Mesoscopic sliding ferroelectricity enabled photovoltaic random access memory for material-level artificial vision system

Abstract

Intelligent materials with adaptive response to external stimulation lay foundation to integrate functional systems at the material level. Here, with experimental observation and numerical simulation, we report a delicate nano-electro-mechanical-opto-system naturally embedded in individual multiwall tungsten disulfide nanotubes, which generates a distinct form of in-plane van der Waals sliding ferroelectricity from the unique combination of superlubricity and piezoelectricity. The sliding ferroelectricity enables programmable photovoltaic effect using the multiwall tungsten disulfide nanotube as photovoltaic random-access memory. A complete “four-in-one” artificial vision system that synchronously achieves full functions of detecting, processing, memorizing, and powering is integrated into the nanotube devices. Both labeled supervised learning and unlabeled reinforcement learning algorithms are executable in the artificial vision system to achieve self-driven image recognition. This work provides a distinct strategy to create ferroelectricity in van der Waals materials, and demonstrates how intelligent materials can push electronic system integration at the material level.

Across‐Layer Sliding Ferroelectricity in 2D Heterolayers

“…transition-metal dichalcogenides (TMDs) like WTe 2 , [6][7][8][9] MoS 2 , [10][11][12][13][14][15][16] MoTe 2 , [17] ReS 2 , [18] InSe [19] and even multiwall nanotubes, [20] and amphidynamic crystal. [21] This mechanism is applicable to most 2D materials except for mono-element systems like graphene and phosphorene, as the inversion symmetry of their bilayers can always be maintained at any interlayersliding vector.…”

Integration of Neuromorphic and Reconfigurable Logic‐in‐Memory Operations in an Electrolyte‐Manipulated Ferroelectric Organic Neuristor

“…Ferroelectric materials possess nonvolatile characteristics, high switching speed, and ferroelectricity with ultralow energy consumption, which is an ideal candidate to build devices integrating memory and computing function. [ 26,38–41 ] Notably, the physical properties of the neuristor inspired by biological neurons are not limited to be applied in neuromorphic computing. Logic‐in‐memory operations can be performed employing a single neuristor due to the multi‐terminal architecture and nonvolatile ferroelectric polarization, which surpasses the performance of conventional logic devices.…”

“…Ferroelectric materials possess nonvolatile characteristics, high switching speed, and ferroelectricity with ultralow energy consumption, which is an ideal candidate to build devices integrating memory and computing function. [26,[38][39][40][41] Notably, the physical properties of the neuristor inspired by biological neurons are not limited to be applied in neuromorphic computing.…”

Silane functionalization of WS2 nanotubes for interaction with poly(lactic acid)

“…A consequence of being rolled into multiwalled nanotubes is a loss of symmetry and the WS 2 becomes an asymmetrical crystal. This results in WS 2 NTs having new properties, including displaying a bulk photovoltaic effect, piezoelectricity and ferroelectricity [49,52,53]. APTES displays characteristic peaks at 3383cm -1 and 2974cm -1 which are related to amine NH 2 stretching.…”

“…This results in WS 2 NTs having new properties, including displaying a bulk photovoltaic effect, piezoelectricity and ferroelectricity. 49,52,53 APTES displays characteristic peaks at 3383 cm −1 and 2974 cm −1 which are related to amine NH 2 stretching. Peaks at 1604 cm −1 and 1483 cm −1 and related peaks are assigned to NH 2 deformation bending modes of amine groups, which are strongly bonded in the hydrogen to the silanol groups to form cyclic structures.…”