We report an experimental observation of both a fast (∼10μs) and a slow (∼10ms) photoluminescence (PL) that coexist in Ge-rich (x>0.5) islandlike, three-dimensional Si/Si1-xGex nanostructures. We present a quantitative model that explains the observed PL lifetime dependence on carrier concentration, temperature, and detection wavelength. The PL dynamics are found to be determined by the excess carrier concentration: the fast PL is associated with a dynamic type I and the slow PL with a type II energy band alignment in Ge-rich Si/SiGe nanostructures.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Nov 15 2005|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics