Combining Freestanding Ferroelectric Perovskite Oxides with Two-Dimensional Semiconductors for High Performance Transistors

Abstract

We demonstrate the fabrication of field-effect transistors based on single-layer MoS2 and a thin layer of BaTiO3 (BTO) dielectric, isolated from its parent epitaxial template substrate. Thin BTO provides an ultrahigh-κ gate dielectric effectively screening Coulomb scattering centers. These devices show mobilities substantially larger than those obtained with standard SiO2 dielectrics and comparable with values obtained with hexagonal boron nitride, a dielectric employed for fabrication of high-performance two-dimensional (2D) based devices. Moreover, the ferroelectric character of BTO induces a robust hysteresis of the current vs gate voltage characteristics, attributed to its polarization switching. This hysteresis is strongly suppressed when the device is warmed up above the tetragonal-to-cubic transition temperature of BTO that leads to a ferroelectric-to-paraelectric transition. This hysteretic behavior is attractive for applications in memory storage devices. Our results open the door to the integration of a large family of complex oxides exhibiting strongly correlated physics in 2D-based devices.

Freestanding Membranes for Unique Functionality in Electronics

“…Since the single-crystalline gate dielectric layer can improve the FET performance more than 2-fold and especially the mobility more than 5-fold relative to polycrystalline material, a single-crystalline high- k material is essential . To avoid direct growth onto the FET, there have been reports on transferred dielectric materials. , Figure a shows a 2D FET with a freestanding BaTiO 3 (BTO) dielectric layer, where the BTO was grown on La 0.7 Sr 0.3 MnO 3 (LSMO)/SrTiO 3 (STO) substrate . The mobility with BTO was measured to be <70 cm 2 V –1 s –1 , which is much improved compared with the results using a SiO 2 dielectric layer (0.1–10 cm 2 V –1 s –1 ).…”

“…(a) Fabrication scheme and device performance of the MoS 2 transistor with BTO dielectric layer. From ref . CC BY 4.0.…”

Research progress of applications of freestanding single crystal oxide thin film

“…(a) Flux-closure domains [53] ; (b) Ferroelectric vortex domains [51] ; (c) Nanoscale Bubble Domains [52] ; (d) Ferroelectric skyrmions [55] ; (e) Dipole waves [54] . 图 5 自支撑单晶氧化薄膜在铁电隧道结和晶体管中的应用。 (a) BTO/LSMO 柔性双层薄膜为 基础的高质量柔性铁电隧道结 [61] ；(b) 柔性 BFO 铁电隧道结与神经突触示意图 [63] ；(c) 薄 BTO 层为铁电介质的单层 MoS 2 场效应晶体管 [65] ；(d)柔性铁电 HZO 电容器 [26] Fig. 5.…”

“…Applications of freestanding single crystal oxide films in ferroelectric tunnel junctions and field-effect transistors. (a) BTO/LSMO based flexible ferroelectric tunnel junction [61] ; (b) Schematic diagram of BFO ferroelectric tunnel junction based artificial synapse [63] ; (c) Monolayer MoS 2 FET with ferroelectric thin BTO layer [65] ; (d) Flexible ferroelectric HZO capacitor [26] .…”

Graphene/III–V Quantum Dot Mixed-Dimensional Heterostructure for Enhanced Radiative Recombinations via Hole Carrier Transfer

“…Mixed-dimension heterostructures have recently emerged as a new promising class of materials for applications including photovoltaics, − photodetectors, − light emitters, − and novel electronic devices. , These hybrid material systems may include 2D/bulk structure, ,,, 2D/QD (0D) structure, ,, and 2D/nanowire (1D) structure. Among them, the 2D/0D mixed-dimensional system holds great promise since combinations of the two materials’ properties would enable novel functionalities that are otherwise unobtainable from conventional material platforms.…”