Manipulation of current rectification in van der Waals ferroionic CuInP2S6

Abstract

Developing a single-phase self-rectifying memristor with the continuously tunable feature is structurally desirable and functionally adaptive to dynamic environmental stimuli variations, which is the pursuit of further smart memristors and neuromorphic computing. Herein, we report a van der Waals ferroelectric CuInP2S6 as a single memristor with superior continuous modulation of current and self-rectifying to different bias stimuli (sweeping speed, direction, amplitude, etc.) and external mechanical load. The synergetic contribution of controllable Cu+ ions migration and interfacial Schottky barrier is proposed to dynamically control the current flow and device performance. These outstanding sensitive features make this material possible for being superior candidate for future smart memristors with bidirectional operation mode and strong recognition to input faults and variations.

Flexoelectric engineering of van der Waals ferroelectric CuInP 2 S 6

“…S4, estimated to be 2.36, 3.8, and 2.16 μm, respectively, corresponding to a strain gradient 1/ R of 0.42, 0.26, and 0.46 μm −1 . With a flexoelectric coupling coefficient ( 14 ) of f 13 = 3 V, the effective electric field is estimated to be 0.78 MV m −1 and larger, resulting in the alignment of the polarization at these topography features. When R increases, as demonstrated in fig.…”

“…Van der Waals layered CuInP 2 S 6 (CIPS) has generated great excitement in recent years because of its room temperature ferroelectricity with out-of-plane spontaneous polarization (1-3), making it an ideal candidate to develop two-dimensional (2D) heterostructures for microelectronic devices (4)(5)(6)(7). Ferroelectric field-effect transistors (6,8), negative capacitance field-effect transistors (9,10), ferroelectric tunneling junctions (1), and memristors (11) have all been demonstrated with CIPS, which are attractive for both logic and memory applications (6,12) enabling future neuromorphic computing (13)(14)(15). Besides technological potentials, CIPS is also fascinating from a materials point of view, exhibiting exotic properties such as giant negative piezoelectricity (16,17), tunable quadruple energy wells (18), large room temperature electrocaloric effect (16,19), and strong coupling between ferroelectric polarization and ionic conductivity (13,20,21).…”

“…Hence, alternative switching mechanisms have to be developed, for example, using electric field induced by ion adsorption (27). In this work, we abandon electric field altogether and explore the prospect of mechanical switching of CIPS instead via flexoelectric effect (14,(28)(29)(30)(31)(32)(33).…”

High-throughput Screening of Plastic Deformable Inorganic Semiconductors

“…High-quality single crystals of CuInP2S6 were synthesized by chemical transportation reaction using the elements in the stoichiometric proportions 15,16 . High-quality single crystals of PbI2 was bought from SixCarbon Technology ShenZhen.…”

“…CuInP2S6 is van der Waals ferroelectrics which shows excellent properties, such as thickness-dependent structural phase transitions and ferroelectricity evolution 15 , superior continuous modulation of current and self-rectifying as a single memristor 16 . Substituting the extracted data of 612 bulk layered materials into formula (6), the calculated plastic deformability factors  are shown in Fig.…”