Strain and Interface-Driven Localized Emission in MoSe2 Monolayers on GaN Nanopillars

Solid-state quantum emitters (QEs) in two-dimensional semiconductors offer compact, chip-compatible sources for quantum photonics. In transition-metal dichalcogenides (TMDs), nanopillars are widely used to induce localized emission, yet the underlying confinement mechanism and the relative roles of strain versus dielectric environment remain unclear. Here we combine hyperspectral superlocalization of photoluminescence with coregistered AFM topography and phase to map localized states (LS) positions in MoSe2 on GaN nanopillars and correlate them with bending strain and the local environment. Contrary to a purely strain-driven picture, LS cluster at suspended–supported interfaces around the pillar apex and span a broad strain range with no clear threshold, while being scarce along high-strain ripples. We discuss the candidate mechanisms, including the local dielectric environment, and suggest coengineering of strain gradients and nanoscale interface heterogeneity for deterministic emitter positioning in TMDs.