Wafer-Scale Tellurium Nanotube Meshes for Optically Modulated and Mechanically Flexible Artificial Synapses

Tellurium (Te) nanotube (NT) meshes fabricated via a scalable low-temperature chemical vapor deposition (CVD) process are being explored for flexible optoelectronic synapse applications. Centimeter-scale meshes composed of highly networked single-crystalline individual Te nanorods are directly grown on polymeric substrates at a low temperature of 350 °C. The Te NT meshes exhibit p-type semiconducting behaviors accompanied by an optical bandgap of ∼0.48 eV coupled with an excellent mechanical deformability. Flexible devices incorporating these materials yield intriguing characteristics essential for optoelectronic artificial synapses, i.e., bending-invariant photoresponsiveness, optical pulse-induced potentiation, and electrical pulse-induced depression. Such features enable the simulation of various biologically inspired synaptic functionalities, including short- and long-term plasticity and paired-pulse facilitation (PPF), as well as demonstrations of Pavlovian associative learning and visual perception emulation. This work addresses key challenges in establishing scalable manufacturing for mechanically reconfigurable and functionally versatile platforms toward emerging neuromorphic applications.