which the P-CGL1 comprises compound 2-1 ((N-9,9-dimethyl-9H-fluoren-2-yl)-N-phenyl-9,9’H-spirobi-fluorene-3-amine, HOMO: -5.26 eV) as a first P-type host and compound 3-1 (LUMO: -4.85 eV) in Formula 7 as a first P-type dopant, and the P-CGL2 comprises compound 4-1 (2,7-bis(carbazol-9-yl)-9,9-spirobifluorene (Spiro-2CBP), HOMO: -5.16 eV) in Formula 9 as a second P-type host and compound 5-1 (CN6-P, LUMO: -5.07 eV) in Formula 10. A glass substrate (40 mm x 40 mm x 40 mm) on which ITO is coated as a thin film was washed by a solvent (e.g., isopropyl alcohol, acetone, and distilled water) and ultrasonically cleaned for 5 minutes, dried in an oven at 100℃. After washing the substrate, the substrate was treated with O2 plasma under vacuum for 2 minutes, and then transferred to a vacuum chamber to deposit the light emitting layer. Subsequently, the light emitting layer and the cathode were deposited by evaporation from a heated boat at a deposition rate of about 5 x 10 -7 to 7 x 10 -7 in the following order and disposed The light emitting layer and the cathode were deposited by evaporation from a heated boat at a deposition rate of about 5 x 10

[0203] HIL (NPD (90 wt%), F4-TCNQ (10 wt%), 1,3,4-oxadiazole (0 wt%), ); HTL1 (NPD, ), blue EML (2-ADN (97 wt%), 1,6-bis(diphenylamino)pyrene (3 wt%), ), ETL1 (TmPyPB, ), N-CGL1 (Bphen (98 wt%), Li (2 wt%), ), P-CGL1 (compound 2-1 (90 wt%), compound 3-1 (10 wt%), ), HTL2 (NPD, ), red EML (CBP (90 wt%), Ir(piq)3 (10 wt%), ), green EML (CBP (90 wt%), Ir(ppy)3 (10 wt%), ), ETL2 (Alq3, ), N-CGL2 (Bphen (98 wt%), Li (2 wt%), ), P-CGL2 (Spiro-2CBP (90 wt%), CB6-CP (10 wt%), ), HTL3 (NPD, ), blue EML (2-AND (97 wt%), 1,6-bis(diphenylamino)pyrene (3 wt%), ), ETL3 (Alq3, ), EIL (LiF, ), cathode (Al, ).

[0204] The device was then encapsulated through glass. After deposition of the light-emitting layer and the cathode, the OLED was transferred from the deposition chamber to a dry box for film formation, and then encapsulated using a UV-curable epoxy resin and a moisture absorbent. The energy band gap between the HOMO level of the first P-type host in P-CGL1 and the LUMO level of the first P-type dopant was 0.41 eV, while the energy band gap between the HOMO level of the second P-type host in P-CGL2 and the LUMO level of the second P-type dopant was 0.09 eV.

[0205] Comparative Example 1 (Ref. 1): Manufacture of an OLED

[0206] A white OLED was fabricated using the same procedure and the same materials as in Example 1, except that Spiro-2CBP (HOMO: -5.16 eV) was used as the first P-type host and the second P-type host in P-CGL1 and P-CGL2, and CBP-CP (LUMO: -5.07 eV) was used as the first P-type dopant and the second P-type dopant. The energy band gap between the HOMO level of the P-type host in P-CGL1 and P-CGL2 and the LUMO level of the P-type dopant was 0.09 eV.

[0207] Comparative Example 2 (Ref. 2): Manufacture of an OLED

[0208] An OLED was fabricated using the same procedure and the same materials as in Example 1, except that Spiro-2CBP (HOMO: -5.16 eV) was used as the first P-type host and the second P-type host in P-CGL1 and P-CGL2, and compound 3-1 (LUMO: -4.85 eV) was used as the first P-type dopant and the second P-type dopant. The energy band gap between the HOMO level of the P-type host in P-CGL1 and P-CGL2 and the LUMO level of the P-type dopant was 0.31 eV.

