The effect of the Si layer thickness on the Er31 photoluminescence properties of the Er-doped
Si/SiO2 superlattice is investigated. We find that the Er31 luminescence intensity increases by over
an order of magnitude as the Si layer thickness is reduced from 3.6 nm down to a monolayer of Si.
Temperature dependence of the Er31 luminescence intensity and time-resolved measurement of
Er31 luminescence intensity identify the increase in the excitation rate as the likely cause for such
an increase, and underscore the importance of the Si/SiO2 interface in determining the Er31