Investigation of Band Structure in Strained Single Crystalline Si_1-X Sn _X

Abstract

We evaluated the optical properties and the band structure of strained single crystalline Si1-x Sn x using spectroscopic ellipsometry. The results suggest a reduction of the band gap at the Γ point and the formation of an optical transition by Van-Hove singularity with higher Sn fraction. In addition, since the reduction of the band gap with increasing Sn fraction at the Γ point is larger than at other points, it is expected the indirect transition type Si1-x Sn x used in this study may eventually change to the direct transition type. Although higher Sn fraction are required to achieve direct transition type Si1-x Sn x , the band structure of strained single crystal Si1-x Sn x was experimentally clarified.