ORGANIC LIGHT-EMPLOYING DIODE AND ORGANIC LIGHT-EMPLOYING DEVICE WITH THE SAME

Abstract

Having organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7): a first electrode (210, 610, 1110); a second electrode (230, 630, 1130) opposite the first electrode (210, 610, 1110); and an emission layer (220, 220A, 220B, 220C, 620, 1120, 1120A) arranged between the first and second electrodes (210, 230; 610, 630; 1110, 1130) and containing at least one emitting material layer (240, 240A, 240B, 340, 440, 640, 1240, 1340, 1440, 1540, 1640, 1740), wherein the at least one emitting material layer (240, 240A, 240B, 340, 440, 640, 1240, 1340, 1440, 1540, 1640, 1740) contains a first compound (DF) and a second compound (FD, FD1), and where the first compound (DF) has the following structure of formula 1 and the second compound (FD, FD1) has the following structure of formula 7: where in Formula 1, each of R 1 to R 9independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is, where two to four of R 1 to R 9 a group with the following structure of formula 2 is, where in Formula 2: each of R 11 to R 18 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30-group is and at least two adjacent of R 11 to R 18 form an unsubstituted or substituted heteroaromatic ring with the following structure of formula 3; and The asterisk in formula 2 indicates a link position. where in Formula 3, X equals NR 25 , O or S is; each of R 21 to R 25 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is; and the dashed line in formula 3 indicates a condensed part, where in Formula 7, each of R 31 to R34 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is optional two adjacent elements of R 31 to R 34 form an unsubstituted or substituted condensed ring with boron and nitrogen; each of R 35 to R 38 independently of each other deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is where each R 35 is identical or different from each other if q is an integer of two or more, each R 36 is identical or different from each other if r is an integer of two or more, each R 37 is identical or different from each other if s is an integer of two or more and each R 38 is identical or different from each other if t is an integer of two or more; q and s are each independently an integer from 0 to 5; r is an integer from 0 to 3; and t is an integer from 0 to 4.

Description

BACKGROUND Technical area

[0001] The present disclosure relates to an organic light-emitting diode and in particular to an organic light-emitting diode with excellent luminous properties and to an organic light-emitting device comprising this diode. Discussion of the related technology

[0002] As display devices become increasingly larger, there is a need for flat display devices with a smaller footprint. Among these flat display devices, one using an organic light-emitting diode (OLED) has become the focus of attention.

[0003] OLEDs can be manufactured as thin films with a thickness of less than 2000 Å and can implement unidirectional or bidirectional images as electrode configurations. Furthermore, OLEDs can be formed on a flexible, transparent substrate such as a plastic substrate, making flexible or foldable displays easily achievable. In addition, OLEDs offer advantages over LCDs (liquid crystal displays); for example, they can operate at a lower voltage of 10 V or less and have very high color purity.

[0004] In an OLED, when electric charges are injected into an emitting material layer between an electron injection electrode (i.e., cathode) and a hole injection electrode (i.e., anode), the electric charges recombine to form excitons and then emit light when the recombined excitons transition to a stable ground state.

[0005] Fluorescent materials from the aforementioned technology have a low luminous efficacy because only singlet excitons are involved in their luminescence process. Phosphorescent materials, in which both triplet and singlet excitons participate in the luminescence process, have a relatively high luminous efficacy compared to fluorescent materials. However, the metal complex, as a representative phosphorescent material, has too short a luminescence lifetime for use in commercial devices.

[0006] JP 2021 - 27169 A, US 2021 / 0 119 134 A1 and US 2021 / 0 167 289 A1 also disclose organic light-emitting diodes with organic boron compounds. OVERVIEW

[0007] Accordingly, embodiments of the present disclosure are directed to an OLED and an organic light-emitting device containing the OLED, which substantially avoids one or more of the problems due to the limitations and disadvantages of the related technology.

[0008] One aspect of the present disclosure is the provision of an OLED that can improve luminous efficacy, color purity and luminous lifetime, and an organic light-emitting device containing this diode.

[0009] Further features and aspects are set out in the following description and some will emerge from the description itself or can be learned through practical application of the inventive concepts provided here. Other features and aspects of the concepts according to the invention can be realized and achieved through the structure and claims, which are particularly highlighted in or can be derived from the written description, as well as through the accompanying drawings.

[0010] To realize these and other aspects of the concepts according to the invention, as illustrated in the embodiments and generally described, an organic light-emitting diode according to claim 1 is provided. Further embodiments are described in the dependent claims.

[26] It should be understood that both the preceding general description and the following detailed description are exemplary and explanatory and serve to further explain the claimed inventive concepts. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The attached drawings, which serve to further understand the disclosure, are an integral part of this application and illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. Fig. Figure 1 is a schematic circuit diagram of an organic light-emitting display device according to the present disclosure. Fig. Figure 2 is a schematic cross-sectional view showing an organic light-emitting display device according to an exemplary aspect of the present disclosure. Fig. Figure 3 is a schematic cross-sectional view showing an organic light-emitting diode (OLED) according to an exemplary aspect of the present disclosure. Fig. Figure 4 is a schematic diagram illustrating that the luminous efficacy and color purity of an OLED can be improved by controlling an onset wavelength of the first compound and the maximum absorption wavelength of the second compound according to an exemplary aspect of the present disclosure. Fig. Figure 5 is a schematic diagram illustrating that the luminous efficacy of an OLED deteriorates if the onset wavelength of the first junction does not have specific wavelength ranges. Fig. Figure 6 is a schematic diagram illustrating that the luminous efficacy and color purity of an OLED deteriorates when the onset wavelength of the first compound is greater than the maximum absorption wavelength of the second compound. Fig. Figure 7 is a schematic diagram illustrating the luminescence mechanism via singlet and triplet energy levels of luminescent materials in an emitting material layer (EML) according to an exemplary aspect of the present disclosure. Fig. Figure 8 is a schematic cross-sectional view showing an OLED according to another exemplary aspect of the present disclosure. Fig. Figure 9 is a schematic diagram illustrating a luminescence mechanism via singlet and triplet energy levels of luminescent materials in EMLs according to another exemplary aspect of the present disclosure. Fig. Figure 10 is a schematic cross-sectional view showing an OLED according to yet another exemplary aspect of the present disclosure. Fig. Figure 11 is a schematic diagram illustrating a luminescence mechanism via singlet and triplet energy levels of luminescent materials in EMLs according to another exemplary aspect of the present disclosure. Fig. Figure 12 is a schematic cross-sectional view showing an OLED according to another exemplary aspect of the present disclosure. Fig. Figure 13 is a schematic cross-sectional view showing an organic light-emitting display device according to another exemplary aspect of the present disclosure. Fig. Figure 14 is a schematic cross-sectional view showing an OLED according to yet another exemplary aspect of the present disclosure. Fig. Figure 15 is a schematic cross-sectional view showing an organic light-emitting display device according to yet another exemplary aspect of the present disclosure. Fig. Figure 16 is a schematic cross-sectional view showing an OLED according to yet another exemplary aspect of the present disclosure. Fig. Figure 17 is a schematic cross-sectional view showing an OLED according to yet another exemplary aspect of the present disclosure. DETAILED DESCRIPTION

[0012] In the following, aspects, embodiments and examples of the disclosure will be referred to and discussed in detail, with some examples illustrated in the attached drawings.

[0013] The present disclosure relates to an organic light-emitting diode (OLED) in which a first compound and a second compound with matched energy levels are used in the same EML or in adjacent EMLs, and to an organic light-emitting device incorporating the OLED. The OLED can be used in an organic light-emitting device such as an organic light-emitting display device and an organic light-emitting luminescent device. An example of a display device using the OLED is described.

[0014] Fig. Figure 1 is a schematic circuit diagram of an organic light-emitting display device according to the present disclosure. As in Fig. As shown in Figure 1, in an organic light-emitting display device 100, a gate line GL, a data line DL, and a power line PL each intersect to define a pixel area P. A switching thin-film transistor Ts, a driver thin-film transistor Td, a storage capacitor Cst, and an organic light-emitting diode D are formed within the pixel area P. The pixel area P can have a first pixel area P1, a second pixel area P2, and a third pixel area P3 ( Fig. 13).

[0015] The switching thin-film transistor Ts is connected to the gate line GL and the data line DL, and the driver 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 driver thin-film transistor Td. When the switching thin-film transistor Ts is switched on by a gate signal applied to the gate line GL, a data signal applied to the data line DL is applied via the switching thin-film transistor Ts to a gate electrode of the driver thin-film transistor Td and an electrode of the storage capacitor Cst.

[0016] The driver thin-film transistor Td is switched on by the data signal applied to its gate electrode, so that currents proportional to the data signal are supplied to the organic light-emitting diode D via the driver thin-film transistor Td from the power line PL. The organic light-emitting diode D then emits light with a luminance proportional to the currents flowing through the driver thin-film transistor Td. In this case, the storage capacitor Cst is charged with voltages proportional to the data signal, so that the voltage of the gate electrode in the driver thin-film transistor Td is kept constant during a frame. Therefore, the organic light-emitting display device 100 can display a desired image.

[0017] Fig. Figure 2 is a schematic cross-sectional view of an organic light-emitting display device 100 according to an exemplary aspect of the present disclosure. In accordance with all aspects of the present disclosure, all components of the organic light-emitting device are functionally coupled and configured. As shown in Fig. As shown in Figure 2, the organic light-emitting display device 100 comprises a substrate 110, a thin-film transistor Tr on the substrate 110 and an organic light-emitting diode (OLED) D, which is arranged above the substrate 110 and connected to the thin-film transistor Tr.

[0018] Substrate 110 can, but is not limited to, glass, thin flexible material, and / or polymer plastics. For example, the flexible material can, but is not limited to, polyimide (PI), polyethersulfone (PES), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC). Substrate 110, on which the thin-film transistor Tr and the OLED D are arranged, forms an array substrate.

[0019] A buffer layer 122 can be arranged above the substrate 110, and the thin-film transistor Tr is arranged above the buffer layer 122. The buffer layer 122 can also be omitted.

[0020] A semiconductor layer 120 is arranged above the buffer layer 122. As an example, the semiconductor layer 120 can contain, but is not limited to, oxide semiconductor materials. In this case, a light-shielding structure can be arranged beneath the semiconductor layer 120. The light-shielding structure can prevent light from reaching the semiconductor layer 120 and thus prevent light degradation of the semiconductor layer 120. Alternatively, the semiconductor layer 120 can also contain, but is not limited to, polycrystalline silicon. In this case, opposing edges of the semiconductor layer 120 can be doped with impurities.

[0021] A gate insulating layer 124 made of an insulating material is arranged on the semiconductor layer 120. The gate insulating layer 124 can contain an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), but is not limited to this.

[0022] A gate electrode 130 made of a conductive material, such as metal, is arranged above the gate insulating layer 124 such that it corresponds to a center of the semiconductor layer 120. While the gate insulating layer 124 in Fig. 2 is arranged over an entire area of ​​the substrate 110, the gate insulating layer 124 can be structured in the same way as the gate electrode 130.

[0023] An intermediate insulating layer 132 made of an insulating material is arranged on the gate electrode 130 and completely covers a surface of the substrate 110. The intermediate insulating layer 132 can contain an inorganic insulating material such as silicon dioxide (SiOx) or silicon nitride (SiNx) or an organic insulating material such as benzocyclobutene or photoacrylic, but is not limited to this.

[0024] The intermediate insulating layer 132 has a first and a second semiconductor layer contact hole 134 and 136, which expose both sides of the semiconductor layer 120. The first and second semiconductor layer contact holes 134 and 136 are arranged on opposite sides of the gate electrode 130 and spaced apart from the gate electrode 130. The first and second semiconductor layer contact holes 134 and 136 are located within the gate insulating layer 124 in Fig. 2 formed. Alternatively, the first and second semiconductor layer contact holes 134 and 136 are formed only within the intermediate insulating layer 132 if the gate insulating layer 124 is structured in the same way as the gate electrode 130.

[0025] On the intermediate insulating layer 132, a source electrode 144 and a drain electrode 146 are arranged, which are formed from a conductive material, such as metal. The source electrode 144 and the drain electrode 146 are spaced apart from each other with respect to the gate electrode 130 and contact both sides of the semiconductor layer 120 accordingly through the first and second semiconductor layer contact holes 134 and 136, respectively.

[0026] The semiconductor layer 120, the gate electrode 130, the source electrode 144, and the drain electrode 146 form the thin-film transistor Tr, which functions as a driver element. The thin-film transistor Tr in Fig. 2 has a coplanar structure in which the gate electrode 130, the source electrode 144, and the drain electrode 146 are arranged above the semiconductor layer 120. Alternatively, the thin-film transistor Tr can have an inverted, staggered structure in which a gate electrode is arranged below a semiconductor layer and a source electrode and a drain electrode are arranged above the semiconductor layer. In this case, the semiconductor layer can contain amorphous silicon.

[0027] The gate line GL and the data line DL, which intersect to define the pixel area P, and the switching element Ts, which is connected to the gate line GL and the data line DL, can further be located in the pixel area P of Fig. 1. The switching element Ts is connected to the thin-film transistor Tr, which is a driver element. In addition, the current line PL is spaced parallel to the gate line GL or to the data line DL, and the thin-film transistor Tr may further contain a storage capacitor Cst, which is configured to keep the voltage of the gate electrode 130 constant for one frame.

[0028] Furthermore, the organic light-emitting display device 100 can include a color filter layer containing dyes or pigments for transmitting light of specific wavelengths from the light emitted by the OLED D. For example, the color filter layer can transmit light of specific wavelengths such as red (R), green (G), and / or blue (B). Red, green, and blue color filter structures can each be arranged separately in each pixel area P. In this case, the organic light-emitting display device 100 can produce a full color through the color filter layer.

[0029] If the organic light-emitting display device 100 is, for example, of the bottom-emission type, the color filter layer can be arranged on the intermediate insulating layer 132, which corresponds to the OLED D. Alternatively, if the organic light-emitting display device 100 is of the top-emission type, the color filter layer can be arranged above the OLED D, i.e., a second electrode 230.

[0030] A passivation layer 150 is arranged on the source electrode 144 and the drain electrode 146 over the entire substrate 110. The passivation layer 150 has a flat top surface and a drain contact hole 152 that exposes the drain electrode 146 of the thin-film transistor Tr. Although the drain contact hole 152 is located on the contact hole 136 of the second semiconductor layer, it can also be spaced apart from the contact hole 136 of the second semiconductor layer.

[0031] The OLED D comprises a first electrode 210, which is arranged on the passivation layer 150 and connected to the drain electrode 146 of the thin-film transistor Tr. The OLED D further comprises an emission layer 220 and a second electrode 230, which are each arranged sequentially on the first electrode 210.

[0032] The first electrode 210 is located in each pixel area. The first electrode 210 can be an anode and contain a conductive material with a relatively high work function. For example, the first electrode 210 can contain a transparent, electrically conductive oxide (TCO). In particular, the first electrode 210 can contain, but is not limited to, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin-zinc oxide (ITZO), tin oxide (SnO), zinc oxide (ZnO), cerium-doped indium oxide (ICO), aluminum-doped zinc oxide (Al:ZnO, AZO).

[0033] In one exemplary aspect, if the organic light-emitting display device 100 is of the bottom-emission type, the first electrode 210 can have a single-layer structure made of a transparent, conductive material. Alternatively, if the organic light-emitting display device 100 is of the top-emission type, a reflective electrode or a reflective layer can be arranged beneath the first electrode 210. For example, the reflective electrode or reflective layer can contain, but is not limited to, silver (Ag) or an aluminum-palladium-copper (APC) alloy. In the case of the top-emission OLED D, the first electrode 210 can have a three-layer structure of ITO / Ag / ITO or ITO / APC / ITO. In addition, a bench layer 160 is arranged on the passivation layer 150 to cover the edges of the first electrode 210.The bank layer 160 exposes a center of the first electrode 210, which corresponds to pixel area P.

[0034] The emission layer 220 is arranged on the first electrode 210. As an example, the emission layer 220 can have a single-layer structure consisting of an emission material layer (EML). Alternatively, the emission layer 220 can have a multi-layer structure consisting of a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), an EML, a hole blocking layer (HBL), an electron transport layer (ETL), and / or an electron injection layer (EIL). Fig. 3, Fig. 8, Fig. 10 and Fig. 12) In one aspect, the emission layer 220 can have a single emitting part. Alternatively, the emission layer 220 can have multiple emitting parts to form a tandem structure.

[0035] The second electrode 230 is arranged above the substrate 110, above which the emission layer 220 is located. The second electrode 230 can be arranged over the entire display area and can contain a conductive material with a relatively low work function compared to the first electrode 210. The second electrode 230 can be a cathode. The second electrode 230 can contain, for example, aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), an alloy of these, or a combination thereof, such as an aluminum-magnesium alloy (Al-Mg), but is not limited to these materials. If the organic light-emitting display device 100 is of the top-emission type, the second electrode 230 is thin, so that it is transmissive (or semi-transmissive).

