A Light‐Programmed Rewritable Lattice‐Mediated Multistate Memory for High‐Density Data Storage

Abstract

Mainstream non‐volatile memory (NVM) devices based on floating gate structures or phase‐change/ferroelectric materials face inherent limitations that compromise their suitability for long‐term data storage. To address this challenge, a novel memory device based on light‐programmed lattice engineering of thin rhenium disulfide (ReS2 ) flakes is proposed. By inducing sulfur vacancies in the ReS2 channel through light illumination, the device's electrical conductivity is modified accordingly and multiple conductance states for data storage therefore are generated. The device exhibits more than 128 distinct states with linearly increasing conductance, corresponding to a sevenfold increase in storage density. Through further optimization to achieve atomic‐level precision in defect creation, it is possible to achieve even higher storage densities. These states are extremely stable in vacuum or inert ambient showing long retention of >10 years, while they can be erased upon exposure to the air. The ReS2 memory device can maintain its stability over multiple program‐erase operation cycles and shows superior wavelength discrimination capability for incident light in the range of 405–785 nm. This device represents a significant contribution to NVM technology by offering the ability to store information in multistate memory and enabling filter‐free color image recorder applications.

Ultrafast Non‐Volatile Floating‐Gate Memory Based on All‐2D Materials

“…Since 2D materials have good photon absorption and light response, [ 52–54 ] the floating gate memory device can also be programmed/erased by a laser pulse in addition to electrical operations to construct multibit optoelectronic memories. [ 39,43,44,49,55–64 ] Figure a,b shows schematic band diagrams for the principles of electrical and optical operations. When a positive V CG, pulse is applied, electrons tunnel into floating MLG while holes are blocked due to the curved energy band diagram of the tunneling hBN.…”

Integration of Ultrathin Hafnium Oxide with a Clean van der Waals Interface for Two-Dimensional Sandwich Heterostructure Electronics

“…The integration of high-κ HfO x on MoS 2 has been demonstrated by oxidizing an HfS 2 layer using ozone, showing promise as a 2D-compatible dielectric with a vdW interface and a low subthreshold swing (SS) of 63.1 mV/decade . Nevertheless, the challenge lies in integrating HfO x within sandwich vdW heterostructures, which is necessary for designing diverse electronic architectures, whereas ozone treatment is valid for only the surface and may cause defects in typical 2D semiconductors. , …”

“…30 Nevertheless, the challenge lies in integrating HfO x within sandwich vdW heterostructures, which is necessary for designing diverse electronic architectures, whereas ozone treatment is valid for only the surface and may cause defects in typical 2D semiconductors. 31,32 In this work, we report the integration of ultrathin high-κ HfO x with high interface quality within vdW heterostructures, which is achieved by selective thermal oxidation of the HfSe 2 precursor at a low temperature while preserving the crystallinity of other 2D materials. A spontaneous self-cleaning process efficiently eliminates the oxidation byproducts, i.e., the anionic element blisters, from the vdW heterostructure.…”

Modulating the ferroelectric phases in cholesteryl-based organic compounds with perfluoroalkyl tail engineering

“…Ferroelectric materials that possess robust spontaneous electrical polarization have attracted widespread attention for their rich physical properties, including piezoelectricity, 1–4 pyroelectricity, 5–7 and second harmonic nonlinear optics. 8–11 These functional materials have been applied in various fields such as data storage, 12,13 energy conversion, 14 and ultrasonic sensing. 15 To date, the research on ferroelectricity mainly focuses on inorganic oxides.…”