Improved Optical Uniformity of WSe ₂ /WS ₂ Moiré Superlattices Grown on hBN toward Quantum Photonics

High Resolution Image Download MS PowerPoint Slide Chemical vapor deposition growth offers advantages for producing large-area moiré superlattices with controlled lattice alignment. However, the use of conventional SiO 2 /Si substrates often induces inhomogeneous lattice strain that obscures their optical properties. In this work, we report the improved uniformity of WSe 2 /WS 2 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 WSe 2 /WS 2 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.