Abstract
Optical memory integrates the function of optical sensing in memory devices,remarkably pro-moting the interconnection between sensory and memory terminals.Silicon charge-coupled photodetectors and floating gate memory have been widely used in imaging and storage technologies,respectively.However,the heterogeneous integration of the two devices requires technological innovation and complex electrical con-nections.In this work,we adopt a three-dimensional layer stacking method to design a novel optical memory device.On the top of Si charge-coupled photodetectors,we successively deposit two-dimensional graphene,hexagonal boron nitride,and molybdenum disulfide as a floating gate layer,a tunneling layer,and a readout layer,respectively.By applying a gate bias on lightly doped Si,a deep depletion layer is formed with a high voltage potential drop.Under dark conditions,the depletion layer cannot be filled,and the electric field across the h-BN tunnel barrier is relatively small.Under light irradiation,the deep depletion layer is gradu-ally filled,and the h-BN tunneling layer withstands the increasing electric field,resulting in charge storage in the floating gate layer.Based on this mechanism,the device exhibits a gate voltage-dependent operation mode,including an integrated optical sensing-memory mode and an electrically driven storage mode.Under moderate gate voltage,the device can effectively detect the optical information with varied intensity and store the optical information in the floating gate,displaying optically controlled memory characteristics.Our work demonstrates a compact device structure for optical memory and displays excellent optically controlled memory performance,which can be applied in artificial vision systems.
基金项目
National Natural Science Foundation of China(62090034)
National Natural Science Foundation of China(62104214)
National Natural Science Foundation of China(62261160574)
National Natural Science Foundation of China(62090030)
National Key R&D Program of China(2022YFA1204303)
Young Elite Scientists Sponsorship Program by CAST(2021QNRC001)
Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education,Jianghan University(JDGD-202202)
Kun-Peng Program of Zhejiang Province()
ZJU Micro-Nano Fabrication Center()
ZJU-Hangzhou Global Scientific and Technological Innovation Center()
NETL
NSTL
万方数据