Measurement of carrier lifetime and interface recombination velocity in Si-Ge waveguides

The carrier lifetime in Si1-xGex planar waveguides with Si cladding was measured as a function of layer thickness d and Ge concentration x by using an optical pump-and-probe technique. The measured lifetimes are in the range of 20-90 ns. The obtained interface recombination velocity S increases with both d and x, taking values in the range from 300 to 4000 cm/s.