Monolithically-Fabricated All-2D PdSe₂ Bendable Arrays With Seamless Interfaces for Multifunctional...

The ongoing miniaturization of electronic devices toward the sub-nanometer node requires alternative material systems and process strategies to overcome complicated challenges such as contact/interface resistance and mechanical rigidity inherent in prevailing silicon technologies. To this end, mechanically compliant all-two-dimensional (2D) optoelectronic platforms are developed using monolithically fabricated palladium diselenide (PdSe₂) layers. Wafer-scale 2D PdSe₂ layers directly synthesized on flexible polyimide (PI) at a low temperature of 330°C exhibit thickness-modulated transport distinctions, i.e., semiconducting (∼3 nm thick) vs. metallic (∼15 nm thick). This intrinsic dimensional tunability enables the seamless formation of 2D/2D channel/electrode interfaces in a patterned array, thereby eliminating issues associated with conventional 3D metal contacts. Here, uniquely structured flexible all-2D device arrays are explored for cutting-edge flexo-opto-electronic applications. Specifically, a comprehensive set of optically modulated and strain-invariant synaptic characteristics is demonstrated, suggesting unprecedented opportunities for mechanically deformable neuromorphic computing. Furthermore, introducing anisotropic strains into all-2D arrays enables flexoelectricity-driven current modulation, manifested as bending-orientation-dependent transport directionality and reversibility. Conclusively, this study establishes 2D PdSe₂ layers and their associated processability as a highly scalable and multifunctional system, offering a promising route toward emerging mechanically adaptive device technologies.