We investigated the origin of broad luminescence observed from an array of site-controlled InGaN nanodots grown by selective area epitaxy (SAE). Epitaxially grown site-controlled nanodots with lateral dimensions <50 nm and an array density of 10 cm 2 have been studied. During the nanoscale SAE, incorporation of adatoms from the SiO2 mask has greater relative importance, resulting in a non-unifo...