Patent Application
20210087179
Korean Patent Application No. 10-2019-0115527, filed on Sep. 19, 2019, in the Korean Intellectual Property Office, and entitled: “Compound for Organic Optoelectronic Device, Composition for Organic Optoelectronic Device, Organic Optoelectronic Device, and Display Device,” and Korean Patent Application No. 10-2020-0114010, filed on Sep. 7, 2020, in the Korean Intellectual Property Office, and entitled: “Compound for Organic Optoelectronic Device, Composition for Organic Optoelectronic Device, Organic Optoelectronic Device, and Display Device,” are incorporated by reference herein in their entirety.
Embodiments relate to a compound for an organic optoelectronic device, a composition for an organic optoelectronic device, an organic optoelectronic device, and a display device.
An organic optoelectronic device (organic optoelectronic diode) is a device that converts electrical energy into photoenergy, and vice versa.
An organic optoelectronic device may be classified as follows in accordance with its driving principles. One is a photoelectric device where excitons generated by photoenergy are separated into electrons and holes and the electrons and holes are transferred to different electrodes respectively and electrical energy is generated, and the other is a light emitting device to generate photoenergy from electrical energy by supplying a voltage or a current to electrodes.
Examples of the organic optoelectronic device include an organic photoelectric device, an organic light emitting diode, an organic solar cell, and an organic photo conductor drum.
Among them, the organic light emitting diode (OLED) has recently drawn attention due to an increase in demand for flat panel displays.
The embodiments may be realized by providing a compound for an organic optoelectronic device, the compound being represented by Chemical Formula 1:
The embodiments may be realized by providing a composition for an organic optoelectronic device, the composition including a first compound, and a second compound, wherein the first compound includes the compound for an organic optoelectronic device according to an embodiment, and the second compound includes a compound represented by Chemical Formula 2:
The embodiments may be realized by providing an organic optoelectronic device including an anode and a cathode facing each other; at least one organic layer between the anode and the cathode, wherein the organic layer includes the compound for an organic optoelectronic device or the composition for an organic optoelectronic device according to an embodiment.
The embodiments may be realized by providing a display device including the organic optoelectronic device according to an embodiment.
Features will be apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which:
Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those skilled in the art.
In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being “on” another layer or element, it can be directly on the other layer or element, or intervening layers may also be present. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. Like reference numerals refer to like elements throughout.
As used herein, when a definition is not otherwise provided, “substituted” refers to replacement of at least one hydrogen of a substituent or a compound by deuterium, a halogen, a hydroxyl group, an amino group, a substituted or unsubstituted C1 to C30 amine group, a nitro group, a substituted or unsubstituted C1 to C40 silyl group, a C1 to C30 alkyl group, a C1 to C10 alkylsilyl group, a C6 to C30 arylsilyl group, a C3 to C30 cycloalkyl group, a C3 to C30 heterocycloalkyl group, a C6 to C30 aryl group, a C2 to C30 heteroaryl group, a C1 to C20 alkoxy group, a C1 to C10 trifluoroalkyl group, a cyano group, or a combination thereof.
In one example, “substituted” refers to replacement of at least one hydrogen of a substituent or a compound by deuterium, a C1 to C30 alkyl group, a C1 to C10 alkylsilyl group, a C6 to C30 arylsilyl group, a C3 to C30 cycloalkyl group, a C3 to C30 heterocycloalkyl group, a C6 to C30 aryl group, a C2 to C30 heteroaryl group, or a cyano group. In addition, in specific examples, “substituted” refers to replacement of at least one hydrogen of a substituent or a compound by deuterium, a C1 to C20 alkyl group, a C6 to C30 aryl group, or a cyano group. In addition, in specific examples, “substituted” refers to replacement of at least one hydrogen of a substituent or a compound by deuterium, a C1 to C5 alkyl group, a C6 to C18 aryl group, or a cyano group. In addition, in specific examples, “substituted” refers to replacement of at least one hydrogen of a substituent or a compound by deuterium, a cyano group, a methyl group, an ethyl group, a propyl group, a butyl group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group.
As used herein, when a definition is not otherwise provided, “hetero” refers to one including one to three heteroatoms selected from N, O, S, P, and Si, and remaining carbons in one functional group.
