Extended Data Fig. 2: Crystal quality of the wurtzite GaAs nanowire cores.
From: Direct-bandgap emission from hexagonal Ge and SiGe alloys
a, Bright-field TEM images recorded in the [11\(\bar{2}\)0] zone axis of five representative GaAs core nanowires of a pure wurtzite crystal (stacking faults indicated with red lines), with a stacking-fault density of 0–6 stacking faults per micrometre. b, A zoomed-in bright-field TEM image of the top part of one of the nanowires in a (blue circle), indicating the purity of the crystal structure. c, HAADF-STEM image of the red box in b, displaying the ABAB stacking of the GaAs atomic columns, which is the hallmark of the hexagonal crystal structure. The red shading highlights a stacking fault forming one cubic layer in the hexagonal structure.
