On-chip waveguide-integrated light sources using MoS2/WSe2 moiré superlattices on a silicon photonic platform.

Moiré superlattices have been widely explored as a unique platform for investigating exotic physics, but their potential applications in integrated photonics remain unexplored. In this work, we demonstrate a waveguide-integrated light source operating at telecom wavelengths with high temporal coherence, enabled by molybdenum disulfide (MoS2)/tungsten diselenide (WSe2) moiré superlattices coupled to a silicon photonic nanobeam cavity. Our results reveal that, at room temperature, the moiré potential in MoS2/WSe2 superlattices strongly boosts light-emission intensity, extends interlayer-exciton lifetime, and redshifts the emission wavelength. Our demonstrated device shows excellent coherence properties with near-unity interference visibility and a coherence length of about 3.8 millimeters, substantially exceeding the performance of previously reported two-dimensional-material light sources. Moreover, these devices exhibit stable performance under ambient conditions, operating within the fiber communication O-band. This work paves the way for leveraging moiré superlattices as a promising material for photonic integrated circuits, highlighting their potential to enhance light-matter interactions and expand the capabilities of on-chip photonic technologies.