Formation of optically active osmium silicide in silica using ion implantation and thermal annealing

Optically active metal silicides offer an interesting direct band gap material that in principle can be integrated into Si-based microelectronics to provide optoelectronic functionality. In particular the isostructual phases of Os2Si3 and Ru2Si3 and their alloys could be tailored to yield a response ranging from the visible blue to the near infrared. The metal-rich phase, Os2Si3 poses some difficulties for the annealing process since it is the low temperature phase, and thus difficult to fabricate in silica due to the high temperature needed for precipitation. Ion implantation of Os and Si ions above the stoichiometric ratio resulted in the formation of Os2Si3 at 1100 °C, as indicated by Rutherford backscattering. Faint visible photoluminescence was detected with a peak centered near (520 nm) corresponding to the previously reported bandgap of 2.3 eV [L. Schellenberg, H.F. Braun, J. Muller, J. Less-Common Met. 144 (1988)]. To the best of our knowledge this is the first reported photoluminescence from this material.