Semiconductor nanocrystals
A semiconductor nanocrystal include a first I-III-VI semiconductor material and have a luminescence quantum yield of at least 10%, at least 20%, or at least 30%. The nanocrystal can be substantially free of toxic elements. Populations of the nanocrystals can have an emission FWHM of no greater than 0.35 eV.
1. A method of making a semiconductor nanocrystal comprising:
preparing a first mixture including:
a coordinating solvent;
a copper salt; and
an indium salt
in a single container before any heating takes place;
heating the first mixture including the coordinating solvent, copper or silver salt, and indium salt in the single container
and
adding an E donor including a Group VI element to the first mixture,
heating the container holding the coordinating solvent, copper or silver salt, and indium salt and E donor at a temperature greater than 200° C.,
synthesizing a population of nanocrystal cores including a first Cu—In-VIA semiconductor material, wherein the nanocrystal has a luminescence quantum yield of at least 10%,
wherein the nanocrystal has a peak luminescence emission wavelength in the range of 540 nm to 975 nm; and
wherein the nanocrystal is a member of a nanocrystal population having an emission FWHM of no greater than 0.35 eV.
2. The method of claim 1 , further comprising forming an overcoating on a surface of the core, the overcoating including a second semiconductor material.
3. The method of claim 1 , further comprising exposing the nanocrystal to a ligand having an affinity for a surface of the semiconductor nanocrystal.
4. The method of claim 1 , wherein molar amount of the indium is more than molar amount of the copper.
5. The method of claim 4 , wherein the semiconductor nanocrystal is a copper indium selenide or a copper indium gallium selenide.
6. The method of claim 1 , wherein the nanocrystal has a luminescence quantum yield of at least 20%.
7. A method of making a semiconductor nanocrystal comprising:
preparing a first mixture including:
a coordinating solvent;
a silver salt; and
an indium salt
in a single container before any heating takes place;
heating the first mixture including the coordinating solvent, copper or silver salt, and indium salt in the single container
and
adding an E donor including a Group VI element to the first mixture,
heating the container holding the coordinating solvent, copper or silver salt, and indium salt and E donor at a temperature greater than 200° C.,
synthesizing a population of nanocrystal cores including a first IB-IIIA-VIA semiconductor material, wherein the nanocrystal has a luminescence quantum yield of at least 10%,
wherein the nanocrystal has a peak luminescence emission wavelength in the range of 540 nm to 975 nm; and
wherein the nanocrystal is a member of a nanocrystal population having an emission FWHM of no greater than 0.35 eV.