Structural basis for homogeneous CdS nanorods: synthesis and HREM characterization

Since the devolution of multiple efforts for producing semiconductor nanorods, the control of size and structure become critical for their applications in nanotechnology. The use of distinct methods has allowed a partial control of the size of the nanorods; however, the internal structure has been reported to be very varied, requiring the consideration of defects and twins in the interpretation of the analytical data. With the help of a solvothermal method, we report the synthesis of a homogeneous sample of CdS nanorods, with size around 50nm in length and 7nm in diameter. The structure of these rods was characterized by high-resolution transmission electron microcopy (HREM) and simulation tools for producing models and simulated images for different orientations. From the experimental and theoretical results we report the preferential axis for growing nanorods and the necessity of CdS fcc-like structures to explain all the nanorods produced in this work and in general those reported in the literature. The use of the calculated images, reported in this paper, opens an easy way to understand HREM images even for a non-specialist. PACS 61.16.Bg; 79.60.Jv; 61.46.+w; 61.50.Ah