Recent Progress of Optoelectronic and All‐Optical Neuromorphic Devices: A Comprehensive Review of Device Structures, Materials, and Applications

Abstract

Figure 6. a) Schematics showing the concept of Pavlov's dog experiment using the neuromorphic devices and the device structure of a CdS/ZTO-based optoelectronic synaptic device. Here, the optical and electrical stimuli correspond to the conditioned (bell ringing) and unconditioned (food feeding) stimuli, respectively. b-f ) The emulation of Pavlov's dog experiment using various combinations of light stimuli. (a-f ) Reproduced with permission. [51] Copyright 2019, Elsevier B.V. g) The structure of a BP-based synapse device and a multineural system using two different light sources. h) The PSC variation depending on the time difference between two light inputs. i) The PSC variation under a single and a pair of light stimuli with a time difference. j) Schematic of the device layout to emulate the STDP behavior. k) The PSC variation depending on the time difference of pre-/postsynaptic pulses. (g-k) Reproduced with permission. [112] Copyright 2019, Wiley-VCH. l) The PSC variations under voltage and optical pulses that correspond to bell ringing and feeding food, respectively. m) The demonstration of Pavlov's dog experiment. (l,m) Reproduced with permission. [113] Copyright 2018, Wiley-VCH.

Emerging Optical In‐Memory Computing Sensor Synapses Based on Low‐Dimensional Nanomaterials for Neuromorphic Networks

“…[ 8–14 ] It is critical and meaningful to investigate the imitation of biological synapses by emerging electronic devices with the IMC technique due to the requirement of lower energy consumption, higher data storage density, and faster operating speed. [ 8,10,15–20 ] The biomimetic device with similar advantages has been named an “artificial synaptic device.” The input information induced by consecutive stimuli is stored in the functional layers of these devices as a form of electric signal and processed by continuous synaptic weight updates, which indicates that it is feasible and promising to explore allowing the computing capability to electronic devices with the long‐term memorizing behaviors by IMC techniques. Current IMC synaptic devices (three‐terminal transistor, two‐terminal memristor, and atomic switch) represented by the popular nonvolatile memory (NVM) are significantly affected by the purely electronic control, which has an important influence on electrical input/output, delay of resistance–capacitance (RC) interconnection, and circuit crosstalk.…”

“…Current IMC synaptic devices (three‐terminal transistor, two‐terminal memristor, and atomic switch) represented by the popular nonvolatile memory (NVM) are significantly affected by the purely electronic control, which has an important influence on electrical input/output, delay of resistance–capacitance (RC) interconnection, and circuit crosstalk. [ 8–11,19,21–27 ]…”

“…Due to neurons (≈10 11 ) and synapses (≈10 15 ), the human brain can handle massive information in ultrashort time with extremely low energy consumption. [ 8–14 ] It is critical and meaningful to investigate the imitation of biological synapses by emerging electronic devices with the IMC technique due to the requirement of lower energy consumption, higher data storage density, and faster operating speed. [ 8,10,15–20 ] The biomimetic device with similar advantages has been named an “artificial synaptic device.” The input information induced by consecutive stimuli is stored in the functional layers of these devices as a form of electric signal and processed by continuous synaptic weight updates, which indicates that it is feasible and promising to explore allowing the computing capability to electronic devices with the long‐term memorizing behaviors by IMC techniques.…”

Recent Advances in Organic Phototransistors: Nonvolatile Memory, Artificial Synapses, and Photodetectors

“…Furthermore, synapses triggered by light pulses have unique advantages in terms of high bandwidth and interference immunity. [ 123 ] Therefore, the development of photonic neuromorphic synapses represents a potential avenue to breaking the von Neumann bottleneck in photocommunication. The basic structure of a photosynaptic transistor is similar to that of a biological synapse, with source/drain electrodes corresponding to pre‐/postsynapses and light pulses corresponding to the action potentials applied presynapse.…”

“…In this section, we introduce photosynaptic devices with the following constituent materials: PVSK NCs, photoactive molecules, organic semiconductors, inorganic semiconductors owing to their respectable photoresponsivity and carrier mobility, and other material developments including metal NPs, ferroelectric gate, and gel electrolyte can be seen in other review literatures. [ 121–123 ]…”