Hydrazine-induced room-temperature transformation of CdTe nanoparticles to nanowires

Abstract

The effect of hydrazine on the photophysical and morphological properties of water-soluble thioglycolic acid-capped cadmium telluride (CdTe) nanoparticles at room temperature has been investigated. At lower concentrations of hydrazine (0.5 M), a large enhancement in the luminescence of CdTe nanoparticles was observed without any shape change; hydrazine saturates the Cd dangling bonds on the nanoparticles' surface through coordination. Interestingly, highly crystalline CdTe nanowires with hexagonal wurtzite structure were obtained at higher concentrations of hydrazine (2.0 M) through the recrystallization of linearly assembled aggregated CdTe nanoparticles with a zinc blend structure. Strong dipole-dipole interaction between the nanoparticles in the presence of hydrazine assists their linear aggregation, and low activation energy for phase-transition drives their recrystallization to nanowires. Extremely simple methodology presented here opens up novel pathways for the synthesis of one-dimensional semiconductor nanostructures at room temperature and provides valuable information about the growth mechanism of nanowires.