Fariha's Moiré Superlattice Study Published in Applied Physics Letters

A study led by group member Nurul Fariha Ahmad, co-authored by Dr. Kozawa and collaborators, has been published in Applied Physics Letters. The work examines how photoluminescence emission is spatially organized across a twisted MoSe₂/WSe₂ heterobilayer moiré superlattice.

Using hyperspectral photoluminescence mapping together with peak-decomposition-free spectral analyses, the team revealed a hierarchical spectral inhomogeneity in the emission: distinct features are organized across micrometer-scale domains rather than varying uniformly. The approach avoids the assumptions inherent in fitting individual peaks, offering a more direct view of the spatial structure of moiré-modulated excitonic states in twisted transition metal dichalcogenide heterostructures.

N. F. Ahmad, Y. Urano, K. Watanabe, T. Taniguchi, D. Kozawa, R. Kitaura, Hierarchical spectral inhomogeneity in photoluminescence of a twisted MoSe₂/WSe₂ heterobilayer moiré superlattice revealed by hyperspectral mapping, Applied Physics Letters, 128, 231901 (2026).