Experimental quantification of atomically-resolved HAADF-STEM images using EDX

Atomically-resolved mappings of the indium composition in InGaN/GaN multi-quantum well structures have been obtained by quantifying contrast HAADF-STEM. The quantification procedure presented here does not rely on computation-intensive simulations, but rather uses EDX measurements to calibrate HAADF-STEM contrast. histogram compositions from mapping provides unique insights into growth InGaN: transition GaN InGaN and vice versa occurs discreet increments composition; each increment corresponds one monolayer interface, indicating that nucleation takes longer than lateral step. Strain-state analysis is also performed applying Peak-Pair Analysis positions atomic columns identified strain yield an estimate good agreement with quantified HAADF-STEM, albeit a lower precision. Possible improvements increase precision are discussed, opening potential pathways for arbitrary quaternary alloys at scales.