Ferroelectrics-Integrated Two-Dimensional Devices toward Next-Generation Electronics

Abstract

Ferroelectric materials play an important role in a wide spectrum of semiconductor technologies and device applications. Two-dimensional (2D) van der Waals (vdW) ferroelectrics with surface-insensitive ferroelectricity that is significantly different from their traditional bulk counterparts have further inspired intensive interest. Integration of ferroelectrics into 2D-layered-material-based devices is expected to offer intriguing working principles and add desired functionalities for next-generation electronics. Herein, fundamental properties of ferroelectric materials that are compatible with 2D devices are introduced, followed by a critical review of recent advances on the integration of ferroelectrics into 2D devices. Representative device architectures and corresponding working mechanisms are discussed, such as ferroelectrics/2D semiconductor heterostructures, 2D ferroelectric tunnel junctions, and 2D ferroelectric diodes. By leveraging the favorable properties of ferroelectrics, a variety of functional 2D devices including ferroelectric-gated negative capacitance field-effect transistors, programmable devices, nonvolatile memories, and neuromorphic devices are highlighted, where the application of 2D vdW ferroelectrics is particularly emphasized. This review provides a comprehensive understanding of ferroelectrics-integrated 2D devices and discusses the challenges of applying them into commercial electronic circuits.

Two-Dimensional Layered Materials Meet Perovskite Oxides: A Combination for High-Performance Electronic Devices

“…Nonvolatile, high-speed, high-density, and low-power memory devices have long been pursued because they can substantially improve the performance of processing and storing information. , Thanks to their atomic thicknesses and diverse electronic properties, 2DLMs offer many possibilities for memory devices working on various mechanisms, including filament forming, charge trapping, and ferroelectric switching. − Dependent on the working mechanisms, a variety of corresponding device architectures have been adopted. Among them, ferroelectric field-effect transistors (FeFETs) are a promising platform to exploit the synergistic coupling between 2DLMs and ferroelectric perovskite oxides for memory devices. − , Compared with other ferroelectric materials, perovskite oxide based ferroelectric materials, such as PZT and PMN-PT, are praised for their large polarization strength, fast switching speed, and environmental stability . Specifically, the Curie temperatures of the perovskite-type ferroelectrics are mostly considerably higher than room temperature, which allows a wide temperature window for the device operation.…”

Interface Engineering and Device Applications of 2D Ultrathin Film/Ferroelectric Copolymer P(VDF‐TrFE)

“…For instance, complex oxides ABO 3 ‐type perovskites and binary oxide HfO 2 with fluorite‐structure are also used in the integration of ferroelectrics into 2D material‐based devices. [ 44,45 ] Compared with traditional inorganic ferroelectric perovskite oxides and binary HfO 2 , ferroelectric polymers PVDF and P(VDF‐TrFE) display distinct features. For example, the inorganic ferroelectrics has some intrinsic drawbacks such as limited mechanical deformation.…”

Photoferroelectric All-van-der-Waals Heterostructure for Multimode Neuromorphic Ferroelectric Transistors

“…Moreover, the versatility and ease of assembling of vdW materials open the door to exploring new ferroelectric heterostructures with unique properties arising from increased interfacial contributions. − Ferroelectric tunneling junctions based on CuInP 2 S 6 (CIPS)/graphene heterostructures have shown record electroresistance values . Mixed dimensional heterostructures, coupling a 2D semiconductor channel to a bulk ferroelectric film, opened the way toward 2D material-based ferroelectric synapses. ,,− Finally, the reduced electromagnetic screening of vdW 2D materials unlocks new means of electrical and optical control in device architectures. , This positions ferroelectric vdW heterostructures as interesting platforms for fundamental understanding as well as emerging photoferroelectric technologies. ,,,,− However, studies of FeFET based on a vdW ferroelectric layer coupled to a vdW semiconductor channel are still very scarce, − while optoelectronic neuromorphic devices based on this platform are mostly uncharted.…”