Quasi-Metallic Electronic Reconstruction at WSe ₂ –Biotite Lateral van der Waals Interfaces

Lateral heterostructures in two-dimensional (2D) materials provide direct access to interfacial electronic reconstruction that cannot be realized in isolated layers. Here, we report the formation of atomically sharp lateral van der Waals heterostructures between monolayer WSe 2 and few-layer biotite, a naturally occurring crystalline silicate, synthesized via chemical vapor deposition. Raman and photoluminescence mapping confirm lateral monolayer continuity of WSe 2 along biotite edges, while Raman peak splitting reveals localized interfacial strain. Kelvin probe force microscopy identifies a pronounced contact potential difference (∼90 meV) across the heterointerface, indicating charge transfer and band bending driven by work-function mismatch. Piezo response force microscopy further highlights the intrinsic electromechanical activity of biotite and its modulation at the interface. Density functional theory calculations elucidate the microscopic origin of these observations, demonstrating interfacial charge redistribution, orbital hybridization, and the emergence of quasi-metallic electronic states confined to the junction. These findings establish crystalline silicate-TMDC lateral heterostructures as a versatile platform for studying coupled electronic and electromechanical interfacial phenomena.