Weak Light-Stimulated Synaptic Hybrid Phototransistors Based on Islandlike Perovskite Films Prepared by Spin Coating

Abstract

An artificial synaptic device that can provide color discrimination, image storage, and image recognition is highly required to mimic the human vision for biological robots. All-inorganic halide perovskites have attracted extensive attention for the reason of their high stability and favorable photoelectric properties. In this study, a light-stimulated synaptic phototransistor based on a CsPbBr 3 /organic semiconductor hybrid film is reported. The fabricated CsPbBr 3 film exhibits an island structure, which reduces the hysteresis effectively and at the same time achieves a high specific detectivity of up to 2 × 10 15 Jones. The decay of the photocurrent can be delayed by changing the gate bias, which is essential for achieving high-performance light-stimulated synaptic devices. Due to the outstanding detectivity of the device, the obvious synaptic functions can be observed when triggered by a light signal with a power of 1.6 nW that is much weaker than previous most perovskite-based hybrid synaptic phototransistors under a low operating voltage of −1 V. The electrical power consumption of the device could be as low as 0.076 pJ when the power of light spike was 7.36 nW. Taking into account this characterization, with changing of light intensity or wavelength, the contrast of the image was enlarged, which can further promote the image recognition accuracy. More significantly, this CsPbBr 3 /TIPS hybrid film can be fabricated by facile and low-cost solution processes. This study indicates the great potential of solution-processed perovskite-based light-stimulated synapses for future artificial visual systems.

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

“…Figure 3e compares operation voltage (V DS ) and E under ms time scales (the details could be found in Table S1, Supporting Information). Our FSP-OFET exhibits the lowest operation voltage of −0.1 V, which is much smaller than the previously reported photosynaptic OFETs [3,9,14,19,22,39] and also lower than the photosynaptic transistors based on inorganic semiconductors, such as 2D materials, [20,37,[40][41][42] metal oxide, [43] and carbon nanotube. [1,32] More importantly, the energy consumption for our FSP-OFET approaches biological synapses and the minimum value of 0.07 fJ is four orders of magnitude lower than that of conventional photosynaptic OFETs.…”

Light‐Stimulated Synaptic Transistor with High PPF Feature for Artificial Visual Perception System Application

“…In addition, optoelectronic synaptic devices that integrate multiple functions into a single chip are greatly reducing the complexity of visual circuits and improving the speed of image processing. [ 18,19 ]…”

“…In addition, optoelectronic synaptic devices that integrate multiple functions into a single chip are greatly reducing the complexity of visual circuits and improving the speed of image processing. [18,19] functions, such as short-term plasticity (STP), long-term potentiation (LTP), long-term depression (LTD), and the short-term memory (STM) transitions to long-term memory (LTM) have been achieved by LSST. And real-time sensing and storage functions of visual perception system were successfully demonstrated utilizing a 2 × 2 imaging chip prepared by our LSST devices, in which the imaging chip also showing the dynamic learning and forgetting process similar to human brain.…”

A Review on Solution-Processed Organic Phototransistors and Their Recent Developments

“…Changes in synaptic, also known as synaptic plasticity weight, is regarded as a change in source-drain output current [149]. A hybrid synaptic phototransistor was designed by using solution-processed perovskite CsPbBr 3 / 6,13-bis(triisopropylsilylethynyl) TIPS in a BGTC configuration [173]. CsPbBr 3 , the light absorption layer, was spin coated, and TIPS, conducting layer was deposited by drop-casting.…”