A quantum dot including a core including a first semiconductor nanocrystal including a Group III-V compound, and a shell disposed on the core and including a semiconductor nanocrystal including a Group II-VI compound, wherein the quantum dots do not include cadmium, the shell includes a first layer disposed directly on the core and including a second semiconductor nanocrystal including zinc and selenium, a second layer, the second layer being an outermost layer of the shell and including a third semiconductor nanocrystal including zinc and sulfur, and a third layer disposed between the first layer and the second layer and including a fourth semiconductor nanocrystal including zinc, selenium, and optionally sulfur, and a difference between a peak emission wavelength of a colloidal solution of the quantum dot and a peak emission wavelength of a film prepared from the colloidal solution is less than or equal to about 5 nanometers (nm).