Electrically Driven Interlayer Excitons in MoSe₂/WSe₂ Heterostructures

Abstract

Heterostructures based on monolayer transition metal chalcogenide (TMD) semiconductors have offered a robust platform for exploring light-matter interactions. The rotational misalignment between two TMDs enables modulation of the electronic band structure through the formation of an in-plane moiré superlattice. Multiple interlayer excitons in TMD heterostructures have been reported under optical excitation, but studies related to optoelectronic devices remain limited. Here, electrically driven multiple interlayer excitons are demonstrated in the transient electroluminescence (EL) of MoSe₂/WSe₂ heterostructures, sandwiched between two layers of hexagonal boron nitride (hBN) and a single graphene. The EL emission from multiple interlayer excitons in the MoSe₂/WSe₂ heterostructures is induced by applying an alternating voltage to a two-terminal device. The EL characteristic of interlayer excitons can be modulated by adjusting gate and pulse parameters, which control charge carrier injection into MoSe₂/WSe₂ heterostructures. Furthermore, distinct recombination processes are reported in MoSe₂/WSe₂ heterostructures with varying hole injection levels. The results provide a foundation for exploiting interlayer excitons in optoelectronic devices based on TMD heterostructures.