According to an additional aspect, a method of making quantum dots having a coating thereon is provided which includes providing a reaction mixture of core quantum dots, a metal carboxylate and a chalcogenide source at a temperature of greater than 240° C. wherein unbound phosphonic acid or unbound metal phosphonate species are substantially absent from the reaction mixture; providing 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 core quantum dots are the same or different from the metal and chalcogenide of the first coating; combining an additional metal carboxylate and an additional chalcogenide source with the first coated quantum dots at a temperature of greater than 280° C. wherein unbound phosphonic acid or unbound metal phosphonate species are substantially absent from the combination; and providing a second coating on the first coated quantum dots from the additional metal carboxylate and the additional chalcogenide source, wherein the metal and chalcogenide of the core quantum dots are different from the metal and chalcogenide of the first coating. According to one aspect, the core quantum dots include group II-VI elements. According to one aspect, the first coating includes group II-VI elements. According to one aspect, the second coating includes group II-VI elements. According to one aspect, the second coating is Cd_XZn_1-XS. According to one aspect, the core quantum dots are CdSe quantum dots. According to one aspect, unbound phosphonic acid or unbound metal phosphonate species are substantially removed from the core quantum dots prior to the core quantum dots receiving a first coating. According to one aspect, unbound phosphonic acid or unbound metal phosphonate species are substantially removed from the core quantum dots by placing the quantum dots in a fluid causing precipitation of the phosphonic acid or metal phosphonate species from the fluid. According to one aspect, the fluid is octadecene. According to one aspect, the core quantum dots have bound phosphonic acid or bound metal phosphonate species. According to one aspect, the bound phosphonic acid or bound metal phosphonate species are removed from the core quantum dots prior to the core quantum dots receiving a first coating. According to one aspect, the metal carboxylate and the chalcogenide source are highly reactive. According to one aspect, the metal carboxylate and the chalcogenide source react substantially immediately with each other at the reaction temperature to form nuclei of a predetermined semiconductor material.