As used herein, “aryl group” refers to a group including at least one hydrocarbon aromatic moiety, and may include a group in which all elements of the hydrocarbon aromatic moiety have p-orbitals which form conjugation, for example a phenyl group, a naphthyl group, and the like, a group in which two or more hydrocarbon aromatic moieties may be linked by a sigma bond, for example a biphenyl group, a terphenyl group, a quarterphenyl group, and the like, and a group in which two or more hydrocarbon aromatic moieties are fused directly or indirectly to provide a non-aromatic fused ring, for example, a fluorenyl group, and the like.
The aryl group may include a monocyclic, polycyclic or fused ring polycyclic (i.e., rings sharing adjacent pairs of carbon atoms) functional group.
As used herein, “heterocyclic group” is a generic concept of a heteroaryl group, and may include at least one heteroatom selected from N, O, S, P, and Si instead of carbon (C) in a ring such as an aryl group, a cycloalkyl group, a fused ring thereof, or a combination thereof. When the heterocyclic group is a fused ring, the entire ring or each ring of the heterocyclic group may include one or more heteroatoms.
For example, “heteroaryl group” refers to an aryl group including at least one heteroatom selected from N, O, S, P, and Si. Two or more heteroaryl groups are linked by a sigma bond directly, or when the heteroaryl group includes two or more rings, the two or more rings may be fused. When the heteroaryl group is a fused ring, each ring may include one to three heteroatoms.
More specifically, the substituted or unsubstituted C6 to C30 aryl group may be a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted naphthacenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted p-terphenyl group, a substituted or unsubstituted m-terphenyl group, a substituted or unsubstituted o-terphenyl group, a substituted or unsubstituted chrysenyl group, a substituted or unsubstituted triphenylene group, a substituted or unsubstituted perylenyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted indenyl group, a substituted or unsubstituted furanyl group, or a combination thereof.
More specifically, the substituted or unsubstituted C2 to C30 heterocyclic group may be a substituted or unsubstituted thiophenyl group, a substituted or unsubstituted pyrrolyl group, a substituted or unsubstituted pyrazolyl group, a substituted or unsubstituted imidazolyl group, a substituted or unsubstituted triazolyl group, a substituted or unsubstituted oxazolyl group, a substituted or unsubstituted thiazolyl group, a substituted or unsubstituted oxadiazolyl group, a substituted or unsubstituted thiadiazolyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted benzimidazolyl group, a substituted or unsubstituted indolyl group, a substituted or unsubstituted quinolinyl group, a substituted or unsubstituted isoquinolinyl group, a substituted or unsubstituted quinazolinyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted benzoxazinyl group, a substituted or unsubstituted benzthiazinyl group, a substituted or unsubstituted acridinyl group, a substituted or unsubstituted phenazinyl group, a substituted or unsubstituted phenothiazinyl group, a substituted or unsubstituted phenoxazinyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group, or a combination thereof.
In the present specification, hole characteristics refer to an ability to donate an electron to form a hole when an electric field is applied and that a hole formed in the anode may be easily injected into the light emitting layer and transported in the light emitting layer due to conductive characteristics according to the highest occupied molecular orbital (HOMO) level.
In addition, electron characteristics refer to an ability to accept an electron when an electric field is applied and that electron formed in the cathode may be easily injected into the light emitting layer and transported in the light emitting layer due to conductive characteristics according to the lowest unoccupied molecular orbital (LUMO) level.
Hereinafter, a compound for an organic optoelectronic device according to an embodiment is described.
The compound for the organic optoelectronic device according to an embodiment may be represented by Chemical Formula 1.
In Chemical Formula 1, le and R2 may each independently be or include, e.g., hydrogen, an unsubstituted phenyl group, or an unsubstituted biphenyl group.
In an implementation, at least one of R1 and R2 may be, e.g., an unsubstituted phenyl group or an unsubstituted biphenyl group.
R3 and R4 may each independently be or include, e.g., an unsubstituted phenyl group or an unsubstituted biphenyl group.
R5 to R9 may each independently be or include, e.g., hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C20 aryl group.
