Nature of P b-like dangling-orbital centers in luminescent porous silicon

Abstract
The Pb-like dangling-orbit centers in luminescent porous silicon (LPSi) have been enhanced to very high concentration (1015 cm−2) by gentle oxidation. High signal-to-noise ratio and very sharp lines enable the g-value maps, and 29Si hyperfine and superhyperfine structures to be clearly resolved by ordinary EPR. Only one Pb-like center is observed, and it is proven to be of the Pb0 variety (⋅Si≡Si3). The relative EPR signal strengths from different g limbs indicate that the LPSi crystallite morphology is not dominated by needles or platelets.