[0036] Furthermore, an encapsulation film 170 can be arranged over the second electrode 230 to prevent external moisture from penetrating the OLED D. The encapsulation film 170 can have, but is not limited to, a laminated structure consisting of a first inorganic insulating film 172, an organic insulating film 174, and a second inorganic insulating film 176.

[0037] Furthermore, the organic light-emitting display device 100 can include a polarizer to reduce external light reflection. The polarizer can, for example, be a circular polarizer. If the organic light-emitting display device 100 is of the bottom-emission type, the polarizer can be located below the substrate 110. Alternatively, if the organic light-emitting display device 100 is of the top-emission type, the polarizer can be located above the encapsulation film 170. In addition, a cover window can be attached to the encapsulation film 170 or to the polarizer. In this case, the substrate 110 and the cover window can be flexible, so that the organic light-emitting display device 100 can be a flexible display device.

[0038] In the following, we will describe OLED technology in more detail. Fig. Figure 3 is a schematic cross-sectional view showing an OLED according to an exemplary aspect of the present disclosure. As in Fig. As shown in Figure 3, the OLED D1 comprises: a first electrode 210 and a second electrode opposite each other, and an emission layer 220 with a single emitting part located between the first electrode 210 and the second electrode 230. The organic light-emitting display device 100 contains a red pixel area, a green pixel area, and a blue pixel area, and the OLED D1 can be located in the blue pixel area.

[0039] The emission layer 220 contains an EML 240 arranged between the first electrode 210 and the second electrode 230. Furthermore, the emission layer 220 may contain at least one HTL 260 arranged between the first electrode 210 and the EML 240, and one ETL 270 arranged between the second electrode 230 and the EML 240. In addition, the emission layer 220 may also contain at least one HIL 250 arranged between the first electrode 210 and the HTL 260, and one EIL 280 arranged between the second electrode 230 and the ETL 270. Alternatively, the emission layer 220 can also contain an EBL 265 located between the HTL 260 and the EML 240, and / or an HBL 275 located between the EML 240 and the ETL 270.

[0040] The first electrode 210 can be an anode that introduces holes into the EML 240. The first electrode 210 can contain, but is not limited to, a conductive material with a relatively high work function, such as a transparent electrically conductive oxide (TCO). By way of example, the first electrode 210 can contain, but is not limited to, ITO, IZO, ITZO, SnO, ZnO, ICO, AZO, and the like.

[0041] The second electrode 230 can be a cathode that introduces electrons into the EML 240. The second electrode 230 can contain a conductive material with a relatively low work function, i.e., a highly reflective material such as Al, Mg, Ca, Ag, an alloy of these, a combination of these, and the like.

[0042] The EML 240 contains a first compound (compound 1) DF, a second compound (compound 2) FD, and optionally a third compound (compound 3) H. For example, the first compound DF can be a delayed fluorescent material, the second compound FD can be a fluorescent material, and the third compound H can be a host.

[0043] When holes and electrons collide to form excitons in the EML 240, singlet excitons with a paired spin state and triplet excitons with an unpaired spin state are generated in a 1:3 ratio through spin alignment. Since conventional phosphors can only utilize singlet excitons, they exhibit low luminous efficacy. Phosphorescent materials can utilize both triplet and singlet excitons, but their lifetimes are too short to be suitable for commercial applications.

[0044] The first compound, DF, can be a thermally activated delayed fluorescence (TADF) material, which can solve the problems associated with conventional fluorescent and / or phosphorescent materials. This delayed fluorescent material has a very narrow energy level band gap ΔE. ST between a singlet energy level S1 DF and a triplet energy level T1 DF ( Fig. 7) Accordingly, both the excitons of the singlet energy level S1 can DF as well as the excitons of the triplet energy level T1 DF in the first compound DF of the fluorescent material is delayed into an intermediate energy level state, i.e. an ICT state (intramolecular charge-transfer state) (S1 DF →ICT→T1 DF ), and then the intermediate-state excitons can be transferred to a ground state (ICT → S0).

[0045] The delayed fluorescent material must have an energy level band gap ΔE ST ( Fig. 7) between the singlet energy level S1 DF and the triplet energy level T1 DF exhibit values ​​of approximately 0.05 to approximately 0.3 eV or less, so that the exciton energy is sufficient in both the singlet energy level S1 DF as well as in the triplet energy level T1 DF can be transferred into the ICT state. The material, which has a narrow energy level band gap ΔE ST between the singlet energy level S1 DF and the triplet energy level T1 DF exhibits joint fluorescence with intersystem crossing (ISC), in which the excitons of the singlet energy level S1 DF in their ground state S0 DF can be transferred, as well as delayed fluorescence with reverse intersystem crossing (RISC), in which the excitons of the triplet energy level T1 DFupwards into the excitons of the singlet energy level S1 DF can be transferred, and then the exciton of the singlet energy level S1 DF , which is from the triplet energy level T1 DF was transferred to the ground state S0 DF can be transferred.

[0046] The first compound DF can be a delayed-fluorescence material containing a first group consisting of an electron acceptor group with boron and oxygen atoms and a second group consisting of several electron donor groups (EDGs). The first delayed-fluorescence compound DF has the following structure of formula 1: where in Formula 1, each of R 1 to R 9 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30-group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is, where two to four of R 1 to R 9 a group with the following structure of formula 2 is, where in Formula 2, each of R 11 to R 18 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is, or two adjacent of R 11 to R 18 form an unsubstituted or substituted heteroaromatic ring with the following structure of formula 3, where at least two adjacent of R 11 to R18 form an unsubstituted or substituted heteroaromatic ring with the following structure of formula 3; and an asterisk indicates a link position, where in Formula 3, X equals NR 25 , O or S is; each of R 21 to R 25 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group; and a dashed line indicates a condensed part.

[0047] As used here, substituent in the term "substituted" includes deuterium, tritium, unsubstituted or deuterium- or halogen-substituted C1-C 20 -Alkyl, unsubstituted or deuterium or halogen-substituted C1-C 20 -Alkoxy, halogen, cyano, -CF3, a hydroxyl group, a carboxyl group, a carbonyl group, an amino group, a C1-C 10 -Alkylamino group, a C6-C 30 -Arylamino group, a C3-C 30 -Heteroarylamino group, a C6-C 30 -Aryl group, a C3-C 30 -Heteroaryl group, a nitro group, a hydracyl group, a sulfonate group, a C1-C 20 -Alkylsilyl group, a C6-C 30 -Arylsilyl group and a C3-C 30 -Heteroarylsilyl group, but is not limited to that.

[0048] For example, any of the aromatic C6-C 30 -group, the heteroaromatic C3-C 30 -group, of aromatic C6-C 20-rings, of the heteroaromatic C3-C 30 -Rings, of the C6-C 30 -Aryls and the C3-C 30 -Heteroaryls, the R 1 to R 9 in Formula 1, R 11 to R 18 in Formula 2 and / or R 21 to R 25 represented in formula 3, being independently unsubstituted or substituted with at least one of deuterium, tritium, C1-C 20 -Alkyl, C6-C 30 -Aryl, C3-C 30 -Heteroaryl, C6-C 30 -Arylamino and C3-C 30 -Heteroarylamino.

[0049] As used herein, the term “hetero” in terms such as “a heteroaromatic group”, “heteroaryl”, “heteroarylalkyl”, “heteroaryloxy”, “heteroarylamino” and “heteroaryl group” means that at least one carbon atom, for example 1-5 carbon atoms, forming an aromatic group or ring, is substituted with at least one heteroatom selected from the group consisting of N, O, S, P and combinations thereof.

[0050] The term “aromatic” or “aryl,” as used herein, is well known to those skilled in the art. The term encompasses monocyclic rings that are covalently bonded or polycyclic groups with fused rings. An aromatic group or aryl can be unsubstituted or substituted. For example, the aromatic C6-C 30 -group, the R 1 to R 9 in Formula 1, R 11 to R 18 in Formula 2 and / or R 21 to R 24can be represented in formula 3, independently of each other C6-C 30 -Aryl, C7-C 30 -Arylalkyl, C6-C 30 -Aryloxy and C6-C 30 -arylamine, but is not limited to it. For example, the aromatic C6-C 30 -group and / or the C6-C 30 -aryl group, which R 1 to R 9 in Formula 1, R 11 to R 18 in Formula 2 and / or R 21 to R 24The aryl group(s) represented in formula 3 can, independently of each other, comprise a non-condensed or condensed aryl group such as phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, pentalenyl, indenyl, indeno-indenyl, heptalenyl, biphenylenyl, indacenyl, phenalenyl, phenanthrenyl, benzo-phenanthrenyl, dibenzo-phenanthrenyl, azulenyl, pyrenyl, fluoranthenyl, triphenylenyl, chrysenyl, tetraphenylenyl, tetracenyl, pleiadenyl, picenyl, pentaphenylenyl, pentacenyl, fluorenyl, indeno-fluorenyl and spiro-fluorenyl, but is / are not limited to these.

[0051] As used herein, the term "heteroaromatic" or "heteroaryl" refers to heterocycles containing heteroatoms selected from N, O, and S in a ring, the ring system being an aromatic ring. The term includes monocyclic rings that are covalently bonded or polycyclic groups with fused rings. A heteroaromatic group can be unsubstituted or substituted. For example, the heteroaromatic C3-C 30 -group, the R 1 to R 9 in Formula 1, R 11 to R 18 in Formula 2 and / or R 21 to R 25 can be represented in formula 3, independently of each other C3-C 30 -Heteroaryl, C4-C 30 -Heteroarylalkyl, C3-C 30 -Heteroaryloxy and C3-C 30 -Heteroarylamino includes, but is not limited to.

[0052] For example, the C3-C 30 -Heteroaryl group, which R 1 to R 9 in Formula 1, R 11to R 18 in Formula 2 and / or R 21 to R 25in Formel 3 darstellen kann, unabhängig voneinander eine nicht kondensierte oder kondensierte Heteroarylgruppe wie Pyrrolyl, Pyridinyl, Pyrimidinyl, Pyrazinyl, Pyridazinyl, Triazinyl, Tetrazinyl, Imidazolyl, Pyrazolyl, Indolyl, Iso-Indolyl, Indazolyl, Indolizinyl, Pyrrolizinyl, Carbazolyl, Benzo-Carbazolyl, Dibenzo-Carbazolyl, Indolo-Carbazolyl, Indeno-Carbazolyl, Benzo-Furo-Carbazolyl, BenzoThieno-Carbazolyl, Carbolinyl, Chinolinyl, Isochinolinyl, Phthalazinyl, Chinoxalinyl, Cinnolinyl, Chinazolinyl, Chinolizinyl, Purinyl, Benzo-Chinolinyl, Benzo-Isochinolinyl, Benzo-Chinazolinyl, Benzo-Chinoxalinyl, Acridinyl, Phenazinyl, Phenoxazinyl, Phenothiazinyl, Phenanthrolinyl, Perimidinyl, Phenanthridinyl, Pteridinyl, Naphthyridinyl, Furanyl, Pyranyl, Oxazinyl, Oxazolyl, Oxadiazolyl, Triazolyl, Dioxanyl, Benzo-Furanyl, Dibenzo-Furanyl, Thiopyranyl, Xanthenyl, Chromenyl, Iso-Chromenyl, Thiazinyl, Thiophenyl, Benzo-Thiophenyl, Dibenzo-Thiophenyl, Difuro-Pyrazinyl, Benzofuro-Dibenzo-Furanyl,Benzothieno-benzo-thiophenyl, benzothieno-dibenzo-thiophenyl, benzothieno-benzo-furanyl, benzothieno-dibenzo-furanyl, N-substituted spiro-fluorenyl, spiro-fluoreno-acridinyl and spiro-fluoreno-xanthenyl are included, but are not limited to.

[0053] Furthermore, the aromatic C6-C 20 -ring and the heteroaromatic C3-C 20 -Ring, which is defined by two adjacent elements of R 11 to R 18 in formula 2, comprising a benzene ring, a naphthalene ring, an indene ring, a phenanthrene ring, an indene ring, a fluorene ring, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an indole ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring and / or combinations thereof, each unsubstituted or with at least one of deuterium, tritium, C1-C 20 -Alkyl, C6-C 30 -Aryl, C3-C 30-Heteroaryl, C6-C 30 -Arylamino and C3-C 30 -Heteroarylamino can be substituted, but are not limited to this.

[0054] For example, each of the aromatic C6-C 20 -group, the heteroaromatic C3-C 30 -group, of the condensed aromatic ring and of the condensed heteroaromatic ring, each of which R 1 to R 9 in Formula 1, R 11 to R 18 in Formula 2 and / or R 21 to R 25 represent in formula 3, unsubstituted or with at least one of C1-C 10 -Alkyl (e.g., C1-C5 alkyl such as tert-butyl), C6-C 30 -Aryl (e.g. C6-C 15 -aryl (such as phenyl), C3-C 30 -Heteroaryl (e.g. C3-C 15 -Heteroaryl such as pyridyl) and / or C6-C 30 -Arylamino (e.g. C6-C 15 -aryl such as diphenylamino) may be substituted.

[0055] In formula 1, the condensed heteroaromatic ring with boron and oxygen atoms acts as an electron acceptor group, and the condensed heteroaromatic ring with at least one nitrogen atom, with the structure of formula 2, acts as an electron donor group (EDG). Accordingly, the organic compound with the structure of formula 1 can exhibit delayed fluorescence.

[0056] Since the electron donor group with the structure of formula 2 has a pentagonal ring with a nitrogen atom between the lateral benzene rings, the group exhibits improved thermal stability because the bond strength between the electron donor and electron acceptor groups is maximized. The first compound DF with delayed fluorescence has excellent luminescence efficiency, allowing the exciton energy to be efficiently transferred from the first compound DF to the second compound FD, enabling the EML 240 to achieve hyperfluorescence.

[0057] The first compound, DF, with the structure of formula 1, contains the first group of the condensed ring with boron and oxygen atoms as the nucleus, acting as an electron acceptor group, and several (e.g., two to four, or two, or three, or two) second groups as electron donor groups, each with the structure of formula 2. Since the electron acceptor group and the electron donor group, each containing multiple condensed rings, are bulky, steric hindrance can be induced in these groups. Furthermore, because several bulky electron donor groups are arranged adjacent to each other within the molecule, steric hindrance can arise between these electron donor groups. This enhances the delayed fluorescence of the first compound, DF.

[0058] The first compound, DF, exhibits a molecular conformation in which the multiple electron donor groups are located adjacent to and outside the electron acceptor group of the central fused heteroring containing boron and oxygen atoms. While part of the HOMO (highest occupied molecular orbital) function overlaps with part of the LUMO (lowest unoccupied molecular orbital) function in the DF molecule, it is possible to minimize the HOMO so that it extends towards the central electron donor group. Consequently, the first compound, DF, with the structure of formula 1, can achieve high intramolecular charge mobility efficiency and a very high quantum yield.

[0059] The first compound DF, which induces multiple electron donor groups, is designed to maximize its molecular steric hindrance, resulting in partial overlap of HOMO and LUMO functions. Due to its intramolecular charge mobility efficiency, the first compound DF exhibits enhanced delayed fluorescence. The energy level band gap ΔE ST between the excited singlet energy level S1 DF and the excited triplet energy level T1 DF is very narrow ( Fig. 7) RISC can occur quickly because the spin-orbital coupling (SOC) becomes strong.

[0060] The first compound DF with formulas 1 to 3 has delayed fluorescence, as well as suitable singlet and triplet energy levels, HOMO and LUMO energy levels and excellent luminescent properties to efficiently transfer exciton energies to the second compound FD.

[0061] For example, the first compound DF can have two electron donor groups, each independently having the structure of formula 2. According to one example, two electron donor groups can each be bonded to a benzene ring formed by the condensation of a boron and an oxygen atom in the condensed heteroring that constitutes the electron acceptor group in the first compound DF. According to another example, two electron donor groups can be bonded to a benzene ring formed by the condensation of a boron and an oxygen atom in the condensed heteroring that constitutes the electron acceptor group in the first compound DF, and similarly to another benzene ring formed by the condensation of two oxygen atoms in the first compound DF.According to yet another exemplary aspect, two electron donor groups can be bonded to the benzene ring formed by the condensation of two oxygen atoms, which represent the electron acceptor groups in the first compound DF. For example, the first compound DF can have the following structure of formula 4: where in formula 4, . each of R 25 , R 26 , R 27 , R 28 and R 29 independently of each other hydrogen, deuterium, protium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylamino, unsubstituted or substituted C6-C 30 -Aryl or unsubstituted or substituted C3-C 30 -Heteroaryl is, where two of R 25 , R 26 , R 27 , R 28 and R 29 have the structure of Formula 2.

[0062] For example, any of C6-C 30-Aryl and C3-C 30 -Heteroaryl of R 25 , R 26 , R 27 , R 28 and R 29 in formula 4 independently unsubstituted or with at least one of deuterium, tritium, C1-C 20 -Alkyl, C6-C 30 -Aryl, C3-C 30 -Heteroaryl, C6-C 30 -Arylamino and C3-C 30 -Heteroarylamino may be substituted.

