Self-Processing Synthesis of Semiconductor-Metal Hybrid Nanostructures

Programmable introduction of heterogeneity at the nanoscale plays a key role in the design of functional building blocks. Synthetic strategies for attaining well-definedheterogeneity in structure, shape, composition, and modulation of the electronic structure at selected regions of the nano system is therefore highly desired. I will present a new type of synthesis for preparing semiconductor-metal hybrid nanosystems using nanowires as the basic building blocks. The synthesis yield hybrid nanostructures with well-defined morphologies by triggering a programmable cascade of events that is autonomously executed and terminated, termed ‘self-processing synthesis’. The self-processing synthesis is demonstrated for preparing coinage metal, Au, Ag, and Cu, -semiconductor hybrid nanostructures. The synthesis involves a sequence of selective etch and deposition steps which are self-initiated and self-terminated resulting in the hybrid nanostructures. The hybrid nanostructures obtained for the coinage metals resemble the morphology of grass flowers, termed here Nano-floret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell cap. The new class of structures is useful in a variety of applications owing to the unique geometrical aspect ratio and electronic properties of the hybrid systems.

Reference

J. Am. Chem. Soc., 138, 4079-4086 (2016)

Nano-floret like structures using SiGe nanowires decorated with Cu, Ag, and Au.