Sensitization of Er by Si-nanoclusters in Erbium doped Si-rich Si nitride films

Er³⁺ luminescent properties from Erbium doped Si-rich Si nitride (SRSN) films were investigated through photoluminescence (PL) and photoluminescence excitation spectroscopy (PLE). These films grown by ultra-high vacuum ion beam sputtering are annealed at high temperature in order to form the Si-nanoclusters (nc-Si). We find that nc-Si can act as efficient sensitizers for Er³⁺, displaying the strong energy transfer form nc-Si to Er ions. Er³⁺ luminescence lifetimes were in the 1-3 msec range at room temperature with complete suppression of temperature quenching of Er³⁺ intensity, indicating high luminescence efficiency as well. The PLE spectrum in film with nc-Si shows efficient Er³⁺ PL intensity, compared with that of pure nitride. These results imply that Er doped SRSN is a promising alternative for compact, high-efficiency Si based light sources.