Neuromorphic Devices Based On Molybdenum Disulfide

Due to excellent optical,electrical,electrochemical,and mechanical properties,transition metal sulfides have always been a hot spot in the research field,and therefore have been widely studied.Molybdenum disulfide,a representative material of transition metal sulfides,has been widely used in field-effect transistor research due to its interesting electronic and optical properties.This paper studies the biosynaptic simulation and neuromorphic computation based on molybdenum disulfide-based transistors.The main work and production of the paper are as follows:1.We designed a dual-gated MoS₂ transistor to realize synaptic functions and programmable logic operations.The channel conductance was modulated via top electrolyte gating to mimic important synaptic functions,such as excitatory postsynaptic current(EPSC),paired-pulse facilitation(PPF),and spike-timing dependent plasticity(STDP).The synaptic transistor exhibits ultra-low energy consumption with 12.7 f J.Furthermore,the MoS₂ transistor can dynamically reconfigure the logic operations of“AND”,“OR”,and“NOT”by combining top electrolyte gating with back gating.Classical Pavlov's dog experiment can be simulated by the dual gated device.These results indicate that the proposed synaptic transistor has potential applications in realizing neuromorphic and programmable logic devices.2.We present a neuromorphic vision sensor with an optoelectronic transistor structure consisting of monolayer molybdenum disulfide and barium titanate ferroelectric film.Beyond conventional electrical tuning of ferroelectric polarization,the optoelectronic transistor can exhibit a light-dosage tunable synaptic behavior with a high switching ratio and good non-volatility,enabled by photo-induced ferroelectric polarization reversal.The wavelength-dependent optical sensing and multi-level optical memory properties are utilized to achieve the in-sensor neuromorphic visual pre-processing.A simulated artificial neural network built from the proposed vision sensors with neuromorphic pre-processing function demonstrated that the image recognition rate could be significantly improved by reducing redundant data.The obtained results suggest that 2D semiconductor/ferroelectric optoelectronic transistors can provide a new possibilities towards constructing high-performance neuromorphic visual systems.