A NOVEL COMBINATION OF A HOST COMPOUND AND A DOPANT COMPOUND AND AN ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING THE SAME

Abstract

Disclosed herein are combinations of a dopant compound and a host compound. The dopant being an Iridium complex and the host being a carbazole derivative. Also made known are electroluminescent devices comprising the same.

Claims

1. A combination of one or more dopant compound represented by the following formula 1, and one or more host compound represented by the following formula 2: ##STR00064## wherein R.sub.1 and R.sub.2 each independently represent hydrogen, deuterium, a halogen, a substituted or unsubstituted (C1-C6)alkyl, or a substituted or unsubstituted (C6-C30)aryl; and a and b each independently represent an integer of 1 to 4; where a or b is an integer of 2 or more, each of R.sub.1 and each of R.sub.2 may be the same or different. ##STR00065## wherein Ma represents a substituted or unsubstituted 5- to 11-membered nitrogen-containing heteroaryl; La represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted 3- to 30-membered heteroarylene; Xa to Xh each independently represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted (C2-C30)alkynyl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C60)aryl, a substituted or unsubstituted 3- to 30-membered heteroaryl, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstituted mono- or di- (C6-C30)arylamino; or are linked to each other to form a substituted or unsubstituted mono- or polycyclic, (C3-C30) alicyclic or aromatic ring, whose carbon atom(s) may be replaced with at least one hetero atom selected from nitrogen, oxygen, and sulfur; provided that when any of Xa to Xh are linked to each other to form a ring, the structure of ##STR00066## where Xc or Xd is hydrogen, is excluded; and the heteroaryl(ene) contains at least one hetero atom selected from B, N, O, S, Si, and P.

2. The combination according to claim 1, wherein in formula 1, R.sub.1 and R.sub.2 each independently represent hydrogen, a halogen, a substituted or unsubstituted (C1-C6)alkyl, or a substituted or unsubstituted (C6-C12)aryl.

3. The combination according to claim 1, wherein in formula 2, La is represented by a single bond, a carbazolylene, or one of the following formulas 3 to 15: ##STR00067## ##STR00068## ##STR00069## wherein Xi to Xp each independently represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted (C2-C30)alkynyl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C60)aryl, a substituted or unsubstituted 3- to 30-membered heteroaryl, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstituted mono- or di- (C6-C30)arylamino; or are linked to each other to form a substituted or unsubstituted, mono- or polycyclic, (C3-C30) alicyclic or aromatic ring, whose carbon atom(s) may be replaced with at least one hetero atom selected from nitrogen, oxygen, and sulfur.

4. The combination according to claim 1, wherein in formula 2, Ma represents a monocyclic ring-type heteroaryl selected from a group consisting of a substituted or unsubstituted pyrrolyl, a substituted or unsubstituted imidazolyl, a substituted or unsubstituted pyrazolyl, a substituted or unsubstituted triazinyl, a substituted or unsubstituted tetrazinyl, a substituted or unsubstituted triazolyl, a substituted or unsubstituted tetrazolyl, a substituted or unsubstituted pyridyl, a substituted or unsubstituted pyrazinyl, a substituted or unsubstituted pyrimidinyl, and a substituted or unsubstituted pyridazinyl, or a fused ring-type heteroaryl selected from a group consisting of a substituted or unsubstituted benzimidazolyl, a substituted or unsubstituted isoindolyl, a substituted or unsubstituted indolyl, a substituted or unsubstituted indazolyl, a substituted or unsubstituted benzothiadiazolyl, a substituted or unsubstituted quinolyl, a substituted or unsubstituted isoquinolyl, a substituted or unsubstituted cinnolinyl, a substituted or unsubstituted quinazolinyl, a substituted or unsubstituted naphthyridinyl, a substituted or unsubstituted quinoxalinyl, a substituted or unsubstituted carbazolyl, and a substituted or unsubstituted phenanthridinyl.

5. The combination according to claim 1, wherein in formula 2, Xa to Xh each independently represent hydrogen, a cyano, a substituted or unsubstituted (C6-C15)aryl, a substituted or unsubstituted 10- to 20-membered heteroaryl, or a substituted or unsubstituted tri(C6-C10)arylsilyl; or are linked to each other to form a substituted or unsubstituted mono- or polycyclic, (C6-C20) aromatic ring.

