Optical Spectroscopy of Nanomaterials
The project is aimed at exploring various physical properties on the nanoscale using optical spectroscopy. In particular a focus on Raman and Optical spectroscopy of nano materials and bulk compounds on the nanoscale to better understand the interplay between numerous physical processes. This not only allows us to explore the basic physical underpinnings of novel effects but better characterize and optimize devices. Three different materials will be the focus of this study, high temperature superconductors, topological insulators and semiconductor nano wires. All three offer unique opportunities to study the emergence of new properties as a material is tuned on the nano scale, while also offering dramatic improvements in multifunctional materials, quantum computation, loss-less energy transmission and thermoelectric power generation.
Particular focus will be given to the Raman spectroscopic response of these materials. Raman is a powerful technique as it can measure the lattice, magnetic, thermal and electronic properties of a material simultaneously. Furthermore every material has a unique Raman signature and thus Raman can be used to “fingerprint” an unknown compound or map out the composition over a large area. This is all achieved through the scattering of a focused laser beam, providing spatial resolution of 1 micron. Recently our group has begun to couple a Raman system with a scanning probe microscope enabling us to measure the Raman response with 10nm resolution. This unparalleled performance will provide key insights into the role of nanoscale inhomogeniety in novel properties as well as fully characterize single nano materials (quantum dots, nano wires, exfoliated material). For example this Tip Enhanced Raman Spectrometer (TERS) can simultaneously map the local temperature, strain and chemical composition of a material or device on the nanoscale. These TERS spectra will be acquired while operating the device to better understand the real limits of its performance as well as the origins of novel behaviour that emerges.
