Semiconductor nanoparticle, dispersion liquid, film, and method of producing semiconductor nanoparticle

• US 10,640,703 B2
• Filed: 02/27/2018
• Issued: 05/05/2020
• Est. Priority Date: 08/31/2015
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Sasaki, Tsutomu
• Primary Examiner(s): Nguyen, Khanh T
• Application Number:
  US15/906,781
• Publication Number:
  US 20180187074A1
• Time in Patent Office: 798 Days
• Field of Search: 257 14
• 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: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: B82Y 5/00 Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
• CPC Class Codes: C01B 25/087 of gallium or indium
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/70 containing phosphorus
• CPC Class Codes: Y10S 977/774 Exhibiting three-dimensional carrier confinement, e.g. quantum dots
• CPC Class Codes: Y10S 977/816 III-N based compounds, e.g. AlxGayInzN
• CPC Class Codes: Y10S 977/818 III-P based compounds, e.g. AlxGayIn2P
• CPC Class Codes: Y10S 977/819 III-As based compounds, e.g. AlxGayInzAs
• CPC Class Codes: Y10S 977/824 Group II-VI nonoxide compounds, e.g. CdxMnyTe
• CPC Class Codes: Y10S 977/892 Liquid phase deposition
• CPC Class Codes: Y10S 977/95 Electromagnetic energy

Abstract

An object of the present invention is to provide a semiconductor nanoparticle having high emission efficiency and excellent durability; a method of producing the same; and a dispersion liquid and a film obtained by using a semiconductor nanoparticle. The semiconductor nanoparticle of the present invention is a semiconductor nanoparticle in which oxygen, zinc, and sulfur are detected by X-ray photoelectron spectroscopy analysis and a peak (I_CH3) which is derived from a hydrocarbon group and present in a range of 2800 cm⁻¹ to 3000 cm⁻¹ and a peak (I_COO) which is derived from COO⁻ and present in a range of 1400 cm⁻¹ to 1600 cm⁻¹ are detected by Fourier transform infrared spectroscopy analysis.

Claims

1. A semiconductor nanoparticle,

wherein oxygen, zinc, and sulfur are detected by X-ray photoelectron spectroscopy analysis, and

a peak (I_CH3) which is derived from a hydrocarbon group and present in a range of 2800 cm⁻

1 to 3000 cm<sup>−

1</sup> and a peak (I_COO) which is derived from COO⁻

and present in a range of 1400 cm<sup>−

1</sup> to 1600 cm<sup>−

1</sup> are detected by Fourier transform infrared spectroscopy analysis,

wherein a molar ratio of oxygen to sulfur which is acquired by X-ray photoelectron spectroscopy analysis satisfies Formula (1), and

a molar ratio of oxygen to zinc which is acquired by X-ray photoelectron spectroscopy analysis satisfies Formula (2),

0.20≤

O/S≤

0.80 

 

(1)

0.30≤

O/Zn≤

1.10 

 

(2)

wherein two or more kinds of ligands are coordinated,

wherein both of a ligand A which is represented by Formula (A) and contains a carboxyl group and a ligand B which is represented by Formula (B) and contains a mercapto group are coordinated,

R¹—

COOH 

 

(A)

R²—

SH 

 

(B)

where R¹ and R² in Formulae (A) and (B) each independently represent an organic group, and

wherein both of R¹ and R² in Formulae (A) and (B) represent a linear aliphatic hydrocarbon group.

2. The semiconductor nanoparticle according to claim 1,

wherein a ratio of peak intensity between the peak (I_CH3) and the peak (I_COO) satisfies Formula (3)

0.22≤

I_COO/I_CH3≤

0.42 

 

(3).

3. The semiconductor nanoparticle according to claim 1,

wherein both of R¹ and R² in Formulae (A) and (B) represent an aliphatic hydrocarbon group having 8 to 25 carbon atoms.

4. The semiconductor nanoparticle according to claim 1,

wherein the ligand A is at least one ligand selected from the group consisting of decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, and erucic acid, and

the ligand B is at least one ligand selected from the group consisting of dodecanethiol, octanethiol, decanethiol, tetradecanethiol, hexadecanethiol, HS—

(CH2)m-OH (in the formula, m represents an integer of 11 to

     16), and HS—

(CH2)m-(O—

CH2CH2)n-OCH3 (in the formula, m represents an integer of 11 to 16, and n represents an integer of 3 to

     6).

5. The semiconductor nanoparticle according to claim 4,

wherein the ligand A is oleic acid, and

the ligand B is dodecanethiol.

6. The semiconductor nanoparticle according to claim 1, comprising:

a core which contains a Group III element and a Group V element; and

a shell which contains a Group II element and a Group VI element that cover at least a part of a surface of the core.