As for the compound represented by Chemical Formula 1, a kinked terphenyl group may be included on a indolocarbazole to help increase stability of the material, and simultaneously, the kinked terphenyl group may be additionally substituted with a C6 to C12 aryl group to help improve electron mobility and thus have improved effects of deposited films and resultantly, realize device characteristics of a low driving, high efficiency, and a long life-span.
In an implementation, the compound for the organic optoelectronic device represented by Chemical Formula 1 may be represented by one of Chemical Formula 1A to Chemical Formula 1C, depending on the aryl group which further substitutes a terphenyl group.
In Chemical Formula 1A to Chemical Formula 1C, R3 to R9 may be the same as described above.
In an implementation, Chemical Formula 1A may be represented by one of Chemical Formula 1A-1 to Chemical Formula 1A-3.
In Chemical Formula 1A-1 to Chemical Formula 1A-3, R3 to R9 may be the same as described above.
In an implementation, Chemical Formula 1B may be represented by one of Chemical Formula 1B-1 to Chemical Formula 1B-6.
In Chemical Formula 1B-1 to Chemical Formula 1B-6, R3 to R9 may be the same as described above.
In an implementation, Chemical Formula 1C may be represented by one of Chemical Formula 1C-1 to Chemical Formula 1C-9.
In Chemical Formula 1C-1 to Chemical Formula 1C-9, R3 to R9 may be the same as described above.
In an implementation, the compound for the organic optoelectronic device may be represented by Chemical Formula 1A-2.
In an implementation, the compound for the organic optoelectronic device represented by Chemical Formula 1 may be a compound of Group 1.
[Group 1]
The composition for the organic optoelectronic device according to another embodiment may include the aforementioned compound (hereinafter referred to as a first compound) and a second compound for an organic optoelectronic device. In an implementation, the composition may include a mixture of the first compound and the second compound. The second compound may be represented by Chemical Formula 2.
In Chemical Formula 2,
Y1 and Y2 may each independently be or include, e.g., a single bond or a substituted or unsubstituted C6 to C20 arylene group,
Ar1 and Ar2 may each independently be or include, e.g., a substituted or unsubstituted C6 to C20 aryl group or a substituted or unsubstituted C2 to C30 heterocyclic group, and
R10 to R15 may each independently be or include, e.g., hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C30 heterocyclic group, a cyano group, or a combination thereof.
The second compound, which is a material having fast and stable hole transfer characteristics, may be used in a light emitting layer together with the first compound having fast and stable electron transfer characteristics to provide a charge balance, to thereby may have a glass transition temperature relative to a molecular weight to provide low driving and long life-span characteristics.
In an implementation, Ar1 and Ar2 of Chemical Formula 2 may each independently be or include, e.g., a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted triphenylenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted fluorenyl group, or a substituted or unsubstituted pyridinyl group, Y1 and Y2 may each independently be or include, e.g., a single bond, a substituted or unsubstituted phenylene group, or a substituted or unsubstituted biphenylene group, and R10 to R15 may each independently be or include, e.g., hydrogen, deuterium, or a substituted or unsubstituted C6 to C12 aryl group.
The “substituted” of Chemical Formula 2 may refer to replacement of at least one hydrogen by deuterium, a C1 to C4 alkyl group, a C6 to C18 aryl group, or a C2 to C30 heteroaryl group.
In an implementation, the moieties *—Y1—Ar1 and *—Y2—Ar2 of Chemical Formula 2 may each independently be a moiety of Group I.
[Group I]
In Group I, * is a linking point.
In an implementation, the second compound represented by Chemical Formula 2 may be a compound of Group 2.
[Group 2]
The first compound and the second compound may be applied in a form of a composition (e.g., a mixture).
In an implementation, the aforementioned (first) compound for the organic optoelectronic device or composition for the organic optoelectronic device may be a host.
The first compound and the second compound may be included in a weight ratio of about 1:99 to about 99:1. Within the range, a desirable weight ratio may be adjusted using an electron transport capability of the first compound and a hole transport capability of the second compound device to realize bipolar characteristics and thus to improve efficiency and life-span. Within the range, they may be, e.g., included in a weight ratio of about 90:10 to about 10:90, about 80:20 to about 20:80, for example about 80:20 to about 30:70, or about 70:30 to about 30:70. In an implementation, they may be included in a weight ratio of about 60:40 to about 30:70, e.g., a weight ratio of about 40:60.
