A Fully Solution‐Printed Photosynaptic Transistor Array with Ultralow Energy Consumption for Artificial‐Vision Neural Networks

Abstract

Photosynaptic organic field‐effect transistors (OFETs) represent a viable pathway to develop bionic optoelectronics. However, the high operating voltage and current of traditional photosynaptic OFETs lead to huge energy consumption greater than that of the real biological synapses, hindering their further development in new‐generation visual prosthetics and artificial perception systems. Here, a fully solution‐printed photosynaptic OFET (FSP‐OFET) with substantial energy consumption reduction is reported, where a source Schottky barrier is introduced to regulate charge‐carrier injection, and which operates with a fundamentally different mechanism from traditional devices. The FSP‐OFET not only significantly lowers the working voltage and current but also provides extraordinary neuromorphic light‐perception capabilities. Consequently, the FSP‐OFET successfully emulates visual nervous responses to external light stimuli with ultralow energy consumption of 0.07–34 fJ per spike in short‐term plasticity and 0.41–19.87 fJ per spike in long‐term plasticity, both approaching the energy efficiency of biological synapses (1–100 fJ). Moreover, an artificial optic‐neural network made from an 8 × 8 FSP‐OFET array on a flexible substrate shows excellent image recognition and reinforcement abilities at a low energy cost. The designed FSP‐OFET offers an opportunity to realize photonic neuromorphic functionality with extremely low energy consumption dissipation.

Optical synaptic devices with ultra-low power consumption for neuromorphic computing

“…Similar to synapses in human brain, artificial synapses are considered as core components in constructing braininspired neuromorphic computing and play significant role in transmitting signals between synaptic neurons [7][8][9] . Up to now, different artificial synapse prototypes have been successfully constructed based on organic materials [10][11][12] , perovskites 13,14 and low-dimensional materials 15,16 . Most of the reported works are focused on electrically stimulated synapses that are trained by electrical signals and thus endowed with learning and cognitive functions 5,9,17,18 .…”

Multifunctional Organic Vertical Photodiodes for Photo‐Detection and Photo‐Synapse Enabled by Modulation of the Interface Energy Barrier

“…To the best of our knowledge, this is also the first vertical photodiode types-based OPS. [25][26][27][28][29] The two distinct optoelectronic functions can be readily switched by only changing the polarity of the external bias. Under negative bias, the optoelectronic devices operated as OPD mode with ultralow dark current density of 8.55 nA cm −2 at −2 V, which exhibited superior shot-noise-limited specific detectivity ( D sh * ) of 6.8 × 10 13 Jones at 880 nm and large linear dynamic range (LDR) of 188 dB at 915 nm.…”

Intrinsically stretchable photonic synaptic transistors for retina-like visual image systems

“…The optical signals are accepted by the retina, which completes the conversion between optical signals and electrical signals, ultimately transported to the visual center of the brain to form the sense of sight. [31][32][33] The retina as the acceptor of the external visible signals plays a key role, no matter whether our eyes are still or in movement tracking a dynamic object in real-time. The image of a flying butterfly can be accepted clearly on the retina, mainly thanks to the adjustment of the ciliary ligament which can drive the retina to deform.…”