Laser‐Assisted Multilevel Non‐Volatile Memory Device Based on 2D van‐der‐Waals Few‐Layer‐ReS<sub>2</sub>/h‐BN/Graphene Heterostructures
Bablu Mukherjee, Amir Zulkefli, Kenji Watanabe, Takashi Taniguchi, Yutaka Wakayama, Shu Nakaharai
Abstract
Abstract Few‐layer rhenium disulfide (ReS 2 ) field‐effect transistors with a local floating gate (FG) of monolayer graphene separated by a thin hexagonal boron nitride tunnel layer for application to a non‐volatile memory (NVM) device are designed and investigated. FG‐NVM devices based on two‐dimensional van‐der‐Waals heterostructures have been recently studied as important components to realize digital electronics and multifunctional memory applications. Direct bandgap multilayer ReS 2 satisfies various requirements as a channel material for electronic devices as well as being a strong light‐absorbing layer, which makes it possible to realize light‐assisted optoelectronic applications. The NVM operation with a high ON/OFF current ratio, a large memory window, good endurance (>1000 cycles), and stable retention (>10 4 s) are observed. The successive program and erase states using 10 ms gate pulses of +10 V and −10 V are demonstrated, respectively. Laser pulses along with electrostatic gate pulses provide multibit level memory access via opto‐electrostatic coupling. The devices exhibit the dual functionality of a conventional electronic memory and can store laser‐pulse excited signal information for future all‐optical logic and quantum information processing.