Visible luminescence from a-SiN films doped with Er and Sm

Relatively strong and narrow red and green light emission has been achieved from amorphous (a-) SiN films independently doped with Er3+ and Sm3+ ions. The films were deposited by cosputtering a Si target partially covered with small pieces of metallic Er (and Sm) in an atmosphere of pure nitrogen. As a consequence of the deposition method and conditions, the films have an amorphous structure, and contents of Er (and Sm) in the low 0.5 at. %. All characterizations were accomplished on as-deposited samples and at room temperature and included: ion-beam analysis (Rutherford backscattering spectrometry and nuclear reaction analysis) and optical techniques (light absorption, Raman scattering, and photoluminescence and cathodoluminescence). A detailed examination of the experimental results allowed the identification of all luminescence features existing in the films.