According to a certain aspect, the use of carboxylate based precursors with small CdSe core quantum dots (less than 500 nm absorbance peak) to further grow the size of the quantum dots results in the surface of the quantum dots having a plurality of carboxylic acid ligands. According to this aspect, the Cd precursor may be carboxylate based including Cd(oleate)₂ and the Se precursor may be dialkylphosphine-selenide such as diisobutylphosphine selenide or diphenylphosphine selenide. The growth process produces high quality monodisperse CdSe cores with a first absorbance peak tunable between 500-600 nm. The growth process allows in-situ high temperature overcoating using Cd_XZn_1-XS for producing red emitters emitting between 600-630 nm with high solution QY (about 80%), narrow FWHM (25-30 nm) and high external quantum efficiency in the solid state (90-95%).

According to one aspect, a method of making quantum dots having a coating thereon is provided including providing a reaction mixture including core quantum dots, one or more metal carboxylates and one or more chalcogenide sources at a temperature of greater than 240° C. to form a first coating on the core quantum dots from the metal carboxylate and chalcogenide source to form first coated quantum dots, wherein the metal and chalcogenide of the first coating are the same or different from elements included in the core and combining one or more metal precursors and one or more chalcogen precursors with the first coated quantum dots to form a second coating on the first coated quantum dots from the one or more metals and one or more chalcogens included in the precursors, wherein the one or more metals and one or more chalcogens included in the second coating comprises a composition that is different from the composition of at least one of the core or the first coating.