Investigation of polarization anisotropy in individual porous silicon nanoparticles

Polarization anisotropy is investigated in single porous silicon nanoparticles containing multiple chromophores. Two forms of nanoparticle samples are studied; low current density (LCD) and high current density (HCD). Photoluminescence measurements reveal that LCD samples exhibit red-shifted spectra and HCD particles display a blue-shifted spectrum. We utilize single molecule spectroscopy to detect the polarization effects of spatially isolated individual nanoparticles, and show that LCD nanoparticles demonstrate strong polarization anisotropy, whereas a dynamic polarization response is collected from HCD nanoparticles.