[0209] Experimental Example: Measurement of light-emitting properties of an OLED

[0210] Each of the OLEDs manufactured in Example 1 and Comparative Examples 1 to 2 having a light-emitting area of 9 mm2was connected to an external power source, and then the light-emitting characteristics of all the OLEDs were evaluated at room temperature using a constant current source (KEITHLEY) and a luminance meter PR650. In particular, the luminous efficiency of green light according to current density, the color coordinates of emitted white light according to current density, and the current density according to voltage were evaluated. 2 Figures 11 to 15 The evaluation results are shown.

[0211] As shown in FIG. 1, in the OLEDs manufactured in Ref. 1 and Ref. 2, as the current density increased, severe roll-off occurred. On the other hand, it was determined that in the OLED manufactured in Example 1, the roll-off of green light was reduced or minimized. Figure 11 As shown in FIG. 2 and FIG. 3, in the case of the OLEDs manufactured in Ref. 1 and Ref. 2, the white light emitted in the low current density portion contained a relatively large amount of green color (CIEy > CIEx), whereas the white light emitted in the high current density portion contained a relatively large amount of red color (CIEx > CIEy). Since color conversion occurs depending on the current density, it can not be possible to properly achieve color compensation.

[0212] Figure 12 Figure 13

[0213] On the other hand, as shown in FIG. 4, in the OLED manufactured in Example, the content of green light of the white light emitted was uniformly higher than the content of red light (CIEy > CIEx) regardless of the current density. Therefore, by compensating for the red light component corresponding to the X axis in the CIE chromaticity distribution from the light emitted from the OLED, white balance can be effectively achieved regardless of the current density. Figure 14

[0214] It will be obvious to those skilled in the art that various modifications and changes can be made in the present disclosure without departing from the scope thereof. It is therefore intended that the present disclosure cover all modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

[0215] These and other changes can be made to the embodiments in light of the above detailed description. In general, in the following claims, the used terms are not intended to be limited to the specific embodiments described herein, but can include all possibilities as well as all equivalents of the claims. Accordingly, the claims are not limited by the disclosure.​​​​​

Claims

1. An organic light emitting diode comprising: a first electrode; a second electrode facing the first electrode; a plurality of light emitting parts between the first electrode and the second electrode; and at least one charge generation layer disposed between the plurality of light emitting parts, wherein the plurality of light emitting parts comprises at least one light emitting part comprising a green light emitting material layer, wherein the at least one charge generation layer comprises a P-type charge generation layer providing holes into the green light emitting material layer, wherein the P-type charge generation layer comprises a P-type host and a P-type dopant, and wherein a band gap between a highest occupied molecular orbital (HOMO) level of the P-type host and a lowest unoccupied molecular orbital (LUMO) level of the P-type dopant satisfies a relationship of Formula A below: wherein the P-type host comprises an organic compound having a structure of Formula 1 or Formula 3 below: Formula A: 0.35 eV < LUMO D - HOMO H ≤ 0.5 eV; wherein LUMO D represents the LUMO level of the P-type dopant, and HOMO H represents the HOMO level of the P-type host, Formula 1 Formula 3 wherein R1to R4are each independently unsubstituted or substituted C6-C 30 aryl or unsubstituted or substituted C3-C 30 heteroaryl; wherein the P-type dopant comprises an organic compound having an axiacycle core, a quinone core, or an indacene core. wherein R5and R6are each independently hydrogen, deuterium, unsubstituted or substituted carbazolyl, or wherein at least one of R5and R6is unsubstituted or substituted carbazolyl, or and wherein R7and R8are each independently unsubstituted or substituted C6-C 30 aryl or unsubstituted or substituted C3-C 30 heteroaryl, and 2.The organic light emitting diode of claim 1, wherein the at least one charge generation layer further comprises an N-type charge generation layer disposed adjacent to the P-type charge generation layer, and wherein the N-type charge generation layer provides electrons to light emitting parts other than the light emitting part comprising the green light emitting material layer. 3.The organic light emitting diode of claim 2, wherein the N-type charge generation layer comprises an N-type host and an N-type dopant, and wherein a content of the P-type dopant in the P-type charge generation layer is 5 times to 60 times a content of the N-type dopant in the N-type charge generation layer. 4.The organic light emitting diode of claim 1, wherein the at least one light emitting part further comprises a red light emitting material layer disposed between the P-type charge generation layer and the second electrode. 5.The organic light emitting diode of claim 4, wherein the green light emitting material layer is disposed between the red light emitting material layer and the second electrode. 6.The organic light emitting diode of claim 5, wherein the at least one light emitting part further comprises a yellow-green or yellow light emitting material layer disposed between the red light emitting material layer and the green light emitting material layer. 7.The organic light emitting diode of claim 1, wherein the plurality of light emitting parts comprises a first light emitting part disposed between the first electrode and the second electrode and a second light emitting part disposed between the first light emitting part and the second electrode, wherein the at least one charge generation layer comprises a first charge generation layer, wherein the first charge generation layer comprises the P-type charge generation layer and an N-type charge generation layer disposed adjacent to the P-type charge generation layer, wherein the second light emitting part comprises the green light emitting material layer, and wherein the P-type charge generation layer is disposed between the first light emitting part and the second light emitting part, and the N-type charge generation layer is disposed between the first light emitting part and the P-type charge generation layer. 8.The organic light emitting diode of claim 7, wherein the first light emitting part comprises a blue light emitting material layer. ​ 9. The organic light emitting diode of claim 7, wherein the plurality of light emitting portions further comprises a third light emitting portion disposed between the second light emitting portion and the second electrode, and the at least one charge generation layer further comprises a second charge generation layer disposed between the second light emitting portion and the third light emitting portion.

