Figure 2
From: Visible and infrared emission from Si/Ge nanowires synthesized by metal-assisted wet etching
RHEED analysis of the grown MQW. The image shows spots of the 2 × 1 surface reconstruction (black arrows) superimposed to those of the initial 1 × 1 symmetry (white arrows). The presence of this diffraction pattern guarantees for a clean surface and a good two-dimensional epitaxial growth.