Quantum dots, a composition or composite including the same, and an electronic device including the same

A quantum dot-polymer composite comprising

• a polymer matrix;
• and
• a plurality of quantum dots dispersed in the polymer matrix,
• wherein the quantum dots comprise
• a core comprising a semiconductor nanocrystal comprising a Group III-V compound;
• and
• a semiconductor nanocrystal shell disposed on the core, the semiconductor nanocrystal shell comprising zinc, selenium, and sulfur, and
• wherein the quantum dot does not comprise cadmium,
• an emission peak wavelength of the quantum dot is in a range of about 500 nanometers to about 550 nanometers,
• an ultraviolet-visible absorption spectrum of the quantum dot comprises a first exciton absorption peak and a second exciton absorption peak, and
• a difference between an energy of the first exciton absorption peak and an energy of the second exciton absorption peak is greater than or equal to about 0.34 electronvolts.

A quantum dot, comprising

• a core comprising a semiconductor nanocrystal comprising a Group III-V compound;
• and
• a semiconductor nanocrystal shell disposed on the core, the semiconductor nanocrystal shell comprising zinc, selenium, and sulfur,
• wherein the quantum dot does not comprise cadmium,
• an emission peak wavelength of the quantum dot is in a range of about 500 nanometers to about 550 nanometers,
• an ultraviolet-visible absorption spectrum of the quantum dot comprises a first exciton absorption peak having a first peak energy and a second exciton absorption peak having a second peak energy, and
• an absolute value of a second derivative of the second peak energy of the second exciton absorption peak is greater than or equal to about 0.001.

A quantum dot, comprising

• a core comprising a semiconductor nanocrystal comprising a Group III-V compound;
• and
• a semiconductor nanocrystal shell disposed on the core, the semiconductor nanocrystal shell comprising zinc, selenium, and sulfur,
• wherein the quantum dot does not comprise cadmium,
• an emission peak wavelength of the quantum dot is in a range of about 500 nanometers to about 550 nanometers,
• an ultraviolet-visible absorption spectrum of the quantum dot comprises a first exciton absorption peak and a second exciton absorption peak, and
• a difference between an energy of the first exciton absorption peak and an energy of the second exciton absorption peak is greater than or equal to about 0.34 electronvolts.