Methods of forming nanocrystals and related crystals and optoelectronic devices

Patent metadata

Field	Value
Publication number	US-12435272-B2
Application number	US-202318312035-A
Country	US
Kind code	B2
Filing date	May 4, 2023
Priority date	Apr 24, 2020
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

Methods of fabricating nanocrystals are disclosed. Such methods may include providing copper sulfide core nanocrystals and providing a lead precursor. Moreover, the copper sulfide core nanocrystals may be reacted with the lead precursor to generate copper doped lead sulfide nanocrystals. Related nanocrystals and optoelectronic devices are also disclosed.

First claim

The invention claimed is:

1. A method of fabricating nanocrystals, the method comprising:
providing copper sulfide core nanocrystals;
providing a lead precursor; and
reacting the copper sulfide core nanocrystals with the lead precursor to generate copper doped lead sulfide nanocrystals.

2. The method according to claim 1 , wherein the lead precursor comprises lead oleate.

3. The method according to claim 1 , further comprising:
providing a sulfur precursor;
wherein reacting comprises reacting the copper sulfide core nanocrystals, the sulfur precursor, and the lead precursor to generate the copper doped lead sulfide nanocrystals.

4. The method according to claim 3 , wherein the sulfur precursor comprises bis(trimethylsilyl)sulfide.

5. The method according to claim 1 , wherein reacting comprises performing a cation exchange reaction to exchange the copper atoms in the copper sulfide core nanocrystal for lead atoms of the lead precursor.

6. The method according to claim 5 , wherein the cation exchange reaction is performed using flash-injection synthesis to generate the copper doped lead sulfide nanocrystals.

7. The method according to claim 1 , wherein reacting comprises reacting a first plurality of the copper sulfide core nanocrystals with the lead precursor to generate the copper doped lead sulfide nanocrystals and reacting a second plurality of the copper sulfide nanocrystals with the lead precursor to generate core/shell nanocrystals, wherein each of the core/shell nanocrystals includes a copper sulfide core and a lead sulfide shell surrounding the copper sulfide core.

8. The method according to claim 1 , wherein the copper doped lead sulfide nanocrystals have uniform concentrations of lead, sulfur, and copper throughout the copper doped lead sulfide nanocrystals.

9. The method according to claim 1 , wherein the copper doped lead sulfide nanocrystals have lattice constants in the range of about 5.95 Angstroms to about 5.99 Angstroms.

10. The method according to claim 1 , wherein the copper doped lead sulfide nanocrystals provide photoemission with a wavelength in the range of about 1330 nm to about 1550 nm.

11. The method according to claim 1 , wherein the copper doped lead sulfide nanocrystals have sizes in the range of 4.5 nm to about 7.5 nm.

12. The method according to claim 1 , wherein the copper doped lead sulfide nanocrystals have atomic ratios of Cu:Pb in the range of about 0.005 to about 0.045.

13. A copper doped lead sulfide crystal providing photoemission with a wavelength in the range of 1330 nm to 1550 nm, wherein the copper doped lead sulfide crystal has uniform concentrations of lead, sulfur, and copper throughout the copper doped lead sulfide crystal.

14. The copper doped lead sulfide crystal according to claim 13 , wherein the copper doped lead sulfide crystal has an atomic ratio of Cu:Pb in the range of about 0.005 to about 0.045.

15. The copper doped lead sulfide crystal according to claim 13 , wherein the copper doped lead sulfide crystal has a lattice constant in the range of about 5.95 Angstroms to about 5.99 Angstroms.

16. A copper doped lead sulfide crystal providing photoemission with a wavelength in the range of 1330 nm to 1550 nm, wherein the copper doped lead sulfide crystal is a copper doped lead sulfide nanocrystal having a size in a range of 4.5 nm to about 7.5 nm.

17. The copper doped lead sulfide crystal according to claim 16 , wherein the copper doped lead sulfide crystal has uniform concentrations of lead, sulfur, and copper throughout the copper doped lead sulfide crystal.

18. An optoelectronic device comprising:
a first electrode;
a colloidal nanocrystal layer on the first electrode, wherein the colloidal nanocrystal layer comprises copper doped lead sulfide nanocrystals; and
a second electrode on the colloidal nanocrystal layer so that the colloidal nanocrystal layer is between the first and second electrodes.

19. The optoelectronic device according to claim 18 , wherein the copper doped lead sulfide nanocrystals have sizes in a range of 4.5 nm to about 7.5 nm.

20. The optoelectronic device according to claim 18 , wherein the copper doped lead sulfide nanocrystals have lattice constants in the range of about 5.95 Angstroms to about 5.99 Angstroms.

21. The optoelectronic device according to claim 18 , wherein the copper doped lead sulfide nanocrystals have atomic ratios of Cu:Pb in the range of about 0.005 to about 0.045.

22. The optoelectronic device according to claim 18 , wherein the copper doped lead sulfide nanocrystals provide photon-emission with a wavelength in the range of about 1330 nm to about 1550 nm.

23. An optoelectronic device comprising:
a first electrode;
a nanocrystal layer on the first electrode, wherein the nanocrystal layer comprises copper doped lead sulfide nanocrystals and core/shell nanocrystals, wherein each of the core/shell nanocrystals includes a copper sulfide core and a lead sulfide shell surrounding the copper sulfide core; and
a second electrode on the nanocrystal layer so that the nanocrystal layer is between the first and second electrodes.

24. The optoelectronic device according to claim 23 , wherein the nanocrystal layer comprises a colloidal nanocrystal layer.

25. The optoelectronic device according to claim 23 , wherein the nanocrystal layer comprises a superlattice including the copper doped lead sulfide nanocrystals and the core/shell nanocrystals.

26. An optoelectronic device comprising:
a first electrode;
a nanocrystal layer on the first electrode, wherein the nanocrystal layer comprises copper doped lead sulfide nanocrystals, wherein the copper doped lead sulfide nanocrystals have uniform concentrations of lead, sulfur, and copper throughout the copper doped lead sulfide nanocrystals; and
a second electrode on the nanocrystal layer so that the nanocrystal layer is between the first and second electrodes.

Assignees

• Us Gov Sec Navy

Inventors

• Yee Patrick Y
• Brittman Sarah F
• Cunningham Paul D
• Boercker Janice E
• Burgess Katherine D
• Stroud Rhonda M
• Erwin Steven C

Classifications

• C01P2004/84

  one phase coated with the other · CPC title

• H10K50/115

  comprising active inorganic nanostructures, e.g. luminescent quantum dots · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title

• C09K11/02

  Use of particular materials as binders, particle coatings or suspension media therefor · CPC title

• B82Y20/00

  Nanooptics, e.g. quantum optics or photonic crystals · CPC title