Distinct Tailoring Excitons in WS₂/MoSe₂ Heterostructure by Rectification of Femtosecond Laser Shock Peening

Exciton manipulation in two-dimensional materials and their heterostructures is pivotal for advancing optoelectronics and quantum technologies. Pressure-based approaches are powerful for tuning excitonic states; however, they face a fundamental limitation in achieving permanent, spatially uniform modulation in the absence of induced structural defects. Herein, we introduce a rectified femtosecond laser shock peening (R-FLSP) strategy for permanent and nondestructive modulation of excitonic states in WS₂/MoSe₂ heterostructures. The hybrid architecture is obtained by integrating an additional air cavity and poly(methyl methacrylate) layer, which enables contact-free, spatially uniform shockwave pressure engineering. Under this rectified pressure, monolayers demonstrate photoluminescence quenching with a biphasic energy shift (blueshift-to-redshift), confirming a direct to indirect bandgap transition. In heterostructures, interlayer excitons display 4-fold intensity augmentation at 1.09 GPa, suggesting enhanced interlayer electronic coupling and exciton transition by the R-FLSP treatment. This study establishes a paradigm for engineering fundamental excitonic characteristics and optoelectronic functionalities in two-dimensional materials.