Ultralow Light‐Power Consuming Photonic Synapses Based on Ultrasensitive Perovskite/Indium‐Gallium‐Zinc‐Oxide Heterojunction Phototransistors

Abstract

The brain‐inspired neuromorphic parallel computing has become one of the most promising technologies for efficient information processing by overcoming the von Neumann bottleneck of sequential operations. Synapses transmit information among neurons and act as the basic component in neuromorphic computing platforms. Despite the rapid advances in developing artificial synapses, most synaptic devices function electronically and thus numerous merits for photonics such as visual/imaging information processing, less corsstalk, and fast response, have to be compromised. Herein, a light‐stimulated synaptic device (photonic synapses) based on perovskite/In‐Ga‐Zn‐O heterojunction phototransistor is reported. The combination of high‐efficiency light absorber, high‐mobility channel, and heterojunction device architecture leads to efficient photon‐to‐electron conversion and intrinsic high‐gain mechanism for such light‐stimulated synapses. As a result, high performance photonic synapses are obtained with the basic functions of excitatory postsynaptic current (EPSC), paired‐pulse facilitation (PPF), and short‐term memory to long‐term memory conversion (STM‐LTM). Importantly, owing to the ultrasensitive photodetection characteristics, the light power consumption of such photonic artificial synapse can be as low as 2.6 picojoule. This study proposes a simple, efficient, and industry‐compatible device concept providing the photosensitive synapses for photonic neural networks by combining the merits of appropriate materials and device architecture.

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

“…This study is very suitable for imaging processing of the human visual system. In 2022, Cao et al [ 186 ] reported an ultralow light power consuming CsPbI 2 Br perovskite nanocrystal/IGZO heterojunction phototransistor, as shown in Figure 10(c) . The designed heterostructure well combines the advantages of the high mobility channel material of IGZO and the highly efficient photoactive layer of perovskite nanocrystals.…”

Hybrid Interfacial Engineering: An Enabling Strategy for Highly Sensitive and Stable Perovskite Quantum Dots/Organic Heterojunction Phototransistors

“…Phototransistors, as one type of photodetectors that directly convert optical signals into electrical signals, have been widely applied to image sensing, − environmental/health monitoring, − chemical/biomedical sensing, , X-ray detection, , and quantum communication. , Among the various semiconductors used as photoactive materials in the phototransistors, all-inorganic perovskites (CsPbX 3 , X = Cl, Br, and I) quantum dots (PQD) stand out due to the superior optoelectronic properties, such as efficient photon absorption, long carrier diffusion length, intrinsically high mobility, and unprecedented photon-to-electron conversion efficiency, consequently offering a great opportunity to develop high-performance phototransistors. ,− However, despite recent advances, the performance of most reported PQD-based phototransistors needs improvement. This is mainly caused by the low carrier extraction/transport efficiency and large trap-state density of solution-assembled PQD films.…”

Sensitization of ZnO Photoconductivity in the Visible Range by Colloidal Cesium Lead Halide Nanocrystals

“…High performance perovskite-containing photosensitive elements operating in the mode of photodiodes, phototransitors and photoresistors have been demonstrated [ 36 , 37 , 38 , 39 ]. There is also an increasing number of studies considering photoconductive perovskite-containing materials as elements of artificial synapses [ 40 , 41 , 42 , 43 , 44 ]. The published results on the effect of perovskite nanocrystals on the photoconductivity of ZnO mainly concern monohalide perovskites with an organic [ 45 , 46 , 47 , 48 , 49 ] or inorganic cation [ 4 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ], while the use of mixed halide perovskites as sensitizers use is also discussed in the literature [ 44 , 58 , 59 , 60 ], however has not been systematically studied so far.…”