7. The semiconductor nanoparticle according to claim 6,

wherein the Group III element contained in the core is In, and

the group V element contained in the core is any of P, N, and As.

8. The semiconductor nanoparticle according to claim 7,

wherein the Group III element contained in the core is In, and

the Group V element contained in the core is P.

9. The semiconductor nanoparticle according to claim 6,

wherein the core further contains a Group II element.

10. The semiconductor nanoparticle according to claim 9,

wherein the Group II element contained in the core is Zn.

11. The semiconductor nanoparticle according to claim 1, comprising:

a core which contains a Group III element and a Group V element;

a first shell which covers at least a part of a surface of the core; and

a second shell which covers at least a part of the first shell.

12. The semiconductor nanoparticle according to claim 11,

wherein the first shell contains a Group II element or a Group III element,

where, in a case where the first shell contains a Group III element, the Group III element contained in the first shell is a Group III element different from the Group III element contained in the core.

13. The semiconductor nanoparticle according to claim 11,

wherein the first shell is a Group II-VI semiconductor which contains a Group II element and a Group VI element or a Group III-V semiconductor which contains a Group III element and a Group V element,

where, in a case where the first shell is the Group III-V semiconductor, the Group III element contained in the Group III-V semiconductor is a Group III element different from the Group III element contained in the core.

14. The semiconductor nanoparticle according to claim 13,

wherein, in a case where the first shell is the Group II-VI semiconductor, the Group II element is Zn and the Group VI element is Se or S, and

in a case where the first shell is the Group III-V semiconductor, the Group III element is Ga and the Group V element is P.

15. The semiconductor nanoparticle according to claim 13,

wherein the first shell is the Group III-V semiconductor,

the Group III element is Ga, and

the Group V element is P.

16. The semiconductor nanoparticle according to claim 11,

wherein the second shell is a Group II-VI semiconductor which contains a Group II element and a Group VI element or a Group III-V semiconductor which contains a Group III element and a Group V element.

17. The semiconductor nanoparticle according to claim 16,

wherein the second shell is the Group II-VI semiconductor,

the Group II element is Zn, and

the Group VI element is S.

18. The semiconductor nanoparticle according to claim 11,

wherein the core, the first shell, and the second shell are respectively a crystal system having a zinc blende structure.

19. The semiconductor nanoparticle according to claim 11,

wherein, among the core, the first shell, and the second shell, a band gap of the core is the smallest, and

the core and the first shell respectively have a type 1 band structure.

20. A dispersion liquid comprising:

the semiconductor nanoparticle according to claim 1.

21. A film comprising:

the semiconductor nanoparticle according to claim 1.

22. A method of producing a semiconductor nanoparticle for synthesizing the semiconductor nanoparticle according to claim 1, comprising:

a mixing step of mixing a semiconductor nanoparticle QD to which one or both of a ligand A which is represented by Formula (A) and contains a carboxyl group and a ligand B which is represented by Formula (B) and contains a mercapto group are not coordinated, the ligand A, and the ligand B,

R¹—

COOH 

 

(A)

R²—

SH 

 

(B)

where R¹ and R² in Formulae (A) and (B) each independently represent an organic group,

wherein both of R¹ and R² in Formulae (A) and (B) represent a linear aliphatic hydrocarbon group.

23. The method of producing a semiconductor nanoparticle according to claim 22,

wherein the semiconductor nanoparticle QD, the ligand A, and the ligand B are mixed at a molar ratio that satisfies Formulae (4) and (5)

0.1≤

(ligand A/ligand B)≤

10 

 

(4)

10≤

{semiconductor nanoparticle QD/(ligand A/ligand B)}≤

1000 

 

(5).

24. The method of producing a semiconductor nanoparticle according to claim 22,

wherein the semiconductor nanoparticle QD, the ligand A, and the ligand B are mixed at a molar ratio that satisfies Formulae (4′

) and (5′

)

0.5≤

(ligand A/ligand B)≤

5 

 

(4′

)

100≤

{semiconductor nanoparticle QD/(ligand A/ligand B)}≤

300 

 

(5′

).

25. The method of producing a semiconductor nanoparticle according to claim 22,

wherein the semiconductor nanoparticle QD, the ligand A, and the ligand B are mixed in a temperature range of 20°

C. to 100°

C.

26. The method of producing a semiconductor nanoparticle according to claim 22,

wherein the semiconductor nanoparticle QD, the ligand A, and the ligand B are mixed under a light shielding condition and/or in a nitrogen atmosphere.

27. The method of producing a semiconductor nanoparticle according to claim 22,

wherein the mixing step is performed for 8 hours or longer.

28. The method of producing a semiconductor nanoparticle according to claim 22, further comprising:

a step of leaving the mixture to rest for 8 hours or longer after the mixing step.