Quantum dots and devices including the same

Patent metadata

Field	Value
Publication number	US-10074770-B2
Application number	US-201615386512-A
Country	US
Kind code	B2
Filing date	Dec 21, 2016
Priority date	Dec 22, 2015
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A quantum dot includes a core-shell structure including a core including a first semiconductor nanocrystal and a shell disposed on the core, and including a material at least two different halogens, and the quantum dot does not include cadmium.

First claim

What is claimed is:

1. A quantum dot having a core-shell structure, the core-shell structure comprising:
a core comprising a first semiconductor nanocrystal; and
a shell disposed on the core, the shell comprising a crystalline or amorphous material and at least two different halogens,
wherein the quantum dot does not include cadmium,
wherein a solid state photoluminescence quantum efficiency of the quantum dot, when measured at 90° C. or greater, is greater than or equal to about 95% of a solid state photoluminescence quantum efficiency of the quantum dot when measured at 25° C., and
wherein the at least two different halogens comprise fluorine and at least one of chlorine and bromine.

2. The quantum dot of claim 1 , wherein the at least two different halogens consist of either fluorine and chlorine or fluorine and bromine.

3. The quantum dot of claim 1 wherein the first semiconductor nanocrystal comprises indium and phosphorous and the crystalline or amorphous material of the shell comprises zinc and at least one of sulfur and selenium.

4. The quantum dot of claim 1 , wherein a solid state photoluminescence quantum efficiency of the quantum dot when measured at 100° C. is greater than or equal to about 95% of the solid state photoluminescence quantum efficiency of the quantum dot when measured at 25° C.

5. The quantum dot of claim 1 , wherein a solid state photoluminescence quantum efficiency of the quantum dot when measured at a 150° C. is greater than or equal to about 80% of the solid state photoluminescence quantum efficiency of the quantum dot when measured at 25° C.

6. The quantum dot of claim 1 , wherein each halogen is present in or on the shell in a doped form or in a form of a metal halide.

7. The quantum dot of claim 1 , wherein the shell has a thickness of at least one monolayer of the material of the shell, and at least one of the halogens is present at or outside the thickness of the one monolayer.

8. The quantum dot of claim 1 , wherein a total amount of the two or more halogens is greater than or equal to about 30 atomic percent, with respect to a total amount of a metal atom included in the core.

9. The quantum dot of claim 1 , wherein the first semiconductor nanocrystal comprises at least one first metal selected from a group consisting of a Group II metal excluding cadmium, a Group III metal, a Group IV metal, and a combination thereof, and
wherein the crystalline or amorphous material of the shell comprises at least one second metal that is different form the first metal and is selected from the group consisting of a Group I metal, a Group II metal excluding cadmium, a Group III metal, a Group IV metal, and a combination thereof.

10. The quantum dot of claim 9 , wherein,
the Group II-VI compound comprises ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, HgZnTeS, HgZnSeS, HgZnSeTe, or a combination thereof,
the Group III-V compound comprises GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, or a combination thereof,
the Group IV-VI compound comprises SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, or a combination thereof,
the Group I-III-VI compound comprises CuInSe 2 , CuInS 2 , CuInGaSe, CuInGaS, or a combination thereof,
the Group II-III-VI compound comprises ZnGaS, ZnAlS, ZnInS, ZnGaSe, ZnAlSe, ZnInSe, ZnGaTe, ZnAlTe, ZnInTe, ZnGaO, ZnAlO, ZnInO, HgGaS, HgAlS, HgInS, HgGaSe, HgAlSe, HgInSe, HgGaTe, HgAlTe, HgInTe, MgGaS, MgAlS, MgInS, MgGaSe, MgAlSe, MgInSe, or a combination thereof,
the Group I-II-IV-VI compound comprises CuZnSnSe, CuZnSnS, or a combination thereof,
the Group IV element compound comprises Si, Ge, SiC, SiGe, or a combination thereof,
the metal-containing halogen compound comprises LiF, NaF, KF, BeF 2 , MgF 2 , CaF 2 , SrF 2 , CuF, AgF, AuF, ZnF 2 , HgF 2 , AlF 3 , GaF 3 , InF 3 , SnF 2 , PbF 2 , LiCl, NaCl, KCl, BeCl 2 , MgCl 2 , CaCl 2 , SrCl 2 , CuCl, AgCl, AuCl, ZnCl 2 , HgCl 2 , AlCl 3 , GaCl 3 , InCl 3 , SnCl 2 , PbCl 2 , LiBr, NaBr, KBr, BeBr 2 , MgBr 2 , CaBr 2 , SrBr 2 , CuBr, AgBr, AuBr, ZnBr 2 , HgBr 2 , AlBr 3 , GaBr 3 , InBr 3 , SnBr 2 , PbBr 2 , LiI, NaI, KI, BeI 2 , MgI 2 , CaI 2 , SrI 2 , CuI, AgI, AuI, ZnI 2 , HgI 2 , AlI 3 , GaI 3 , InI 3 , SnI 2 , PbI 2 , or a combination thereof, and
the metal oxide comprises In 2 O 3 , PbO, HgO, MgO, Ga 2 O 3 , Al 2 O 3 , ZnO, SiO 2 , zinc oxysulfide, zinc oxyselenide, zinc oxysulfide selenide, indiumphosphide oxide, indiumphosphide oxysulfide, or a combination thereof.

