Optoelectronic synaptic devices, which combine the functions of photosensitivity and information processing, are essential for the development of artificial visual perception systems. Nevertheless, improving the paired pulse facilitation (PPF) index of optoelectronic synaptic devices, which is an urgent problem in the construction of high‐precision artificial visual perception systems, has received less attention so far. Herein, a light‐stimulated synaptic transistor (LSST) device with an ultra‐high PPF index (≈196%) is presented by introducing an ultra‐thin carrier regulator layer hexagonal boron nitride (h‐BN) into a classic graphene‐based hybrid transistor frame (graphene/CsPbBr3 quantum dots). Crucially, analysis of the rate‐limiting effect of h‐BN on photogenerated carriers reveals the mechanism behind the LSST ultra‐high PPF index. Furthermore, a two‐layer artificial neural network connected by LSST devices demonstrate ≈91.5% recognition accuracy of handwritten digits. This work provides an effective method for constructing artificial visual perception systems using a hybrid transistor frame in the future.

Light‐Stimulated Synaptic Transistors Optoelectronic synaptic devices with a high paired pulse facilitation index are essential for constructing high‐precision artificial visual perception systems. In article number 2113053, Jun Wang and co‐workers develop a light‐stimulated synaptic transistor with an ultra‐high PPF index (≈196%) by introducing hexagonal boron nitride into a classic graphene‐based hybrid transistor framework, which provides an effective method for constructing artificial visual perception systems in the future.

Three dimensional topological insulators have a thriving application prospect in broadband photodetectors due to the possessed topological quantum states. Herein, a large area and uniform topological insulator bismuth telluride (Bi 2 Te 3 ) layer with high crystalline quality is directly epitaxial grown on GaAs(111)B wafer using a molecular beam epitaxy process, ensuring efficient out-of-plane carriers transportation due to reduced interface defects influence. By tiling monolayer graphene (Gr) on the as-prepared Bi 2 Te 3 layer, a Gr/Bi 2 Te 3 / GaAs heterojunction array prototype was further fabricated, and our photodetector array exhibited the capability of sensing ultrabroad photodetection wavebands from visible (405 nm) to mid-infrared (4.5 μm) with a high specific detectivity (D*) up to 10 12 Jones and a fast response speed at about microseconds at room temperature. The enhanced device performance can be attributed to enhanced light−matter interaction at the high-quality heterointerface of Bi 2 Te 3 /GaAs and improved carrier collection efficiency through graphene as a charge collection medium, indicating an application prospect of topological insulator Bi 2 Te 3 for fast-speed broadband photodetection up to a mid-infrared waveband. This work demonstrated the potential of integrated topological quantum materials with a conventional functional substrate to fabricate the next generation of broadband photodetection devices for uncooled focal plane array or infrared communication systems in future.

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Although germanium-and silicon-based detectors have been commercialized for NIR photodetection, [4,5] their response speeds and sensitivities still have potential for improvement. It has also been reported that 2D materials have great potential for application in low-cost, room temperature, and large-area visible-near-infrared (VIS-NIR) photodetection applications owing to their excellent optical and electronic properties, [6][7][8][9][10][11][12] and various VIS-NIR photodetectors based on 2D materials have been reported. For example, graphene has been demonstrated to exhibit a rapid photoresponse; however, its lack of a bandgap, low light absorption properties, and low intrinsic sensitivity hinder its potential applications in VIS-NIR detection. [13,14] As alternatives, transition metal dichalcogenides (TMDs) exhibit large bandgaps for infrared detection, [15,16] and black phosphorus (BP) exhibits a good performance in infrared photodetection owing to its suitable bandgap and fast carrier mobility; [17,18] however, the latter suffers from a poor air stability. Furthermore, despite the fact that heterostructure photodetectors have been shown to exhibit high performances, they require complex transfer processing. [19][20][21] Considering the above systems, it is therefore apparent that the development of suitable VIS-NIR-responsive materials would be highly attractive.In this context, Bi 2 O 2 Se has recently attracted increasing attention because of its suitable electronic bandgap (≈0.8 eV), high carrier mobility (≈450 cm 2 V −1 s −1 at 300 K), excellent air stability, high conductivity, and environmental non-toxicity, which render it an ideal candidate for VIS-NIR detection. [22][23][24][25][26][27][28] However, its high carrier concentration leads to a large dark current in detectors based on Bi 2 O 2 Se nanosheets, which restricts any further performance improvement being achieved. To address this issue, previous studies have examined the use of gate voltage regulation [29,30] and heterostructure construction. [31][32][33] However, the application of extremely high gate voltages increases the power consumption of the device, and the construction of heterostructures often requires complex transfer processes. In addition, the reported Bi 2 O 2 Se photodetectors tend to show poor response speeds in the NIR waveband (i.e., tens of milliseconds), which limits their application in high-speed detection. [27,34] Owing to its suitable electronic bandgap, excellent air stability, and high carrier mobility at room temperature, low-dimensional bismuth oxyselenide (Bi 2 O 2 Se) has become attractive in the context of visible-near-infrared (VIS-NIR) detection. However, the high carrier concentration and bolometric effect of Bi 2 O 2 Se nanosheets are not conducive to reducing the dark current and improving the response speed, which hinders Bi 2 O 2 Se nanosheet-based photodetectors from achieving an optimal performance. In this study, a Bi 2 O 2 Se nanoribbon is controllably synthesized on a fluorophlogopite substrate by m...