Organic electroluminescence device and organometallic compound for organic electroluminescence device
An organic electroluminescence device includes an organometallic compound represented by Formula 1 in an emission layer to achieve high efficiency, low driving voltage, high luminance, and long life:
1. An organic electroluminescence device, comprising:
a first electrode;
a hole transport region on the first electrode;
an emission layer on the hole transport region;
an electron transport region on the emission layer; and
a second electrode on the electron transport region,
wherein the emission layer comprises an organometallic compound represented by Formula 2:
wherein in Formula 2,
X 1 to X 4 are each independently a carbon atom or a nitrogen atom,
R 1 to R 4 are each independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and/or bonded to an adjacent group to form a ring,
a1 to a4 are each independently an integer of 0 to 4,
L 2 is a direct linkage,
a substituted or unsubstituted divalent alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms,
R 5 to R 8 are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring forming carbon atoms, and/or bonded to an adjacent group to form a ring,
at least one selected from among A1 and A4 is a mesoionic carbene group represented by any one of 1-1 to 1-6, and
A2, A3, and any remaining ligand selected from among A1 and A4 are each independently represented by any one of 2-1 to 2-4:
wherein in 1-1 to 1-6,
any one selected from among Y 1 and Y 2 is CH and an other one selected from among Y 1 and Y 2 is NR 24 ,
is a position of binding to a neighboring ligand or a position of binding to L 2 ,
-* is a position of binding to Pt,
A11 is a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,
any one selected from among Y 3 and Y 4 is
and an other one selected from among Y 3 and Y 4 is C-*
Y 5 is NR 26 or
R 11 to R 15 are each independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and/or bonded to an adjacent group to form a ring,
R 21 to R 26 are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,
a11 to a13 are each independently an integer of 0 to 2, and
a14 is an integer of 0 to 4:
wherein in 2-1 to 2-4,
Y 11 is a carbon atom or a nitrogen atom,
Y 12 is CR 31 or
Y 13 to Y 19 are each independently CR 35 or a nitrogen atom, and
R 31 to R 41 are each independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and/or bonded to an adjacent group to form a ring, and
wherein:
when A1 is the mesoionic carbene group represented by 1-1, A2 is a group represented by 2-1 in which Y 11 is the carbon atom and Y 12 is
A3 is represented by 2-1 in which Y 11 is the carbon atom and Y 12 is
or is represented by 2-2 in which Y 13 to Y 19 are each independently CR 35 , A4 is represented by 2-1 in which Y 11 is the nitrogen atom and Y 12 is CR 31 or is represented by 2-4, then a11 of 1-1 is 0, and
when A4 is the mesoionic carbene group represented by 1-1, A3 is a group represented by 2-1 in which Y 11 is the carbon atom and Y 12 is
A2 is represented by 2-1 in which Y 11 is the carbon atom and Y 12 is
or is represented by 2-2 in which Y 13 to Y 19 are each independently CR 35 , A1 is represented by 2-1 in which Y 11 is the nitrogen atom and Y 12 is CR 31 or is represented by 2-4, then a11 of 1-1 is 0.
2. The organic electroluminescence device of claim 1 , wherein:
the emission layer comprises a host and a dopant, and
the dopant comprises the organometallic compound.
3. The organic electroluminescence device of claim 1 , wherein the emission layer is to emit green light having a center wavelength of 500 nm to 600 nm through phosphorescence.
4. The organic electroluminescence device of claim 1 , wherein 1-6 is represented by 1-6-1:
wherein in Formula 1-6-1,
Y 3 , Y 4 , R 15 , R 26 , and a14 are each independently the same as defined in connection with 1-6.
5. The organic electroluminescence device of claim 1 , wherein the organometallic compound represented by Formula 2 is represented by at least one of Formulae 3-1 to 3-7:
wherein in Formulae 3-1 and 3-2, A1 is represented by any one of 1-1 to 1-5,
in Formulae 3-3 and 3-5, at least one selected from among A1 and A4 is represented by any one of 1-1 to 1-5,
in Formula 3-4, A1 is represented by any one of 1-1 to 1-5,
in Formulae 3-6 and 3-7, A1 is represented by 1-6,
in Formulae 3-1 to 3-6, R 51 to R 64 are each independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and/or bonded to an adjacent group to form a ring,
Z is a carbon atom or a nitrogen atom,
a21, a23, a24, a26, a27, a29, a30, a32, a33, and a34 are each independently an integer of 0 to 3,
a22, a28, and a31 are each independently an integer of 0 to 4,
a25 is an integer of 0 to 2, and
Y 13 to Y 19 , and L 2 are each independently the same as defined in connection with 2-2, and
wherein:
in Formula 3-1, when A1 is represented by 1-1, Y 13 to Y 19 are each independently CR 35 , then a11 of 1-1 is 0,
in Formula 3-3, when one selected from among A1 and A4 is represented by 1-1, an other one selected from among A1 and A4 is represented by 2-1 in which Y 11 is the nitrogen atom and Y 12 is CR 31 or is represented by 2-4, then a11 of 1-1 is 0, and
in Formula 3-5, when one selected from among A1 and A4 is represented by 1-1, an other one selected from among A1 and A4 is represented by 2-1 in which Y 11 is the nitrogen atom and Y 12 is CR 31 or is represented by 2-4, then a11 of 1-1 is 0.
