Electronic Structure of Si _1-x IV_x/Si Superlattices on Si (001)

We have preformed systematical ab initio studies of the structural and electronic properties of short-period Si _1-x IV_x/Si/Si (x=0.125, 0.25, 0.5, IV=Ge, Sn) superlattices (SLs) grown along the 001 direction on bulk Si. The present calculations reveal that the Si _0.875 Ge _0.125/Si, Si _0.75 Ge _0.25/Si and
Si _0.875 Ge _0.125/Si are the Γ-point direct bandgap semiconductors. The technological importance lies in the expectation that the direct gap Si _1-x IV_x/Si/Si SLs may be used as components in integrated optoelectronic devices, in conjunction with the already well-established and highly advanced silicon technology.