NANODOT ELECTROLUMINESCENT DIODE OF TANDEM STRUCTURE AND METHOD FOR FABRICATING THE SAME

• US 20080238299A1
• Filed: 01/22/2008
• Published: 10/02/2008
• Est. Priority Date: 01/22/2007
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: CHOI, Byoung Lyong, CHO, Kyung Sang, KWON, Soon Jae
• Application Number:
  US12/017,677
• Publication Number:
  US 20080238299A1
• Time in Patent Office: Days
• US Class Current: 313/503
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths

Abstract

A nanodot electroluminescent diode is disclosed. The nanodot electroluminescent diode comprises a lower electrode, an upper electrode, and unit cells interposed between the electrodes, wherein the unit cells comprise a quantum dot electroluminescent layer and also include an organic layer and/or an inorganic layer in addition to the quantum dot electroluminescent layer. The disclosed nanodot electroluminescent diode provides high efficiency, stability, and high luminance, and mixed colors, multi-colors, full color, and white electroluminescence can be obtained.

Claims

1. A multiple nanodot electroluminescent diode comprising:

a lower electrode;

an upper electrode that is opposedly disposed to the lower electrode; and

a plurality of unit cells interposed between the lower electrode and upper electrode;

each unit cell comprising a quantum dot electroluminescent layer and an organic layer and/or an inorganic layer.

2. The multiple nanodot electroluminescent diode of claim 1, wherein the organic layer and/or the inorganic layer comprise a hole injection layer or a hole transport layer.

3. The multiple nanodot electroluminescent diode of claim 1, wherein the organic layer and/or the inorganic layer comprise an electron injection layer or an electron transport layer.

4. The multiple nanodot electroluminescent diode of claim 1, wherein the unit cells further include an electrode layer.

5. The multiple nanodot electroluminescent diode of claim 1, wherein the unit cells comprise a hole transport layer, a quantum dot electroluminescent layer, and an electron transport layer.

6. The multiple nanodot electroluminescent diode of claim 1, wherein the unit cells comprise a hole transporting layer, a quantum dot electroluminescent layer, an electron transport layer, and an electrode layer.

7. The multiple nanodot electroluminescent diode of claim 1, wherein the unit cells comprise a hole injection layer, a hole transport layer, a quantum dot electroluminescent layer, and an electron transport layer.

8. The multiple nanodot electroluminescent diode of claim 1, wherein the quantum dot electroluminescent layer comprises a group II-VI compound, the group II-VI compound being a binary compound that comprises CdSe, CdTe, ZnS, ZnSe, or ZnTe, a ternary compound that comprises CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, CdZnS, CdZnSe, or CdZnTe, or a quaternary compound that comprises CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, or HgZnSTe;

a group III-V compound;

the group III-V compound being a binary compound that comprises GaN, GaP, GaAs, GaSb, InP, InAs, or InSb, a ternary compound that comprises GaNP, GaNAs, GaNSb, GaPAs, GaPSbInNP, InNAs, InNSb, InPAs, InPSb, or GaAlNP, or a quaternary compound that comprises GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb;

a group IV-VI compound the group IV-VI compound being a binary compound that comprises PbS, PbSe, and PbTe, a ternary compound that comprises PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, and SnPbTe, or a quarternary compound that comprises SnPbSSe, SnPbSeTe, or SnPbSTe;

a group VI compound the group VI compound being a single element compound that comprises Si or Ge;

or a binary compound including SiC or SiGe;

or a combination comprising at least one of the foregoing materials.

9. The multiple nanodot electroluminescent diode of claim 1, wherein the quantum dot electroluminescent layer included within each unit cell luminesces in the same color for each unit cell.

10. The multiple nanodot electroluminescent diode of claim 1, wherein the quantum dot electroluminescent layer included within each unit cell luminesces in a different color for each unit cell.

11. The multiple nanodot electroluminescent diode of claim 1, wherein the quantum dot electroluminescent layer included in each unit cell is disposed in the same configuration as that of an organic layer and/or an inorganic layer.

12. The multiple nanodot electroluminescent diode of claim 1, wherein the quantum dot electroluminescent layer included in each unit cell is disposed in a configuration different from that of an organic layer and/or an inorganic layer.

13. A method for fabricating a multiple nanodot electroluminescent diode using a wet method, the nanodot electroluminescent diode comprising a lower electrode, an upper electrode, and a plurality of unit cells interposed between the electrodes, the method comprising:

forming the unit cells by sequentially disposing the lower electrode, the quantum dot electroluminescent layer, and an organic layer and/or an inorganic layer by using a solution coating method selected from the group consisting of spin coating, a sol-gel method, deep coating, casting, printing, and spraying, and a combination comprising at least one of the foregoing methods;

successively depositing the unit cells using the solution coating method; and

forming the upper electrode on the uppermost layer of the last unit cell.

14. The method of claim 13, wherein the organic layer and/or the inorganic layer of the unit cells include a hole injection layer and/or a hole transport layer.

15. The method of claim 13, wherein the organic layer and/or the inorganic layer of the unit cells comprise an electron injection layer and an electron transport layer.

16. The method of claim 13, wherein the unit cells further comprise an electrode layer.

17. The method of any one of claim 13 to claim 15, wherein the electron injection layer or the electron transport layer is formed by a dry coating method selected from the group consisting of thermal deposition, e-beam deposition, sputtering, and vacuum deposition, and a combination comprising at least one of the foregoing methods.