Fig. 2: Atom probe tomography of stoichiometric CuInSe2 (CIS-S).
From: Chemical instability at chalcogenide surfaces impacts chalcopyrite devices well beyond the surface
a Cu concentration map (cf. Cu atomic % coloured scalebar) and corresponding Na and K elemental distributions, acquired to highlight the location of a grain boundary. The labelled arrows identify orientations of the regions of interests (ROI) 1 and 2. b Integral compositional depth profile from the whole specimen volume with highlighted off-stoichiometry: deficiency of selenium (∆Se) and excess of copper (∆Cu) and indium (∆In) with respect to stoichiometric CIS (50 at.% Se and 25 at.% In and Cu). c Compositional profile along ROI 2, revealing a portion with Cu concentration far exceeding stoichiometry (dotted circle).
