Fig. 5

Dislocation/void interaction in the Ge/Si interface. a Low magnification bright field transmission electron microscopy (BF-TEM) images of the Ge/Si reference substrate and b the NVS with very few defects within the Ge layer. Scale bars 200 nm. High-resolution TEM images from the Ge/Si reference (c) and the NVS (d) show a dense dislocation network close to the Ge/Si interface. Scale bars of c and d are 10 and 20 nm, respectively. e, f Experimental strain components ε_xx at the Ge/Si heterostructure interface for both substrates exhibit a better strain relaxation of the Ge layer in the case of the NVS. Scale bars 10 nm. g Selected area electron diffraction (SAED) patterns from the NVS show a monocrystalline quality of the Ge layer. h Atomic-resolution TEM image shows the annihilation of dislocation segments coming from the Ge/Si interface at the void located in the Si substrate. The arrows in h shows two dislocations bend towards the voided area, instead of emerging at the Ge surface. Scale bar 5 nm