Short‐Wave Infrared Synaptic Phototransistor with Ambient Light Adaptability for Flexible Artificial Night Visual System

Abstract

Flexible organic monitoring system that can work in short-wave infrared (SIR) region has great potential in autonomous driving, night driving safety, military encryption, biomedical imaging, and robot engineering. Especially, the development of infrared artificial vision system device that can autonomously improve the computing speed and adapt to different brightness ambient light is very important. However, it is a challenge for mimicking infrared visual adaptation because of the need for infrared absorbing materials and the need to control the concentration of carriers. In this study, inorganic quantum dot material is combined with organic materials to promote carrier separation and introduce interface defects that adjust the carrier concentration in transistors, which induce the synaptic behavior under SIR (1100 nm) light in darkness and the ability to adapt to white ambient light. Furthermore, the device array realizes the image recognition of SIR light at night with white ambient light of different brightness, exhibiting good self-adaptability, and strong antiinterference ability. These results demonstrate promising applications of the infrared synaptic phototransistors in adapted bionic optoelectronic devices.

Retina‐Inspired Artificial Synapses with Ultraviolet to Near‐Infrared Broadband Responses for Energy‐Efficient Neuromorphic Visual Systems

“…[18][19][20] To realize the high-efficiency data processing and utilize the superiority of the human visual system, retina-inspired optoelectronic synaptic transistors that integrate visual perception, processing, and memorization functionalities into one single device have become a type of promising candidate for constructing neuromorphic visual systems. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Besides, the three-terminal architecture enables such devices to achieve accelerating signal processing function utilizing the gateadjustable plasticity compared with two-terminal synaptic devices. [37][38][39][40] Although currently reported optoelectronic synaptic transistors have also presented the capability of signal preprocessing, most of them respond to the photonic stimulation with specific wavelengths or limited wavelength range, and neglect the effect of gate voltage on data preprocessing.…”

Emerging photoelectric devices for neuromorphic vision applications: principles, developments, and outlooks

“…However, the emulation of infrared vision adaptation is a challenge. Recently, the organic/inorganic infrared optoelectronic heterojunction transistor proposed by Huang et al [ 200 ] has successfully emulated adaptation to ambient light. The device array can achieve image recognition of infrared light under ambient light of different luminance.…”

Organic All-Photonic Artificial Synapses Enabled by Anti-Stokes Photoluminescence

“…Organic artificial synapses are promising technologies for future neuromorphic electronics due to their advantages of easily tunable physicochemical properties, high compatibility with solution processes, low energy consumption, and mechanical flexibility/stretchability with a low elastic modulus. − However, electrical synapses inevitably require extra electrical consumption, although many efforts have been made to reduce their driving voltages. − Also, it is hard to achieve noncontact information reading and writing in electrical and optoelectrical devices . To solve these problems, all-photonic synaptic devices based on various inorganic materials were developed upon modulating their transmittance or afterglow properties under irradiation, of which input and output signals are both of optical quantity. − To the best of our knowledge, organic all-photonic synapses have never been reported.…”