A quantum dot including: a core including a first semiconductor nanocrystal material including zinc, tellurium, and selenium; and a semiconductor nanocrystal shell disposed on the core, the semiconductor nanocrystal shell including zinc, selenium, and sulfur, wherein the quantum dot does not include cadmium, and in the quantum dot, a mole ratio of the sulfur with respect to the selenium is less than or equal to about 2.4:1. A production method of the quantum dot and an electronic device including the same are also disclosed.