BAND-EDGE AND DEEP-LEVEL PHOTOLUMINESCENCE OF PSEUDOMORPHIC SI1-X-YGEXCY ALLOYS

Photoluminescence of strained Si1-x-yGexCy alloys grown by rapid therm al chemical vapor deposition on Si(100) is investigated. Two dominant features are reported: At low pump intensities, the photoluminescence is dominated by a deep level broad luminescence peak around 800 meV wh ereas at high pump intensities, a well-resolved band-edge luminescence (no phonon and transverse optic replica) is observed. At 77 K, we att ribute this band-edge feature to an electron-hole plasma luminescence of the ternary alloy. The dependences of the deep level and band-edge peaks versus the excitation power density are, respectively square-roo t-like or superlinear. A blue shift of the energy gap of Si1-x-yGexCy alloys with respect to Si1-xGex alloy is observed. The blue shift incr ease with carbon content corresponds to what is expected for the bulk alloy. An eventual influence of the strain relaxation cannot be exclud ed.