Abstract: Metal quantum dots are produced from a solution of the metal salt when the solution is passed through an electrostatic capillary nozzle (3) into a chamber (7). The nozzle (3) produces an aerosol of droplets (4) of the solution which is then irradiated using laser light (8). The solution evaporates from the droplets to form quantum dots of the metal element on a substrate 5 in the chamber 7.

Abstract: Quantum dots of a metal or metal compound are made by a method of providing a solution in an evaporable solvent at a predetermined concentration of a chosen metal and forming droplets of the solution of a substantially uniform predetermined size. The droplets are thereafter brought into contact with a gas phase reagent thereby forming the metal or metal compound quantum dots desired. The solvent may be removed before, during or after the contacting of the droplets with the gas phase reagent. The metal or metal compound quantum dots so formed are deposited on a substrate. The quantum dots may be contained within a polymer as a film. By control of the concentration of the solution and the size of the droplets the size of the quantum dots may be closely controlled.