Semiconductor nanocrystal particles, production methods thereof, and devices including the same
A method of producing a quantum dot comprising zinc selenide, the method comprising: providing an organic ligand mixture comprising a carboxylic acid compound, a primary amine compound, a secondary amide compound represented by Chemical Formula 1, and a first organic solvent: RCONHR Chemical Formula 1 wherein each R is as defined herein; heating the organic ligand mixture in an inert atmosphere at a first temperature to obtain a heated organic ligand mixture; adding a zinc precursor, a selenium precursor, and optionally a tellurium precursor to the heated organic ligand mixture to obtain a reaction mixture, wherein the zinc precursor does not comprise oxygen; and heating the reaction mixture at a first reaction temperature to synthesize a first semiconductor nanocrystal particle.
1. A quantum dot comprising:
a core comprising a first semiconductor nanocrystal material comprising zinc, tellurium, and selenium; and
a shell disposed on at least a portion of the core and comprising a second semiconductor nanocrystal material different from the first semiconductor nanocrystal material,
wherein the quantum dot does not comprise cadmium,
wherein a maximum luminescent emission peak of the quantum dot is in a wavelength range from about 440 nanometers to about 560 nanometers,
wherein the quantum dot has a quantum efficiency of greater than or equal to about 60%,
wherein the first semiconductor nanocrystal material comprises ZnTe x Se 1−x , wherein x is greater than 0 and less than or equal to about 0.2, and
wherein the second semiconductor nanocrystal material comprises Zn and at least one of Se and S.
2. The quantum dot of claim 1 , wherein the x is less than or equal to about 0.09.
3. The quantum dot of claim 1 , wherein the second semiconductor nanocrystal material comprises zinc and selenium.
4. The quantum dot of claim 1 , wherein the second semiconductor nanocrystal material comprises zinc and sulfur.
5. The quantum dot of claim 1 , wherein the second semiconductor nanocrystal material comprises zinc, selenium, and sulfur.
6. The quantum dot of claim 1 , wherein the shell has a first layer comprising a third semiconductor nanocrystal and a second layer disposed on the first layer and comprising a fourth semiconductor nanocrystal that is different from the third semiconductor nanocrystal.
7. The quantum dot of claim 6 , wherein the third semiconductor nanocrystal comprises zinc, selenium, and optionally sulfur, and wherein the fourth semiconductor nanocrystal comprises zinc and sulfur.
8. The quantum dot of claim 1 , wherein a plurality of the quantum dots are water-insoluble.
9. The quantum dot of claim 1 , wherein in the quantum dot, a mole ratio of a sum of S and Se with respect to Zn is greater than or equal to about 0.3.
10. The quantum dot of claim 1 , wherein in the quantum dot, a mole ratio of sulfur with respect to zinc is greater than or equal to about 0.1.
11. The quantum dot of claim 1 , wherein the quantum dot further 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, RPO(OH) 2 , RHPOOH, RHPOOH, or a combination thereof, wherein R is the same or different and independently is a C1 to C40 aliphatic hydrocarbon group, a C6 to C40 aromatic hydrocarbon group, or a combination thereof.
12. The quantum dot of claim 1 , wherein the maximum luminescent emission peak of the quantum dot has a full width at half maximum of less than or equal to about 50 nanometers.
13. The quantum dot of claim 1 , wherein the quantum dot has a multi-pod shape.
14. The quantum dot of claim 1 , wherein the quantum dot has a quantum efficiency of greater than or equal to about 70%.
15. An electronic device comprising the quantum dot of claim 1 .
16. An electroluminescent device comprising an anode and a cathode facing each other and a quantum dot emission layer comprising a plurality of quantum dots, wherein the plurality of quantum dots comprises the quantum dot of claim 1 .
17. The electroluminescent device of claim 16 , further comprising a charge auxiliary layer between the anode and the cathode.
18. An electronic device comprising a quantum dot,
wherein the quantum dot comprises zinc, tellurium, and selenium;
wherein the quantum dot does not comprise cadmium,
wherein in the quantum dot, a mole ratio of tellurium with respect to selenium is greater than or equal to about 0.001 and less than or equal to about 0.1,
wherein a maximum luminescent emission peak of the quantum dot is in a wavelength range from about 440 nanometers to about 470 nanometers, and
wherein the quantum dot has a quantum efficiency of greater than or equal to about 60%.
19. The electronic device of claim 18 , wherein in the quantum dot, the mole ratio of the tellurium with respect to the selenium is less than or equal to about 0.08.
20. The electronic device of claim 18 , wherein in the quantum dot, a mole ratio of tellurium with respect to zinc is greater than or equal to about 0.0001 and less than or equal to about 0.03.
21. The electronic device of claim 18 , wherein the quantum dot comprises sulfur and in the quantum dot, a mole ratio of sulfur with respect to zinc is greater than or equal to about 0.1.
22. The electronic device of claim 18 , wherein the quantum dot has a multipod shape having at least two branches and a valley between the branches.
23. The electronic device of claim 18 , further comprising an anode and a cathode facing each other; and a layer disposed between the anode and the cathode, wherein the quantum dot is included in the layer.