In preparing an emission layer for a device, the aforementioned (first) compound for an organic optoelectronic device or composition for an organic optoelectronic device may further include a dopant. The dopant may be, e.g., a phosphorescent dopant. In an implementation, the dopant may be, e.g., a red, green, or blue phosphorescent dopant, or a red or green phosphorescent dopant.
The dopant may be a material mixed in a small amount to facilitate light emission, and may be a material such as a metal complex that emits light by multiple excitation into a triplet or more. The dopant may be, e.g. an inorganic, organic, or organic/inorganic compound, and one or more types thereof may be used.
Examples of the dopant may include a phosphorescent dopant and examples of the phosphorescent dopant may include an organic metal compound including Ir, Pt, Os, Ti, Zr, Hf, Eu, Tb, Tm, Fe, Co, Ni, Ru, Rh, Pd, or a combination thereof. The phosphorescent dopant may be, e.g., a compound represented by Chemical Formula Z.
L3MXA [Chemical Formula Z]
In Chemical Formula Z, M may be a metal, and L3 and XA may each independently be a ligand to form a complex compound with M.
The M may be, e.g., Ir, Pt, Os, Ti, Zr, Hf, Eu, Tb, Tm, Fe, Co, Ni, Ru, Rh, Pd, or a combination thereof, and the L4 and X may be, e.g., a bidendate ligand.
The (first) compound for the organic optoelectronic device or the composition for the organic optoelectronic device may be formed or deposited by a dry film formation method such as chemical vapor deposition.
Hereinafter, an organic optoelectronic device to which the aforementioned (first) compound for the organic optoelectronic device or composition for the organic optoelectronic device is applied is described.
The organic optoelectronic device may be a suitable device to convert electrical energy into photoenergy and vice versa, e.g., an organic photoelectric device, an organic light emitting diode, an organic solar cell, or an organic photo-conductor drum.
Herein, an organic light emitting diode as one example of an organic optoelectronic device is described referring to drawings.
Referring to
The anode 120 may be made of a conductor having a large work function to facilitate hole injection, e.g., a metal, a metal oxide, or a conductive polymer. The anode 120 may be, e.g., a metal such as nickel, platinum, vanadium, chromium, copper, zinc, gold, or the like or an alloy thereof; a metal oxide such as zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), or the like; a combination of a metal and an oxide such as ZnO and Al or SnO2 and Sb; or a conductive polymer such as poly(3-methylthiophene), poly(3,4-(ethylene-1,2-dioxy)thiophene) (PEDOT), polypyrrole, or polyaniline.
The cathode 110 may be made of a conductor having a small work function to facilitate electron injection, and may be, e.g., a metal, a metal oxide, or a conductive polymer. The cathode 110 may be, e.g., a metal such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum silver, tin, lead, cesium, barium, or the like, or an alloy thereof; or a multi-layer structure material such as LiF/Al, LiO2/Al, LiF/Ca, LiF/Al, and BaF2/Ca.
The organic layer 105 may include a light emitting layer 130 that includes the aforementioned (first) compound or composition for the organic optoelectronic device.
The light emitting layer 130 may include, e.g., the above-described (first) compound or composition.
Referring to
The hole auxiliary layer 140 may include, e.g., a compound of Group A.
In an implementation, the hole auxiliary layer 140 may include a hole transport layer between the anode 120 and the light emitting layer 130 and a hole transport auxiliary layer between the light emitting layer 130 and the hole transport layer, and a compound of Group A may be included in the hole transport auxiliary layer.
[Group A]
In the hole transport auxiliary layer, compounds disclosed in U.S. Pat. No. 5,061,569A, JP1993-009471A, WO1995-009147A1, JP1995-126615A, JP1998-095972A, or the like, and compounds similar thereto may be used in addition to the compounds described above.
In an implementation, the organic light emitting diode may further include an electron transport layer, an electron injection layer, or a hole injection layer as the organic layer 105.
