A cadmium free quantum dot includes zinc, tellurium, and selenium, and lithium. A full width at half maximum of a maximum luminescent peak of the cadmium free quantum dot is less than or equal to about 50 nanometers and the cadmium free quantum dot has a quantum efficiency of greater than 1%.

A quantum-dot-containing composition contains: either quantum dots each having a surface provided with only one equivalent crystal plane, or quantum dots each having a surface provided with two or more different equivalent crystal planes; and one selected from (A), (B), and (C) below: (A) two or more compounds; (B) one or more compounds, and single atoms formed of one or more halogens or chalcogens; and (C) single atoms formed of two or more halogens or chalcogens.