(317h) Self-Assembly and Chiroptical Response of Homochiral Semiconductor Nanohelices

Chiral semiconductor nanostructures provide a rich materials platform for polarization optics, photocatalysis, and biomimetics. However, unlike noble metals (such as Au or Ag), the relationship between the geometry of chiral semiconductors and their chiroptical properties remains enigmatic. Enantioselective preparation of semiconductor nanohelices from cadmium telluride nanoparticles (CdTe NPs) opens an opportunity to simulate and experimentally validate complex relationships between geometrical parameters and chiroptical properties of semiconductor nanostructures using circular dichroism (CD) spectroscopy. Simulated CD spectra not only accurately reproduced experimental results, but also provided spectral predictions for geometrical parameter modification. Comparisons between nanohelices made of CdTe and noble metals such as Au and Ag, revealed distinctly different simulated chiroptical responses. This is due to the occurrence of multipole plasmon resonance associated with relatively large size and aspect ratio nanostructures of noble metals.