Time-resolved D-band luminescence in strain-relieved SiGe/Si

Abstract

Temporal decay characteristics of dislocation-related luminescence bands (D1–D4) were explored in strain-relieved epitaxial SiGe/Si(100). Close similarity of the decay profiles was observed not only between D1 and D2 bands but also between D3 and D4 bands. The decay transients of the D1 and D2 bands at low temperatures are characterized by long decay times, τ≳200 ns, whereas the D3 and D4 bands exhibit even sharper transients with τ<60 ns. Temperature dependence of ‘‘radiative’’ lifetimes implies a free-to-bound nature of the D1 and D2 bands, while a bound-to-bound character of the luminescence origins for the D3, D4 bands.