Photoluminescence of nanometric single silicon quantum wells

We performed low temperature photoluminescence studies on nanometric thickness silicon single quantum wells. We show that electron hole recombination spectra are strongly dependent on the well thickness t and that carriers are in a strong quantum confinement regime for t ⩽ 3 nm. A set of fixed lines is identified and attributed to discrete and confined ground state levels or activated trap levels. A significant increase in the quantum efficiency is observed in the confinement regime and is associated with the progressive transformation of the Si layer into a planar distribution of two dimensional “nanoplates”.