The organic light emitting diodes 100 and 200 may be produced by forming an anode or a cathode on a substrate, forming an organic layer using a dry film formation method such as a vacuum deposition method (evaporation), sputtering, plasma plating, or ion plating, and forming a cathode or an anode thereon.
The organic light emitting diode may be applied to an organic light emitting display device.
The following Examples and Comparative Examples are provided in order to highlight characteristics of one or more embodiments, but it will be understood that the Examples and Comparative Examples are not to be construed as limiting the scope of the embodiments, nor are the Comparative Examples to be construed as being outside the scope of the embodiments. Further, it will be understood that the embodiments are not limited to the particular details described in the Examples and Comparative Examples.
Hereinafter, starting materials and reactants used in Examples and Synthesis Examples were purchased from Sigma-Aldrich Co. Ltd., TCI Inc., Tokyo chemical industry or P&H tech as far as there in no particular comment or were synthesized by known methods.
(Preparation of Compound for Organic Optoelectronic Device)
The compound was synthesized through the following steps.
(Preparation of First Compound for Organic Optoelectronic Device)
3-bromo-5-chloro-1,1′-biphenyl (30 g, 112.8 mmol), 3-phenylbenzeneboronic acid (22.3 g, 112.8 mmol), K2CO3 (34.2 g, 248 mmol), and Pd(PPh3)4 (6.5 g, 5.6 mmol) were put in a round-bottomed flask and then, dissolved in 300 ml of THF and 150 ml of distilled water and then, stirred under reflux at 80° C. for 20 hours. When a reaction was complete, after removing a water layer, the residue was treated through column chromatography (hexane:DCM (20%)) to obtain 35 g (81%) of Intermediate 1.
Intermediate 1 (25 g, 73.5 mmol) was put along with 11,12-dihydroindolo[2,3-a]carbazole (20.7 g, 80.8 mmol), Pd2(dba)3 (2 g, 2.2 mmol), P(t-Bu)3 (1.4 g, 7.4 mmol), and sodium tert-butoxide (7.7 g, 80.8 mmol) in a round-bottomed flask and then, stirred under reflux in 220 ml of xylene at 140° C. for 20 hours. When a reaction was complete, the resultant was cooled down to ambient temperature and then, slowly poured into distilled water and stirred for 1 hour. A solid therein was filtered, dissolved in ethyl acetate, and dried with MgSO4. After removing an organic solvent under a reduced pressure, the residue was vacuum-dried to obtain 32 g (78%) of Intermediate 2.
Intermediate 2 (18.6 g, 33.2 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (11.5 g, 43.1 mmol), and sodium hydride (1.2 g, 49.8 mmol) were put in a round-bottomed flask and then, stirred in 130 ml of DMF at ambient temperature for 12 hours. The produced solid was filtered and then, stirred in a water layer for 30 minutes. The solid was filtered and dried to obtain 22 g (83%) of Compound A-1.
(Preparation of Second Compound for Organic Optoelectronic Device)
Compound B-71 was synthesized by a suitable method.
The following comparative compounds were synthesized by suitable methods.
(Production of Organic Light Emitting Diode)
A glass substrate coated with ITO (Indium tin oxide) having a thickness of 1,500 Å was washed with distilled water. After the washing with the distilled water, the glass substrate was ultrasonically washed with isopropyl alcohol, acetone, or methanol, and dried and then, moved to a plasma cleaner, cleaned by using oxygen plasma for 10 minutes, and moved to a vacuum depositor. This obtained ITO transparent electrode was used as an anode, Compound A was vacuum-deposited on the ITO substrate to form a 700 Å-thick hole injection layer, and Compound B was deposited to be 50 Å-thick on the injection layer, and then Compound C was deposited to be 1,020 Å-thick to form a hole transport layer. On the hole transport layer, 400 Å-thick light emitting layer was formed by using Compound A-1 obtained in Synthesis Example 3 as a host and doping 7 wt % of PhGD as a dopant by a vacuum-deposition. Subsequently, on the light emitting layer, a 300 Å-thick electron transport layer was formed by simultaneously vacuum-depositing Compound D and Liq in a weight ratio of 1:1, and on the electron transport layer, Liq and Al were sequentially vacuum-deposited to be 15 Å-thick and 1,200 Å-thick, producing an organic light emitting diode.
