Electromagnetic Field Enhancement on Axially Heterostructured NWs

Semiconductor nanowires (NWs) present unique optical properties as compared with their bulk counterparts, such as scattering and absorption resonances depending on the NW diameter. This novel behavior, together with their growth versatility, makes semiconductor NWs promising building blocks of future optoelectronic nanodevices. In order to obtain useful NWs for device applications, it is important to control heterojunction (HJ) fabrication and the characterization of their properties. In this seminar we will discuss the optical properties of axial heterojunctions on semiconductor NWs, focusing on the enhancement and localization of the electromagnetic field provided by this structures. The NWs are studied by μ-Raman Spectroscopy which allow to obtain indirect measurements of the electromagnetic field distribution inside the NW. The electromagnetic interaction of the incident laser beam and the heterostructured NW result in an enhancement of the Raman signal when the HJ is illuminated. This effect expands the possible applications of axially heterostructured NWs in devices based on light-matter interaction, such as solar cells, nanophotonics, sensors, etc.