PHOTOLUMINESCENCE IN SI1-XGEXCY ALLOYS

We report photoluminescence from Si1-x-yGexCy films grown epitaxially on Si(100) by chemical vapor deposition. We observe significant energy shifts but no dramatic changes in the photoluminescence line shape ca used by the presence of carbon. Using standard deformation potential t heory to correct the epitaxial strain shifts, we conclude that the ban d gap of relaxed Si1-x-yGexCy alloys has a lower energy than the band gap of relaxed Si1-xGex with the same Si/Ge ratio. We propose an expla nation of these results based on the assumption that carbon forms a re sonant level within the conduction band of Si1-xGex. (C) 1997 American Institute of Physics.