Tadpole-shaped AgInSe2 nanocrystals from a single molecular precursor and its nonlinear optical properties

Abstract

Orthorhombic tadpole-shaped AgInSe2 nanocrystals have been synthesized from the single molecular precursor [(PPh3) 2AgIn(SeC{O}Ph)4]. Reaction parameters such as temperature, surfactant concentration, and heating duration have been optimized to get monodispersed AgInSe2 nanotadpoles. Severe stacking faults were observed in the crystal lattice of the tadpole nanostructure, which indicate that these AgInSe2 nanotadpoles experience strain while the particles were grown in solution. A possible mechanism proposed involves disassociation of the precursor when dissolved in oleylamine and dodecanethiol solution, and the dissociated products further decomposed into Ag2Se nanocubes together with probably, indium-based decomposed products. In the extended heating process, these two react to form the AgInSe2 tadpole-shaped nanoparticles. The obtained tadpole-shaped AgInSe2 nanocrystals exhibit significant third-order nonlinear optical properties. © 2010 American Chemical Society.