One-pot synthesis of high-quality metal chalcogenide nanocrystals without precursor injection
View Patent ↗A method of forming monodisperse metal chalcogenide nanocrystals without precursor injection, comprising the steps of: combining a metal source, a chalcogen oxide or a chalcogen oxide equivalent, and a fluid comprising a reducing agent in a reaction pot at a first temperature to form a liquid comprising assembly; increasing the temperature of the assembly to a sufficient-temperature to initiate nucleation to form a plurality of metal chalcogenide nanocrystals; and growing the plurality of metal chalcogenide nanocrystals without injection of either the metal source or the chalcogen oxide at a temperature equal to or greater than the sufficient-temperature, wherein crystal growth proceeds substantially without nucleation to form a plurality of monodisperse metal chalcogenide nanocrystals. Well controlled monodispersed CdSe nanocrystals of various sizes can be prepared by choice of the metal source and solvent system.
1. A method of forming monodisperse metal chalcogenide nanocrystals without precursor injection, comprising the steps of:
combining a metal source, a chalcogen oxide or a chalcogen oxide equivalent, and a fluid comprising a reducing agent in one pot at a first temperature to form a liquid comprising assembly;
increasing the temperature of said assembly to a sufficient-temperature to initiate nucleation to form a plurality of metal chalcogenide nanocrystals, and
growing said plurality of metal chalcogenide nanocrystals without injection of either said metal source or said chalcogen oxide at a temperature equal to or greater than said sufficient-temperature, wherein crystal growth proceeds substantially without nucleation to form a plurality of monodisperse metal chalcogenide nanocrystals.
2. The method of claim 1 , wherein said chalcogen oxide comprises selenium dioxide.
3. The method of claim 1 , wherein said metal source provides Zn, Cd, Hg, Pb, Sn, Eu, Mn, Pd, Fe, Co, Ni, Cu, Ag or any combination thereof.
4. The method of claim 1 , wherein said metal source comprises cadmium myristate or cadmium docosanate, said chalcogen oxide comprises selenium dioxide, and said metal chalcogenide nanocrystals are CdSe nanocrystals.
5. The method of claim 1 , wherein said reducing agent comprises a reducing solvent.
6. The method of claim 5 , wherein said reducing solvent comprises a 1-alkene wherein the boiling point of said 1-alkene is equal to or grater than the highest temperature for said crystal growth.
7. The method of claim 6 , wherein said 1-alkene is 1-octadecene.
8. The method of claim 1 , wherein said solvent further comprises a diol or polyol.
9. The method of claim 8 , wherein said diol is 1,2-hexadecanediol.
10. The method of claim 1 , wherein said metal source comprises a plurality of different precursors with a common metal or with different metals.
11. The method of claim 10 , wherein said plurality of said precursors have different rates of nucleation and crystal growth.
12. The method of claim 10 , wherein said precursors with said common metal are cadmium myristate and cadmium acetate.
13. The method of claim 1 , wherein said metal source comprises lead oleate, said chalcogen oxide comprises selenium oxide, and said metal chalcogenide nanocrystals are PbSe nanocrystals.
14. The method of claim 1 , wherein said metal source comprises palladium (II) acetylacetonate, said chalcogen oxide comprises selenium oxide, and said metal chalcogenide nanocrystals are Pd 9 Se 2 nanocrystals.
15. The method of claim 1 , wherein the steps of combining, increasing and growing are performed in an air atmosphere.