Organic light-emitting device comprising host, phosphorescent dopant and fluorescent dopant

Patent metadata

Field	Value
Publication number	US-10418573-B2
Application number	US-201515112630-A
Country	US
Kind code	B2
Filing date	Jul 27, 2015
Priority date	Feb 17, 2015
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

According to an aspect, an organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an emission layer disposed between the first electrode and the second electrode and including a host and a dopant, wherein the host is an exciplex host, which is a combination of a hole transporting host and an electron transporting host which form an exciplex, or a delayed fluorescent organic compound, and the dopant includes both a phosphorescent dopant and a fluorescent dopant.

First claim

The invention claimed is:

1. An organic light-emitting device comprising:
a first electrode;
a second electrode facing the first electrode; and
an emission layer disposed between the first electrode and the second electrode and comprising a delayed fluorescent host and a dopant,
wherein the delayed fluorescent host comprises:
an exciplex host which is a combination of a hole transporting host and an electron transporting host that combine together to form an exciplex; or
a delayed fluorescent organic compound in the form of D-C-A (an electron donation group: D—a connecting group: C—an electron accepting group: A), in the form of D-C-A-C-D, or in the form of A-C-D-C-A, and
the dopant comprises both a phosphorescent dopant and a fluorescent dopant
wherein a triplet excited state energy level of the phosphorescent dopant is higher than a singlet excited state energy level and a triplet excited state energy level of the fluorescent dopant, and
wherein a photoluminescence spectrum of the delayed fluorescent host overlaps an absorption spectrum of the fluorescent dopant, and a photoluminescence spectrum of the phosphorescent dopant overlaps an absorption spectrum of the fluorescent dopant.

2. The organic light-emitting device of claim 1 , wherein a difference between a singlet exciplex energy level and a triplet exciplex energy level of the exciplex host is about 0 eV or more to less than about 0.3 eV.

3. The organic light-emitting device of claim 1 , wherein the singlet exciplex energy level and the triplet exciplex energy level of the exciplex host are higher than a singlet excited energy level of the fluorescent dopant.

4. The organic light-emitting device of claim 1 , wherein a lower unoccupied molecular orbital (LUMO) of the hole transporting host is higher than that of the electron transporting host by about 0.2 eV or more, but not as high as a band gap of the hole transporting host, and a highest occupied molecular orbital (HOMO) of the hole transporting host is higher than that of the electron transporting host by about 0.2 eV or more, but not as high as a band gap of the hole transporting host.

5. The organic light-emitting device of claim 1 , wherein, when the delayed fluorescent host comprises the exciplex host, a weight ratio of the hole transporting host to the electron transporting host is in a range of about 20:80 to about 80:20.

6. The organic light-emitting device of claim 1 , wherein, when the delayed fluorescent host comprises the delayed fluorescent organic compound, a difference between a singlet excited state energy level and a triplet excited state energy level of the delayed fluorescent organic compound is about 0 eV or more to less than about 0.3 eV.

7. The organic light-emitting device of claim 1 , wherein, when the delayed fluorescent host comprises the delayed fluorescent organic compound, a singlet excited state energy level and a triplet excited state energy level of the delayed fluorescent organic compound are higher than a singlet excited state energy level of the fluorescent dopant.

8. The organic light-emitting device of claim 1 , wherein a singlet excited state energy of the exciplex or a singlet excited state energy of the delayed fluorescent organic compound is transferred to the fluorescent dopant.

9. The organic light-emitting device of claim 1 , wherein the hole transporting host comprises a carbazole derivative or an aromatic amine compound.

10. The organic light-emitting device of claim 1 , wherein the electron transporting host comprises a π-electron deficient heteroaromatic ring.

11. The organic light-emitting device of claim 1 , wherein the electron transporting host comprises a phosphine oxide group-containing compound, a sulfur oxide group-containing group, or a triazine derivative.

12. The organic light-emitting device of claim 1 , wherein the phosphorescent dopant comprises a transition metal complex.

13. The organic light-emitting device of claim 1 , wherein the phosphorescent dopant comprises a complex comprising iridium (Ir), platinum (Pt), osmium (Os), gold (Au), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm).

14. The organic light-emitting device of claim 1 , wherein a weight ratio of the delayed fluorescent host:phosphorescent dopant:fluorescent dopant is in a range of about 99.8:0.1:0.1 to about 70:15:15.

15. The organic light-emitting device of claim 1 , further comprising a hole transporting region between the emission layer and the first electrode.

16. The organic light-emitting device of claim 1 , further comprising an electron transporting region between the emission layer and the second electrode.

Assignees

• Seoul Nat Univ R&Db Foundation

Inventors

• Kim Jang-Joo
• Kim Hyun-Gu
• Kim Kwon-Hyeon
• Sun Jin-Won

Classifications

• C09K2211/185

  of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd · CPC title

• C09K11/87

  containing platina group metals · CPC title

• C09K11/06

  containing organic luminescent materials · CPC title

• H01L51/5056

  Electricity · mapped topic

• H01L51/5004 Primary

  Electricity · mapped topic