Chemical vapor deposition growth offers advantages for producing large-area moiré superlattices with controlled lattice alignment. However, the use of conventional SiO2/Si substrates often induces inhomogeneous lattice strain that obscures their optical properties. In this work, we report the improved uniformity of WSe2/WS2 moiré superlattices directly grown on hexagonal boron nitride (hBN). The hBN-supported samples exhibit well-ordered moiré structures as confirmed by transmission electron microscopy. At low temperatures, they show interlayer exciton peaks that are highly sensitive to excitation power, with a blueshift rate of ∼120 meV/μW, nearly 2 orders of magnitude larger than previously reported. This pronounced shift indicates the enhanced repulsive dipolar interaction of interlayer excitons confined in the moiré potential of WSe2/WS2 heterobilayers, enabled by the reduction of inhomogeneous strain and interlayer disorder on hBN. These results highlight the potential of directly grown moiré superlattices on hBN for quantum dot arrays, offering a route toward quantum photonics.
Tamogami et al. (2026) studied this question.