Abstract
We have studied photoluminescence (PL) properties of surface-oxidized Si nanocrystals fabricated with a plasma cell. The size dependence of the PL spectrum, the PL decay dynamics, and site-selective excitation spectroscopy show that the efficient and broad PL band around ∼1.65 eV originates from excitons localized at the interface between crystalline Si and the surface layer. The PL from the crystalline Si core state in large nanocrystals appears in the infrared spectral region. By comparison between surface-oxidized Si nanocrystals and as-prepared porous Si, the size and surface dependence of the coupling between electronic and vibrational excitations are discussed.
DOI:https://doi.org/10.1103/PhysRevB.55.R7375
©1997 American Physical Society