(Invited) Growth and Applications of Si1-xSnxThin Films

Toward creation of a direct gap group-IV semiconductor, we have developed a new method of growing Si1-xSnx layers with various Sn content including a very high Sn content around 40% by using solid phase epitaxy. Crystallographic analyses indicate that grown Si1−xSnx layers are nearly lattice-matched to the substrates, specifically, the substitutional Sn contents of ~20 and ~40% are achieved for case of growth on (001)-oriented Ge and InP substrates, respectively. Although band structure of the Si0.6Sn0.4 layers grown on InP is still indirect band gap, the difference between the indirect and direct band gap energies decreases from 3.01 (Si) to 0.14 eV (Si0.6Sn0.4) following Sn substitution.