The electronic and structural properties of an In x Ga 1Àx As quantum well (QW) stacking between AlAs barriers grown on 300 mm (001) silicon substrate by metalorganic chemical vapor deposition were investigated. Nanometer scale and spatially colocalized characterization combining low temperature cathodoluminescence (CL) and scanning transmission electron microscopy was performed. The combined interpretation of luminescence and strain measurement provides an exhaustive landscape of such complex sample. Particularly, CL analysis highlights luminescent regions characterized by quasicircular shapes and a peculiar optical emission consisting of a double peak. The characterizations provide a comprehensive analysis of these specific luminescence features. These luminescent regions, detected all over the sample, seem to be correlated to local increases in carbon and indium content in AlAs barriers and in the InGaAs QW, respectively, induced by local strain variations. These modifications alter InGaAs QW properties and thus its optical emission efficiency. Published by the AVS. https://doi.org/10.1116/1.5033363