The organic light emitting diode had a five-layered organic thin layer, and specifically the following structure.
ITO/Compound A (700 Å)/Compound B (50 Å)/Compound C (1,020 Å)/EML[Compound A-1: PhGD (7 wt %)] (400 Å)/Compound D:Liq (300 Å)/Liq (15 Å)/Al (1,200 Å)
Compound A: N4,N4′-diphenyl-N4,N4′-bis(9-phenyl-9H-carbazol-3-yl)biphenyl-4,4′-diamine
Compound B: 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN)
Compound C: N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine
Compound D: 8-(4-(4,6-di(naphthalen-2-yl)-1,3,5-triazin-2-yl)phenyl)quinoline
Example 2 and Comparative Examples 1 to 12
Organic light emitting diodes were produced in the same manner as in Example 1, except that the compositions were changed according to Table 1 and Table 2.
Evaluation
Driving voltages, luminous efficiency, and life-span characteristics of the organic light emitting diodes according to Examples 1 and 2 and Comparative Example 1 to 12 were evaluated.
Specific measurement methods are as follows, and the results are shown in Tables 1 and 2.
(1) Measurement of Current Density Change Depending on Voltage Change
The obtained organic light emitting diodes were measured regarding a current value flowing in the unit device, while increasing the voltage from 0 V to 10 V using a current-voltage meter (Keithley 2400), and the measured current value was divided by area to provide the results.
(2) Measurement of Luminance Change Depending on Voltage Change
Luminance was measured by using a luminance meter (Minolta Cs-1000A), while the voltage of the organic light emitting diodes was increased from 0 V to 10 V.
(3) Measurement of Luminous Efficiency
Luminous efficiency (cd/A) at the same current density (10 mA/cm2) were calculated by using the luminance and current density from the items (1) and (2).
(4) Measurement of Life-Span
The results were obtained by measuring a time when luminous efficiency (cd/A) was decreased down to 95%, while luminance (cd/m2) was maintained to be 24,000 cd/m2.
(5) Measurement of Driving Voltage
A driving voltage of each diode was measured using a current-voltage meter (Keithley 2400) at 15 mA/cm2.
(6) Calculation of T95 Life-Span Ratio (%)
When a single host or a mixed host including the same second host was used, T95(h) ratios of example (a first compound as a first host) and comparative examples (respectively applying the comparative compounds as the first host) were exhibited.
T95 life-span ratio (%)={[T95(h) of example, comparative examples (a first compound alone or as a mixed host)]/[T95(h) of reference data (a comparative compound alone or as the mixed host)]}×100
(7) Calculation of Driving Voltage Ratio (%)
When the single host or the mixed host including the same second host was used, driving voltage ratios of example (the first compound as the first host) and comparative examples (respectively applying the comparative compounds as the first host) were exhibited.
Driving voltage ratio (%)={[driving voltage (V) of example, comparative examples (the first compound alone or as the mixed host)]/[driving voltage (V) of reference data (a comparative compound alone or as the mixed host)]}×100
(8) Calculation of Power Efficiency Ratio (%)
When the single host or the mixed host including the same second host was used, power efficiency ratios of example (a first compound as a first host) and comparative examples (respectively applying the comparative compounds as the first host) are exhibited.
Power efficiency ratio (%)={[power efficiency (Cd/A) of example, comparative examples (the first compound alone or the mixed host)]/[power efficiency (Cd/A) of reference data (a comparative compound alone or as the mixed host)]}×100
Referring to Tables 1 and 2, the material used in the Examples (including an additional phenyl group or biphenyl group in addition to the kinked terphenyl structure) exhibited equal or higher driving voltages and power efficiency and simultaneously, a greatly increased life-span, compared with the materials including no kinked terphenyl structure or no additional substituent in addition to the kinked terphenyl structure.
By way of summation and review, an organic light emitting diode converts electrical energy into light, and the performance of organic light emitting diode may be influenced by the organic materials disposed between electrodes.
One or more embodiments may provide a compound for an organic optoelectronic device capable of realizing an organic optoelectronic device having high efficiency and long life-span.
Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2019-0115527 | Sep 2019 | KR | national |
| 10-2020-0114010 | Sep 2020 | KR | national |
