Correlation between photoluminescence efficiency and density of paramagnetic defects in Er-doped hydrogenated amorphous silicon

Photoluminescence and electron paramagnetic resonance in layers of hydrogenated amorphous silicon doped with erbium and oxygen have been investigated. The intensity of Er-related photoluminescence (1.54 μm) depends non-monotonically on the ratio between erbium and oxygen content varied from 0.1 to 3. The photoluminescence efficiency correlates with the density of spin centers (most likely Si dangling bonds (DBs)) that gives evidence for the role of Si DBs in the electronic excitation of Er-ions.