6. The combination according to claim 1, wherein the compound represented by formula 1 is selected from the group consisting of: ##STR00070## ##STR00071## ##STR00072## ##STR00073## ##STR00074## ##STR00075## ##STR00076## ##STR00077## ##STR00078## ##STR00079## ##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085##

7. The combination according to claim 1, wherein the compound represented by formula 2 is selected from the group consisting of: ##STR00086## ##STR00087## ##STR00088## ##STR00089## ##STR00090## ##STR00091## ##STR00092## ##STR00093## ##STR00094## ##STR00095## ##STR00096## ##STR00097## ##STR00098## ##STR00099## ##STR00100## ##STR00101## ##STR00102## ##STR00103## ##STR00104## ##STR00105## ##STR00106## ##STR00107## ##STR00108## ##STR00109## ##STR00110## ##STR00111## ##STR00112## ##STR00113## ##STR00114## ##STR00115## ##STR00116## ##STR00117## ##STR00118## ##STR00119## ##STR00120## ##STR00121##

8. An organic electroluminescent device which comprises the combination according to claim 1.

Description

DEVICE EXAMPLE 1

Preparation of an OLED Device Comprising the Dopant and the Host of the Present Invention

[0050] An OLED device was produced using the dopant and host compounds according to the present invention. A transparent electrode indium tin oxide (ITO) thin film (10 Ω/sq) on a glass substrate for an organic light-emitting diode (OLED) device (Geomatec) was subjected to an ultrasonic washing with trichloroethylene, acetone, ethanol, and distilled water, sequentially, and then was stored in isopropanol. The ITO substrate was then mounted on a substrate holder of a vacuum vapor depositing apparatus. N.sup.4,N.sup.4′-diphenyl-N.sup.4,N.sup.4′-bis(9-phenyl-9H-carbazol-3-yl)-[1,1′-biphenyl]-4,4′-diamine (compound HI-1) was introduced into a cell of said vacuum vapor depositing apparatus, and then the pressure in the chamber of said apparatus was controlled to 10.sup.-6 torr. Thereafter, an electric current was applied to the cell to evaporate the above introduced material, thereby forming a first hole injection layer having a thickness of 80 nm on the ITO substrate. Next, 1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (compound HI-2) was introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a second hole injection layer having a thickness of 5 nm on the first hole injection layer. N-([1,1′-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluorene-2-amine (compound HT-1) was then introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a first hole transport layer having a thickness of 10 nm on the second hole injection layer. N-(4-(9,9-diphenyl-9H,9′H-[2,9′-bifluoren-9′-yl)phenyl)-9,9-dimethyl-N-phenyl-9H-fluorene-2-amine (compound HT-2) was then introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a second hole transport layer having a thickness of 60 nm on the first hole transport layer. A host compound listed in Table 1 was introduced into one cell of said vacuum vapor depositing apparatus as a host, and a dopant compound was introduced into another cell. The host material was evaporated while the dopant was evaporated at a different rate from the host material, so that the dopant was deposited in a doping amount of 3 wt % based on the total amount of the host and dopant to form a light-emitting layer having a thickness of 40 nm on the second hole transport layer. 2,4-bis(9,9-dimethyl-9H-fluoren-2-yl)-6-(naphthalen-2-yl)-1,3,5-triazine (compound ET-1) and lithium quinolate (compound El-1) were then introduced into two cells of the vacuum vapor depositing apparatus, respectively, and evaporated at 1:1 rate to form an electron transport layer having a thickness of 30 nm on the light-emitting layer. After depositing lithium quinolate (compound El-1) as an electron injection layer having a thickness of 2 nm on the electron transport layer, an Al cathode having a thickness of 80 nm was deposited by another vacuum vapor deposition apparatus. Thus, an OLED device was produced.

##STR00061## ##STR00062##

COMPARATIVE EXAMPLE 1

Preparation of an OLED Device Comprising the Host Compound of the Present Invention and a Conventional Dopant Compound

[0051] An OLED device was produced in the same manner as in Device Examples 1, except for using compound RD-1 as a dopant of the light-emitting layer.

##STR00063##

[0052] The evaluation results of the OLED device produced in Device Example 1 and

[0053] Comparative Example 1 are shown in Table 1 below.

TABLE-US-00001 TABLE 1 Voltage Efficiency Color Coordinates Lifespan Host Dopant (V) (cd/A) (x, y) T95 (hr) Device H2-16 D-29 4.1 32.2 660 339 583 Example 1 Comparative H2-16 RD-1 4.1 29.9 661 338 502 Example 1

[0054] When the dopant and host compounds according to the present invention are used, an organic EL device having higher luminous efficiency and longer lifespan than the conventional devices is provided.