Large-Area Growth of Two-Dimensional Rhenium Disulfide Depicting Robust Artificial Photoreceptor-cum-Optic Nerve Synaptic Functionality

Abstract

The impact of artificial vision is surging all around, starting from automotive industries to neuromorphic computing, and it needs both software and hardware platforms. Despite massive progress through software-based simulations for artificial vision systems, hardware implementation still needs to catch up due to the material processing and device fabrication complexity. Here, we demonstrated a very simple two-terminal planar photodetector device to mimic functions of photoreceptors similar to the retina followed by potentiation of optic nerve synapse using a chemical vapor deposition (CVD)-grown two-dimensional rhenium disulfide (2D ReS2) monolayer film. First, large-area 2D ReS2 monolayer growth facilitated through organic seeding promoted the chemical vapor deposition route. The direct band gap of 1.5 eV and Peierls distorted 1T crystalline phase of ReS2 were identified from the Tauc plot analysis and transmission electron microscopy results. Then, the photodetection property and photoreceptor functionality were measured after depositing interdigitated palladium electrodes. Raman scattering and temporal photoresponse confirm that the oxide-interface-induced photogating effect plays a significant role in such functionalities. Photomodulated visual nervous system-related basic functions, including excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), and the simplest Atkinson–Shiffrin memory model, are verified efficiently even at elevated temperatures. Overall, this work can lead to an innovative research direction toward developing atomically thick photonic devices, which would be an innovative technology for artificial intelligence (AI), machine learning (ML), and optogenetics in the future.