[0063] At least two adjacent to R 11 to R 18 In formula 2, the condensed heteroaromatic ring with the structure of formula 3 can form. For example, at least two adjacent R 11 to R 18In formula 2, an unsubstituted or substituted indene ring, an unsubstituted or substituted indole ring, an unsubstituted or substituted benzofuran ring, or an unsubstituted or substituted benzothiopene ring may form. Accordingly, the heteroaromatic group with the structure of formula 2, which acts as an electron donor group, may include, but is not limited to, an unsubstituted or substituted indenocarbazolyl group, an unsubstituted or substituted indolocarbazolyl group, an unsubstituted or substituted benzofurocarbazolyl group, and an unsubstituted or substituted benzothienocarbazolyl group. For example, the electron donor group with the structure of formula 2 may be selected from, but is not limited to, the following groups of formula 5:

[0064] In particular, the first compound DF can be selected from organic compounds with the following structure of formula 6, but is not limited to this:

[0065] The first compound DF of the delayed fluorescent material has a narrow energy band gap ΔE ST between the excited singlet energy level S1 DF and the excited triplet energy level T1 DF of equal to or less than approximately 0.3 eV ( Fig. 7) and exhibits excellent quantum yield, as the excited triplet exciton energy of the first compound DF is transferred to the excited singlet exciton via RISC. However, the first compound DF has a deformed chemical conformation due to the bonding structure between the electron donor group and the electron acceptor group. Since the first compound DF utilizes triplet excitons, an additional charge-transfer transition (CT transition) is induced in the first compound DF. The first compound DF, with the structures of formulas 1 to 6, has a limit in terms of color purity due to the wide full width at half maximum (FWHM) caused by the CT luminescence mechanism.

[0066] If the EML 240 contains only the first compound DF as an emitter, the triplet exciton energy of the first compound DF cannot contribute efficiently to light emission, and the luminous lifetime of the OLED D1 may be reduced due to quenching processes such as TTA (triplet-triplet annihilation) and / or TPA (triplet-polaron annihilation).

[0067] The EML 240 contains the second compound FD of the fluorescent material to maximize the luminescence properties of the first compound DF of the delayed-release fluorescent material and achieve hyperfluorescence. As described above, the first compound DF of the delayed-release fluorescent material can utilize both singlet and triplet exciton energies. If the EML 240 contains the second compound FD of the fluorescent material at suitable energy levels compared to the first compound DF of the delayed-release fluorescent material, the second compound FD can absorb exciton energies released by the first compound DF. The second compound FD can then generate 100% singlet excitons by utilizing the absorbed exciton energies for maximum luminous efficacy.

[0068] The singlet exciton energy of the first compound DF, which comprises the singlet exciton energy of the first compound DF converted from its own triplet exciton energy and the initial singlet exciton energy in the EML 240, is transferred to the second compound FD of the fluorescent material in the same EML 240 via the Förster resonance energy transfer (FRET) mechanism. Emission ultimately occurs via the second compound FD. Organic material with an absorption spectrum that largely overlaps with the photoluminescence spectrum of the first compound DF can be used as the second compound FD, allowing the exciton energy generated in the first compound DF to be efficiently transferred to the second compound FD.Since the ultimately emitting second compound FD has a narrow FWHM and excellent luminescence lifetime, the color purity and luminescence lifetime emitted by the OLED D1 can be improved.

[0069] The second compound FD in the EML 240 can be a blue fluorescent material. For example, the second compound FD incorporated into the EML 240 can be a boron-based fluorescent material with a FWHM of approximately 35 nm or less. The second compound FD of the boron-based fluorescent material has the following structure of formula 7: where in Formula 7, each of R 31 to R 34 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20-Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is optional two adjacent elements of R 31 to R 34 form an unsubstituted or substituted condensed ring with boron and nitrogen; each of R 35 to R 38 independently of each other deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is where each R 35 is identical or different from each other if q is an integer of two or more, each R 36is identical or different from each other if r is an integer of two or more, each R 37 is identical or different from each other if s is an integer of two or more and each R 38 is identical or different from each other if t is an integer of two or more; q and s are each independently an integer from 0 to 5; r is an integer from 0 to 3; and t is an integer from 0 to 4.

[0070] For example, each of the aromatic C6-C 30 -group, the heteroaromatic C3-C 30 -group and of the condensed ring with boron and nitrogen, which R 31 to R 38 represent, independently of each other unsubstituted or with at least one of deuterium, tritium, C1-C 20 -Alkyl, C6-C 30 -Aryl, C3-C 30 -Heteroaryl C6-C 30 -Arylamino and / or C3-C 30-Heteroarylamino may be substituted.

[0071] Similar to formulas 1 to 3, the aromatic C6-C 30 -group, each of R 31 to R 38 as represented in Formula 7, independently of each other C6-C 30 -Aryl, C7-C 30 -Arylalkyl, C6-C 30 -Aryloxy and C6-C 30 -arylamine, but is not limited to it. The heteroaromatic C3-C 30 -group, each of R 31 to R 38 as represented in formula 7, C3-C can be independently of each other. 30 -Heteroaryl, C4-C 30 -Heteroarylalkyl, C3-C 30 -Heteroaryloxy and C3-C 30 -Heteroarylamino is included, but is not limited to it.

[0072] The second compound FD, based on boron and with the structure of formula 7, has excellent luminescent properties. Because this second boron-based compound FD, with its structure of formula 7, has a broad platelet-like molecular conformation, it can efficiently absorb exciton energies released by the first compound DF, thus maximizing the light output in the EML 240.

[0073] According to one exemplary aspect, R 31 to R 34 in formula 7, they can be linked together. Alternatively, R 32 and R 33 In formula 7, the condensed ring with boron and nitrogen atoms is formed. For example, the second compound FD can contain a boron-based organic compound with the structure of formulas 8A to 8C. where in formulas 8A to 8C, each of R 41 to R 44 and R 51 to R 55independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, unsubstituted or substituted C 6 -C 30 -Arylamino, unsubstituted or substituted C6-C 30 -Aryl or unsubstituted or substituted C3-C 30 -Heteroaryl is.

[0074] For example, any of C6-C 30 -Aryl and C3-C 30 -Heteroaryl of the R 41 to R 44 and R 51 to R 55 independently unsubstituted or with at least one of deuterium, tritium, C1-C 20 -Alkyl, C6-C 30 -Aryl, C3-C 30 -Heteroaryl, C6-C 30 -Arylamino and / or C3-C 30 -Heteroarylamino may be substituted.

[0075] In particular, the second compound FD of the boron-based organic compound can be selected from an organic compound with the following structure of formula 9, but is not restricted:

[0076] The third compound H in the EML 240 can contain any organic compound that has a larger band gap between a HOMO energy level and a LUMO energy level compared to the first compound DF and / or the second compound FD. For example, if the EML 240 contains the third compound H of the host, the first compound DF can be a first dopant and the second compound FD a second dopant.

[0077] Gemäß einem beispielhaften Aspekt kann die dritte Verbindung H, die in der EML 240 enthalten sein kann, enthalten: 4,4'-Bis(N-carbazolyl)-1,1'-biphenyl (CBP), 3,3'-Bis(N-carbazolyl)-1,1'-biphenyl (mCBP), 1,3-Bis(carbazol-9-yl)benzol (mCP), 9-(3-(9H-carbazol-9-yl)phenyl)-9H-carbazol-3-carbonitril (mCP-CN), Oxybis(2,1-phenylen))bis(diphenylphosphinoxid (DPEPO), 2,8-Bis(diphenylphosphoryl)dibenzothiophen (PPT), 1,3, 5-Tri[(3-pyridyl)-phen-3-yl]benzol (TmPyPB), 2,6-Di(9H-carbazol-9-yl)pyridin (PYD-2Cz), 2,8-Di(9H-carbazol-9-yl)dibenzo[b,d]thiophen (DCzDBT), 3', 5'-Di(carbazol-9-yl)-[1,1'-bipheyl]-3,5-dicarbonitril (DCzTPA), 4'-(9H-Carbazol-9-yl)biphenyl-3,5-dicarbonitril (4'-(9H-Carbazol-9-yl)biphenyl-3, 5-Dicarbonitril (pCzB-2CN), 3'-(9H-Carbazol-9-yl)biphenyl-3,5-dicarbonitril (mCzB-2CN), Diphenyl-4-triphenylsilylphenyl-phosphinoxid (TSPO1), 9-(9-Phenyl-9H-carbazol-6-yl)-9H-carbazol (CCP), 4-(3-(Triphenylen-2-yl)phenyl)dibenzo[b,d]thiophen, 9-(4-(9H-carbazol-9-yl)phenyl)-9H-3,9'-Bicarbazole, 9-(3-(9H-Carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole, 9-(6-(9H-Carbazol-9-yl)pyridin-3-yl)-9H-3,9'-bicabazole and combinations thereof, but is not limited to these.

[0078] In one exemplary aspect, if the EML 240 contains the first compound DF, the second compound FD, and the third compound H, the concentration of the third compound H in the EML 240 can be greater than the concentration of the first compound DF in the EML 240, and the concentration of the first compound DF in the EML 240 can be greater than the concentration of the second compound FD in the EML 240. If the concentration of the first compound DF is greater than the concentration of the second compound FD, the exciton energy can be effectively transferred from the first compound DF to the second compound FD via the FRET mechanism. For example, the content of the third compound H in EML 240 can be approximately 55 wt.% to approximately 85 wt.%, the content of the first compound DF in EML 240 can be approximately 10 wt.% to approximately 40 wt.%, for example approximately 10 wt.% to approximately 30 wt.%, and the content of the second compound FD in EML 240 can be approximately 0.1 wt.% to approximately 5 wt.%.The percentage may be -%, for example approximately 0.1 wt.% to approximately 2 wt.%, but is not limited to this.

[0079] It is necessary to control a photoluminescence wavelength and an absorption wavelength between the first junction DF and the second junction FD in order to improve the luminous efficacy and color purity of the OLED D1. Fig. Figure 4 is a schematic diagram showing that the luminous efficacy and color purity of an OLED can be improved by controlling an onset wavelength of the first compound and a maximum absorption wavelength of the second compound, in accordance with an exemplary aspect of the present disclosure.

[0080] As in Fig. As shown in Figure 4, the transfer efficiency of exciton energies from the first compound DF to the second compound FD can be improved if the degree of overlap between the photoluminescence (PL) spectrum PL DFthe first compound DF and the absorption spectrum Abs FD The second compound FD becomes large. For example, the distance between the maximum photoluminescence wavelength λ can be PL.max DF the first compound DF and the maximum absorption wavelength λ Abs.max FD The wavelength of the second compound, FD, should be equal to or less than approximately 30 nm, for example, approximately 20 nm. The maximum PL wavelength λ PL.max DF The wavelength of the first compound DF can be between approximately 460 nm and approximately 480 nm, for example between approximately 470 nm and approximately 480 nm.

[0081] According to one exemplary aspect, the onset wavelength λ onset DFThe onset wavelength of the first compound, DF, lies between approximately 430 nm and approximately 440 nm. As used herein, the term "onset wavelength" refers to a wavelength value at the point where the extrapolation line and an x-axis (wavelength) intersect in a linear region of a short-wavelength area in the PL spectrum of the organic compound. More precisely, the onset wavelength can be defined as a wavelength corresponding to a shorter wavelength than one of two wavelengths whose emission intensity is 1 / 10 of the maximum value in the PL spectrum. The onset wavelength λ onset DF The first compound DF can be equal to or shorter than the maximum absorption wavelength λ. Abs.max FD of the second compound FD. For example, the maximum absorption wavelength λ can be Abs.max FDThe second compound FD should be equal to or longer than approximately 440 nm, for example between approximately 440 nm and approximately 470 nm or between approximately 450 nm and approximately 460 nm.

[0082] If the onset wavelength λ onset DF The wavelength of the first compound DF lies between approximately 430 nm and approximately 440 nm and is equal to or shorter than the maximum absorption wavelength λ. Abs.max FD Since the second compound FD is, both the initial singlet exciton energy and the singlet exciton energy converted by the RISC mechanism of the first compound DF can be efficiently transferred to the second compound FD.

[0083] Since the first compound DF contains multiple electron donor groups, it exhibits very high steric hindrance. Therefore, controlling the HOMO and LUMO in the first compound DF can maximize the efficiency of intramolecular charge mobility, and thus the conversion to the singlet state from the triplet state in the first compound DF can occur rapidly. Accordingly, the triplex exciton generated in the first compound DF can be converted upwards to its own singlet exciton via the RISC mechanism without being transferred to the second compound FD. The singlet exciton energies generated in the first compound DF are transferred to the second compound FD via the FRET mechanism, which occurs very rapidly.

[0084] Since the triplet exciton generated in the first junction DF is converted upwards into its own singlet exciton, the converted singlet exciton of the first junction DF can be rapidly transferred to the singlet exciton of the second junction FD. Accordingly, the exciton energy can be efficiently transferred from the first junction DF to the second junction FD, thus maximizing the luminous efficacy of the OLED D1.

[0085] On the contrary, as in Fig. 5 shown when the onset wavelength λ onset DF If the wavelength of the first compound DF is less than 430 nm, the first compound DF may exhibit lower delayed fluorescence and / or the second compound H, as the host transferring exciton energies to the first compound DF, must have a very high excited triplet energy level T1. HThis occurs when the triplet exciton generated in the first junction DF is not converted into its own singlet exciton by RISC and transferred to the triplet exciton of the second junction FD. Since the triplet exciton transferred to the second junction FD is quenched without participating in the luminescence process, the luminescence efficiency of the OLED can be reduced.

[0086] If the onset wavelength λ onset DF If the wavelength of the first compound is longer than 440 nm, the maximum PL wavelength λ is... PL.max DF The first compound DF is also excessively far from the maximum absorption wavelength λ. Abs.max FD the second compound FD removed. Since the degree of overlap between the PL spectrum PLDF of the first compound DF and the absorption spectrum Abs FDAs the exciton energy transfer from the first junction DF to the second junction FD decreases, the efficiency of exciton energy transfer from the first junction DF to the second junction FD also decreases. Since the exciton not transferred to the second junction FD remains in the first junction FD, the luminous efficacy of the OLED D1 decreases because the excitons remaining in the first junction DF are quenched as non-emission. Furthermore, the color purity of the OLED D1 can deteriorate because the first junction DF and the second junction FD emit light simultaneously.

[0087] Similarly, as in Fig. Figure 6 shows the efficiency of exciton energy transfer from the first compound DF to the second compound FD when the onset wavelength λ onset DF The wavelength of the first compound DF is longer than the maximum absorption wavelength λ. Abs.max FDof the second compound FD, since the degree of overlap between the PL spectrum PLDF of the first compound DF and the absorption spectrum Abs FD The second junction FD decreases. Since the exciton that is not transferred to the second junction FD remains in the first junction FD, the luminous efficacy of the OLED D1 decreases because the excitons remaining in the first junction DF are quenched as non-emission. Furthermore, the color purity of the OLED D1 can deteriorate because the first junction DF and the second junction FD emit light simultaneously.

[0088] In other words, if the onset wavelength λ onset DF the first compound DF lies beyond 440 nm and / or the onset wavelength λ onset DF The wavelength of the first compound DF is longer than the maximum absorption wavelength λ. Abs.max FDIn the second compound FD, some of the excitons are in the excited singlet energy level S1. DF the first compound DF through inter-system crossing (ISC) into the excited triplet energy level T1 DF converted. The excitons at the triplet energy level T1 DF In the first connection, no upward conversion via RISC to the excited singlet energy level S1 occurs. DF They are converted so that triplet excitons are generated and remain at the excited triplet energy level T1DF. Since such triplet excitons interact with peripheral triplet excitons or polarons, they are quenched by TTA and / or TPA.

[0089] Furthermore, the HOMO and / or LUMO energy levels of the third compound H of the host, the first compound DF of the delayed fluorescent material, and the second compound FD of the fluorescent material in the EML 240 should be correctly adjusted. To achieve hyperfluorescence, for example, the host must allow the triplet excitons generated in the delayed fluorescent material to participate in the luminescence process without being quenched via non-radiative recombination. For this purpose, the energy levels between the third compound H of the host, the first compound DF of the delayed fluorescent material, and the second compound FD of the fluorescent material should be adjusted.

[0090] For example, the HOMO energy level HOMO H The third connection H of the host lies lower than the HOMO energy level HOMO DFthe first compound DF of the delayed fluorescent material, and the LUMO energy level LUMO H The third compound H can be flatter than the LUMO energy level LUMO DF of the first compound DF. In other words, the band gap of the energy level between the HOMO energy level HOMO H and the LUMO energy level LUMO H The third compound H can be wider than the band gap of the energy level between the HOMO energy level HOMO DF and the LUMO energy level LUMO DF the first connection. DF.

[0091] For example, an energy level band gap (|HOMO) H -HOMO DF |) between the HOMO energy level (HOMO H ) the third compound H and the HOMO energy level (HOMO DF ) of the first connection DF or an energy level band gap (|LUMO) H -LUMO DF |) between the LUMO energy level (LUMO H) the third compound H and the LUMO energy level (LUMO DF ) of the first junction DF equal to or less than approximately 0.5 eV, for example between approximately 0.1 eV and approximately 0.5 eV. In this case, the charges can be efficiently transported from the third junction H to the first junction DF, thereby improving the final luminous efficacy in the OLED D1.

