Nanoparticles and method for making the same
View Patent ↗A method for making nanoparticles, nanoparticle inks and device layers therefrom is disclosed. In accordance with the present invention, nanoparticles are isolated from a composite material that is formed by treating a metal oxide precursor to form the metal nanoparticles and a metal oxide matrix. The nanoparticles are then isolated from the composite material by etching at least a portion of the metal oxide matrix to release the metal nanoparticles. In accordance with the embodiments of the invention, the nanoparticles are treated with surfactants and wetting agents either while etching or after etching, are isolated from the etchant and dispersed in a solvent medium and/or are otherwise treated or modified for use in a nanoparticle inks. A layer of the metal nanoparticle ink can then be used to form doped, undoped, patterned and unpatterned device layers or structures in micro-devices.
1. A method of making a nanoparticle ink comprising:
a. isolating nanoparticles from a composite material comprising a metal oxide of the metal and nanoparticles; wherein the nanoparticles comprises (a) treating one or more metal monoxide precursors to form the composite material and (b) treating the composite material with an etchant comprising a hydrogen fluoride source to release the Nan particles from the composite material and
b. dispersing the nanoparticles into a solvent medium.
2. The method of claim 1 , wherein the solvent medium comprises a molecular precursor.
3. The method of claim 2 , wherein the molecular precursor comprises a material selected from the group consisting of a polysilane, silylenes and organo-silanes.
4. The method of claim 3 , wherein the molecular precursor comprises a hetero-atom selected from the group consisting of arsenic, phosphorus and boron.
5. The method of claim 2 , wherein the molecular precursor comprises a material selected from the group consisting of a polygermane, germylenes and organo-germanes.
6. The method of claim 5 , wherein the molecular precursor comprises a hetero atom selected from the group consisting of arsenic, phosphorus and boron.
7. The method of claim 3 , wherein molecular precursor comprises a cyclic polysilane.
8. The method of claim 1 , wherein the one or more metal monoxide precursors comprise silicon.
9. The method of claim 1 , wherein the one or more metal monoxide precursors comprise germanium.
10. The method of claim 1 , wherein the etchant comprises a surfactant.
11. The method of claim 1 , wherein the hydrogen fluoride source comprises a fluoride material selected from the group consisting of NH 4 F, HF, KHF 2 and KF.
12. The method of claim 1 , wherein the etchant further comprises an ammonium salt.
13. The method of claim 1 , wherein the etchant further comprises a wetting agent.
14. The method of claim 13 , wherein the wetting agent is a fluorinated wetting agent.
15. The method of claim 1 , wherein treating the one or more metal monoxide precursors is performed in the presence of a dopant and wherein the dopant is incorporated into the nanoparticles.
16. The method of claim 1 , wherein one or more metal monoxide precursors comprises a metal selected from the group consisting of cobalt, vanadium, manganese, niobium, iron, nickel, copper, silicon, titanium, germanium, zirconium and tin.
17. The method of claim 1 , wherein the solvent medium comprises an organic solvent.
18. The method of claim 1 , wherein the solvent medium comprises a surfactant.
19. The method of claim 18 , wherein the surfactant is selected from the group consisting of an amine, an amine oxide, a quatenary ammonium salt, a betaine, a sulfobentaine, a ether, a polyglycol, a polyether, a polymer, an organic ester, an alcohol, a phosphine, a phosphate, a carboxylic acid, a carboxylate, a thiol, a sulfonic acid, a sulfonate, a sulfate, a ketone and a silicone.
20. The method of claim 1 , wherein the solvent medium comprises a molecular precursor.
21. The method of claim 1 , wherein the solvent medium further comprises a crystallization promoter.
22. The method of claim 21 , wherein the crystallization promoter is an organometallic compound comprising a element selected from the group consisting of Ni, Au, Al and Fe.
23. The method of claim 21 , wherein the crystallization promoter comprises nanoparticles comprising an element selected from the group consisting of Ni, Au, Al and Fe.