Fig. 1: Structural and optical characterizations of GeSe.
From: Unconventional (anti)ferroelectricity in van der Waals group-IV monochalcogenides
a, d The side-views of the atomic structures along armchair (a) and zigzag (d) directions. b, e HAADF-STEM images and corresponding atomic-level EDS maps (c, f) of GeSe along [010] (armchair direction, b) and [100] zone axis (zigzag direction, e) (where the armchair/zigzag direction is along the b/a lattice vector, respectively), where the insets in b, e are the simulated HAADF-STEM images. The scale bars are 1 nm. g The XRD pattern from the (00 l) surface. h Linearly polarized Raman spectra along armchair (θ = 0) and zigzag (θ = 90) directions in either parallel (//) or cross (\(\perp\)) geometries at 300 K. i Linearly polarized transmission spectra along armchair and zigzag directions at 300 K, together with Tauc-plot as the inset.