[0092] Furthermore, the band gap (|HOMO) DF -HOMO FD |) between the HOMO energy level HOMO DF the first compound DF and the HOMO energy level HOMO FThe energy D of the second compound is less than approximately 0.3 eV, for example, equal to or less than approximately 0.2 eV. In this case, the holes injected into the EML 240 can be rapidly transferred to the first compound DF. Accordingly, the first compound DF can achieve an internal quantum yield of 100% by utilizing both the initial singlet exciton energy and the singlet exciton energy converted from the triplet exciton energy by the RISC mechanism, and the first compound DF can efficiently transfer the exciton energy to the second compound FD.

[0093] According to another exemplary aspect, the LUMO energy level LUMO DF The first compound DF is identical to the LUMO energy level LUMO FD The second connection may be FD or flatter than this one. For example, the energy level band gap between the LUMO energy level LUMO DFthe first connection DF and the LUMO energy level LUMO FD The voltage of the second compound must be equal to or less than approximately 0.5 eV, for example, approximately 0.2 eV. In this case, the electrons injected into the EML 240 can be rapidly transferred to the first compound DF.

[0094] If, on the other hand, the band gap (|HOMO DF -HOMO FD |) between the HOMO energy level HOMO DF the first compound DF and the HOMO energy level HOMO FDIf the energy of the second compound FD is equal to or greater than 0.3 eV, the holes injected into the EML 240 are not transferred from the third compound H of the host to the first compound DF, but are trapped in the second compound FD. The holes trapped in the second compound FD are directly recombined and form excitons with emission. Since the triplet exciton energy of the first compound DF is quenched without contributing to light emission, the light output of the EML 240 is lower.

[0095] When the LUMO energy level LUMO DF The first connection DF lies lower than the LUMO energy level LUMO FDIn the second compound FD, an exciplex forms between the holes trapped in the second compound FD and the electrons transferred to the first compound FD. Since the triplet exciton energy of the first compound DF is quenched by non-emission, the luminous efficacy of the EML 240 can decrease. Furthermore, because the energy band gap between the LUMO and HOMO energy levels, which form the exciplex, is excessively narrow, light with longer wavelengths is emitted. Since both the first compound DF and the second compound FD emit light simultaneously, the EML 240 emits light with poorer color purity due to its wider FWHM.

[0096] For example, the first compound DF can be a HOMO energy level HOMO DF between approximately -5.5 eV and approximately -5.7 eV and a LUMO energy level LUMO DFThe energy levels range between approximately -2.5 eV and approximately 2.8 eV, but are not limited to this range. The second compound, FD, can be the HOMO energy level. FD between approximately -5.3 eV and approximately -5.6 eV and the LUMO energy level LUMO FD between approximately -2.7 eV and approximately -2.9 eV, but is not limited to this.

[0097] The energy level band gap between the HOMO energy level HOMO DF and the LUMO energy level LUMO DF The first compound DF can be wider than the energy level band gap between the HOMO energy levels HOMO FD and the LUMO energy level LUMO FD of the second compound FD. According to an exemplary aspect, the energy level band gap between the HOMO energy level HOMO DF and the LUMO energy level LUMO DFThe first connection DF lies between approximately 2.6 eV and approximately 3.1 eV, for example, approximately 2.7 eV and approximately 3.0 eV. The energy level band gap between the HOMO energy level HOMO FD and the LUMO energy level LUMO FD The exciton energy of the second compound FD can lie between approximately 2.4 eV and approximately 2.9 eV, for example between approximately 2.5 eV and approximately 2.8 eV. In this case, the exciton energies generated in the first compound DF can be efficiently transferred to the second compound FD, in which sufficient light emissions occur.

[0098] By matching the photoluminescence wavelength ranges of the first compound DF and the absorption wavelength ranges of the second compound FD, as well as the HOMO and LUMO energy levels between these compounds, excitons in the first compound DF of the delayed-release fluorescent material can recombine, enabling an internal quantum yield of 100% via the RISC mechanism. The excited singlet exciton energy generated in the first compound DF via RISC is transferred to the second compound FD of the fluorescent material by FRET, allowing for efficient light emission in the second compound FD. Consequently, the OLED D1 can be realized with excellent color purity.

[0099] The luminescence mechanism is now described in EML 240. Fig. Figure 7 is a schematic diagram illustrating a luminescence mechanism through singlet and triplet energy levels under luminescent materials in an EML in accordance with an exemplary aspect of the present disclosure. As in Fig. Figure 7 shows the singlet energy level S1 schematically. H the third compound H, which the host in the EML 240 can be, higher than the singlet energy level S1 DF the first compound DF with delayed fluorescence. In addition, the triplet energy level T1 can H The third compound H must be higher than the triplet energy level T1 DF the first compound DF. For example, the triplet energy level T1 H The energy level of the third compound H must be at least approximately 0.2 eV higher than the triplet energy level T1, for example at least approximately 0.3 eV, such as at least approximately 0.5 eV. DF the first connection DF.

[0100] When the triplet energy level T1 H and / or the singlet energy level S1 H the third compound H is / are not high enough to reach the triplet energy level T1 DF and / or the singlet energy level S1 DF To reach the first compound DF, the excitons can reach the triplet energy level T1. DF the first compound DF in the reverse direction to the triplet energy level T1 H to the third compound H. In this case, the triplet exciton, which was transferred in the reverse direction to the third compound H, where the triplet exciton cannot be emitted, is quenched as non-emission, so that the triplet exciton energy of the first compound DF with delayed fluorescence cannot contribute to the luminescence. For example, the first compound DF with delayed fluorescence can have an energy level band gap ΔE ST between the singlet energy level S1 DFand the triplet energy level T1 DF exhibit values ​​of approximately 0.3 eV or less, for example between approximately 0.05 eV and approximately 0.3 eV.

[0101] Furthermore, the singlet exciton energy generated in the first compound DF of the delayed fluorescent material, which is converted into an ICT complex by RISC in the EML 240, should be efficiently transferred to the second compound FD of the fluorescent material to realize OLED D1 with high luminous efficacy and high color purity. For this purpose, the singlet energy level S1 DF The first compound DF of the delayed fluorescent material has a higher energy level than the singlet energy level S1. FD the second compound FD of the fluorescent material. Optionally, the triplet energy level T1 can be used. DF The energy level of the first compound DF must be higher than the triplet energy level T1. FD the second connection FD.

[0102] Since the second compound FD can utilize both the singlet and triplet exciton energies of the first compound DF, the luminous efficacy of the OLED D1 can be maximized. Furthermore, the luminous lifetime of the OLED D1 can be significantly improved by minimizing quenching phenomena such as TTA and / or TPA.

[0103] Back to Fig. 3: The HIL 250 is arranged between the first electrode 210 and the HTL 260 and improves an interface property between the inorganic first electrode 210 and the organic HTL 260.According to one exemplary aspect, HIL 250 can contain 4,4',4"-Tris(3-methylphenylamino)triphenylamine (MTDATA), 4,4',4''-Tris(N,N-diphenyl-amino)triphenylamine (NATA), 4,4',4''-Tris(N-(naphthalen-1-yl)-N-phenyl-amino)triphenylamine (1T-NATA), 4,4',4''-Tris(N-(naphthalen-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-ethylenedioxythiphen)polystyrenesulfonate (PEDOT / PSS), 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 to these. HIL 250 may be omitted in accordance with a structure of OLED D1.

[0104] The HTL 260 is positioned between the HIL 250 and the EML 240. According to one example, the HTL 260 can be N,N'-Diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), NPB, 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), Di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane (TAPC), 5-Di(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-fluoren-2-amine, N-(Biphenyl-4-yl)-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)biphenyl-4-amine and combinations thereof, but is not limited to these.

[0105] The ETL 270 and the EIL 280 can be layered sequentially between the EML 240 and the second electrode 230. The ETL 270 contains material with high electron mobility to ensure a uniform supply of electrons to the EML 240 via rapid electron transport. By way of example, the ETL 270 can contain, but is not limited to, oxadiazole-based compounds, triazole-based compounds, phenanthroline-based compounds, benzoxazole-based compounds, benzothiazole-based compounds, benzimidazole-based compounds, triazine-based compounds, and the like.

[0106] The ETL 270 can, for example, aluminum tris-(8-hydroxyquinoline) (Alq3), 2-biphenyl-4-yl-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD), spiro-PBD, lithium quinolate (Liq), 1,3,5-tris (N-phenylbenzimidazol-2-yl)benzene (TPBi), Bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-olato)aluminum (BAlq), 4,7-diphenyl-1,10-phenanthroline (Bphen), 2,9-bis(naphthalen-2-yl)4,7-diphenyl-1,10-phenanthroline (NBphen), 2,9-dimethyl-4, 7-Diphenyl-1,10-phenathroline (BCP), 3-(4-Biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(Naphthalin-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 1,3,5-Tri(p-pyrid-3-yl-phenyl)benzene (TpPyPB), 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]-alt-2,7-(9,9-dioctylfluorene)] (PFNBr), Tris(phenylquinoxaline) (TPQ), TSPO1 and combinations thereof, is included, but is not limited to.

[0107] The EIL 280 is positioned between the second electrode 230 and the ETL 270 and can improve the physical properties of the second electrode 230, thus increasing the luminous lifetime of the OLED D1. By way of example, the EIL 280 can contain, but is not limited to, 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 lithium quinolate, lithium benzoate, sodium stearate, and the like.

[0108] If holes are transferred via the EML 240 to the second electrode 230 and / or electrons are transferred via the EML 240 to the first electrode 210, the OLED D1 may exhibit a short lifetime and reduced luminous efficacy. To prevent these phenomena, the OLED D1 may, according to this aspect of the present disclosure, have at least one exciton-blocking layer adjacent to the EML 240.

[0109] For example, according to the exemplary aspect, the OLED D1 contains the EBL 265 between the HTL 260 and the EML 240 to control and prevent electron transfer. According to another exemplary aspect, the EBL 265 may contain, but is not limited to, TCTA, Tris[4-(Diethylamino)phenyl]amine, N-(Biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, TAPC, MTDATA, mCP, mCBP, CuPc, N,N'-Bis[4-(bis(3-methylphenyl)amino)phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (DNTPD), TDAPB, 3,6-Bis(N-carbazolyl)-N-phenylcarbazole, and combinations thereof.

[0110] Furthermore, the OLED D1 can incorporate the HBL 275 as a second exciton-blocking layer between the EML 240 and the ETL 270, thus preventing hole transfer from the EML 240 to the ETL 270. By way of example, the HBL 275 can contain oxadiazole-based, triazole-based, phenanthroline-based, benzoxazole-based, benzothiazole-based, benzimidazole-based, and triazine-based compounds, any of which can be used in the ETL 270, but is not limited to them.

[0111] HBL 275, for example, may contain a compound with a relatively low HOMO energy level compared to the HOMO energy level of the phosphors in EML 240. HBL 275 may contain, but is not limited to, BCP, BAlq, Alq3, PBD, spiro-PBD, Liq, 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.

[0112] In the aspect above, the first compound DF with the delayed-release fluorescent material and the second compound FD with the fluorescent material are contained in the same EML. In contrast, in this aspect, the first compound and the second compound are contained in separate EMLs.

[0113] Fig. Figure 8 is a schematic cross-sectional view showing an OLED according to another exemplary aspect of the present disclosure. Fig. Figure 9 is a schematic diagram illustrating the luminescence mechanism via singlet and triplet energy levels in luminescent materials in EMLs according to another exemplary aspect of the present disclosure.

[0114] As in Fig. As shown in Figure 8, the OLED D2 comprises a first electrode 210 and a second electrode 230, which are opposite each other, and an emission layer 220A with a single emitting part arranged between the first electrode 210 and the second electrode 230. The organic light-emitting display device 100 ( Fig. 2) has a red pixel area, a green pixel area and a blue pixel area, and the OLED D2 can be located in the blue pixel area.

[0115] According to one exemplary aspect, the emission layer 220A contains an EML 240A. Furthermore, the emission layer 220A can contain at least one HTL 260 arranged between the first electrode 210 and the EML 240A, and one ETL 270 arranged between the second electrode 230 and the EML 240A. Additionally, the emission layer 220A can contain at least one of the following: an HTL 250 arranged between the first electrode 210 and the HTL 260, and an ETL 280 arranged between the second electrode 230 and the ETL 270. Alternatively, the emission layer 220A can also contain an EBL 265, which is arranged between the HTL 260 and the EML 240A, and / or an HBL 275, which is arranged between the EML 240A and the ETL 270.The configuration of the first electrode 210 and second electrode 230, as well as other layers except the EML 240A in the emission layer 220A, can be essentially identical to the corresponding electrodes and layers in the OLED D1.

[0116] The EML 240A contains a first EML (EML1, lower EML, first layer) 242, which is arranged between the EBL 265 and the HBL 275, and a second EML (EML2, upper EML, second layer) 244, which is arranged between the EML1 242 and the HBL 275. Alternatively, the EML2 244 can also be arranged between the EBL 265 and the EML1 242.

[0117] One of the EML1 242 and the EML2 244 contains the first compound (first dopant) DF of the delayed-release fluorescent material, and the other of the EML1 242 and the EML2 244 contains the second compound (second dopant) FD of the fluorescent material. Furthermore, both EML1 242 and EML2 244 contain a third compound (compound 3) H1 of a first host and a fourth compound (compound 4) H2 of a second host. For example, EML1 242 can contain the first compound DF and the third compound H1, and EML2 244 can contain the second compound FD and the fourth compound H2.

[0118] The first compound DF in EML1 242 can contain any delayed-fluorescence material with the structure of formulas 1 to 6. The triplet exciton energy of the first delayed-fluorescence compound DF can be converted up to its own singlet exciton energy via the RISC mechanism. While the first compound DF has a high internal quantum yield, it exhibits low color purity due to a large FWHM.

[0119] EML2 244 contains the second compound FD of the fluorescent material. The second compound FD includes any organic compound with the structure of formulas 7 to 9. Due to its narrow FWHM (e.g., equal to or less than approximately 35 nm), the second compound FD of the fluorescent material with the structure of formulas 7 to 9 offers an advantage in terms of color purity.

[0120] In this exemplary aspect, the singlet exciton energy as well as the triplet exciton energy of the first compound DF with delayed fluorescence in the EML1 242 can be transferred to the second compound FD in the EML2 244, which is located next to the EML1 242, via the FRET mechanism, and the light emission ultimately takes place in the second compound FD within the EML2 244.

[0121] In other words, the triplet exciton energy of the first compound DF in EML1 242 is converted upwards to its own singlet exciton energy via the RISC mechanism. Subsequently, both the initial singlet exciton energy and the converted singlet exciton energy of the first compound DF are transferred to the singlet exciton energy of the second compound FD in EML2 244. The second compound FD in EML2 244 can emit light using either the triplet exciton energy or the singlet exciton energy.

[0122] Since the singlet exciton energy generated in the first compound DF in EML1 242 is efficiently transferred to the second compound FD in EML2 244, the OLED D2 can achieve hyperfluorescence. In this case, while the first compound DF, with its delayed fluorescence, only transfers exciton energy to the second compound FD, significant light emission occurs in EML2 244, which contains the second compound FD. The quantum yield and color purity with a narrow FWHM of the OLED D2 can be improved.

[0123] Each of the EML1 242 and the EML2 244 contains the third compound H1 and the fourth compound H2, respectively. The third compound H1 can be identical to or different from the fourth compound H2. For example, each of the third compound H1 and the fourth compound H2 can contain the third compound H, as described above, but is not limited to it.

[0124] As described above, the onset wavelength λ onset DF the wavelength of the first compound DF is equal to or shorter than the maximum absorption wavelength λ Abs.max FD The second compound FD might be located, for example, between approximately 430 nm and approximately 440 nm. Furthermore, the first compound DF and the second compound FD can exhibit the HOMO and LUMO energy levels described above.

[0125] Also an energy level band gap (|HOMO) H -HOMO DF |) between the HOMO energy levels (HOMO H1 and HOMOH2 ) the third compound H1 and the fourth compound H2 and the HOMO energy level (HOMO DF ) of the first connection DF, or an energy level band gap (|LUMO) H -LUMO DF |) between the LUMO energy levels (LUMO H1 and LUMO H2 ) the third compound H1 and the fourth compound H2 and the LUMO energy level (LUMO DFThe energy level of the first compound DF can be equal to or less than approximately 5 eV. If the HOMO or LUMO energy level band gap between the third compound H1, the fourth compound H2, and the first compound DF does not satisfy this condition, the exciton energy in the first compound DF may be quenched as non-radiative recombination, or exciton energies may not be efficiently transferred from the third compound H1 and the fourth compound H2 to the first compound DF and / or the second compound FD, thereby reducing the internal quantum yield in the OLED D2.

