Method of synthesizing bismuth-antimony seleno-telluride nanocrystals

1. A method of synthesizing thermoelectric nanocrystals, the method comprising:

synthesizing an oxidative chalcogen precursor, the synthesizing including:

dissolving a chalcogen in acidified deionized water by reacting the chalcogen with a caustic solution in the acidified deionized water to synthesize a first solution, and

adjusting at least one of: a pH level or a pE level of the first solution;

exposing the oxidative chalcogen precursor to a pnictogen precursor to create nanoseeds; and

subjecting the nanoseeds to a microwave thereby synthesizing the thermoelectric nanocrystals.

2. The method of claim 1 , wherein the chalcogen includes at least one of: tellurium, selenium, a tellurium oxide, a selenium oxide, tellurous acid, telluric acid, sodium tellurate, selenous acid, or selenic acid.

3. The method of claim 1 , wherein the caustic solution includes hydrogen peroxide.

4. The method of claim 1 , wherein the adjusting the pH level and the pE level of the first solution includes reacting the first solution with at least one of: sodium hydroxide, potassium hydroxide, a pyridine, an amine, or ammonium hydroxide.

5. The method of claim 1 , wherein the pnictogen precursor includes at least one of: bismuth or antimony.

6. The method of claim 1 , wherein the subjecting the nanoseeds to the microwave includes subjecting the nanoseeds to a microwave energy dose of approximately equal to or greater than 2.5 kilojoules per gram (KJ/g).

7. The method of claim 1 , further comprising separating the thermoelectric nanocrystals via at least one of: filtration or centrifugation.

8. The method of claim 1 , wherein the adjusting the pH level of the first solution includes adjusting the pH level to approximately 4.5 to approximately 6.5.

9. The method of claim 1 , wherein the adjusting the pE level of the first solution includes adjusting the pE level to approximately 10 millivolts (mV) to approximately 35 mV.

10. The method of claim 1 ,

wherein the adjusting the pE level of the first solution includes dissolving a reducing agent by adjusting the pH level to greater than 11 using at least one of: sodium hydroxide, potassium hydroxide, a pyridine, an amine, or ammonium hydroxide; and

wherein the reducing agent includes at least one of: sodium hydride, lithium hydride, aluminum hydride, sodium borohydride, potassium borohydride, lithium borohydride or aluminum borohydride.

11. The method of claim 1 , wherein the thermoelectric nanocrystals have a particle size of approximately 5 nanometers (nm) to approximately 100 nm.

12. The method of claim 1 , wherein the dissolving the chalcogen in acidified deionized water by reacting the chalcogen with the caustic solution in the acidified deionized water to synthesize the first solution includes providing 20% excess of the caustic solution relative to the first solution.

13. The method of claim 1 , wherein the thermoelectric nanocrystals include Sb 2-x Bi x Se 3-y Te y , wherein 0≤x≤2 and 0≤y≤3.

14. The method of claim 1 , wherein the thermoelectric nanocrystals are doped with sodium up to 1 atomic percent.

15. A method of synthesizing thermoelectric nanocrystals, the method comprising:

synthesizing an oxidative chalcogen precursor, the synthesizing including:

dissolving a chalcogen in acidified deionized water by reacting the chalcogen with hydrogen peroxide in the acidified deionized water to synthesize a first solution, the chalcogen including at least one of: tellurium, selenium a tellurium oxide, a selenium oxide, tellurous acid, telluric acid, sodium tellurate, selenous acid, or selenic acid; and

adjusting at least one of: a pH level or a pE level of the first solution;

exposing the oxidative chalcogen precursor to a pnictogen precursor to create nanoseeds; and

subjecting the nanoseeds to a microwave thereby synthesizing the thermoelectric nanocrystals.

16. The method of claim 15 , wherein the adjusting the pH level and the pE level of the first solution includes reacting the first solution with at least one of: sodium hydroxide, potassium hydroxide, a pyridine, an amine, or ammonium hydroxide.

17. The method of claim 15 , wherein the pnictogen precursor includes at least one of: bismuth or antimony.

18. The method of claim 15 , wherein the subjecting the nanoseeds to the microwave includes subjecting the nanoseeds to a microwave energy dose of approximately equal to or greater than 2.5 kilojoules per gram (KJ/g).

19. The method of claim 15 , further comprising separating the thermoelectric nanocrystals via at least one of: filtration or centrifugation.

20. The method of claim 15 , wherein the adjusting the pH level of the first solution includes adjusting the pH level to approximately 4.5 to approximately 6.5.

21. The method of claim 15 , wherein the adjusting the pE level of the first solution includes adjusting the pE level to approximately 10 millivolts (mV) to approximately 35 mV.

22. The method of claim 15 ,

wherein the adjusting the pE level of the first solution includes dissolving a reducing agent by adjusting the pH level to greater than 11 using at least one of: sodium hydroxide, potassium hydroxide, a pyridine, an amine, or ammonium hydroxide; and

wherein the reducing agent includes at least one of: sodium hydride, lithium hydride, aluminum hydride, sodium borohydride, potassium borohydride, lithium borohydride or aluminum borohydride.

23. The method of claim 15 , wherein the thermoelectric nanocrystals include Sb 2-x Bi x Se 3-y Te y , wherein 0≤x≤2 and 0≤y≤3.

24. The method of claim 15 , wherein the thermoelectric nanocrystals are doped with sodium up to 1 atomic percent.