Signature of lattice dynamics in twisted 2D homo/hetero-bilayers

Abstract Twisted 2D bilayer materials are created by artificial stacking of two monolayer crystal networks with a desired twisting angle θ . The material forms moiré superlattice due to the periodicity both top and bottom layer structure. optical properties modified lattice reconstruction phonon renormalization, which makes spectroscopy an ideal characterization tool study novel physics phenomena. Here, we report Raman investigation on full period twisted (tB) WSe 2 (i.e. 0 ° ⩽ θ 60 ∘ ). We observe that intensity ratio peaks, $B_{2g}$?> B 2 g $E_{2g}/A_{1g}$?> E / A 1 correlates evolution period. as function follows exponential profile matching local maxima at minimum 30 Using series temperature-dependent photoluminescence measurements well ab initio calculations, $I_{B_{2g}}/I_{{E_{2g}}/{A_{1g}}}$?> I is explained signature dynamics in tB superlattices. By further exploring different combinations hetero-bilayers, results extended for all kinds Mo- W-based transition metal dichalcogenides.