[0126] Furthermore, each of the exciton energies generated in each of the third compound H1 in EML1 242 and the fourth compound H2 of EML2 244 should be transferred primarily to the first compound DF of the delayed fluorescent material and then to the second compound FD of the fluorescent material to achieve efficient light emission. As in Fig. As shown in 9, each of the singlet energy levels is S1. H1 the third connection H1 and S1 H2 the fourth compound H2 is higher than the singlet energy level S1 DF the first compound DF with delayed fluorescence. Each of the triplet energy levels T1 can also be H1 the third connection H1 and T1 H2 The fourth compound H2 must be higher than the triplet energy level T1. DF the first compound DF. For example, the triplet energy levels T1 H1 the third connection H1 and T1 H2The energy level of the fourth compound H2 must be at least approximately 0.2 eV higher than the triplet energy level T1, for example at least 0.3 eV higher than at least 0.5 eV higher than the triplet energy level T1. DF the first connection DF.

[0127] Furthermore, the singlet energy level S1 H2 The fourth compound H2 of the second host is higher than the singlet energy level S1. FD the second compound FD of the fluorescent material. Optionally, the triplet energy level T1 can be used. H2 The fourth compound H2 must be higher than the triplet energy level T1. FD of the second compound FD. In this case, the singlet exciton energy generated in the fourth compound H2 can be transferred to the singlet energy of the second compound FD.

[0128] Furthermore, the singlet exciton energy generated in the first delayed-fluorescence compound DF, which is converted into an ICT complex by RISC in EML1 242, should be efficiently transferred to the second fluorescent compound FD in EML2 244. For this purpose, the singlet energy level S1 DF The first compound DF of the delayed fluorescent material in EML1 242 is higher than the singlet energy level S1. FD the second compound FD of the fluorescent material in EML2 244. Optionally, the triplet energy level T1 can be DF The first compound DF in EML1 242 is higher than the triplet energy level T1. FD the second connection FD in the EML2 244.

[0129] Each of the contents of the third compound H1 and the fourth compound H2 in EML1 242 and EML2 244 can be, in a corresponding manner, greater than or equal to each of the contents of the first compound DF and the second compound FD in the same layer. Likewise, the content of the first compound DF in EML1 242 can be greater than the content of the second compound FD in EML2 244. In this case, the exciton energy is efficiently transferred from the first compound DF to the second compound FD via the FRET mechanism. For example, EML1 242 can contain the first compound DF between about 1 wt% and about 50 wt%, for example, about 10 wt% and about 40 wt%, such as about 20 wt% and about 40 wt%. EML2 244 can contain the second compound FD between about 1 wt% and about 10 wt%, for example, about 1 wt% and 5 wt%.

[0130] According to one example, if the EML2 244 is arranged adjacent to the HBL 275, the fourth compound H2 in the EML2 244 can be made of the same material as the HBL 275. In this case, the EML2 244 can have both a hole-blocking and an emission function. In other words, the EML2 244 can serve as a buffer layer for blocking holes. Alternatively, the HBL 275 can be omitted if the EML2 244 can function as both a hole-blocking and an emission layer.

[0131] According to another example, if EML2 244 is arranged next to EBL 265, the fourth compound H2 in EML2 244 can be the same as in EBL 265. In this case, EML2 244 can have both an electron-blocking and an emission function. In other words, EML2 244 can serve as a buffer layer to block electrons. Alternatively, EBL 265 can be omitted if EML2 244 can function as both an electron-blocking and an emission layer.

[0132] An OLED with a three-layer EML is explained. Fig. Figure 10 is a schematic cross-sectional view showing an OLED according to another exemplary aspect of the present disclosure. Fig. Figure 11 is a schematic diagram illustrating the luminescence mechanism via singlet and triplet energy levels among the luminescent materials in EMLs according to another exemplary aspect of the present disclosure.

[0133] As in Fig. As shown in Figure 10, the OLED D3 comprises a first electrode 210 and a second electrode 230, which are opposite each other, and an emission layer 220B, which is arranged between the first electrode 210 and the second electrode 230. The organic light-emitting display device 100 ( Fig. 2) has a red pixel area, a green pixel area and a blue pixel area, and the OLED D3 can be arranged in the blue pixel area.

[0134] According to one exemplary aspect, the emitting layer 220B with a single emitting part contains a three-layer EML 240B. The emitting layer 220B can contain at least one HTL 260 arranged between the first electrode 210 and the EML 240B, and one ETL 270 arranged between the second electrode 230 and the EML 240B. Furthermore, the emission layer 220B can contain at least one HIL 250 arranged between the first electrode 210 and the HTL 260, and one EIL 280 arranged between the second electrode 230 and the ETL 270. Alternatively, the emission layer 220B can also contain an EBL 265 located between the HTL 260 and the EML 240B, and / or an HBL 275 located between the EML 240B and the ETL 270.The designs of the first electrode 210 and the second electrode 230 as well as the other layers with the exception of the EML 240B in the emission layer 220B are essentially identical to the corresponding electrodes and layers in the OLEDs D1 and D2.

[0135] The EML 240B contains a first EML (EML1, middle EML, first layer) 242, a second EML (EML2, lower EML, second layer) 244, and a third EML (EML3, upper EML, third layer) 246. The EML1 242 is arranged between the EBL 265 and the HBL 275, the EML2 244 is arranged between the EBL 265 and the EML1 242, and the EML3 246 is arranged between the EML1 242 and the HBL 275.

[0136] EML1 242 contains the first compound (first dopant) DF of the delayed-release fluorescent material. EML2 244 and EML3 246 each contain the second compound (second dopant) FD1 and a fifth compound (compound 5, third dopant) FD2, respectively, which represent the fluorescent material. Furthermore, EML1 242, EML2 244, and EML3 246 each contain the third compound H1 of the first host, the fourth compound H2 of the second host, and a sixth compound (compound 6) H3 of a third host, respectively.

[0137] According to this aspect, both the singlet and triplet energy of the first compound DF of the delayed fluorescent material in EML1 242 can be transferred via the FRET mechanism to the second compound FD1 and the fifth compound FD2 of the fluorescent materials, which are contained in EML2 244 and EML3 246 respectively, located adjacent to EML1 242. Accordingly, emission ultimately occurs in the second compound FD1 and the fifth compound FD2 in EML2 244 and EML3 246.

[0138] In other words, the triplet exciton energy of the first compound DF, exhibiting delayed fluorescence in EML1 242, is converted upwards to its own singlet exciton energy via the RISC mechanism. Then, the singlet exciton energy, including both the initial and converted singlet exciton energy of the first compound DF, is transferred to the singlet exciton energy of the second compound FD1 and the fifth compound FD2 in EML2 244 and EML3 246, respectively, since the first compound DF occupies a singlet energy level S1. DF has which is higher than any of the singlet energy levels S1 FD1 and S1 FD2 the second compound FD1 and the fifth compound FD2. The singlet exciton energy of the first compound DF in EML1 242 is transferred by the FRET mechanism to the second compound FD1 and the fifth compound FD2 in EML2 244 and EML3 246, which are located adjacent to EML1 242.

[0139] Both the second compound FD1 and the fifth compound FD2 in the EML2 244 and the EML3 246 can emit light by utilizing both the singlet exciton energy and the triplet exciton energy from the first compound DF. Each of the second compound FD1 and the fifth compound FD2 has a narrow FWHM (e.g., equal to or less than approximately 35 nm) compared to the first compound DF. The quantum efficiency and color purity of the OLED D3 can be improved due to the narrow FWHM. The emission ultimately takes place in the EML2 244 and the EML3 246, which contain the second compound FD1 and the fifth compound FD2, respectively.

[0140] The first compound DF of the delayed-release fluorescent material contains any organic compound with the structure of formulas 1 to 6. Each of the second compound FD1 and the fifth compound FD2 of the fluorescent material independently contains an organic compound with the structure of formulas 7 to 9. The third compound H1, the fourth compound H2, and the sixth compound H3 can be identical or different from each other. For example, each of the third compound H1, the fourth compound H2, and the sixth compound H3 can independently contain, but is not limited to, the third compound H, as described above.

[0141] Similar to the first and second aspects, the onset wavelength λ onset DF the first compound DF identical to or shorter than any of the maximum absorption wavelengths λ Abs.max FDThe energy levels of the second compound FD1 and the fifth compound FD2 could be, for example, between approximately 430 nm and approximately 440 nm. Furthermore, the first compound FD1, the second compound FD1, and the fifth compound FD2 can exhibit the HOMO and LUMO energy levels described above.

[0142] Also an energy level band gap (|HOMO) H -HOMO DF |) between the HOMO energy levels (HOMOH) 1 , HOMOH 2 and HOMOH 3 ) the third, fourth and sixth compounds H1, H2 and H3 and the HOMO energy level (HOMO DF ) of the first connection DF, or an energy level band gap (|LUMO) H -LUMO DF |) between the LUMO energy levels (LUMOH) 1 , LUMOH 2 and LUMOH 3 ) the third, fourth and sixth compounds H1, H2 and H3 and the LUMO energy level (LUMO DF The DF of the first connection can be equal to or less than approximately 0.5 eV.

[0143] The singlet and triplet energy levels of the luminescent materials should be correctly adjusted to achieve efficient luminescence. (Referring to...) Fig. 11 is each of the singlet energy levels S1 H1 , S1 H2 and S1 H3 The third, fourth, and sixth connections H1, H2, and H3 of the first to third hosts are higher than the singlet energy level S1. DF the first compound DF with delayed fluorescence. Each of the triplet energy levels T1 can also be H1 , T1 H2 and T1 H3 The third, fourth and sixth compounds H1, H2 and H3 must be higher than the triplet energy level T1. DF the first connection DF.

[0144] Furthermore, the singlet exciton energy generated in the first delayed-fluorescence compound DF, which is converted into an ICT complex by RISC in EML1 242, should be efficiently transferred to each of the second compound FD1 and the fifth compound FD2 of the fluorescent material in EML2 244 and EML3 246. For this purpose, the triplet energy level S1 DF the first compound DF of the delayed fluorescent material in EML1 242 higher than any of the singlet energy levels S1 FD1 and S1 FD2 the second compound FD1 and the fifth compound FD2 of the fluorescent material in EML2 244 and EML3 246. Optionally, the triplet energy level T1 can be DF The energy level of the first compound DF in EML1 242 is higher than any of the triplet energy levels T1. FD1 and T1 FD2 the second connection FD1 and the fifth connection FD2 in the EML2 244 and the EML3 246.

[0145] Furthermore, the exciton energy transferred from the first compound DF to the second compound FD1 and fifth compound FD2 should not be transferred to the fourth compound H2 and sixth compound H3 in order to achieve efficient luminescence. For this purpose, each of the singlet energy levels S1 is appropriately H2 the fourth compound H2 and the singlet energy level S1 H3 the sixth compound H3, which can be the second and third hosts respectively, higher than any of the singlet energy levels S1 FD1 third compound FD1 and the singlet energy level S1 FD2 the sixth compound FD2 of the fluorescent material. Optionally, each of the triplet energy levels T1 is used. H2 the fifth compound H2 and the triplet energy level T1 H3 the sixth compound H3 higher than any of the triplet energy levels T1 FD1the third compound FD1 and the triplet energy level T1 FD2 the sixth connection FD2.

[0146] For example, EML1 242 may contain the first compound DF in amounts between approximately 1 wt% and approximately 50 wt%, for example, approximately 10 wt% and approximately 40 wt% or approximately 20 wt% and approximately 40 wt%. Each of EML2 244 and EML3 246 may contain the second compound FD1 and the fifth compound FD2 in amounts between approximately 1 wt% and approximately 10 wt%, for example, approximately 1 wt% and 5 wt%.

[0147] According to one example, if EML2 244 is arranged next to EBL 265, the fourth compound, H2, in EML2 244 can be the same material as EBL 265. In this case, EML2 244 can have both an electron-blocking and an emission function. In other words, EML2 244 can act as a buffer layer to block electrons. Alternatively, EBL 265 can be omitted if EML2 244 can function as both an electron-blocking and an emission layer.

[0148] If the EML3 246 is located adjacent to the HBL 275, the sixth compound H3 in the EML3 246 can be made of the same material as the HBL 275. In this case, the EML3 246 can have both a hole-blocking and an emission function. In other words, the EML3 246 can serve as a buffer layer for blocking holes. From one perspective, the HBL 275 can be omitted if the EML3 246 can function as both a hole-blocking and an emission layer.

[0149] According to another exemplary aspect, the fourth compound H2 in EML2 244 can be the same material as EBL 265, and the sixth compound H3 in EML3 246 can be the same material as HBL 275. According to this aspect, EML2 244 can have both an electron-blocking and an emission function, and EML3 246 can have both a hole-blocking and an emission function. In other words, both EML2 244 and EML3 246 can serve as buffer layers for blocking electrons and holes, respectively. According to another aspect, EBL 265 and HBL 275 can be omitted, with EML2 244 being both an electron-blocking and an emission layer, and EML3 246 being both a hole-blocking and an emission layer.

[0150] According to an alternative perspective, an OLED can have multiple emitting parts. Fig. Figure 12 is a schematic cross-sectional view showing an OLED according to another exemplary aspect of the present disclosure.

[0151] As in Fig. As shown in Figure 12, the OLED D4 comprises a first electrode 210 and a second electrode 230, which are opposite each other, as well as an emission layer 220C with two emitting parts, which are arranged between the first electrode 210 and the second electrode 230. The organic light-emitting display device 100 ( Fig. 2) has a red pixel area, a green pixel area, and a blue pixel area, and the OLED D4 can be located in the blue pixel area. The first electrode 210 can be an anode and the second electrode 230 can be a cathode.

[0152] The emission layer 220C contains a first emitting part 320, which includes a first EML (lower EML, EML1) 340, and a second emitting part 420, which includes a second EML (upper EML, EML2) 440. The emission layer 220C may further include a charge-generating layer (CGL) 380, which is arranged between the first emitting part 320 and the second emitting part 420.

[0153] The CGL 380 is arranged between the first emitting part 320 and the second emitting part 420, such that the first emitting part 320, the CGL 380, and the second emitting part 420 are arranged sequentially on the first electrode 210. In other words, the first emitting part 320 is arranged between the first electrode 210 and the CGL 380, and the second emitting part 420 is arranged between the second electrode 230 and the CGL 380.

[0154] The first emitting part 320 contains the EML1 340. The first emitting part 320 may further comprise at least one HIL 350 arranged between the first electrode 210 and the EML1 340, a first HTL (HTL1) 360 arranged between the HIL 350 and the EML1 340, and a first ETL (ETL1) 370 arranged between the EML1 340 and the CGL 380. Alternatively, the first emitting part 320 may also comprise a first EBL (EBL1) 365 between the HTL1 360 and the EML1 340 and / or a first HBL (HBL1) 375 between the EML1 340 and the ETL1 370.

[0155] The second emitting part 420 contains the EML2 440. The second emitting part 420 may further comprise at least one second HTL (HTL2) 460 arranged between the CGL 380 and the EML2 440, a second ETL (ETL2) 470 arranged between the EML2 440 and the second electrode 230, and an EIL 480 arranged between the ETL2 470 and the second electrode 230. Alternatively, the second emitting part 420 may also comprise a second EBL (EBL2) 465 between the HTL2 460 and the EML2 440 and / or a second HBL (HBL2) 475 between the EML2 440 and the ETL2 470.

[0156] The CGL 380 is located between the first emitting part 320 and the second emitting part 420. The first emitting part 320 and the second emitting part 420 are connected via the CGL 380. The CGL 380 can be a PN transition CGL, which connects an N-type CGL (N-CGL) 382 to a P-type CGL (P-CGL) 384.

[0157] The N-CGL 382 is located between the ETL1 370 and the HTL2 460, and the P-CGL 384 is located between the N-CGL 382 and the HTL2 460. The N-CGL 382 transports electrons to the EML1 340 of the first emitting part 320, and the P-CGL 384 transports holes to the EML2 440 of the second emitting part 420.

[0158] According to this aspect, each of the EML1 340 and the EML2 440 can be a blue-emitting material layer. For example, at least one of the EML1 340 and the EML2 440 can contain the first compound DF of the delayed fluorescent material, the second compound FD of the fluorescent material, and optionally the third compound H of the host.

[0159] For example, if EML1 340 and / or EML2 440 contain the first to third compounds DF, FD, and H, the concentration of the third compound H in EML1 340 and / or EML2 440 can be greater than or equal to the concentration of the first compound DF, and the concentration of the first compound DF can be greater than the concentration of the second compound FD. In this case, the exciton energy can be efficiently transferred from the first compound DF to the second compound FD.

[0160] According to one exemplary aspect, the EML2 440 can contain the first compound DF and the second compound FD, and optionally the third compound H, in the same way as the EML1 340. Alternatively, the EML2 440 can contain a different compound that differs from at least one of the first compound DF and the second compound FD in the EML1 340, and thus the EML2 440 can emit light that differs from the light emitted by the EML1 340, or have a different luminous efficacy that differs from the luminous efficacy of the EML1 340.

