Patent ID: 8420155

Claim:
A method of producing a ternary concentration-gradient quantum dot comprising an alloy of a first semiconductor AB and a second semiconductor AC, wherein A is a species that is common to the first semiconductor and the second semiconductor and B and C are each a species found in only one of the first semiconductor and the second semiconductor, and wherein the alloy comprises CdSeTe and has a molecular formula CdSe 1-x Te x , the alloy comprises CdSSe and has a molecular formula CdS 1-x Se x , the alloy comprises CdSTe and has a molecular formula CdS 1-x Te x , the alloy comprises ZnSeTe and has a molecular formula ZnSe 1-x Te x , the alloy comprises ZnCdTe and has a molecular formula Zn 1-x Cd x Te, the alloy comprises CdHgS and has a molecular formula Cd 1-x Hg x S, the alloy comprises HgCdTe and has a molecular formula HgCdTe, the alloy comprises InGaAs and has a molecular formula InGaAs, the alloy comprises GaAlAs and has a molecular formula GaAlAs, or the alloy comprises InGaN and has a molecular formula InGaN, wherein x is any fraction between 0 and 1, which method comprises: (i) providing a first solution under conditions which allow nanocrystal formation to take place, (ii) providing a second solution comprising A, B, and C at a molar ratio under conditions which do not allow nanocrystal formation to take place, wherein each of B and C are present in the second solution at a concentration that is reaction-limiting, (iii) adding the second solution to the first solution, thereby allowing nanocrystal formation to take place, and (iv) changing the conditions to conditions that halt nanocrystal growth and formation.