The potential of semiconductor nanowires to add new functionality in a wide array of application areas lies not simply in the downscaling of conventional materials, but in the possibility to access new materials and structures not available in bulk, such as new crystal phases, alloy materials or heterostructure combinations. The development of these materials requires a fundamental understanding of the processes governing the formation of 1D crystalline structures on the nanoscale. Since nanowire growth is performed in a vapour phase atmosphere at high temperature, the dynamic processes controlling their formation cannot be directly deduced by analyzing only the final grown nanostructure. In this talk I will discuss in-situ growth of nanowires in environmental TEM, a technique which offers insights into the growth processes unparalleled by any other method. In particular, in-situ TEM has given important insights into nucleation processes, morphology of the growth front, and transport pathways of the precursor species. In addition to discussing the results for nanowire growth obtained at in a UHV system, I will describe the latest developments using a dedicated CVD-TEM system able to resolve growth processes in high resolution at pressures comparable to standard growth conditions.
Kimberly Thelander is a Professor in Materials Science at Lund University, Lund, Sweden, appointed jointly at the division of Solid State Physics and the Center for Analysis and Synthesis. She completed undergraduate studies in Chemical Physics at the University of Waterloo, Canada, followed by a PhD in Physics from Lund University. Her research is focused on the development of novel materials in nanostructures, specifically focused on unusual polytypes and alloy semiconductors in III-V nanowires. Most recently she is involved in the development of in-situ TEM for real-time investigations of nanowire growth.