The appearance of broad photoluminescence (PL) bands in the energy range 0.70–0.96 eV in SiGe/Si heterostructures is shown to be related to the ion bombardment during the molecular beam epitaxy. From the optically detected cyclotron resonance, polarization, and postgrowth treatments, the PL is shown to be composed of at least two components. No evidence of lattice distortion is found for the main PL band, while the low energy tail is believed to arise from lattice distorted regions. Both PL centers are demonstrated to originate from the SiGe quantum wells by PL excitation measurements. ©1995 American Institute of Physics.