Influence of Sn incorporation and growth temperature on crystallinity of Ge1 − xSnx layers heteroepitaxially grown on Ge(110) substrates

► We investigated the epitaxial growth of Ge and GeSn on Ge(110) at 150 °C and 200 °C. ► Ge layers exhibit defective structures including stacking faults. ► Incorporation of Sn effectively improves on the crystallinity of a Ge layer. ► The anisotropic strain relaxation in a Ge1 − xSnx layer on Ge(110) is observed.