Formation of 1-D ZnTe nanocrystals by aerosol-assisted spray pyrolysis

One-dimensional (1-D) ZnTe nanowires were prepared by aerosol-assisted spray pyrolysis using a mixture of ZnO (1 mmol)/OA (4 mL)/TOPO (0.8 g)/ODE (4 mL) as Zn precursor and Te/TOP (3 mL of 0.75M) as Te precursor. The shape, size, and crystal structure of products were characterized by means of transmission electron microscope (TEM) and X-ray diffraction (XRD). The shape evolution of ZnTe nanocrystals from nanodots to nanowires was achieved by controlling the reaction temperature. ZnTe nanodots with average diameter of 8.3 nm were synthesized at 300 °C. “Earthworm-like” shaped ZnTe (linear ZnTe aggregates) consisting of primary ZnTe nanodots of about 16 nm in diameter were obtained at 400 °C. In addition, 1-D ZnTe nanowires were prepared at reaction temperature higher than 450 °C. Those experimental results suggest that ZnTe nanowires with zinc blende structure are formed from ZnTe nanodots by the oriented attachment due to insufficient surface capping of surfactant molecules and by strong dipole-dipole interaction of nanodots, followed by self-organization of linear aggregates at higher reaction temperatures. The linear ZnTe aggregates consisting of primary ZnTe nanodots may be an intermediate stage in the formation process of nanowires from nanodots.