[0161] In Fig. 12 Both EML1 340 and EML2 440 have a single-layer structure. Alternatively, EML1 340 and EML2 440, which can each contain the first to third compounds DF, FD and H, can accordingly have a two-layer structure ( Fig. 8) or a three-layered structure ( Fig. 10).

[0162] In the OLED D4, the singlet exciton energy of the first compound DF of the delayed-release fluorescent material is transferred to the second compound FD of the fluorescent material, and emission ultimately occurs in the second compound FD. Accordingly, the luminous efficacy and color purity of the OLED D4 can be improved. In particular, at least the EML1 340 contains the first compound DF with the structure of formulas 1 to 6 and the second compound FD with the structure of formulas 7 to 9, which further improves the luminous efficacy and color purity of the OLED D4. Since the OLED D4 also features a double-stack structure of a blue-emitting material layer, the color impression of the OLED D4 can be further improved and the luminous efficacy of the OLED D4 can be further optimized.

[0163] Fig. Figure 13 is a schematic cross-sectional view illustrating an organic light-emitting display device according to another exemplary aspect of the present disclosure. As in Fig. Figure 13 shows an organic light-emitting display device 500 comprising a substrate 510 defining the first to third pixel regions P1, P2 and P3, a thin-film transistor Tr arranged above the substrate 510, and an OLED D arranged above and connected to the thin-film transistor Tr. For example, the first pixel region P1 can be a blue pixel region, the second pixel region P2 can be a green pixel region, and the third pixel region P3 can be a red pixel region.

[0164] The substrate 510 can be a glass substrate or a flexible substrate. The flexible substrate can be, for example, a PL substrate, a PES substrate, a PEN substrate, a PET substrate, or a PC substrate. A buffer layer 512 is arranged over the substrate 510, and the thin-film transistor Tr is arranged over the buffer layer 512. The buffer layer 512 can also be omitted. As shown in Fig. As shown in Figure 2, the thin-film transistor Tr contains a semiconductor layer, a gate electrode, a source electrode and a drain electrode and serves as a driver element.

[0165] A passivation layer 550 is arranged over the thin-film transistor Tr. The passivation layer 550 has a flat top surface and contains a drain contact hole 552 that exposes a drain electrode of the thin-film transistor Tr.

[0166] The OLED D is arranged above the passivation layer 550 and comprises a first electrode 610, which is connected to the drain electrode of the thin-film transistor Tr, as well as an emitting layer 620 and a second electrode 630, each arranged sequentially on the first electrode 610. The OLED D is positioned in each of the first to third pixel areas P1, P2, and P3, and emits different light in each pixel area. For example, the OLED D can emit blue light in the first pixel area P1, green light in the second pixel area P2, and red light in the third pixel area P3.

[0167] The first electrode 610 is formed separately for each of the first to third pixel regions P1, P2 and P3, and the second electrode 630 corresponds to the first to third pixel regions P1, P2 and P3 and is formed integrally.

[0168] The first electrode 610 can be an anode or a cathode, and the second electrode 630 can be the other of the anode and cathode. Furthermore, one of the first electrode 610 and the second electrode 630 can be a transmissive (or semi-transmissive) electrode, and the other of the first electrode 610 and the second electrode 630 can be a reflective electrode.

[0169] For example, the first electrode 610 can be an anode and contain conductive material with a relatively high work function, i.e., a transparent conductive oxide (TCO) layer. The second electrode 630 can be a cathode and contain conductive material with a relatively low work function, i.e., a metal layer of a low-resistance metal. For example, the first electrode 610 can contain any of ITO, IZO, ITZO, SnO, ZnO, ICO, and AZO, and the second electrode 630 can contain Al, Mg, Ca, Ag, an alloy thereof (e.g., Mg-Ag), or a combination thereof.

[0170] If the organic light-emitting display device 500 is of the bottom-emission type, the first electrode 610 can have a single-layer structure consisting of a transparent conductive oxide layer. Alternatively, if the organic light-emitting display device 500 is of the top-emission type, a reflective electrode or a reflective layer can be arranged beneath the first electrode 610. For example, the reflective electrode or reflective layer can contain, but is not limited to, Ag or an APC alloy. In the case of the top-emission OLED D, the first electrode 610 can have a three-layer structure of ITO / Ag / ITO or ITO / APC / ITO. The second electrode 630 is also thin to be transmissive (or semi-transmissive).

[0171] A bench layer 560 is arranged on the passivation layer 550 to cover the edges of the first electrode 610. The bench layer 560 corresponds to each of the first to third pixel areas P1, P2 and P3 and exposes the center of the first electrode 610.

[0172] An emission layer 620 is arranged on the first electrode 610. By way of example, the emission layer 620 can have a single-layer structure of an EML. Alternatively, the emission layer 620 can contain at least one of the following: a HIL, an HTL, and an EBL arranged sequentially between the first electrode 610 and the EML, and / or an HBL, an ETL, and an EIL arranged sequentially between the EML and the second electrode 630.

[0173] According to an exemplary aspect, the EML of the emission layer 630 in the first pixel region P1 of the blue pixel region can contain the first compound DF of the delayed fluorescent material with the structure of formulas 1 to 6, the second compound FD of the fluorescent material with the structure of formulas 7 to 9 and optionally the third compound H.

[0174] An encapsulation film 570 is arranged over the second electrode 630 to prevent external moisture from penetrating the OLED D. The encapsulation film 570 can have, but is not limited to, a three-layer structure consisting of a first inorganic insulating film, an organic insulating film, and a second inorganic insulating film.

[0175] The organic light-emitting display device 500 may include a polarizer to reduce external light reflection. For example, the polarizer may be a circular polarizer. If the organic light-emitting display device 500 is of the bottom-emission type, the polarizer may be located below the substrate 510. Alternatively, if the organic light-emitting display device 500 is of the top-emission type, the polarizer may be located above the encapsulation film 570.

[0176] Fig. Figure 14 is a schematic cross-sectional view showing an OLED according to yet another exemplary aspect of the present disclosure. As in Fig. As shown in Figure 14, the OLED D5 comprises a first electrode 610, a second electrode 630 facing the first electrode 610, and an emission layer 620 located between the first electrode 610 and the second electrode 630.

[0177] The first electrode 610 can be an anode and the second electrode 630 can be a cathode. For example, the first electrode 610 can be a reflective electrode and the second electrode 630 can be a transmissive (or semi-transmissive) electrode.

[0178] The emission layer 620 contains an EML 640. The emission layer 620 can contain at least one HTL 660 arranged between the first electrode 610 and the EML 640, and one ETL 670 arranged between the EML 640 and the second electrode 630. Furthermore, the emission layer 620 can contain at least one HIL 650 arranged between the first electrode 610 and the HTL 660, and one EIL 680 arranged between the ETL 670 and the second electrode 630. In addition, the emission layer 620 can also contain at least one EBL 665 arranged between the HTL 660 and the EML 640, and one HBL 675 arranged between the EML 640 and the ETL 670.

[0179] Furthermore, the emission layer 620 can contain an additional hole transport layer (auxiliary HTL) 662, which is arranged between the HTL 660 and the EBL 665. The auxiliary HTL 662 can contain a first auxiliary HTL 662a, located in the first pixel region P1, a second auxiliary HTL 662b, located in the second pixel region P2, and a third auxiliary HTL 662c, located in the third pixel region P3.

[0180] The first auxiliary HTL 662a has a first thickness, the second auxiliary HTL 662b has a second thickness, and the third auxiliary HTL 662c has a third thickness. The first thickness is less than the second thickness, and the second thickness is less than the third thickness. Accordingly, the OLED D5 has a microcavity structure.

[0181] Since the first to third auxiliary HTLs 662a, 662b, and 662c have different thicknesses, the distance between the first electrode 610 and the second electrode 630 in the first pixel area P1, which emits light in the first wavelength range (blue light), is smaller than the distance between the first electrode 610 and the second electrode 630 in the second pixel area P2, which emits light in the second wavelength range (green light), which is longer than the first wavelength range. Furthermore, the distance between the first electrode 610 and the second electrode 630 in the second pixel area P2 is smaller than the distance between the first electrode 610 and the second electrode 630 in the third pixel area P3, which emits light in the third wavelength range (red light), which is longer than the second wavelength range. Accordingly, the luminous efficacy of the OLED D5 is improved.

[0182] In Fig. In section 14, the first auxiliary HTL 662a is located in the first pixel region P1. Alternatively, the OLED D5 can also implement the micro-cavity structure without the first auxiliary HTL 662a. Furthermore, a cover layer can be arranged over the second electrode 630 to improve the extraction of the light emitted by the OLED D5.

[0183] The EML 640 contains a first EML (EML1) 642, located in the first pixel region P1, a second EML (EML2) 644, located in the second pixel region P2, and a third EML (EML3) 646, located in the third pixel region P3. Each of the EML1 642, the EML2 644, and the EML3 646 can be a blue EML, a green EML, and a red EML, respectively.

[0184] According to one exemplary aspect, the EML1 642, located in the first pixel region P1, can contain the first compound of the delayed-release fluorescent material with the structure of formulas 1 to 6, the second compound FD of the fluorescent material with the structure of formulas 7 to 9, and optionally the third compound H of the host. The EML1 642 can have a single-layer structure, a two-layer structure ( Fig. 8) or a three-layered structure ( Fig. 10).

[0185] In EML1 642, the concentration of the third compound H can be greater than or equal to the concentration of the first compound DF, and the concentration of the first compound DF can be greater than the concentration of the second compound FD. In this case, the exciton energy can be efficiently transferred from the first compound DF to the second compound FD.

[0186] The EML2 644 in the second pixel area P2 can contain a host and a green dopant, and the EML3 646 in the third pixel area P3 can contain a host and a red dopant. For example, the host in both the EML2 644 and the EML3 646 can contain the third compound H, and each of the green and red dopants can independently contain at least one of a green or red phosphorescent material, a green or red fluorescent material, and a green or red delayed fluorescent material.

[0187] The OLED D5 emits blue, green, and red light in each of the first to third pixel areas P1, P2, and P3, so that the organic light-emitting display device 500 ( Fig. 13) can produce a full-color image.

[0188] The organic light-emitting display device 500 can further include a color filter layer corresponding to the first to third pixel areas P1, P2, and P3 in order to improve the color purity of the light emitted by the OLED D. For example, the color filter layer can have a first color filter layer (blue color filter layer) corresponding to the first pixel area P1, the second color filter layer (green color filter layer) corresponding to the second pixel area P2, and the third color filter layer (red color filter layer) corresponding to the third pixel area P3.

[0189] If the organic light-emitting display device 500 is a bottom-emission type, the color filter layer can be arranged between the OLED D and the substrate 510. Alternatively, if the organic light-emitting display device 500 is a top-emission type, the color filter layer can be arranged above the OLED D.

[0190] Fig. Figure 15 is a schematic cross-sectional view showing an organic light-emitting display device according to yet another exemplary aspect of the present disclosure. As in Fig. As shown in Figure 15, the organic light-emitting display device 1000 comprises a substrate 1010 defining a first pixel area P1, a second pixel area P2, and a third pixel area P3, a thin-film transistor Tr arranged over the substrate 1010, an OLED D arranged over and connected to the thin-film transistor Tr, and a color filter layer 1020 corresponding to the first to third pixel areas P1, P2, and P3. For example, the first pixel area P1 can be a blue pixel area, the second pixel area P2 can be a green pixel area, and the third pixel area P3 can be a red pixel area.

[0191] The substrate 1010 can be a glass substrate or a flexible substrate. For example, the flexible substrate can be a PL substrate, a PES substrate, a PEN substrate, a PET substrate, or a PC substrate. The thin-film transistor Tr is located on top of the substrate 1010. Alternatively, a buffer layer can be placed on top of the substrate 1010, and the thin-film transistor Tr can be placed on top of the buffer layer. As shown in Fig. As shown in Figure 2, the thin-film transistor Tr contains a semiconductor layer, a gate electrode, a source electrode and a drain electrode and serves as a driver element.

[0192] The color filter layer 1020 is located above the substrate 1010. For example, the color filter layer 1020 can contain: a first color filter structure 1022, corresponding to the first pixel area P1; a second color filter structure 1024, corresponding to the second pixel area P2; and a third color filter structure 1026, corresponding to the third pixel area P3. The first color filter structure 1022 can be a blue color filter structure, the second color filter structure 1024 can be a green color filter structure, and the third color filter structure 1026 can be a red color filter structure. For example, the first color filter structure 1022 can contain at least one blue dye and one blue pigment, the second color filter structure 1024 can contain at least one green dye and one green pigment, and the third color filter structure 1026 can contain at least one red dye and one red pigment.

[0193] A passivation layer 1050 is arranged over the thin-film transistor Tr and the color filter layer 1020. The passivation layer 1050 has a flat top surface and contains a drain contact hole 1052 that exposes a drain electrode of the thin-film transistor Tr.

[0194] The OLED D is positioned above the passivation layer 1050 and corresponds to the color filter layer 1020. The OLED D comprises a first electrode 1110, which is connected to the drain electrode of the thin-film transistor Tr, as well as an emission layer 1120 and a second electrode 1130, each arranged sequentially on the first electrode 1110. The OLED D emits white light in the first to third pixel areas P1, P2, and P3.

[0195] The first electrode 1110 is configured separately for each of the first to third pixel areas P1, P2, and P3, and the second electrode 1130 corresponds to the first to third pixel areas P1, P2, and P3 and is configured integrally. The first electrode 1110 can be an anode or a cathode, and the second electrode 1130 can be the other of the anode or the cathode. Furthermore, the first electrode 1110 can be a transmissive (or semi-transmissive) electrode, and the second electrode 1130 can be a reflective electrode.

[0196] For example, the first electrode 1110 can be an anode and contain conductive material with a relatively high work function, i.e., a transparent conductive oxide (TCO) layer. The second electrode 1130 can be a cathode and contain conductive material with a relatively low work function, i.e., a metal layer of a low-resistance metal. The transparent conductive oxide layer of the first electrode 1110 can, for example, contain ITO, IZO, ITZO, SnO, ZnO, ICO, and AZO, and the second electrode 1130 can contain Al, Mg, Ca, Ag, an alloy thereof (e.g., Mg-Ag), or a combination thereof.

[0197] The emission layer 1120 is arranged on the first electrode 1110. The emission layer 1120 contains at least two emitting parts that emit different colors. Each of the emitting parts can have a single-layer structure of an EML. Alternatively, each of the emitting parts can contain at least one of a HIL, an HTL, an EBL, an HBL, an ETL, and an EIL. In addition, the emission layer 1120 can also contain a CGL arranged between the emitting parts.

[0198] At least one of the at least two emitting parts can contain the first compound DF of the delayed fluorescent material with the structure of formulas 1 to 6, the second compound FD of the boron-based fluorescent material of the structure of formulas 7 to 9 and optionally the third compound H of the host.

[0199] A bank layer 1060 is arranged on the passivation layer 1050 to cover the edges of the first electrode 1110. The bank layer 1060 corresponds to each of the first to third pixel regions P1, P2, and P3, exposing the center of the first electrode 1110. Since the OLED D, as described above, emits white light in the first to third pixel regions P1, P2, and P3, the emission layer 1120 can be formed as a single, unified layer without being separated into the first to third pixel regions P1, P2, and P3. The bank layer 1060 is formed to prevent leakage current from the edges of the first electrode 1110 and can therefore be omitted.

[0200] Furthermore, the organic light-emitting display device 1000 can include an encapsulation film arranged on the second electrode 1130 to prevent external moisture from penetrating the OLED D. Additionally, the organic light-emitting display device 1000 can include a polarizer arranged beneath the substrate 1010 to reduce external light reflection.

[0201] In the organic light-emitting display device 1000 in Fig. In Figure 15, the first electrode 1110 is a transmissive electrode, the second electrode 1130 is a reflective electrode, and the color filter layer 1020 is arranged between the substrate 1010 and the OLED D. That is, the organic light-emitting display device 1000 is of the bottom-emission type. Alternatively, the first electrode 1110 can be a reflective electrode, the second electrode 1120 can be a transmissive (or semi-transmissive) electrode, and the color filter layer 1020 can be arranged above the OLED D in the top-emission organic light-emitting display device 1000.

[0202] In the organic light-emitting display device 1000, the OLED D, which is located in the first to third pixel areas P1, P2 and P3, emits white light, and the white light passes through each of the first to third pixel areas P1, P2 and P3, so that a blue color, a green color and a red color are displayed in the corresponding first to third pixel areas P1, P2 and P3 respectively.

[0203] A color conversion film can be arranged between the OLED D and the color filter layer 1020. The color conversion film corresponds to the first to third pixel areas P1, P2, and P3 and contains a green color conversion film, a red color conversion film, and a blue color conversion film, each of which can convert the white light emitted by the OLED D into green, red, and blue light, respectively. For example, the color conversion film can contain quantum dots. Accordingly, the organic light-emitting display device 1000 can further improve its color purity. Alternatively, the color conversion layer can replace the color filter layer 1020.

