Phonon dynamics in as grown twisted bilayer MoS₂ homojunction and MoS­­₂/WS₂ heterojunction

The van der Waals homojunction and heterojunctions of two-dimensional (2D) materials presents unique properties suitable for diverse electronic and optoelectronic applications. The precise understanding of the interlayer stacking pattern, twisting angle, and coupling is crucial for tuning the properties. Herein, we have investigated the interlayer shearing and low-frequency Raman breathing modes using low temperature Raman spectroscopy on chemical vapor deposition (CVD) grown twisted MoS₂ homojunction. Also, we have studied the phonon dynamics properties in in-situ grown MoS₂/WS₂ heterojunction employing the Raman spectroscopy and density functional theory. Our elementary results pave the way for the understanding of fundamental physics behind the twisted junctions and transport properties of nanoscale devices and photonic devices based on twisted 2D materials.