Ionizing Radiation Induced Strain Engineering for Exciton Dynamics in Atomically Thin Semiconductor

Uncovering and controlling exciton dynamics in atomically thin semiconductors is crucial for excitonic devices. While conventional techiniques often damage materials, ionizing radiation offers a non‐contact, low‐cost modulation method. Here, we introduce a non‐destructive strain‐engineering approach using low‐energy (≤1000 eV) alpha‐particle irradiation in monolayer WSe 2 . The irradiation induces helium accumulation beneath the monolayer, forming defect‐free nanobubbles that can be merged via annealing. These bubbles create an exciton funneling effect, boosting photoluminescence and causing a spectral redshift. The induced strain gradient enhances exciton localization and raises the optimal temperature for emission and transport. This work demonstrates controlled ionizing radiation as a powerful tool for tuning 2D exciton dynamics, with potential for sensing, energy harvesting, and quantum technologies.