[0204] Fig. Figure 16 is a schematic cross-sectional view showing an OLED according to yet another exemplary aspect of the present disclosure. As in Fig. As shown in Figure 16, the OLED D6 comprises a first electrode 1110 and a second electrode 1130, which are opposite each other, and an emissive layer 1120, which is arranged between the first electrode 1110 and the second electrode 1130. The first electrode 1110 can be an anode and the second electrode 1130 can be a cathode. For example, the first electrode 1110 can be a transmissive electrode and the second electrode 1130 can be a reflective electrode.

[0205] The emission layer 1120 contains a first emitting part 1220 with a first EML (lower EML, EML1) 1240, a second emitting part 1320 with a second EML (middle EML, EML2) 1340, and a third emitting part 1420 with a third EML (upper EML, EML3) 1440. Furthermore, the emission layer 1120 can contain a first charge-generating layer (CGL1) 1280, located between the first emitting part 1220 and the second emitting part 1320, and a second charge-generating layer (CGL2) 1380, located between the second emitting part 1320 and the third emitting part 1420. Accordingly, the first emitting part 1220, the CGL1 1280, the second emitting part 1320, the CGL2 1380 and the third emitting part 1420 are arranged successively above the first electrode 1110.

[0206] The first emitting part 1220 may further comprise at least one HIL 1250 arranged between the first electrode 1110 and the EML1 1240, one HTL (HTL1) 1260 arranged between the EML1 1240 and the HIL 1250, and one ETL (ETL1) 1270 arranged between the EML1 1240 and the CGL1 1280. Alternatively, the first emitting part 1220 may further comprise at least one EBL (EBL1) 1265 arranged between the HTL1 1260 and the EML1 1240, and one HBL (HBL1) 1275 arranged between the EML1 1240 and the ETL1 1270.

[0207] The second emitting part 1320 may further comprise at least one second HTL (HTL2) 1360, which is arranged between the CGL1 1280 and the EML2 1340, and a second ETL (ETL2) 1370, which is arranged between the EML2 1340 and the CGL2 1380. Alternatively, the second emitting part 1320 may further comprise a second EBL (EBL2) 1365, which is arranged between the HTL2 1360 and the EML2 1340, and / or a second HBL (HBL2) 1375, which is arranged between the EML2 1340 and the ETL2 1370.

[0208] The third emitting part 1420 may further comprise at least one third HTL (HTL3) 1460, which is arranged between the CGL2 1380 and the EML3 1440, one third ETL (ETL3) 1470, which is arranged between the EML3 1440 and the second electrode 1130, and one EIL 1480, which is arranged between the ETL3 1470 and the second electrode 1130. Alternatively, the third emitting part 1420 may further comprise a third EBL (EBL3) 1465, which is arranged between the HTL3 1460 and the EML3 1440, and / or a third HBL (HBL3) 1475, which is arranged between the EML3 1440 and the ETL3 1470.

[0209] The CGL1 1280 is located between the first emitting part 1220 and the second emitting part 1320. That is, the first emitting part 1220 and the second emitting part 1320 are connected via the CGL1 1280. The CGL1 1280 can be a PN transition CGL, which connects a first N-type CGL (N-CGL1) 1282 with a first P-type CGL (P-CGL1) 1284.

[0210] The N-CGL1 1282 is located between the ETL1 1270 and the HTL2 1360, and the P-CGL1 1284 is located between the N-CGL1 1282 and the HTL2 1360. The N-CGL1 1282 transports electrons to the EML1 1240 of the first emitting part 1220, and the P-CGL1 1284 transports holes to the EML2 1340 of the second emitting part 1320.

[0211] The CGL2 1380 is positioned between the second emitting part 1320 and the third emitting part 1420. That is, the second emitting part 1320 and the third emitting part 1420 are connected via the CGL2 1380. The CGL2 1380 can be a PN transition CGL that connects a second N-type CGL (N-CGL2) 1382 to a second P-type CGL (P-CGL2) 1384.

[0212] The N-CGL2 1382 is located between the ETL2 1370 and the HTL3 1460, and the P-CGL2 1384 is located between the N-CGL2 1382 and the HTL3 1460. The N-CGL2 1382 transports electrons to the EML2 1340 of the second emitting part 1320, and the P-CGL2 1384 transports holes to the EML3 1440 of the third emitting part 1420.

[0213] According to this aspect, one of the first to third EMLs 1240, 1340 and 1440 can be a blue EML, another of the first to third EMLs 1240, 1340 and 1440 can be a green EML and the third of the first to third EMLs 1240, 1340 and 1440 can be a red EML.

[0214] For example, EML1 1240 can be a blue EML, EML2 1340 can be a green EML, and EML3 1440 can be a red EML. Alternatively, EML1 1240 can be a red EML, EML2 1340 can be a green EML, and EML3 1440 can be a blue EML. The OLED D6, where EML1 1240 is a blue EML, EML2 1340 is a green EML, and EML3 1440 is a red EML, is described in more detail below.

[0215] EML1 1240 can contain the first compound DF of the delayed-release fluorescent material with the structure of formulas 1 to 6, the second compound FD of the fluorescent material with the structure of formulas 7 to 9, and optionally the third compound H of the host. EML1 1240, which contains the first to third compounds DF, FD, and H, can have a single-layer structure or a two-layer structure ( Fig. 8) or a three-layered structure ( Fig. 10).

[0216] In EML1 1240, the concentration of the third compound H can be equal to or greater than the concentration of the first compound DF, and the concentration of the first compound DF can be greater than the concentration of the second compound FD. If the concentration of the first compound DF is greater than the concentration of the second compound FD, the exciton energy can be sufficiently transferred from the first compound DF to the second compound FD.

[0217] The EML2 1340 can contain a host and a green dopant, and the EML3 1440 can contain a host and a red dopant. For example, the host can contain the third compound H, and each of the green and red dopants can, according to each of the EML2 1340 and the EML3 1440 respectively, contain at least one of green or red phosphorescent material, one of green or red fluorescent material, and one of green or red delayed-release fluorescent material.

[0218] The OLED D6 emits white light in each of the first to third pixel areas P1, P2 and P3, and the white light passes through the color filter layer 1020 ( Fig. 15), which is arranged correspondingly in the first to third pixel areas P1, P2 and P3. Accordingly, the organic light-emitting display device can 1000 ( Fig. 15) Create a full-color image.

[0219] Fig. Figure 17 is a schematic cross-sectional view showing an OLED according to yet another exemplary aspect of the present disclosure. As in Fig. As shown in Figure 17, the OLED D7 comprises a first electrode 1110 and a second electrode 1130, which are opposite each other, and an emission layer 1120A, which is arranged between the first electrode 1110 and the second electrode 1130. The first electrode 1110 can be an anode and the second electrode 1130 can be a cathode. For example, the first electrode 1110 can be a transmissive electrode and the second electrode 1130 can be a reflective electrode.

[0220] The emission layer 1120A contains a first emitting part 1520 having an EML1 (lower EML) 1540, a second emitting part 1620 having an EML2 (middle EML) 1640, and a third emitting part 1720 having an EML3 (upper EML) 1740. Furthermore, the emission layer 1120A may contain a CGL1 1580 located between the first emitting part 1520 and the second emitting part 1620, and a CGL2 1680 located between the second emitting part 1620 and the third emitting part 1720. Accordingly, the first emitting part 1520, the CGL1 1580, the second emitting part 1620, the CGL2 1680 and the third emitting part 1720 are arranged successively on the first electrode 1110.

[0221] The first emitting part 1520 may further comprise at least one HIL 1550 arranged between the first electrode 1110 and the EML1 1540, one HTL1 1560 arranged between the EML1 1540 and the HIL 1550, and one ETL1 1570 arranged between the EML1 1540 and the CGL1 1580. Alternatively, the first emitting part 1520 may also comprise an EBL1 1565 arranged between the HTL1 1560 and the EML1 1540, and / or an HBL1 1575 arranged between the EML1 1540 and the ETL1 1570.

[0222] The EML2 1640 of the second emitting part 1620 contains a middle lower EML (first layer) 1642 and a middle upper EML (second layer) 1644. The middle lower EML 1642 is located adjacent to the first electrode 1110, and the middle upper EML 1644 is located adjacent to the second electrode 1130. Furthermore, the second emitting part 1620 may contain at least one HTL2 1660, which is arranged between the CGL1 1580 and the EML2 1640, or one ETL2 1670, which is arranged between the EML2 1640 and the CGL2 1680. Alternatively, the second emitting part 1620 may also contain at least one EBL2 1665, which is arranged between the HTL2 1660 and the EML2 1640, and one HBL2 1675, which is arranged between the EML2 1640 and the ETL2 1670.

[0223] The third emitting part 1720 may further comprise at least one HTL3 1760 arranged between the CGL2 1680 and the EML3 1740, one ETL3 1770 arranged between the EML3 1740 and the second electrode 1130, and one EIL 1780 arranged between the ETL3 1770 and the second electrode 1130. Alternatively, the third emitting part 1720 may also comprise an EBL3 1765 arranged between the HTL3 1760 and the EML3 1740, and / or an HBL3 1775 arranged between the EML3 1740 and the ETL3 1770.

[0224] The CGL1 1580 is located between the first emitting part 1520 and the second emitting part 1620. That is, the first emitting part 1520 and the second emitting part 1620 are connected to each other via the CGL1 1580. The CGL1 1580 can be a PN transition CGL, which connects an N-CGL1 1582 to a P-CGL1 1584. The N-CGL1 1582 is located between the ETL1 1570 and the HTL2 1660, and the P-CGL1 1584 is located between the N-CGL1 1582 and the HTL2 1560.

[0225] The CGL2 1680 is located between the second emitting part 1620 and the third emitting part 1720. That is, the second emitting part 1620 and the third emitting part 1720 are connected via the CGL2 1680. The CGL2 1680 can be a PN transition CGL, connecting an N-CGL2 1682 to a P-CGL2 1684. The N-CGL2 1682 is located between the ETL2 1570 and the HTL3 1760, and the P-CGL2 1684 is located between the N-CGL2 1682 and the HTL3 1760.

[0226] According to this aspect, each of the EML1 1540 and the EML3 1740 can be a blue EML. According to an exemplary aspect, each of the EML1 1540 and the EML3 1740 can contain the first compound DF of the delayed fluorescent material with the structure of formulas 1 to 6, the second compound FD of the fluorescent material with the structure of formulas 7 to 9, and optionally the third compound H.

[0227] According to one example, the EML3 1740 can contain the first compound DF and the second compound, and optionally the third compound H, just like the EML1 1540. Alternatively, the EML3 1740 can contain a different compound that differs from at least one of the first compound DF and the second compound FD in the EML1 1540, and thus the EML3 1740 can emit light that differs from the light emitted by the EML1 1540, or have a different luminous efficacy that differs from the luminous efficacy of the EML1 1540.

[0228] For example, each of the EML1 1540 and the EML3 1740 contains the first to third compounds DF, FD, and H, where in each of the EML1 1540 and the EML3 1740, the content of the third compound H can be equal to or greater than the content of the first compound DF, and the content of the first compound DF can be greater than the content of the second compound FD. In this case, the energy can be sufficiently transferred from the first compound DF to the second compound FD.

[0229] One of the middle lower EML 1642 and one of the middle upper EML 1644 of the EML2 1640 can be a green EML, and the other of the middle lower EML 1642 and one of the middle upper EML 1644 of the EML2 1640 can be a red EML. The green EML and the red EML are arranged sequentially and form the EML2 1640.

[0230] For example, the middle lower EML 1642 of the green EML can contain the host and the green dopant, and the middle upper EML 1644 can contain the host and the red dopant. For example, the host in the middle lower EML 1642 and the middle upper EML 1644 can contain the third compound H, and each of the green and red dopants can contain at least one of green and red phosphorescent material, one of green and red fluorescent material, and one of green and red delayed-release fluorescent material, respectively.

[0231] The OLED D7 emits white light in each of the first to third pixel areas P1, P2 and P3, and the white light passes through the color filter layer 1020 ( Fig. 15), which is arranged correspondingly in the first to third pixel areas P1, P2 and P3. Accordingly, the organic light-emitting display device can 1000 ( Fig. 16) Create a full-color image.

[0232] In Fig. 17. The OLED D7 has a triple-stack structure with the first to third emitting parts 1520, 1620, and 1720, which contain EML1 1540 and EML3 1740 as blue EMLs. Alternatively, the OLED D7 can also have a double-stack structure in which one of the first emitting part 1520 and one of the third emitting part 1720, which each contain EML1 1540 and EML3 1740 as blue EMLs, is omitted. Example 1 (Ex. 1): Manufacturing an OLED

[0233] An OLED was fabricated in which an EML 2,8-di(9H-carbazol-9-yl)dibenzo[b,d]thiophene (DCzDBT) is used as a host and compound 1-1 of formula 6 (HOMO: -5.58 eV, LUMO: -2.6 eV, maximum photoluminescence wavelength (PL.λmax): 472 nm, onset wavelength: 433 nm) is used as the first compound DF. The ITO substrate was washed by UV-ozone treatment prior to use and transferred to a vacuum chamber for deposition of the emission layer. Subsequently, an anode, an emission layer, and a cathode were deposited by evaporation from a heating boat under 10 -7 Torr vacuum deposited with a deposition rate of 1 Å / s in the following sequence:

[0234] An anode (ITO, 50 nm); a HIL (HAT-CN, 7 nm); an HTL (NPB, 45 nm); an EBL (TAPC, 10 nm); an EML (DCzDBT (70 wt%), Compound 1-1 (30 wt%), 30 nm); an HBL (B3PYMPM, 10 nm); an ETL (TPBi, 25 nm); an EIL (LiF); and a cathode (AI).

[0235] After the emissive layer and cathode were deposited, the OLED was transferred from the deposition chamber to a dry box to form a film and then encapsulated with UV-cured epoxy and water-capture getter. The materials used in the emissive layer are listed below: Example 2 (Ex. 2): Manufacturing an OLED

[0236] An OLED was fabricated using the same materials as in Example 1, with the difference that DczDBT (69 wt%) was used as the host, compound 1-1 (30 wt%) as the first compound, and compound 2-20 (HOMO: -5.4 eV, LUMO: -2.8 eV, maximum absorption wavelength: 457 nm, 1 wt%) of formula 9 was used as the second compound FD in the EML. Example 3 (Ex. 3): Manufacturing an OLED

[0237] An OLED was fabricated using the same materials as in Example 2, with the difference that compound 2-21 (HOMO: -5.5 eV, LUMO: -2.8 eV, maximum absorption wavelength (Absλmax): 459 nm) of formula 9 was used as the second compound FD in the EML instead of compound 2-20. Example 4 (Ex. 4): Manufacturing an OLED

[0238] An OLED was fabricated using the same materials as in Example 2, with the difference that compound 2-36 (HOMO: -5.4 eV, LUMO: -2.8 eV, Absλmax: 457 nm) of formula 9 was used as the second compound FD in the EML instead of compound 2-20. Example 5 (Ex. 5): Manufacturing an OLED

[0239] An OLED was fabricated using the same materials as in Example 1, with the difference that compound 1-5 (HOMO: -5.58 eV, LUMO: -2.6 eV, PLλmax: 470 nm, Onset wavelength: 435 nm) of formula 6 was used as the first compound DF in the EML instead of compound 1-1. Example 6 (Ex. 6): Manufacturing an OLED

[0240] An OLED was fabricated using the same materials as in Example 5, with the difference that DczDBT (69 wt%) was used as the host, compound 1-5 (30 wt%) as the first compound, and compound 2-20 (1 wt%) of formula 9 (as the second compound FD) was used in the EML. Example 7 (Ex. 7): Manufacturing an OLED

[0241] An OLED was fabricated using the same materials as in Example 6, with the difference that compound 2-21 of formula 9 was used as the second compound FD in the EML instead of compound 2-20. Example 8 (Ex. 8): Manufacturing an OLED

[0242] An OLED was fabricated using the same materials as in Example 6, with the difference that compound 2-36 of formula 9 was used as the second compound FD in the EML instead of compound 2-20. Example 9 (Ex. 9): Manufacturing an OLED

[0243] An OLED was fabricated using the same materials as in Example 1, with the difference that compound 1-7 (HOMO: -5.6 eV, LUMO: -2.7 eV, PLλmax: 472 nm, Onset wavelength: 434 nm) of formula 6 was used as the first compound DF in the EML instead of compound 1-1. Example 10 (Ex. 10): Manufacturing an OLED

[0244] An OLED was fabricated using the same materials as in Example 9, with the difference that DczDBT (69 wt%) was used as the host, compound 1-7 (30 wt%) as the first compound, and compound 2-20 (1 wt%) of formula 9 as the second compound FD in the EML. Example 11 (Ex. 11): Manufacturing an OLED

[0245] An OLED was fabricated using the same materials as in Example 10, with the difference that compound 2-21 of formula 9 was used as the second compound FD in the EML instead of compound 2-20. Example 12 (Ex. 12): Manufacturing an OLED

[0246] An OLED was fabricated using the same materials as in Example 10, with the difference that compound 2-36 of formula 9 was used as the second compound FD in the EML instead of compound 2-20. Example 13 (Ex. 13): Manufacturing an OLED

