Luminescent silicon nanoparticles surface-modified with chiral molecules

Abstract

Active surface of luminescent silicon nanoparticles was terminated by the photochemical reaction of chiral molecules, (S)- or (R)-5-allyl-2-oxabicyclo[3,3,0]oct-8-ene ((S) - or (R) - AOBE) under UV light. The particle size and shapes were characterized using Transmission Electron Microscope (TEM). The average particle size was found to be 5.7 nm. Circular dichroism (CD) signals with large dissymmetry factors from silicon nanoparticles terminated with (S) - and (R) - AOBE were observed at around 300 nm and 500 nm, which were much larger than those of (S)- and (R)-AOBE molecules. The silicon nanoparticles covered with (S)- or (R)-AOBE provided red luminescence based on the indirect electronic transition. Effective circular polarized luminescence (CPL) was not observed from indirect transition band.