Piezostrain-Driven Bidirectional Enhancement of Optical Synaptic Plasticity in Wafer-Scale Co-Phased Tin Selenide Layers

with distinct functionalities and identify a strong interplay between their mechanical and optoelectrical characteristics. Mechanically, they display a strain-dependent piezoelectricity upon an anisotropic deformation of convex vs concave bending. Optoelectrically, they present an optical pulse-induced potentiation and synaptic plasticity accompanying a wavelength-tunable photoconduction upon visible to near-infrared (IR) illuminations. Harnessing these two independent features in a coupled manner enables a drastic enhancement of their synaptic responsiveness by >40% with a piezostrain of <1%. These findings suggest opportunities for atomically thin semiconductors in mechano-optical neuromorphic device applications.