Core shell quantum dot, production method thereof, and electronic device including the same
A core-shell quantum dot including a core including a first semiconductor nanocrystal, the first semiconductor nanocrystal including zinc, tellurium, and selenium and a semiconductor nanocrystal shell disposed on the core, the semiconductor nanocrystal shell including zinc and selenium, sulfur, or a combination thereof and a production thereof are disclosed, wherein the core-shell quantum dot does not include cadmium, lead, mercury, or a combination thereof, wherein the core-shell quantum dot(s) includes chlorine, wherein in the core-shell quantum dot, a mole ratio of chlorine with respect to tellurium is greater than or equal to about 0.01:1 and wherein a quantum efficiency of the core-shell quantum dot is greater than or equal to about 10%.
1. A core-shell quantum dot comprising
a core comprising a first semiconductor nanocrystal, the first semiconductor nanocrystal comprising zinc, tellurium, and selenium; and
a semiconductor nanocrystal shell disposed on the core, the semiconductor nanocrystal shell comprising
zinc; and
selenium, sulfur, or a combination thereof,
wherein the core-shell quantum dot does not comprise cadmium, lead, mercury, or a combination thereof,
wherein the core-shell quantum dot further comprises chlorine,
wherein in the core-shell quantum dot, a mole ratio of chlorine with respect to tellurium is greater than or equal to about 0.01:1, and
wherein a quantum efficiency of the core-shell quantum dot is greater than or equal to about 10%.
2. The core-shell quantum dot of claim 1 , wherein in the core-shell quantum dot, a mole ratio of tellurium with respect to selenium is greater than about 0.4:1.
3. The core-shell quantum dot of claim 1 , wherein in the core-shell quantum dot, a mole ratio of tellurium with respect to selenium is greater than or equal to about 0.1:1 and less than or equal to about 4:1.
4. The core-shell quantum dot of claim 1 , wherein in the core-shell quantum dot, a mole ratio of chlorine with respect to tellurium is greater than or equal to about 0.05:1.
5. The core-shell quantum dot of claim 1 , wherein the core does not comprise a Group III-V compound comprising indium or gallium.
6. The core-shell quantum dot of claim 1 , wherein the core-shell quantum dot further comprises aluminum, gallium, lithium, fluorine, or a combination thereof.
7. The core-shell quantum dot of claim 1 , wherein the first semiconductor nanocrystal comprises ZnTe x Se 1-x , wherein x is greater than or equal to about 0.4 and less than or equal to about 0.9.
8. The core-shell quantum dot of claim 1 , wherein the semiconductor nanocrystal shell comprises selenium and sulfur and a mole ratio of sulfur with respect to selenium is greater than 0:1 and less than or equal to about 4:1.
9. The core-shell quantum dot of claim 1 , wherein a maximum luminescent peak wavelength of the core-shell quantum dot is in a range of greater than about 470 nanometers and less than or equal to about 600 nanometers.
10. The core-shell quantum dot of claim 1 , wherein the maximum photoluminescent peak of the core-shell quantum dot has a full width at half maximum of less than or equal to about 40 nanometers.
11. The core-shell quantum dot of claim 1 , wherein the quantum efficiency of the core-shell quantum dot is greater than or equal to about 20%.
12. The core-shell quantum dot of claim 1 , wherein the core-shell quantum dot comprises an organic ligand and the organic ligand comprises RCOOH, RNH 2 , R 2 NH, R 3 N, RSH, RH 2 PO, R 2 HPO, R 3 PO, RH 2 P, R 2 HP, R 3 P, ROH, RCOOR′, RHPO(OH), RPO(OH) 2 , R 2 POOH, a polymeric organic ligand, or a combination thereof, wherein R and R′ are the same or different and are each independently a substituted or unsubstituted C1 to C40 aliphatic hydrocarbon group, a substituted or unsubstituted C6 to C40 aromatic hydrocarbon group, or a combination thereof.
13. A quantum dot population comprising a plurality of the core-shell quantum dot of claim 1 ,
wherein an average roundness of the plurality of the core-shell quantum dots is greater than or equal to about 0.70; or
wherein an average solidity of the plurality of the core-shell quantum dots is greater than or equal to about 0.8.
14. The quantum dot population of claim 13 , wherein an average size of the plurality of the core-shell quantum dots is greater than or equal to about 7 nanometers.
15. A method of manufacturing the core-shell quantum dot of claim 1 , comprising:
preparing a zinc precursor organic solution comprising a zinc precursor and a first organic ligand in a first organic solvent; and
while heating the zinc precursor organic solution, adding a first selenium precursor, a tellurium precursor, a metal hydride compound, and a second organic ligand to the zinc precursor organic solution to prepare a core particle,
reacting a zinc precursor with a second selenium precursor, a sulfur precursor, or a combination thereof in a third organic solvent in the presence of the core particle and a shell formation organic ligand to form a semiconductor nanocrystal shell on the core particle, and
adding a chlorine precursor to a reaction system during preparation of the core particle, during formation of the semiconductor nanocrystal shell, or during the preparation of the core particle and the formation of the semiconductor nanocrystal shell.
16. The method of claim 15 , further comprising adding a fluorine precursor to the reaction system during preparation of the core particle, during formation of the semiconductor nanocrystal shell, or during the preparation of the core particle and the formation of the semiconductor nanocrystal shell.
17. The method of claim 15 , wherein the tellurium precursor comprises tellurium dispersed in a second organic solvent and wherein a concentration of the tellurium in the tellurium precursor is greater than about 0.1 moles per liter.
18. The method of claim 15 , further comprising mixing the tellurium precursor, the metal hydride compound, and the second organic ligand to form a mixed solution at a temperature of less than about 80° C. prior to adding to the zinc precursor organic solution.
19. The method of claim 15 , further comprising preparing the chlorine precursor by dissolving a chlorine compound in a fourth organic solvent, wherein the fourth organic solvent comprises a C1 to C30 alcohol, a C2 to C30 ketone solvent, a C1 to C40 alkylphosphine solvent, or a combination thereof.
20. A display device comprising
a light emitting element,
wherein the light emitting element comprises a plurality of the core-shell quantum dot of claim 1 .
21. The display device of claim 20 , wherein the light emitting element comprises a stacked structure comprising a substrate and a patterned light emitting layer, wherein the patterned light emitting layer comprises a first repeating section configured to emit light at a predetermined wavelength, and
wherein the first repeating section comprises the plurality of the core-shell quantum dots.
22. The core-shell quantum dot of claim 1 , wherein the core-shell quantum dot is configured to emit green light.
23. The core-shell quantum dot of claim 1 , wherein the semiconductor nanocrystal shell comprises chlorine.
24. The core-shell quantum dot of claim 1 , wherein the core comprises chlorine.