Method of preparing quantum dot, quantum dot prepared thereby, and optical member and electronic apparatus including the quantum dot

A method of preparing a quantum dot, the method comprising:

• preparing a first composition comprising:
• a first precursor comprising a first element;
• a second precursor comprising a second element;
• a third precursor comprising a third element;
• a fatty acid having a number of carbon atoms in a range of 2 to 12;
• and
• a solvent;
• heating the first composition to a first temperature of 110° C. to 130° C.;
• preparing a second composition comprising a fourth precursor comprising a fourth element;
• and
• preparing a core by combining the second composition with the first composition to provide a first mixture, and heating the first mixture to a second temperature greater than the first temperature, wherein
• the first element and the second element are each a Group III element, and the first element is different from the second element,
• the third element is a Group II element,
• the fourth element is a Group V element,
• wherein the core of the quantum dot comprises the first element, the second element, and the fourth element, and
• a number of moles of the first element is n1,
• a number of moles of the second element is n2,
• a number of moles of the fourth element is n4, and
• a mole ratio of a sum of the number of moles of the first element and the number of moles of the second element to the number of moles of the fourth element in the core (n1+n2)/n4 is in a range of about 1.0 to about 2.0.