2D Materials Based Optoelectronic Memory: Convergence of Electronic Memory and Optical Sensor.

Feichi Zhou,Xiaoming Tao,Xinran Wang,Yang Chai,Jiewei Chen

doi:10.34133/2019/9490413

Feichi Zhou, Xiaoming Tao + Show 3 more

Open Access

https://doi.org/10.34133/2019/9490413

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Abstract

The continuous development of electron devices towards the trend of “More than Moore” requires functional diversification that can collect data (sensors) and store (memories) and process (computing units) information. Considering the large occupation proportion of image data in both data center and edge devices, a device integration with optical sensing and data storage and processing is highly demanded for future energy-efficient and miniaturized electronic system. Two-dimensional (2D) materials and their heterostructures have exhibited broadband photoresponse and high photoresponsivity in the configuration of optical sensors and showed fast switching speed, multi-bit data storage, and large ON/OFF ratio in memory devices. In addition, its ultrathin body thickness and transfer process at low temperature allow 2D materials to be heterogeneously integrated with other existing materials system. In this paper, we overview the state-of-the-art optoelectronic random-access memories (ORAMs) based on 2D materials, as well as ORAM synaptic devices and their applications in neural network and image processing. The ORAM devices potentially enable direct storage/processing of sensory data from external environment. We also provide perspectives on possible directions of other neuromorphic sensor design (e.g., auditory and olfactory) based on 2D materials towards the future smart electronic systems for artificial intelligence.

Highlights

The advance of digital technology enables data storage and processing in binary form with high speed, accuracy and density
The constructed optic-neural network through optoelectronic random-access memories (ORAMs) synaptic devices can potentially simplify the circuitry for neuromorphic image processing and reduce the power consumption during the data transmission
The ORAM synaptic device is integrated with a WSe2/h-BN photodetector and a synaptic device based on WSe2/weight control layer (WCL)/h-BN (Figure 10)

Summary

Introduction

The advance of digital technology enables data storage and processing in binary form with high speed, accuracy and density. As 2D materials have exhibited a broad response from ultraviolet to infrared light with high responsibility or fast response speed, it is possible to integrate the optical sensing and data storage together by rationally designing device structures, which is potential for the various applications, such as image sensors. The visible light pulses induce the photo-generated holes in MoS2 layer, tunneling through the low hole barrier of MoS2/BN and combining with the stored electrons in the graphene layer, and RESET the device to HRS (Figure 7(d)) This operation scheme leads to a high ON/OFF ratio of 106 and over 16 distinct storage levels by tuning the light intensities [47]. In sharp contrast to the conventional photodetector or image sensors, ORAM synaptic devices sense information in ways like neural signals with light-tunable and time-dependent plasticity, implicating the potential application in the construction of neuromorphic visual systems. In contrast to the conventional memory synaptic devices operated by electrical method, the ORAM

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Findings

Conclusions and Perspectives