Highly luminescent color-selective nanocrystalline materials
A nanocrystal capable of light emission includes a nanoparticle having photoluminescence having quantum yields of greater than 30%.
1. A method of producing a population of coated nanocrystals that exhibit photoluminescence having a quantum yield of greater than about 30%, comprising:
synthesizing a plurality of nanocrystal cores made from a first semiconductor material; and
size-separating a select population of nanocrystal cores from the plurality of synthesized cores, wherein the population of coated nanocrystals emit light in a spectral range of no greater than about 40 nm full width at half max (FWHM) when irradiated.
2. The method of claim 1 , further comprising depositing an overcoating of ZnS on a member of the population of size-selected nanocrystal cores.
3. The method of claim 2 , wherein said depositing comprises depositing one to two monolayers of ZnS on the population of size-selected nanocrystal cores.
4. The method of claim 2 , wherein said depositing comprises depositing about 1.3 monolayers of ZnS on the population of size-selected nanocrystal cores.
5. The method of claim 1 , wherein the separating includes size-selecting the select population of nanocrystal cores by size-selective precipitation.
6. The method of claim 1 , wherein the population of coated nanocrystals exhibit photoluminescence having a quantum yield of between about 30% and 50%.
7. The method of claim 1 , wherein the first semiconductor material is selected from CdS, CdSe, CdTe, and mixtures thereof.
8. The method of claim 1 , wherein the population of size-selected nanocrystal cores is substantially monodisperse.
9. The method of claim 8 , wherein the population of size-selected nanocrystal cores have diameters having no greater than 10% rms deviation.
10. The method of claim 1 , further comprising depositing an organic layer on the outer surface of the population of coated nanocrystals.