10. The organic light emitting diode of claim 9, wherein the third light emitting portion comprises a layer of blue light emitting material.

11. The organic light emitting diode of claim 9, wherein the second charge generation layer comprises a second P-type charge generation layer disposed between the second light emitting portion and the third light emitting portion and providing holes to the third light emitting portion, and wherein the second P-type charge generation layer comprises a second P-type host and a second P-type dopant.

12. The organic light emitting diode of claim 11, wherein an energy band gap between a HOMO energy level of the P-type host and a LUMO energy level of the P-type dopant in the first charge generation layer is different from an energy band gap between a HOMO energy level of the second P-type host and a LUMO energy level of the second P-type dopant in the second charge generation layer.

13. The organic light emitting diode of claim 12, wherein the energy band gap between the HOMO energy level of the second P-type host and the LUMO energy level of the second P-type dopant satisfies a relationship of the following Formula B:

14. The organic light emitting diode of claim 11, wherein the P-type host comprises an organic compound selected from the group consisting of: Formula B: 0.05 eV < LUMO D2 - HOMO H2 ≤ 0.20 eV; wherein LUMO D2 represents the LUMO level of the second P-type dopant, and HOMO H2 represents the HOMO level of the second P-type host.

15. The organic light emitting diode of claim 1, wherein the P-type dopant comprises an organic compound selected from the group consisting of:

