Photogeneration of Long‐Lived and High‐Mobility Charge Carriers in Graphene via Doped MoSe₂ Interface

A doping‐based strategy is presented to control interlayer charge transfer in transition metal dichalcogenide/graphene heterostructures. In a system combining monolayer graphene with Nb‐doped MoSe 2 , a built‐in electric field forms at the interface due to ground‐state hole transfer. This field effectively suppresses the transfer of photoexcited holes while allowing electrons to move into the graphene layer, resulting in unipolar electron injection. Transient absorption spectroscopy reveals a prolonged carrier lifetime of approximately 180 picoseconds in the doped heterostructure, compared to only a few picoseconds in the undoped case. Transient absorption microscopy confirms that the transferred carriers exhibit fast in‐plane diffusion in graphene, consistent with high mobility and free carrier transport. This approach enables precise tuning of photocarrier dynamics and provides a general framework for designing van der Waals heterostructures with enhanced optoelectronic performance, suitable for applications such as photodetectors and ultrafast optical devices.