Deposition of semiconductor nanocrystals for light emitting devices
A method of depositing semiconductor nanocrystals on a surface can include applying a voltage to the nanocrystals.
1. A method for depositing a film of semiconductor nanocrystals comprising:
applying a voltage between two electrodes in a solution that includes a plurality of semiconductor nanocrystals, wherein the voltage creates an electric field that drives the plurality of semiconductor nanocrystals to be deposited onto a surface of the two electrodes to form a semiconductor nanocrystal film, and wherein a thickness of the semiconductor nanocrystal film is less than 100 nm,
washing a surface of the two electrodes with a solvent while applying a voltage bias.
2. The method of claim 1 , wherein the plurality of semiconductor nanocrystals are colloidal semiconductor nanocrystals.
3. The method of claim 1 , wherein the plurality of semiconductor nanocrystals include a Group II-VI compound, a Group II-V compound, a Group III-VI compound, a Group III-V compound, a Group IV-VI compound, a Group I-III-VI compound, a Group II-IV-VI compound, or a Group II-IV-V compound.
4. The method of claim 1 , wherein the plurality of semiconductor nanocrystals include CdSe and ZnS.
5. The method of claim 1 , wherein a quantum yield of the plurality of semiconductor nanocrystals is at least 10%.
6. The method of claim 1 , wherein a quantum yield of the plurality of semiconductor nanocrystals is at least 50%.
7. The method of claim 1 , wherein a quantum yield of the plurality of semiconductor nanocrystals is at least 80%.
8. The method of claim 1 , wherein the semiconductor nanocrystal film includes a monolayer formed from the plurality of semiconductor nanocrystals.
9. The method of claim 1 , wherein the thickness of the semiconductor nanocrystal film is less than 50 nm.
10. The method of claim 1 , wherein the thickness of the semiconductor nanocrystal film is less than 10 nm.
11. The method of claim 1 , wherein the solution includes a compound capable of removing passivating ligands surrounding the plurality of the semiconductor nanocrystals.
12. The method of claim 11 , wherein the compound includes acetonitrile.
13. The method of claim 1 , wherein the solvent includes chloroform.
14. The method of claim 1 , wherein the electric field is between 25 V cm −1 and 50 V cm −1 .
15. The method of claim 1 , wherein the semiconductor nanocrystal film has a root mean square roughness of less than 5 nm.