Methods of forming nanoparticle based monolayer films with high particle density and devices including the same
The present invention provides methods of forming uniform nanoparticle based monolayer films with a high particle density on the surface of a substrate comprising (a) forming a surface modifying layer on a substrate using a material comprising a first functional group that chemically binds to the substrate and a second functional group comprising a group capable of forming van der Waals forces, (b) applying to the surface modifying layer a solution comprising nanoparticles, and (c) curing the resultant structure formed at step (b) for a predetermined time to form a nanoparticle based monolayer film. The present invention further provides substrates and devices comprising the nanoparticle based monolayer films.
1. A method of forming a nanoparticle based monolayer film comprising:
(a) forming a surface modifying layer on a substrate using a material comprising a first functional group that chemically binds to the substrate and a second functional group comprising a group capable of forming van der Waals forces;
(b) applying to the surface modifying layer a solution comprising nanoparticles; and
(c) curing the resultant structure formed at step (b) for a predetermined time to form a nanoparticle based monolayer film, wherein the nanoparticles are immobilized on the monolayer film by van der Waals interactions.
2. The method of claim 1 , wherein the substrate comprises a metal material, an insulating material, a high dielectric material, a polysilicon material, a metal silicide material, or a combination thereof.
3. The method of claim 1 , wherein the substrate comprises gold (Au), silver (Ag), silicon (Si), silicon oxide (SiO), glass, indium tin oxide (ITO), or a combination thereof.
4. The method of claim 1 , wherein the group forming van der Waals forces comprises CH 3 .
5. The method of claim 1 , wherein applying to the surface modifying layer a solution comprising nanoparticles comprises depositing a self-assembled monolayer.
6. The method of claim 5 , wherein the self-assembled monolayer comprises an alkylsiloxane, an alkylsilane, an alkylthiol, or a combination thereof.
7. The method of claim 1 , wherein the curing step is performed at an atmospheric pressure in a range from about 3 minutes to about 25 minutes.
8. The method of claim 1 , wherein the nanoparticles comprise a particle size of about 100 nm or less.
9. The method of claim 1 , wherein the nanoparticles comprise a particle size in a range of about 10 nm to about 30 nm.
10. The method of claim 1 , wherein the nanoparticles comprise an average particle size distribution of within about 15 percent.
11. The method of claim 1 , wherein the nanoparticles comprise gold (Au), silver (Ag), iron (Fe), nickel (Ni), palladium (Pd), platinum (Pt), cobalt (Co), an alloy thereof or a combination thereof.
12. The method of claim 1 , wherein the nanoparticles comprise CdS, CdSe, PbSe, or a combination thereof.
13. The method of claim 1 , wherein the solution comprises a solvent or a surfactant.
14. The method of claim 13 , wherein the solvent comprises n-hexane, chloroform, toluene, deionized water, or ethanol.
15. The method of claim 1 , wherein the solution further comprises a surfactant that forms a capping film around the nanoparticles, wherein the capping film forms a van der Waals bond with the surface modifying layer.
16. The method of claim 15 , wherein the surfactant comprises a carbon-based material.
17. The method of claim 1 , further comprising removing the solution remaining after formation of the nanoparticle based monolayer film in step (c).
18. The method of claim 1 , further comprising spinning the resultant structure formed at step (c) in a range from about 2000 rpm to about 10,000 rpm for a period of time in a range from about 20 seconds to about 300 seconds.
19. The method of claim 1 , wherein the nanoparticle based monolayer film is formed on a predetermined region of the substrate.
20. The method of claim 1 , wherein the nanoparticle based monolayer film is applied during a post-deposition patterning process or a post-patterning deposition process.
21. The method of claim 1 , wherein the nanoparticle based monolayer film has a high particle density of at least about 10 12 particles/cm 2 .
22. A substrate comprising a nanoparticle based monolayer film, wherein the substrate comprises a surface modifying layer formed using a material comprising a first functional group that chemically binds to the substrate and a second functional group comprising a group that forms van der Waals forces, and further comprises a nanoparticle based monolayer film,
wherein the nanoparticle based monolayer film is attached to the surface modifying layer through van der Waals forces.
23. The substrate of claim 22 , wherein the surface modifying layer is formed by deposition of a self assembled monolayer.
24. The substrate of claim 23 , wherein the self-assembled monolayer comprises an alkylsiloxane, an alkylsilane, an alkylthiol, or a combination thereof.
25. The substrate of claim 22 , wherein the nanoparticle based monolayer film comprises nanoparticles and a surfactant,
wherein the surfactant surrounds the nanoparticles and binds to the surface modifying layer through van der Waals forces.
26. The substrate of claim 25 , wherein the nanoparticles comprise gold (Au), silver (Ag), iron (Fe), nickel (Ni), palladium (Pd), platinum (Pt), cobalt (Co), an alloy thereof or a combination thereof.
27. The substrate of claim 25 , wherein the nanoparticles comprise CdS, CdSe, PbSe, or a combination thereof.
28. A device comprising a nanoparticle based monolayer film, comprising:
a substrate;
a surface modifying layer formed on the substrate using a material comprising a first functional group that chemically binds to the substrate and a second functional group comprising a group that forms van der Waals forces; and
a nanoparticle based monolayer film formed on the surface modifying layer by binding with the surface modifying layer through van der Waals forces.
29. The device of claim 28 , wherein the surface modifying layer is formed by deposition of a self-assembled monolayer.
30. The device of claim 29 , wherein the self-assembled monolayer comprises an alkylsiloxane, an alkylsilane, an alkylthiol, or a combination thereof.
31. The device of claim 28 , wherein the nanoparticle monolayer film comprises nanoparticles surrounded by a capping film, wherein the capping film forms a van der Waals bond with the surface modifying layer.
32. The device of claim 28 , wherein the nanoparticles comprise gold (Au), silver (Ag), iron (Fe), nickel (Ni), palladium (Pd), platinum (Pt), cobalt (Co), an alloy thereof or combination thereof.
33. The device of claim 28 , wherein the nanoparticles comprise CdS, CdSe, PbSe, or a combination thereof.
34. The device of claim 28 , wherein the nanoparticle based monolayer film is formed on an entire surface of the substrate or a predetermined region of the substrate.