Ultralow Power Optical Synapses Based on MoS₂ Layers by Indium‐Induced Surface Charge Doping for Biomimetic Eyes

Abstract

Biomimetic eyes, with their excellent imaging functions such as large fields of view and low aberrations, have shown great potentials in the fields of visual prostheses and robotics. However, high power consumption and difficulties in device integration severely restrict their rapid development. In this study, an artificial synaptic device consisting of a molybdenum disulfide (MoS2) film coated with an electron injection enhanced indium (In) layer is proposed to increase the channel conductivity and reduce the power consumption. This artificial synaptic device achieves an ultralow power consumption of 68.9 aJ per spike, which is several hundred times lower than those of the optical artificial synapses reported in literature. Furthermore, the multilayer and polycrystalline MoS2 film shows persistent photoconductivity performance, effectively resulting in short‐term plasticity, long‐term plasticity, and their transitions between each other. A 5 × 5 In/MoS2 synaptic device array is constructed into a hemispherical electronic retina, demonstrating its impressive image sensing and learning functions. This research provides a new methodology for effective control of artificial synaptic devices, which have great opportunities used in bionic retinas, robots, and visual prostheses.

A Vis‐SWIR Photonic Synapse with Low Power Consumption Based on WSe2/In2Se3 Ferroelectric Heterostructure

“…Such a low power consumption is due to the p-n junction at the WSe 2 /In 2 Se 3 interface which suppresses the PSC to the level of 10 −11 A. Furthermore, in Figure 6d, we compare the power consumption of the present heterojunction device with that of the reported artificial synaptic devices in the literature [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] including both electrical synaptic devices and photonic synapses. It shows that the power consumption per spike of our WSe 2 /In 2 Se 3 heterostructure synaptic devices is in the lowest class among these synaptic transistors.…”

Bio-Inspired Electronic Eyes and Synaptic Photodetectors for Mobile Artificial Vision

“…An open-mesh design was adopted to release the induced strain effectively during the integration In another example, a hemispherical synaptic PD array with a high energy efficiency was developed by depositing discontinuous indium islands on a hemispherical MoS 2 film [see Fig. 5(e)] [75]. The hemispherical MoS 2 film was grown on a hemispherical quartz substrate; thus, other device design strategies, such as strain-isolation structures or Kirigami device designs, were not required to achieve a curved form factor.…”

Nanostructured Materials and Architectures for Advanced Optoelectronic Synaptic Devices

“…Recently, an artificial synaptic device made of MoS 2 film coated with an electron injection enhanced indium (In) layer has been proposed to increase channel conductivity and reduce power consumption by up to 68.9 FJ per spike, which is hundreds of times lower than that of optoelectronic artificial synapses previously reported in the literature. [61] Such type of design strategies provided a highly effective neural architecture with associative learning activity and diverse types of synaptic plasticity through multimode stimuli including photoactive mood.…”