Template-assisted synthesis of CdS nanocrystal arrays in chemically inhomogeneous pores using a vapor–solid mechanism

Abstract

An ordered array of CdS nanocrystals was synthesized by a vapor–solid mechanism using a template of chemically inhomogeneous pores in the form of nanocavities in a thin silicon nitride layer on a SiO₂/Si wafer. The silicon oxide at the bottom of the Si₃N₄ cavities served for nucleation of the CdS crystals, whereas no affinity of CdS to silicon nitride was found. Tetra- and multi-pod morphologies of the nanocrystals have been obtained. These morphologies were attributed to a competition between nucleation rates and growth of different crystallographic planes at the Si₃N₄/SiO₂ and Si₃N₄/CdS interfaces, which is different from the polymorphism growth model.