A Layered Wide-Bandgap BiOF Gate Dielectric with a High Dielectric Constant

作者：Jiabiao Chen, Xiulin Dong, Yameng Hou, Xiang Chen, Lan Lan, Zhaochao Liu, Fengbo Yan, Zunxian Lv, Yuyu He, Ming Yang, Huixia Fu, Xuewen Fu, Wenbin Li, Feng Luo, Jinxiong Wu · 发表于：ACS Nano · 年份：2026 · DOI：10.1021/acsnano.5c18038 · 被引用次数：3 · 研究领域：2D Materials and Applications、Transition Metal Oxide Nanomaterials、Ferroelectric and Negative Capacitance Devices

The ongoing downscaling of semiconductor devices necessitates gate dielectric materials that simultaneously possess a wide bandgap and ultrahigh dielectric constant to ensure efficient gate control. However, such materials remain scarce due to the inherent trade-off between bandgap widening and dielectric response enhancement in conventional insulators. Here, we demonstrate bismuth oxyfluoride (BiOF) as a promising dielectric candidate with a wide bandgap ( E g ≈ 4.5 eV) and a high out-of-plane dielectric constant (κ = 22.5). Moreover, we develop a scalable solid-state route for synthesizing phase-pure BiOF powder and achieve the chemical vapor deposition (CVD) growth of ultrathin BiOF nanosheets. The free-standing characteristic, temperature-stable dielectric properties, and inert van der Waals (vdW) surface of BiOF facilitate its seamless integration with two-dimensional (2D) materials to enhance device performance. Few-layer graphene double-encapsulated by BiOF demonstrates superior electron Hall mobility (μ e,2K ≈ 134,000 cm 2 V –1 s –1 ) and pronounced Shubnikov-de Haas (SdH) oscillations at 2 K. Our work not only expands the library of high-κ vdW materials but also overcomes the intrinsic trade-off between dielectric constant and bandgap.