Unique Scattering Properties of Silicon Nanowires Embedded with Porous Segments

The development of advanced imaging tools is important for the investigation of the fundamental properties of nanostructures composed of single or multiple nanomaterials. However, complicated preparation processes and irreversible alterations of samples to be examined are inevitable in most current imaging techniques. In this work, we developed a simple method based on polarization-resolved light scattering measurements to characterize the structural and optical properties of complex nanomaterials. In particular, we examined single Si nanowire embedded with porous Si segments, in which the porous Si could not be easily distinguished from solid Si by scanning electron microscopy. The dark-field optical images and polarization-resolved scattering spectra showed unique optical features of porous and solid Si. In particular, the porosity, diameter, and number of porous Si segments in a single Si nanowire were identified from the scattering measurements. In addition, we performed systematic optical simulations...