We report simulations of electrically pumped waveguide emitters in which the emissive layer contains silicon nanoclusters and erbium ions. Plasmonic coupling to metallic or semi-metallic overlayers provides enhancement of the radiative rate of erbium ions, enabling high quantum efficiency emission. Using 2D and 3D finite difference time domain (FDTD) simulations we show that up to 75% of the light emitted from the active layer can be coupled into a nanowire silicon rib waveguide. Our results suggest that such devices, which can readily be fabricated using CMOS processing techniques, pave the way for viable waveguide optical sources to be realized in silicon photonics. © 2011 Optical Society of America.