Fabrication and photoluminescence properties of Tb-doped nitrogen-rich silicon nitride films

Terbium (Tb) doped nitrogen‐rich silicon nitride thin films were prepared on [100] Si substrate by reactive magnetron co‐sputtering in pure nitrogen atmosphere. The microstructure and optical properties of the films were investigated by means of ellipsometric spectroscopy (ES), atomic force microscopy (AFM), X‐ray diffraction (XRD), Raman scattering and Fourier transform infrared (FTIR) spectroscopies as well as by photoluminescence (PL) experiments. A notable emission from Tb3+ ions was obtained for the as‐deposited layer, while the maximum intensity was found from 600 °C‐annealed sample. Deducing from PL excitation (PLE) analysis, a mechanism of excitation of Tb3+ ions was proposed: the band tail states of matrix play a minor role in the energy transfer process, while the host carriers across the optical gap acted as effective sensitizers for Tb3+ ions