Controllable Photoluminescence and Photocarrier Dynamics via Ozone Engineering in 2D Heterostructures

Controllable interface engineering is essential for tuning excitonic and photocarrier behavior in two-dimensional van der Waals heterostructures. Here, we investigate the effect of ozone treatment on interfacial coupling in type-II transition metal dichalcogenide (TMD) and type-I WS₂/ozone-irradiated graphene (OI-graphene) heterostructures. Controlled ozone intercalation modulates local charge doping and dielectric screening, enabling reversible tuning of photoluminescence (PL) intensity from quenching to enhancement in type-II TMD heterostructures. This behavior likely arises from partial suppression of interlayer exciton formation by ozone molecules, which can be partially reversed via subsequent laser irradiation. In WS₂/OI-graphene heterostructures, ozone-induced doping reduces interfacial charge transfer efficiency and slows photocarrier diffusion, as revealed by transient absorption and spatially resolved pump-probe measurements. The consistent PL modulation and carrier dynamics observed across these systems suggest a general role of ozone in regulating interfacial electronic interactions. These findings provide quantitative insights into exciton behavior and photocarrier transport, establishing a controllable platform for interface-engineered studies in two-dimensional heterostructures.