Aerosol fabrication of nanocrystals of InP and related materials

Indium phosphide nanocrystals, with diameters of around 10 nm, have been produced via an aerosol route. The method is based on the formation of monodisperse indium droplets and the subsequent reaction with phosphine at elevated temperature. The size of the final InP nanocrystal is self-limited by the size of the introduced size-selected In droplet. This size can be tuned carefully, thus this method allows a narrow size distribution of the nanocrystals. The kinetics of the reaction of In to produce InP depends on the temperature and the phosphine flow. Extensive high resolution transmission electron microscopy studies lead to a consistent picture of the process. This process has been demonstrated for the fabrication of InP as well as GaAs nanocrystals. Our approach opens the possibility for efficient production of size-selected semiconductor nanocrystals and it will allow new types of self-assembly and control of quantum dots.