Li Yixiang, Jian Chuanyong, Yuan Jiashuai, Hong Wenting, Yao Yu, Fu Zhipeng, Wang Bicheng, Cai Qian, Liu Wei
State Key Lab of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
College of Chemistry and Materials, Fujian Normal University, Fuzhou, Fujian, 350007, China.
Adv Mater. 2025 Feb;37(5):e2409773. doi: 10.1002/adma.202409773. Epub 2024 Dec 12.
The development of dielectrics with atomic planes and van der Waals (vdW) interfaces is essential for enhancing the performance of 2D devices. However, vdW dielectrics often have smaller bandgaps compared to traditional 3D dielectrics, limiting their options. This study introduces AZBX (AZn₂BO₃X₂, where A = K or Rb, X = Cl or Br), a nonlinear deep-ultraviolet optical crystal, as a quasi-vdW layered dielectric ideal for 2D electronic devices. Focusing on KZBB, it's excellent dielectric properties, including a wide bandgap, high dielectric constant (high-κ), and smooth interfaces are demonstrated. When used as the top gate dielectric in a KZBB/MoS₂ field-effect transistor (FET) with MoS₂ channels and graphene contacts, the device exhibits outstanding performance, with a steep subthreshold swing (≈ 73 mV dec), high on/off ratio (≈ 10⁷), negligible hysteresis (0-8 mV), and stable, low leakage current (≈10⁻⁷ A cm ) before breakdown. This work expands the 2D material and dielectric landscape and highlights the strong potential of AZBX as high-performance dielectrics.
具有原子平面和范德华（vdW）界面的电介质的开发对于提高二维器件的性能至关重要。然而，与传统的三维电介质相比，范德华电介质的带隙通常较小，这限制了它们的选择。本研究引入了AZBX（AZn₂BO₃X₂，其中A = K或Rb，X = Cl或Br），一种非线性深紫外光学晶体，作为二维电子器件理想的准范德华层状电介质。以KZBB为例，展示了其优异的介电性能，包括宽带隙、高介电常数（高κ）和光滑界面。当用作具有MoS₂沟道和石墨烯接触的KZBB/MoS₂场效应晶体管（FET）的顶栅电介质时，该器件表现出出色的性能，具有陡峭的亚阈值摆幅（≈73 mV/dec）、高开关比（≈10⁷）、可忽略的滞后（0 - 8 mV）以及在击穿前稳定的低漏电流（≈10⁻⁷ A/cm）。这项工作扩展了二维材料和电介质的领域，并突出了AZBX作为高性能电介质的强大潜力。