[0247] An OLED was fabricated using the same materials as in Example 1, with the difference that compound 1-16 (HOMO: -5.6 eV, LUMO: -2.6 eV, PLλmax: 473 nm, Onset wavelength: 434 nm) of formula 6 was used as the first compound DF in the EML instead of compound 1-1. Example 14 (Ex. 14): Manufacturing an OLED

[0248] An OLED was fabricated using the same materials as in Example 13, with the difference that DczDBT (69 wt%) was used as the host, compound 1-16 (30 wt%) as the first compound, and compound 2-20 (1 wt%) of formula 9 as the second compound FD in the EML. Example 15 (Ex. 15): Manufacturing an OLED

[0249] An OLED was fabricated using the same materials as in Example 14, with the difference that compound 2-21 of formula 9 was used as the second compound FD in the EML instead of compound 2-20. Example 16 (Ex. 16): Manufacturing an OLED

[0250] An OLED was fabricated using the same materials as in Example 14, with the difference that compound 2-36 of formula 9 was used as the second compound FD in the EML instead of compound 2-20. Comparative example 1 (cf. 1): Manufacturing an OLED

[0251] An OLED was fabricated using the same materials as in Example 1, with the difference that the following Ref. 1 compound (HOMO: -5.5 eV, LUMO: -2.7 eV, PLλmax: 487 nm, Onset wavelength: 449 nm) was used as the first compound DF in the EML instead of compound 1-1. Comparative example 2 (cf. 2): Manufacturing an OLED

[0252] An OLED was fabricated using the same materials as in Comparative Example 1, with the difference that DczDBT (69 wt%) was used as the host, the Ref. 1 compound (30 wt%) as the first compound, and compound 2-20 (1 wt%) of formula 9 as the second compound FD in the EML. Comparative example 3 (cf. 3): Manufacturing an OLED

[0253] An OLED was fabricated using the same materials as in Example 1, with the difference that the following Ref. 2 compound (HOMO: -5.6 eV, LUMO: -2.6 eV, PLλmax: 460 nm, Onset wavelength: 421 nm) was used as the first compound DF in the EML instead of compound 1-1. Comparative example 4 (cf. 4): Manufacturing an OLED

[0254] An OLED was fabricated using the same materials as in Comparative Example 3, with the difference that DczDBT (69 wt%) was used as the host, the Ref. 2 compound (30 wt%) as the first compound, and compound 2-20 (1 wt%) of formula 9 as the second compound FD in the EML. Comparative example 5 (cf. 5): Manufacturing an OLED

[0255] An OLED was fabricated using the same materials as in Example 1, with the difference that the following Ref. 3 compound (HOMO: -5.6 eV, LUMO: -2.7 eV, PLλmax: 462 nm, Onset wavelength: 426 nm) was used as the first compound DF in the EML instead of compound 1-1. Comparative example 6 (cf. 6): Production of an OLED

[0256] An OLED was fabricated using the same materials as in Comparative Example 6, with the difference that DczDBT (69 wt%) was used as the host, the Ref. 3 compound (30 wt%) as the first compound, and compound 2-20 (1 wt%) of formula 9 as the second compound FD in the EML. Comparative example 7 (cf. 7): Manufacturing an OLED

[0257] An OLED was fabricated using the same materials as in Example 1, with the difference that the following Ref. 4 compound (HOMO: -5.7 eV, LUMO: -2.7 eV, PLλmax: 458 nm, Onset wavelength: 422 nm) was used as the first compound DF in the EML instead of compound 1-1. Comparative example 8 (cf. 8): Manufacturing an OLED

[0258] An OLED was fabricated using the same materials as in Comparative Example 6, with the difference that DczDBT (69 wt%) was used as the host, the Ref. 3 compound (30 wt%) as the first compound, and compound 2-20 (1 wt%) of formula 9 as the second compound FD in the EML. [Reference links] Experimental Example 1: Measuring the luminescent properties of an OLED

[0259] Each of the OLEDs produced in Example 1-16 and See 1-8 was connected to an external current source, and the luminescence properties of all diodes were then evaluated at room temperature using a constant current source (KEITHLEY) and a PR650 photometer. Specifically, the operating voltage (V), current efficiency (cd / A), external quantum efficiency (EQE, %), and maximum electroluminescence (EL Amax, nm) were measured at a current density of 8.6 mA / cm². 2The OLEDs were measured. The measurement results for the OLEDs are shown in Tables 1 and 2 below: Table 1: Lighting properties of OLEDs Probe DF FD V cd / A EQE CIEy EL λmax l onset DF Bsp. 1 1-1 - 3,49 33,1 18,2 0,271 478 433 Bsp. 2 1-1 2-23 3,6 28,2 24,1 0,159 470 433 Bsp. 3 1-1 2-24 3,52 30,5 24,6 0,183 474 433 Bsp. 4 1-1 2-39 3,94 34,2 24,7 0,197 470 433 Bsp. 5 1-5 - 3,36 28,2 14,6 0,295 480 435 Bsp. 6 1-5 2-23 3,63 26,6 23,8 0,153 472 435 Bsp. 7 1-5 2-24 3,48 27,7 21,5 0,179 470 435 Bsp. 8 1-5 2-39 3,2 27,5 20,6 0,192 472 435 Bsp. 9 1-7 - 3,32 26,7 15,1 0,264 478 434 Bsp. 10 1-7 2-23 3,6 24,5 22,7 0,146 470 434 Bsp. 11 1-7 2-24 3,4 22,4 19 0,193 472 434 Bsp. 12 1-7 2-39 3,8 35,8 22,6 0,232 472 434 Bsp. 13 1-16 - 3,4 26,9 14,3 0,285 478 434 Bsp. 14 1-16 2-23 3,62 25,3 24,2 0,145 472 434 Bsp. 15 1-16 2-24 3,38 34,4 21,6 0,237 472 434 Bsp. 16 1-16 2-39 3,8 35,9 20,8 0,26 472 434 DF: first connection; FD: second connection; λ onset DF : Onset wavelength of the first connection Table 2: Lighting properties of OLEDs Probe DF FD V cd / A EQE CIEy EL λmax l onset DF Vgl. 1 Ref. 1 - 3,46 43 20,1 0,354 490 449 Vgl. 2 Ref. 1 2-23 3,58 29,4 21,2 0,201 472 449 Vgl. 3 Ref. 2 - 3,56 13,2 7,5 0,251 474 421 Vgl. 4 Ref. 2 2-23 3,6 21,9 14,5 0,229 474 421 Vgl. 5 Ref. 3 - 3,25 15,5 9 0,248 474 426 Vgl. 6 Ref. 3 2-23 3,31 18,9 16,2 0,168 474 426 Vgl. 7 Ref. 4 - 3,94 14,6 8,9 0,226 470 422 Vgl. 8 Ref. 4 2-23 4,18 11,3 10,9 0,165 472 422 DF: first connection; FD: second connection; λ onset DF : Onset wavelength of the first connection

[0260] As shown in Tables 1 and 2, the OLEDs produced in Examples 2-4, 6-8, 10-12 and 14-16, in which the first compound was used as the sole dopant in the EML, showed a greatly improved luminous efficacy and emitted deep blue light compared to the OLEDs produced in Examples 1, 5, 9 and 13, in which the first compound had multiple electron donor groups and an onset wavelength between 430 nm and 440 nm and the second compound was used in the EML. On the other hand, compared to the OLEDs produced in Cf. 1, 3, 5 and 7, where the first compound was used as the sole dopant in the EML, and the OLEDs produced in Cf. 2, 4, 6 and 8, where the first compound had only one electron donor group and an onset wavelength of less than 430 nm or more than 440 nm and the second compound was used in the EML, the luminous efficacy was slightly improved or greatly reduced.

[0261] In particular, compared to the OLEDs produced in Eqs. 2, 4, 6 and 8, where the first compound used only one electron donor group and the second compound was used in the EML, the OLEDs produced in Eqs. 2-4, 6-8, 10-12 and 14-16, where the first compound used multiple electron donor groups and the second compound was used in the EML, reduced their operating voltages by a maximum of 23.4% and improved their current efficiency and power efficiency by a maximum of 217.7% and 174.4% respectively.

Claims

[1] Including an organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7): a first electrode (210, 610, 1110); a second electrode (230, 630, 1130) opposite the first electrode (210, 610, 1110); and an emission layer (220, 220A, 220B, 220C, 620, 1120, 1120A) arranged between the first and second electrodes (210, 230; 610, 630; 1110, 1130) and containing at least one emitting material layer (240, 240A, 240B, 340, 440, 640, 1240, 1340, 1440, 1540, 1640, 1740), wherein the at least one emitting material layer (240, 240A, 240B, 340, 440, 640, 1240, 1340, 1440, 1540, 1640, 1740) contains a first compound (DF) and a second compound (FD, FD1), and where the first compound (DF) has the following structure of formula 1 and the second compound (FD, FD1) has the following structure of formula 7: where in Formula 1, each of R 1 to R 9independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is, where two to four of R 1 to R 9 a group with the following structure of formula 2 is, where in Formula 2: each of R 11 to R 18 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30-group is and at least two adjacent of R 11 to R 18 form an unsubstituted or substituted heteroaromatic ring with the following structure of formula 3; and The asterisk in formula 2 indicates a link position. where in Formula 3, X equals NR 25 , O or S is; each of R 21 to R 25 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is; and the dashed line in formula 3 indicates a condensed part, where in Formula 7, each of R 31 to R 34independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30 -group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is optional two adjacent elements of R 31 to R 34 form an unsubstituted or substituted condensed ring with boron and nitrogen; each of R 35 to R 38 independently of each other deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20 -Alkylamino, an unsubstituted or substituted aromatic C6-C 30-group or an unsubstituted or substituted heteroaromatic C3-C 30 -group is where each R 35 is identical or different from each other if q is an integer of two or more, each R 36 is identical or different from each other if r is an integer of two or more, each R 37 is identical or different from each other if s is an integer of two or more and each R 38 is identical or different from each other if t is an integer of two or more; q and s are each independently an integer from 0 to 5; r is an integer from 0 to 3; and t is an integer from 0 to 4. [2] Organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7) according to claim 1, wherein an onset wavelength of the first compound (DF) is smaller than a maximum absorption wavelength of the second compound (FD). [3] Organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7) according to claim 2, wherein the onset wavelength of the first compound (DF) is between 430 nm and 440 nm. [4] Organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7) according to any one of claims 1 to 3, wherein the first compound (DF) comprises an organic compound having the following structure of formula 4: where in Formula 4, each of R 25 , R 26 , R 27 , R 28 and R 29 independently of each other hydrogen, deuterium, protium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C1-C 20 -Alkylamino, unsubstituted or substituted C6-C 30 -Aryl or unsubstituted or substituted C3-C 30 -Heteroaryl is, where two of R 25 , R 26 , R 27 , R 28 and R 29 have the structure of Formula 2. [5] Organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7) according to any one of claims 1 to 4, wherein the group having the structure of formula 2 is selected from the following groups: [6] Organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7) according to any one of claims 1 to 3, wherein the first compound (DF) is selected from: [7] Organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7) according to any one of claims 1 to 6, wherein the second compound (FD) comprises an organic compound having the following structure of formula 8A to 8C: where in formulas 8A to 8C, each of R 41 to R 44 and R 51 to R 55 independently of each other hydrogen, deuterium, tritium, halogen, unsubstituted or substituted C1-C 20 -Alkyl, unsubstituted or substituted C 1 -C 20 -Alkylsilyl, unsubstituted or substituted C1-C 20-Alkylamino, unsubstituted or substituted C 6 -C 30 -Arylamino, unsubstituted or substituted C6-C 30- Aryl or unsubstituted or substituted C3-C 30 -Heteroaryl is. [8] Organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7) according to any one of claims 1 to 6, wherein the second compound (FD) is selected from: [9] Organic light-emitting diode (D, D1, D4, D5, D6, D7) according to any one of claims 1 to 8, wherein the at least one emitting material layer (240, 340, 440, 640, 1240, 1340, 1440, 1540, 1640, 1740) comprises a single layer of emitting material. [10] Organic light-emitting diode (D, D1, D4, D5, D6, D7) according to claim 9, wherein the single-layer emitting material layer further comprises a third compound (H). [11] Organic light-emitting diode (D, D1, D4, D5, D6, D7) according to claim 10, wherein the single-layer emitting material layer comprises: the first compound (DF) of 10 to 40 wt.%, the second compound (FD) of 0.1 to 5 wt.% and the third compound (H) of 55 to 85 wt.%. [12] Organic light-emitting diode (D, D1, D4, D5, D6, D7) according to claim 10 or 11, wherein the lowest excited triplet exciton energy level of the third compound (H) is higher than the lowest excited triplet exciton energy level of the first compound (DF) and the lowest excited triplet exciton energy level of the first compound (DF) is higher than the lowest excited triplet exciton energy level of the second compound (FD). [13] Organic light-emitting diode (D, D1, D4, D5, D6, D7) according to any one of claims 10 to 12, wherein the lowest excited singlet exciton energy level of the third compound (H) is higher than the lowest excited singlet exciton energy level of the first compound (DF) and the lowest excited singlet exciton energy level of the first compound (DF) is higher than the lowest excited singlet exciton energy level of the second compound (FD). [14] Organic light-emitting diode (D, D2, D3, D7) according to any one of claims 1 to 8, wherein the at least one emitting material layer (240A, 240B, 1640) comprises: a first emitting material layer (242, 1642) arranged between the first and second electrodes (210, 230; 1110, 1130), and a second emitting material layer (244, 1644) arranged between the first electrode (210, 1110) and the first emitting material layer (242, 1642) or between the first emitting material layer (242, 1642) and the second electrode (230, 1130), and wherein the first emitting material layer (242, 1642) contains the first compound (DF) and the second emitting material layer (244, 1644) contains the second compound (FD, FD1). [15] Organic light-emitting diode (D, D2, D3, D7) according to claim 14, wherein the first emitting material layer (242, 1642) further contains a third compound (H1) and the second emitting material layer (244, 1644) further contains a fourth compound (H2). [16] Organic light-emitting diode (D, D2, D3, D7) according to claim 15, wherein the lowest excited triplet exciton energy level of the third compound (H1) is higher than the lowest excited triplet exciton energy level of the first compound (DF) and the lowest excited triplet exciton energy level of the first compound (DF) is higher than the lowest excited triplet exciton energy level of the second compound (FD, FD1). [17] Organic light-emitting diode (D, D2, D3, D7) according to claim 15 or 16, wherein the lowest excited singlet exciton energy level of the third compound (H1) is higher than the lowest excited singlet exciton energy level of the first compound (DF) and the lowest excited singlet exciton energy level of the first compound (DF) is higher than the lowest excited singlet exciton energy level of the second compound (FD, FD1). [18] Organic light-emitting diode (D, D2, D3, D7) according to any one of claims 15 to 17, wherein the lowest excited singlet energy level of the fourth compound (H2) is higher than the lowest excited singlet energy level of the second compound (FD). [19] Organic light-emitting diode (D, D3) according to any one of claims 14 to 18, wherein the at least one emitting material layer (240B) further comprises a third emitting material layer (246) which is arranged opposite the second emitting material layer (244) with respect to the first emitting material layer (242). [20] Organic light-emitting diode (D, D3) according to claim 19, wherein the third emitting material layer (246) contains a fifth compound (FD2) and a sixth compound (H3), and wherein the fifth compound (FD2) contains the organic compound with the structure according to formula 7. [21] Organic light-emitting diode (D, D4, D6, D7) according to any one of claims 1 to 20, wherein the emission layer (220C, 1120, 1120A) contains a first emitting part (320, 1220, 1520) arranged between the first and second electrodes (210, 230; 1110, 1130), a second emitting part (420, 1320, 1620) arranged between the first emitting part (320, 1220, 1520) and the second electrode (230, 1130), and a charge-generating layer (380, 1280, 1580) arranged between the first and second emitting parts (320, 420; 1220, 1320; 1520, 1620), and wherein at least one of the first emitting part (320, 1220, 1520) and the second emitting part (420, 1320, 1620) contains the at least one emitting material layer (340, 440, 1240, 1340, 1540, 1640). [22] Organic light-emitting diode (D, D4, D6, D7) according to claim 21, wherein the first emitting part contains the at least one emitting material layer, and the second emitting part is configured to emit red light and / or green light. [23] Organic light-emitting diode (D, D6, D7) according to claim 21 or 22, wherein the emission layer (1120, 1120A) further comprises: a third emitting part (1420, 1720) arranged between the second emitting part (1320, 1620) and the second electrode (1130), and a second charge-generating layer (1380, 1680) arranged between the second and third emitting part (1320, 1420, 1620, 1720), and wherein at least one of the first emitting part (1220, 1520) and the third emitting part (1420, 1720) comprises the at least one emitting material layer (1240, 1440, 1540, 1740). [24] An organic light-emitting device (100, 1000) comprising: a substrate (1010); and the organic light-emitting diode (D, D1, D2, D3, D4, D5, D6, D7) according to any one of claims 1 to 23, which is arranged above the substrate (1010).

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