Erbium-thulium interaction in broadband infrared luminescent silicon-rich silicon oxide

The Er–Tm interaction and its effect on the luminescence from Er–Tm codoped silicon-rich silicon oxide (SRSO) is investigated. Er and Tm ions were implanted into SRSO films, which consist of Si nanocrystals embedded in a SiO2 matrix. A broad luminescence spectrum extending from 1.5 to 2.0 μm was observed under excitation with a single light source due to the simultaneous, nonresonant excitation of both Er3+ and Tm3+ via Si nanocrystals. The absolute Er3+ luminescence intensity, however, is reduced relative to the case without Tm codoping. Comparison of the Er3+ and Tm3+ luminescence intensities, lifetimes, and their pump power dependence suggest that Er–Tm interaction leading to an energy transfer from the Er3+:4I13/2 state to the excited Tm3+:3H4 state is responsible for the reduction in the Er luminescence intensity.