Charge Transfer Dynamics in WS2/NiPS3 Heterostructures

Magnetic van der Waals (vdW) heterostructures (HSs), whose interface engineering enables versatile manipulation of charge and spin transfer, have received considerable interest. However, the dynamics underlying these exotic interfacial phenomena require deeper investigation. In this work, we investigated the interfacial charge transfer dynamics in a HS comprising layered antiferromagnetic NiPS3 and transition metal dichalcogenide WS2. Under resonant excitation of WS2, we observed significant enhancement of the d-d transition in NiPS3, driven by the charge transfer from the WS2 to Ni 3d orbital. Additionally, an anomalous enhancement of trion emission in WS2 was observed, accompanied by a relatively slow (∼23 ps) charge transfer from NiPS3 to WS2, attributed to the localized feature of Ni 3d orbitals. Our findings highlight the unique localization property of the d-orbital in magnetic materials and provide valuable insights into the interfacial dynamics of magnetic vdW HS, which are fundamentally important for designing novel devices.