[摘要]：SixGe1-x-ySny alloys were grown by molecular beam epitaxy at low temperature, followed by ex-situ annealing. The crystal quality of SixGe1-x-ySny layers was characterized by atomic force microscopy and transmission electron microscopy. The compositions and lattice constants of the alloys were studied by x-ray photoelectron spectroscopy and x-ray diffraction. The results show that Vegard's law is a good approximation for SixGe1-x-ySny alloys. Photoreflectance spectroscopy at room temperature was used to determine the direct bandgap energy of SixGe1-x-ySny layers. Analyzing the relationship between composition and direct bandgap energy reveals a negative energy bowing parameter for SiSn. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3701732]
