QDev Seminar: Sonia Conesa Boj

Technische Universiteit Eindhoven

Cracking the Nanowire Code: Electron Microscopy and the design of novel nanomaterials

In the last decade a significant progress has been made in controlling the growth and properties of low-dimensional systems, such as nanowires. Their small radial dimension enables more freedom for the combination of different materials. The ability of nanowire systems to overcome existing limitations of heterostructures is one of the key ingredients for the design of next generation devices. In turn, this requires a detailed understanding of the crystalline structure and the mechanisms for strain relaxation in these systems, in order to eliminate defect formation and thus to boost optical and electronic properties. Therefore, the characterization of their structure and chemical composition with atomic resolution is essential to achieve a full understanding of how their various physical properties are correlated. Transmission electron microscopy (TEM) provides a unique toolbox to achieve this goal. TEM is extremely versatile, combining within a single instrument the complementary capabilities of imaging, diffraction and spectroscopy. In this talk I discuss the crucial role that electron microscopy plays in the characterization of the structure, properties and performance of nanomaterials, and then present the results of recent studies illustrating this central role for the specific case of core-shell nanowires.