Methods and devices for forming nanostructure monolayers and devices including such monolayers
View Patent ↗Methods for forming or patterning nanostructure arrays are provided. The methods involve formation of arrays on coatings comprising nanostructure association groups, formation of arrays in spin-on-dielectrics, solvent annealing after nanostructure deposition, patterning using resist, and/or use of devices that facilitate array formation. Related devices for forming nanostructure arrays are also provided, as are devices including nanostructure arrays (e.g., memory devices).
1. A method for forming a nanostructure array, the method comprising:
providing a first layer;
depositing a population of preformed nanostructures on the first layer; and
exposing the nanostructures deposited on the first layer to extrinsic solvent vapor of a first solvent, whereby the nanostructures assemble into a monolayer array; wherein depositing the population of nanostructures of the first layer comprises: dispersing the nanostructures in a solution comprising at least one second solvent, and disposing the solution on the first layer.
2. The method of claim 1 , wherein exposing the nanostructures to extrinsic solvent vapor comprises providing the first solvent in liquid form and heating the first solvent to produce the solvent vapor.
3. The method of claim 2 , wherein the first solvent is heated to a temperature between 50° C. and the boiling point of the first solvent.
4. The method of claim 1 , the second solvent is the same compound as the first solvent.
5. The method of claim 1 , comprising evaporating the second solvent to provide dry nanostructures deposited on the first layer, after disposing the solution on the first layer and prior to exposing the nanostructures to the solvent vapor.
6. The method of claim 5 , comprising exposing the dry nanostructures deposited on the first layer to air, prior to exposing the nanostructures to the solvent vapor.
7. The method of claim 1 , wherein disposing the solution on the first layer comprises spin coating, spray coating, flow coating, capillary coating, dip coating, or roll coating the first layer with the solution.
8. The method of claim 1 , wherein the first layer comprises a dielectric material.
9. The method of claim 1 , wherein the first layer is disposed on a substrate.
10. The method of claim 1 , wherein the monolayer array of nanostructures comprises an ordered array.
11. The method of claim 1 , wherein the monolayer array of nanostructures comprises a disordered array.
12. The method of claim 1 , wherein the monolayer array of nanostructures has a density greater than about 1×10 10 nanostructures/cm 2 , greater than about 1×10 11 nanostructures/cm 2 , greater than about 1×10 12 nanostructures/cm 2 , or greater than about 1×10 13 nanostructures/cm 2 .
13. The method of claim 1 , wherein the nanostructures comprise substantially spherical nanostructures or quantum dots.
14. The method of claim 1 , wherein the nanostructures have a work function of about 4.5 eV or higher.
15. The method of claim 1 , wherein the first layer comprises an oxide or a nitride.
16. The method of claim 1 , wherein the first layer comprises a material selected from the group consisting of: silicon oxide, hafnium oxide, and alumina.