11. The quantum dot of claim 1 , wherein the first semiconductor nanocrystal comprises a Group II-VI compound excluding a cadmium-containing compound, a Group III-V compound, a Group IV-VI compound, a Group IV element or compound, a Group II-III-VI compound, a Group I-III-VI compound, a Group I-II-IV-VI compound, or a combination thereof, and
wherein the material of the shell comprises a Group II-VI compound excluding a cadmium-containing compound, a Group III-V compound, a Group IV-VI compound, a Group IV element or compound, a Group II-III-VI compound, a Group I-III-VI compound, a Group I-II-IV-VI compound, a metal-containing halogen compound, a metal oxide, or a combination thereof.

12. The quantum dot of claim 1 , wherein the first semiconductor nanocrystal comprises a Group III-V compound, and the shell comprises a Group II-VI compound.

13. The quantum dot of claim 1 , wherein the quantum dot has a quantum yield of greater than or equal to about 85%.

14. A quantum dot polymer composite comprising
a polymer matrix; and
the quantum dot of claim 1 dispersed in the polymer matrix.

15. The quantum dot polymer composite of claim 14 , wherein the polymer matrix comprises a thiolene polymer, a (meth)acrylate polymer, a urethane polymer, an epoxy polymer, a vinyl polymer, a silicone polymer, or a combination thereof.

16. An electronic device comprising the quantum dot of claim 1 .

17. A method of producing a quantum dot, the method comprising:
obtaining a first mixture comprising a first precursor, a ligand compound, and a solvent;
adding a second precursor, a first halogen source, and a first semiconductor nanocrystal to the first mixture to obtain a second mixture;
heating the second mixture to a reaction temperature effective to perform a reaction between the first precursor and the second precursor; and
adding a second halogen source to the second mixture after initiation of the reaction between the first precursor and the second precursor,
wherein a core-shell structure of the quantum dot comprises
a core comprising a first semiconductor nanocrystal, and a shell comprising a crystalline or amorphous material disposed on the core,

wherein the quantum dot does not include cadmium, and
wherein the shell comprises at least two different halogens.

18. The method of claim 17 , wherein a solid state photoluminescence quantum efficiency of the quantum dot when measured at 90° C. or greater is greater than or equal to about 95% of a solid state photoluminescence quantum efficiency the quantum dot when measured at 25° C.

19. The method of claim 17 , wherein the first precursor comprises a Group II metal excluding cadmium, a Group III metal, a Group

Assignees

• Samsung Electronics Co Ltd

Inventors

• Park Garam
• Kim Tae Hyung
• Jang Eun Joo
• Jang Hyo Sook
• Jun Shin Ae
• Kim Yongwook
• Kim Taekhoon
• MIN Jihyun
• Won Yuho

Classifications

• C09K11/883

  with zinc or cadmium · CPC title

• C09K11/615

  Halogenides · CPC title

• C09K11/70

  containing phosphorus · CPC title

• C09K11/025 Primary

  non-luminescent particle coatings or suspension media · CPC title

• C09K11/722 Primary

  Chalcogenides · CPC title