Ferroelectric‐Induced Phase Change Device with Polymorphic Mo _1‐x W _x Te ₂ for Neuromorphic Computing

Abstract While phase change devices have emerged as promising candidates for implementing artificial synapses, conventional phase change materials have faced challenges such as high‐power consumption and limited reliability, originating from their Joule heating‐driven phase transition mechanisms. Here, a phase change device based on a 2D material, Mo _0.95 W _0.05 Te ₂ is demonstrated, which exhibits a phase transition between semiconducting 2H and semimetallic 1T’ structural phases, facilitated by a ferroelectric substrate. The structural phase transitions are confirmed by Raman spectroscopy under drain or gate voltage bias. These bias conditions allow two types of operation to be realized in a single device structure, resulting in gate voltage modulation and drain voltage modulation with a ferroelectric substrate. The ferroelectric‐induced phase change device exhibits key synaptic functions, including short‐term and long‐term plasticity, along with highly linear and symmetric multilevel conductance states. Furthermore, polymorphic Mo _0.95 W _0.05 Te ₂ enables energy consumption as low as 5.3 pJ per switching event at monolayer thickness beyond conventional 3D phase change memory. These features highlight the potential of 2D material‐based phase change devices on ferroelectric substrates as energy‐efficient and high‐performance components for next‐generation neuromorphic computing systems.