ORGANIC LIGHT-EMITTING DIODE CONTAINING CO-HOSTS FORMING EXCIPLEX, AND LIGHTING DEVICE AND DISPLAY APPARATUS INCLUDING SAME

• US 20150069352A1
• Filed: 04/10/2013
• Published: 03/12/2015
• Est. Priority Date: 04/10/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Seoul National University R&DB Foundation (Seoul National University)
• Inventors: Lee, Sung Hun, Kim, Jang Joo, Park, Young Seo, Kim, Kwon Hyeon
• Granted Patent: US 10,177,329 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 2101/10 Triplet emission
• 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 50/12 comprising dopants
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/16 Electron transporting layers
• CPC Class Codes: H10K 85/322 comprising boron
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/622 containing four rings, e.g. pyrene
• 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 85/658 Organoboranes

Abstract

Provided are an organic light-emitting diode (“OLED”) including a bottom electrode, a top electrode disposed opposite to the bottom electrode, and an organic layer that is interposed between the bottom electrode and the top electrode and includes a hole-transporting host and an electron-transporting host forming an exciplex and a phosphorescent dopant having a triplet energy which is lower than the triplet energy of the hole-transporting host, the triplet energy of the electron-transporting host, and the triplet energy of the exciplex, and a lighting device and a display apparatus including the OLED. Instead of a phosphorescent dopant, the fluorescent dopant having a singlet energy which is lower than the singlet energy of the exciplex may be also used.

Claims

1. An organic light-emitting diode (OLED) comprising:

a bottom electrode;

a top electrode disposed opposite to the bottom electrode; and

an organic layer that is interposed between the bottom electrode and the top electrode and comprises a hole-transporting host and an electron-transporting host forming an exciplex and a phosphorescent dopant having a triplet energy which is lower than the triplet energy of the hole-transporting host, the triplet energy of the electron-transporting host, and the triplet energy of the exciplex.

2. The OLED of claim 1, wherein the hole-transporting host and the electron-transporting host satisfy the following relational expressions 1 and 2:

(1) Lowest unoccupied molecular orbital (LUMO) energy of the hole-transporting host−

LUMO energy of the electron-transporting host>

0.2 eV and

(2) Highest occupied molecular orbital (HOMO) energy of the hole-transporting host−

HOMO energy of the electron-transporting host>

0.2 eV.

3. The OLED of claim 1, wherein the organic layer comprises a light emitting layer.

4. The OLED of claim 1, wherein the organic layer comprises a light emitting layer, a hole transport layer disposed between the light emitting layer and the bottom electrode, and an electron transport layer disposed between the light emitting layer and the top electrode,

wherein the hole-transporting host, the electron-transporting host, and the phosphorescent dopant are included in the light emitting layer.

5. The OLED of claim 4, wherein the hole transport layer comprises a hole-transporting material that is the same as the hole-transporting host, and the electron transport layer comprises an electron-transporting material that is the same as the electron-transporting host.

6. The OLED of claim 1, wherein the hole-transporting host, the electron-transporting host, and the phosphorescent dopant are mixed at a molar ratio of 100:

30 to 300;

1 to 100.

7. The OLED of claim 1, wherein the hole-transporting host and the electron-transporting host are mixed in a combination selected from TCTA:

B3PYMPM, TCTA;

TPBi, TCTA;

3TPYMB, TCTA;

BmPyPB, TCTA;

BSFM, CBP;

B3PYMPM, and NPB;

BSFM.

15. A lighting device comprising the OLED according to claim 1.

17. A display apparatus comprising the OLED according to claim 1.

8. An organic light-emitting diode (OLED) comprising:

a bottom electrode;

a top electrode disposed oppositely to the bottom electrode; and

an organic layer that is disposed between the bottom electrode and the top electrode and comprises a hole-transporting host and an electron-transporting host, and a fluorescent dopant,

wherein the hole-transporting host and the electron-transporting host form an exciplex and have less than 0.3 eV of an energy difference between a singlet energy and a triplet energy of the exciplex, and the fluorescent dopant has a singlet energy which is lower than the singlet energy of the exciplex.

9. The OLED of claim 8, wherein the hole-transporting host and the electron-transporting host satisfy the following relational expressions 1 and 2:

(1) LUMO energy of the hole-transporting host−

LUMO energy of the electron-transporting host>

0.2 eV and

(2) HOMO energy of the hole-transporting host−

HOMO energy of the electron-transporting host>

0.2 eV.

10. The OLED of claim 8, wherein the organic layer comprises a light emitting layer.

11. The OLED of claim 8, wherein the organic layer comprises a light emitting layer, a hole transport layer disposed between the light emitting layer and the bottom electrode, and an electron transport layer disposed between the light emitting layer and the top electrode,

wherein the hole-transporting host, the electron-transporting host and the fluorescent dopant are included in the light emitting layer.

12. The OLED of claim 11, wherein the hole transport layer comprises a hole-transporting material that is the same as the hole-transporting host, and the electron transport layer comprises an electron-transporting material that is the same as the electron-transporting host.

13. The OLED of claim 8, wherein the hole-transporting host, the electron-transporting host, and the fluorescent dopant are mixed at a molar ratio of 100:

30 to 300;

1 to 100.

14. The OLED of claim 8, wherein the hole-transporting host and the electron-transporting host are mixed in a combination selected from TCTA:

B3PYMPM, TCTA;

TPBi, TCTA;

3TPYMB, TCTA;

BmPyPB, TCTA;

BSFM, CBP;

B3PYMPM, and NPB;

BSFM.

16. A lighting device comprising the OLED according to claim 8.

18. A display apparatus comprising the OLED according to claim 8.