Electrically Tunable Tunneling and Spectral Response in WSe ₂ /h‐BN/CdSe/Graphene Heterostructure

ABSTRACT Mixed‐dimensional heterostructures consisting of zero‐ and two‐dimensional materials offer a promising platform for optoelectronic devices, as the versatility of material combination allows tunable optical properties. Bias‐induced approaches provide an additional means to tune the optical properties beyond the intrinsic band alignment of van der Waals junctions. Here, bias‐induced tunneling characteristics are achieved in vertically stacked WSe 2 /h‐BN/CdSe quantum dots/graphene heterostructures by employing the top graphene electrode to regulate carrier transport across the h‐BN barrier. The electrical analyses based on the Simmons approximation demonstrate tunneling‐mediated charge transfer through thin h‐BN layers and bias‐dependent modulation of the barrier height. Furthermore, tunneling‐induced exciton dissociation in WSe 2 and CdSe QDs is observed through spectral responsivity and scanning photocurrent measurements. This work establishes a voltage‐dependent tunneling platform that enables deterministic control of carrier dynamics in mixed‐dimensional optoelectronic devices.