16. An organic light emitting diode comprising: a first electrode; a second electrode facing the first electrode; and a light emitting layer disposed between the first electrode and the second electrode, wherein the light emitting layer comprises: a first light emitting portion disposed between the first electrode and the second electrode, a second light emitting portion disposed between the first light emitting portion and the second electrode, a third light emitting portion disposed between the second light emitting portion and the second electrode, a first charge generation layer disposed between the first light emitting portion and the second light emitting portion, and a second charge generation layer disposed between the second light emitting portion and the third light emitting portion, wherein the second light emitting portion comprises a layer of green light emitting material and a layer of red light emitting material, wherein the first charge generation layer comprises a first P-type charge generation layer providing holes to the second light emitting portion and a first N-type charge generation layer providing electrons to the first light emitting portion, wherein the second charge generation layer comprises a second P-type charge generation layer providing holes to the third light emitting portion and a second N-type charge generation layer providing electrons to the second light emitting portion, wherein the first P-type charge generation layer comprises a first P-type host and a first P-type dopant, wherein the second P-type charge generation layer comprises a second P-type host and a second P-type dopant, and wherein the first N-type charge generation layer comprises a first N-type host and a first N-type dopant. ​ wherein an energy band gap between the highest occupied molecular orbital (HOMO) level of the first P-type host and the lowest unoccupied molecular orbital (LUMO) level of the first P-type dopant is different from an energy band gap between the HOMO level of the second P-type host and the LUMO level of the second P-type dopant, wherein the first P-type host comprises an organic compound having a structure of Formula 1 or Formula 3: Formula 1 wherein R1to R4are each independently unsubstituted or substituted C6-C 30 aryl or unsubstituted or substituted C3-C 30 heteroaryl; Formula 3 wherein R5and R6are each independently hydrogen, deuterium, unsubstituted or substituted carbazolyl, or wherein at least one of R5and R6is unsubstituted or substituted carbazolyl, or and wherein R7and R8are each independently unsubstituted or substituted C6-C 30 aryl or unsubstituted or substituted C3-C 30 heteroaryl, wherein the first P-type dopant comprises an organic compound having an acene core, a quinone core, or an indacene core, wherein the second P-type host comprises a spirofluorene-based compound having a structure of Formula 8: wherein R 31 and R 32 are each independently hydrogen, deuterium, carbazolyl or wherein R 31 and R 32 are each independently hydrogen, deuterium, carbazolyl or R 33 and R 34 are each independently C6-C 30 aryl or C3-C 30 heteroaryl, wherein carbazolyl, aryl and heteroaryl are each independently unsubstituted or substituted with at least one C1-C 10 alkyl, and at least one of R 33 and R 34 is polycyclic aryl or polycyclic heteroaryl, and wherein the second P-type dopant has an acenylene structure or comprises an aromatic or heteroaromatic compound, each of which is substituted with at least one strong electron withdrawing group, wherein the strong electron withdrawing group comprises a cyano group, a halogen atom, a C1-C 10 haloalkyl group, or a nitro group.

17. The organic light emitting diode of claim 16, wherein an energy band gap between the HOMO level of the first P-type host and the LUMO level of the first P-type dopant satisfies a relationship of Formula A: Formula A: 0.35 eV < LUMO D - HOMO H ≤ 0.5 eV; wherein LUMO D represents the LUMO level of the first P-type dopant, and HOMO H represents the HOMO level of the first P-type host.

18. The organic light emitting diode of claim 16, wherein an energy band gap between the HOMO level of the second P-type host and the LUMO level of the second P-type dopant satisfies a relationship of Formula B: Formula B: 0.05 eV < LUMO D2 - HOMO H2 ≤ 0.20 eV; wherein LUMO D2 represents the LUMO level of the second P-type dopant, and HOMO H2 represents the HOMO level of the second P-type host.

19. The organic light emitting diode of claim 16, wherein the green light emitting material layer is disposed between the first charge generation layer and the second charge generation layer, and the red light emitting material layer is disposed between the first charge generation layer and the green light emitting material layer.

20. The organic light emitting diode of claim 19, wherein the second light emitting part further comprises a yellow-green or yellow light emitting material layer disposed between the red light emitting material layer and the green light emitting material layer.

21. The organic light emitting diode of claim 16, wherein at least one of the first light emitting part and the third light emitting part comprises a blue light emitting material layer.

22. The organic light emitting diode of claim 16, wherein a content of the first P-type dopant in the first P-type charge generation layer is 5 times to 60 times a content of a first N-type dopant in the first N-type charge generation layer.

23. The organic light emitting diode of claim 16, wherein the first P-type host comprises an organic compound selected from the group consisting of:

24. The organic light emitting diode of claim 16, wherein the first P-type dopant comprises an organic compound selected from the group consisting of:

25. An organic light emitting device comprising: a substrate; and the organic light emitting diode of claim 1 over the substrate.

26. The organic light emitting device of claim 25, wherein the organic light emitting device further comprises at least one of a thin film transistor over the substrate and connected to the organic light emitting diode, and a color filter layer disposed between the substrate and the organic light emitting diode or over the organic light emitting diode.

27. An organic light emitting device comprising: a substrate; and the organic light emitting diode of claim 16 over the substrate.

28. The organic light emitting device of claim 27, wherein the organic light emitting device further comprises at least one of a thin film transistor over the substrate and connected to the organic light emitting diode, and a color filter layer disposed between the substrate and the organic light emitting diode or over the organic light emitting diode.

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