6. The organic electroluminescence device of claim 1 , wherein the emission layer comprises at least one of the compounds represented by Compound Group 1 and Compound Group 2:
7. An organometallic compound represented by Formula 2:
wherein in Formula 2,
A1 to A4 are each independently a substituted or unsubstituted mesoionic carbene group having 1 to 20 ring-forming carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and at least one of A1 to A4 is a substituted or unsubstituted mesoionic carbene group having 1 to 20 ring-forming carbon atoms,
X 1 to X 4 are each independently a carbon atom or a nitrogen atom,
R 1 to R 4 are each independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and/or bonded to an adjacent group to form a ring,
a1 to a4 are each independently an integer of 0 to 4,
L 2 is a direct linkage,
a substituted or unsubstituted divalent alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms,
R 5 to R 8 are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and/or bonded to an adjacent group to form a ring,
at least one selected from among A1 and A4 is a mesoionic carbene group represented by any one of 1-1 to 1-6, and
A2, A3, and any remaining ligand selected from among A1 and A4 are each independently represented by any one of 2-1 to 2-4:
wherein in 1-1 to 1-6,
any one selected from among Y 1 and Y 2 is CH and the other is NR 24 ,
is a position of binding to a neighboring ligand or a position of binding to L 2
-* is a position of binding to Pt,
A11 is a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,
any one selected from among Y 3 and Y 4 is
and the other is C-*,
Y 5 is NR 26 or
R 11 to R 15 are each independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and/or bonded to an adjacent group to form a ring,
R 21 to R 26 are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms,
a11 to a13 are each independently an integer of 0 to 2, and
a14 is an integer of 0 to 4:
wherein in 2-1 to 2-4,
Y 11 is a carbon atom or a nitrogen atom,
Y 12 is CR 31 or
Y 13 to Y 19 are each independently CR 35 or a nitrogen atom, and
R 31 to R 41 are each independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and/or bonded to an adjacent group to form a ring, and
wherein:
when A1 is the mesoionic carbene group represented by 1-1, A2 is a group represented by 2-1 in which Y 11 is the carbon atom and Y 12 is
A3 is represented by 2-1 in which Y 11 is the carbon atom and Y 12 is
or is represented by 2-2 in which Y 13 to Y 19 are each independently CR 35 , A4 is represented by 2-1 in which Y 11 is the nitrogen atom and Y 12 is CR 31 or is represented by 2-4, then a11 of 1-1 is 0, and
when A4 is the mesoionic carbene group represented by 1-1, A3 is a group represented by 2-1 in which Y 11 is the carbon atom and Y 12 is
A2 is represented by 2-1 in which Y 11 is the carbon atom and Y 12 is
or is represented by 2-2 in which Y 13 to Y 19 are each independently CR 35 , A1 is represented by 2-1 in which Y 11 is the nitrogen atom and Y 12 is CR 31 or is represented by 2-4, then a11 of 1-1 is 0.
8. The organometallic compound of claim 7 , wherein 1-6 is represented 1-6-1:
wherein in 1-6-1,
Y 3 , Y 4 , R 15 , R 26 , and a14 are each independently the same as defined in connection with 1-6.
9. The organometallic compound of claim 7 , wherein the organometallic compound represented by Formula 2 is represented by at least one of Formulae 3-1 to 3-7:
wherein in Formulae 3-1 and 3-2, A1 is represented by any one of 1-1 to 1-5,
in Formulae 3-3 and 3-5, at least one selected from among A1 and A4 is represented by any one of 1-1 to 1-5,
in Formula 3-4, A1 is represented by any one of 1-1 to 1-5,
in Formulae 3-6 and 3-7, A1 is represented by 1-6,
in Formulae 3-1 to 3-6,
R 51 to R 64 are each independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and/or bonded to an adjacent group to form a ring,
Z is a carbon atom or a nitrogen atom,
a21, a23, a24, a26, a27, a29, a30, a32, a33, and a34 are each independently an integer of 0 to 3,
a22, a28, and a31 are each independently an integer of 0 to 4,
a25 is an integer of 0 to 2, and
Y 13 to Y 19 , and L 2 are each independently the same as defined in connection with 2-2, and
wherein:
in Formula 3-1, when A1 is represented by 1-1, Y 13 to Y 19 are each independently CR 35 , then a11 of 1-1 is 0,
in Formula 3-3, when one selected from A1 and A4 is represented by 1-1, an other one selected from among A1 and A4 is represented by 2-1 in which Y 11 is the nitrogen atom and Y 12 is CR 31 or is represented by 2-4, then a11 of 1-1 is 0, and
in Formula 3-5, when one selected from among A1 and A4 is represented by 1-1, an other one selected from among A1 and A4 is represented by 2-1 in which Y 11 is the nitrogen atom and Y 12 is CR 31 or is represented by 2-4, then a11 of 1-1 is 0.
10. The organometallic compound of claim 7 , wherein the organometallic compound represented by Formula 1 is any one of the compounds represented by Compound Group 1 and Compound Group 2: