Organic electroluminescent element and electronic device

Patent metadata

Field	Value
Publication number	US-9905779-B2
Application number	US-201414777679-A
Country	US
Kind code	B2
Filing date	Dec 24, 2014
Priority date	Dec 26, 2013
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

An organic electroluminescence device includes: an anode; an emitting layer; and a cathode, the emitting layer containing a first material, a second material and a third material, the first material being a fluorescent material, the second material being a delayed fluorescent material, the third material having a singlet energy larger than a singlet energy of the second material.

First claim

The invention claimed is:

1. An organic electroluminescence device, comprising:
an anode;
an emitting layer; and
a cathode, the emitting layer comprising a first material, a second material and a third material, the first material being a fluorescent material, the second material being a delayed fluorescent material, the third material having a singlet energy larger than a singlet energy of the second material,
wherein an energy gap Eg 77K (M2) at 77 [K] of the second material is larger than an energy gap Eg 77K (M1) at 77 [K] of the first material,
wherein an energy gap Eg 77K (M3) at 77 [K] of the third material is larger than the energy gap Eg 77K (M2) at 77 [K] of the second material,
wherein when the singlet energy of the second material is defined as EgS(M2) and a singlet energy of the first material is defined as EgS(M1), EgS(M2) is larger than EgS(M1).

2. The organic electroluminescence device according to claim 1 , wherein a difference ΔST(M2) between the singlet energy EgS(M2) of the second material and the energy gap Eg 77K (M2) at 77 [K] of the second material satisfies a relationship of a numerical formula (Numerical Formula 1) below,
Δ ST ( M 2)= EgS ( M 2)− Eg 77K ( M 2)<0.3[eV]  Numerical Formula 1.

3. The organic electroluminescence device according to claim 1 , wherein a difference ΔST(M1) between the singlet energy EgS(M1) of the first material and the energy gap Eg 77K (M1) at 77 [K] of the first material satisfies a relationship of a numerical formula (Numerical Formula 2) below,
Δ ST ( M 1)= EgS ( M 1)− Eg 77K ( M 1)>0.3[eV]  Numerical Formula 2.

4. The organic electroluminescence device according to claim 1 , wherein a difference ΔST(M3) between the singlet energy EgS(M3) of the third material and the energy gap Eg 77K (M3) at 77 [K] of the third material satisfies a numerical formula (Numerical Formula 3) below,
Δ ST ( M 3)= EgS ( M 3)− Eg 77K ( M 3)>0.3[eV]  Numerical Formula 3.

5. The organic electroluminescence device according to claim 1 , wherein an ionization potential Ip(M3) of the third material and an ionization potential Ip(M2) of the second material satisfy a relationship of a numerical formula (Numerical Formula 4) below,
Ip ( M 3)≧ Ip ( M 2)  (Numerical Formula 4).

6. The organic electroluminescence device according to claim 1 , wherein the energy gap Eg 77K (M3) at 77 [K] of the third material is 2.9 eV or more.

7. The organic electroluminescence device according to claim 1 , wherein the ionization potential Ip(M3) of the third material is 6.3 eV or more.

8. The organic electroluminescence device according to claim 1 , wherein an electron affinity Af(M3) of the third material is 2.8 eV or more.

9. The organic electroluminescence device according to claim 1 , wherein the third material is an aromatic hydrocarbon compound or an aromatic heterocyclic compound.

10. The organic electroluminescence device according to claim 1 , wherein the third material comprises at least one of a moiety represented by a formula (31) below and a moiety represented by a formula (32) below in one molecule,

where:
X 31 to X 36 in the formula (31) each independently represent a nitrogen atom, or a carbon atom bonded to another atom in the molecule of the third material, at least one of X 31 to X 36 being the carbon atom bonded to another atom in the molecule of the third material;
Y 31 to Y 38 in the formula (32) each independently represent a nitrogen atom, or a carbon atom bonded to another atom in the molecule of the third material, at least one of Y 31 to Y 38 being the carbon atom bonded to another atom in the molecule of the third material; and
Y 39 in the formula (32) represents a nitrogen atom, oxygen atom or sulfur atom.

11. The organic electroluminescence device according to claim 10 , wherein the moiety represented by the formula (31) is in a form of a group selected from the group consisting of formulae (33) and (34) below and contained in the third material,

where:
X 31 , X 32 , X 34 and X 36 in the formulae (33) and (34) each independently represent a nitrogen atom or CR 31 ;
R 31 is a hydrogen atom or a substituent, the substituent being selected from the group consisting of a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 ring carbon atoms, a substituted or unsubstituted trialkylsilyl group, a substituted or unsubstituted arylalkylsilyl group, a substituted or unsubstituted triarylsilyl group, a substituted or unsubstituted diarylphosphine oxide group, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, the substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms being a non-fused ring; and
wavy lines in the formulae (33) and (34) each show a bonding position with another atom or another structure in the molecule of the third material.

12. The organic electroluminescence device according to claim 11 , wherein R 31 is a hydrogen atom or a substituent, the substituent being selected from the group consisting of a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, the substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms being a non-fused ring.

13. The organic electroluminescence device according to claim 11 , wherein R 31 is a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms.

14. The organic electroluminescence device according to claim 11 , wherein X 31 , X 32 , X 34 and X 36 each independently represent CR 31 .

15. The organic electroluminescence device according to claim 10 , wherein the moiety represented by the formula (32) is in a form of at least one group selected from the group consisting of formulae (35), (36), (37), (38), (39) and (30a) below and contained in the third material,

where:
Y 31 to Y 38 in the formulae (35) to (39) and (30a) each independently represent a nitrogen atom or CR 32 ;
R 32 is a hydrogen atom or a substituent, the substituent being selected from the group consisting of a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 ring carbon atoms, a substituted or unsubstituted trialkylsilyl group, a substituted or unsubstituted arylalkylsilyl group, a substituted or unsubstituted triarylsilyl group, a substituted or unsubstituted diarylphosphine oxide group, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, the substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms being a non-fused

Assignees

• Idemitsu Kosan Co

Inventors

• Ogiwara Toshinari
• Yoshida Kei
• Hashimoto Ryohei
• Mizuki Yumiko

Classifications

• C07D403/14

  containing three or more hetero rings · CPC title

• C09K2211/1096

  containing other heteroatoms · CPC title

• H01L51/0054

  Electricity · mapped topic

• C07D307/91

  Dibenzofurans; Hydrogenated dibenzofurans · CPC title

• H01L2251/55

  Electricity · mapped topic