Methods for forming passivated semiconductor nanoparticles
View Patent ↗Compositions, inks and methods for forming a patterned silicon-containing film and patterned structures including such a film. The composition generally includes (a) passivated semiconductor nanoparticles and (b) first and second cyclic Group IVA compounds in which the cyclic species predominantly contains Si and/or Ge atoms. The ink generally includes the composition and a solvent in which the composition is soluble. The method generally includes the steps of (1) printing the composition or ink on a substrate to form a pattern, and (2) curing the patterned composition or ink. In an alternative embodiment, the method includes the steps of (i) curing either a semiconductor nanoparticle composition or at least one cyclic Group IVA compound to form a thin film, (ii) coating the thin film with the other, and (iii) curing the coated thin film to form a semiconducting thin film. The semiconducting thin film includes a sintered mixture of semiconductor nanoparticles in hydrogenated, at least partially amorphous silicon and/or germanium. The thin film exhibits improved conductivity, density, adhesion and/or carrier mobility relative to an otherwise identical structure made by an identical process, but without either the semiconductor nanoparticles or the hydrogenated Group IVA element polymer. The present invention advantageously provides semiconducting thin film structures having qualities suitable for use in electronics applications, such as display devices or RF ID tags, while enabling high-throughput printing processes that form such thin films in seconds or minutes, rather than hours or days as with conventional photolithographic processes.
1. A method of making passivated semiconductor nanoparticles, comprising:
a) reacting hydrogen-terminated semiconductor nanoparticles with a compound containing one or more unsaturated carbon-carbon bond(s) to form said passivated semiconductor nanoparticles; and
b) isolating said passivated semiconductor nanoparticles.
2. The method of claim 1 , wherein said hydrogen-terminated semiconductor nanoparticles comprise one or more crystalline region(s) and/or phase(s).
3. The method of claim 2 , wherein said hydrogen-terminated semiconductor nanoparticles further comprise one or more amorphous region(s) and/or phase(s).
4. The method of claim 1 , wherein said hydrogen-terminated semiconductor nanoparticles comprise silicon and/or germanium.
5. The method of claim 4 , wherein said hydrogen-terminated semiconductor nanoparticles further comprise a dopant.
6. The method of claim 1 , wherein said compound containing one or more unsaturated carbon-carbon bond(s) includes a carbon-carbon double bond.
7. The method of claim 6 , wherein said compound including a carbon-carbon bond double bond comprises one or more compound(s) selected from the group consisting of polyunsaturated alkenes.
8. The method of claim 7 , wherein said polyunsaturated alkene comprises an alkadiene.
9. The method of claim 7 , wherein said polyunsaturated alkene is present in an amount of from about 1 to 10 mol %.
10. The method of claim 1 , wherein said compound containing one or more unsaturated carbon-carbon bond(s) includes one or more compound(s) selected from the group consisting of C 4 -C 20 branched or unbranched alkenes.
11. The method of claim 1 , wherein said compound comprises an unsaturated alcohol.
12. The method of claim 1 , wherein said passivated semiconductor nanoparticles have an average diameter of less than 5 nm.
13. The method of claim 12 , wherein said passivated semiconductor nanoparticles have an average diameter of less than 4 nm.
14. The method of claim 13 , wherein said passivated semiconductor nanoparticles have an average diameter of less than 3.5 nm.
15. The method of claim 1 , wherein said passivated semiconductor nanoparticles have a size distribution range such that at least 90% of the passivated silicon nanoparticles have a diameter of from 0.1 nm to 10 nm.
16. The method of claim 15 , wherein said passivated semiconductor nanoparticles have a diameter of from 0.2 nm to 5 nm.
17. The method of claim 16 , wherein said passivated semiconductor nanoparticles have a diameter of from 0.5 nm to 5 nm.
18. The method of claim 15 , wherein at least 95% of the passivated silicon nanoparticles have a diameter of from 0.1 nm to 10 nm.
19. The method of claim 18 , wherein at least 98% of the passivated silicon nanoparticles have a diameter of from 0.1 nm to 10 nm.
20. The method of claim 1 , wherein said passivated semiconductor nanoparticles comprise soluble passivated semiconductor nanoparticles.
21. The method of claim 1 , wherein said passivated semiconductor nanoparticles consist essentially of silicon and a passivation layer consisting essentially of said compound.