ORGANIC LIGHT-EMITTING DEVICE

• US 20150318511A1
• Filed: 08/13/2014
• Published: 11/05/2015
• Est. Priority Date: 05/02/2014
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: KIM, Seul-Ong, SHIN, Dong-Woo, LEE, Jung-Sub, KIM, Youn-Sun, ITO, Naoyuki
• Granted Patent: US 9,728,729 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H10K 2101/30 Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values
• CPC Class Codes: H10K 2101/40 Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
• CPC Class Codes: H10K 2101/90 Multiple hosts in the emissive layer
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/121 for assisting energy transfer, e.g. sensitization
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 50/181 Electron blocking layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/40 Organosilicon compounds, e.g. TIPS pentacene
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: H10K 85/622 containing four rings, e.g. pyrene
• CPC Class Codes: H10K 85/626 containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: H10K 85/654 comprising only nitrogen as heteroatom H10K85/652 takes precedence
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: H10K 85/6576 comprising only sulfur in the heteroaromatic polycondensed ring system, e.g. benzothiophene

Abstract

An organic light-emitting device and a flat panel display, the device including an anode; a cathode; and an organic layer therebetween, the organic layer including an EML, the EML including a first host and a second host that are different from one another, a hole transport region between the anode and the EML, the hole transport region including at least one of a hole injection layer (HIL), a hole transport layer (HTL), a butler layer, or an electron blocking layer (EBL), an electron transport region between the EML and the cathode, the electron transport region including at least one of a hole blocking layer (HBL), an electron transport layer (ETL), or an electron injection layer (EIL), and an intermediate layer between the EML and the electron transport region; wherein the intermediate layer includes a compound having an electron affinity of more than 0 eV and less than 2.5 eV.

Claims

1. An organic light-emitting device, comprising:

an anode;

a cathode; and

an organic layer between the anode and the cathode, the organic layer including;

an emission layer (EML), the EML including a first host and a second host that are different from one another,

a bole transport region between the anode and the EML, the hole transport region including at least one of a hole injection layer (HIL), a hole transport layer (HTL), a buffer layer, or an electron blocking layer (EBL),

an electron transport region between the EML and the cathode, the electron transport region including at least one of a hole blocking layer (HBL), an electron transport layer (ETL), or an electron injection layer (EIL), and

an intermediate layer between the EML and the electron transport region;

wherein the intermediate layer includes a compound having an electron affinity of more than 0 eV and less than 2.5 eV.

2. The organic light-emitting device as claimed in claim 1, wherein the EML is a phosphorescent EML.

3. The organic light-emitting device as claimed in claim 1, wherein a relationship of electron affinities (EA_host1) and (EA_host2) and ionization potentials (IP_host1) and (IP_host2) of the first host and the second host satisfy at least one of the following expressions:

EA_host1≧

EA_host2+0.3 eV 

 

(1)

IP_host2≧

IP_host+0.3 eV 

 

(2).

4. The organic light-emitting device as claimed in claim 1, wherein the EML is a phosphorescent EML, the EML including a dopant that emits phosphorescence having a main peak of at least 450 nm.

5. The organic light-emitting device as claimed in claim 1, wherein:

the EML is a phosphorescent EML, the EML including a dopant that emits phosphorescence having a main peak of at least 450 nm, and

at least one of the first host or the second host is a compound that includes a tryphenylene moiety or a carbazole moiety.

6. The organic light-emitting device as claimed in claim 1, wherein:

the intermediate layer contacts the EML, and

the compound having an electron affinity of more than 0 eV and less than 2.5 eV includes a tryphenylene moiety or a carbazole moiety.

7. The organic light-emitting device as claimed in claim 1, wherein an electron affinity of the intermediate layer compound [EA_{intermediate layer}] and an electron affinity of a compound of the ETL [EA_ETL] satisfy a relationship represented by the following expression:

EA_ETL≧

EA_{intermediate layer}+0.3 eV.

8. The organic light-emitting device as claimed in claim 4, wherein a triplet energy of the intermediate layer compound [E^T_IL(eV)] is greater than that of the dopant that emits phosphorescence [E^T_d(eV)].

9. The organic light-emitting device as claimed in claim 1, wherein:

the intermediate layer compound has a triplet energy of at least 2.2 eV when the EML emits red phosphorescence,

the intermediate layer compound has a triplet energy of at least 2.4 eV when the EML emits green phosphorescence, and

the intermediate layer compound has a triplet energy of at least at least 2.6 eV when the EML emits blue phosphorescence.

10. The organic light-emitting device as claimed in claim 1, wherein the hole transport region includes a p-dopant.

11. The organic light-emitting device as claimed in claim 1, wherein the hole transport region includes a p-dopant, the p-dopant including a quinone derivative, a metal oxide, or a cyano group-containing compound.

12. The organic light-emitting device as claimed in claim 1, wherein the EML is a phosphorescent EML and the EML includes a dopant, the dopant including an Ir-complex, a Pt-complex, an Os-complex, or a Cu-complex.

13. The organic light-emitting device as claimed in claim 1, wherein the intermediate layer compound is represented by Formula 1 below:

14. The organic light-emitting device as claimed in claim 13, wherein R₁ to R₄ are each independently a hydrogen, a deuterium, a substituted or an unsubstituted C₁-C₃₀ alkyl group, a substituted or unsubstituted C₁-C₃₀ heteroalkyl group, a substituted or unsubstituted C₆-C₃₀ arylamine group, or a group represented by one of Formulae 2a to 2x below:

15. The organic light-emitting device as claimed in claim 13, wherein L is a single bond or a group represented by one of Formulae 3a to 3z below:

16. The organic light-emitting device as claimed in claim 11, wherein at least one of the first host or the second host is one of the following compounds:

17. The organic light-emitting device as claimed in claim 4, wherein the EML is a phosphorescent EML, the phosphorescent EML including an Ir-complex as a dopant.

18. The organic light-emitting device as claimed in claim 1, wherein the intermediate layer compound is one of the following compounds:

19. The organic light-emitting device as claimed as claim 1, wherein the organic layer is formed by performing a wet process.

20. A flat panel display comprising the organic light-emitting device as claimed in claim 1, wherein the first electrode of the organic light-emitting device is electrically connected to a source electrode or a drain electrode of a thin film transistor.