Laser‐Assisted Multilevel Non‐Volatile Memory Device Based on 2D van‐der‐Waals Few‐Layer‐ReS₂/h‐BN/Graphene Heterostructures

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 lightabsorbing 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.

ReS2/h‐BN/Graphene Heterostructure Based Multifunctional Devices: Tunneling Diodes, FETs, Logic Gates, and Memory

“…Here, the Gr layer was found to be initially hole doped from the absorption of oxygen and/or water molecules from the air. [ 25 ] Typical I–V characteristics of fabricated diodes show that all the MIS‐type diodes exhibited a highly rectifying feature (Figure 2b). Room temperature output characteristics with different bias voltages are shown in Figure S1, Supporting Information, where electron accumulation and hole inversion in the ReS 2 layer are clearly observed.…”

“…The details of NVM operation with extended multilevel operation under laser excitation with a similar device structure have been reported elsewhere. [ 25 ] Here, we achieved NVM operation under a moderate electric field with a +/– 10 V gate bias, which can be further reduced if we use high quality h‐BN as the dielectric layer for the control gate ( p ++ Si) instead of using a SiO 2 dielectric layer. For an all 2D‐material‐based NVM device with low gate bias operation, the FG‐Gr can be isolated by both a top h‐BN (≈6–10 nm thick) and a bottom h‐BN (≈30–40 nm thick) subsequently insulated with another bottom Gr as a control gate electrode.…”

“…Recently, we have developed a laser-assisted non-volatile memory device for multi-level storage applications using a heterostructure consisting of various 2D materials. 25 A similar heterostructure device can be used for logic gate device applications, which further expands the possibilities to multi-functional device applications.…”

“…Recently, we have developed a laser‐assisted NVM device for multi‐level storage applications using a heterostructure consisting of various 2D materials. [ 25 ] A similar heterostructure device can be used for logic gate device applications, which further expands the possibilities to multi‐functional device applications. Quantum tunneling phenomena can be incorporated in a designed heterostructure in order to obtain almost temperature independent operation in the fabricated diodes.…”

Single‐Crystalline Silicon Frameworks: A New Platform for Transparent Flexible Optoelectronics

“…With the behavior of operation at zero bias voltage and the excellent photo response, sc‐SiF‐based devices can be applied in self‐powered electronics and digital electronics. [ 59–61 ] These devices also show great potential for integrated optoelectronic applications. Multi‐band photodetecting systems were successfully achieved by integrating sc‐SiF‐based TFPDs with commercial IR or UV photodetectors.…”