Low-temperature photoluminescence in SiGe single quantum wells

We have investigated the low-temperature photoluminescence properties of n-type modulation doped Si1-xGex single quantum wells (x = 0.19) grown by rapid thermal chemical vapor deposition at 625 degrees C, A well-resolved strong excitonic luminescence with TO-phonon and no-phonon transitions with a full width at half-maximum as low as 6 meV is observed for a quantum well of 98 Angstrom. The photoluminescence emission shows a significant blue shift and a broadening with excitation intensity. The results are analysed in terms of localization of photoinduced charge carriers at the heterointerfaces.