Excitonic response in transition metal dichalcogenide heterostructures from first principles: Impact of stacking, twisting, and interlayer distance

The authors use many-body perturbation theory to predict how stacking, twisting, and interlayer distance affect intralayer and interlayer excitons in the transition metal dichalcogenide van der Waals heterostructures MoS₂/WS₂ and MoSe₂/WSe₂. They find ``gray'' excitons, visible only for in-plane detection. Their analysis into the excitonic lifetimes supports the idea of exciton transport for innovative applications in quantum information systems, next-generation electronic devices, photodetectors light-emitting devices, and lasers. Additionally, the authors observe that the misaligned heterostructure shows a unique state with two intralayer excitons degenerate in energy.