An effect of Si nanoparticles on enhancing Er3+ electroluminescence in Si-rich SiO2:Er films

Er-doped Si-rich SiO2 (SRSO:Er) films have been deposited on n+-Si substrates by the magnetron sputtering technique, and both photoluminescence (PL) and electroluminescence (EL) at 1.54 μm have been observed from the films at room temperature. Dependence of PL and EL intensities on the excess-Si content and annealing temperature has been studied. It is found that proper Si content and annealing temperature can evidently enhance EL intensity. An SRSO:Er film with 20% excess Si (area ratio of the Si target to the whole target) had more intense EL than a SiO2:Er film without excess Si, both annealed at 800°C, by a factor of 5. This fact clearly demonstrates that energy coupling between Si nanometer particles and Er3+ ions also exists in the EL process as well as in the PL process. Experimental results also indicate that crystallization is not a prerequisite for NSPs enhancing luminescence in SRSO:Er films. The PL and EL spectra of the SRSO:Er films have much broader full widths at half maximum (FWHM, ∼60 nm) than those of the other Er-doped materials reported. This wide FWHM can perhaps be used in wavelength division multiplexing in optical communication in future.