Two-dimensional hafnium-based semiconductors and their heterostructures with native oxides have been shown unique physical properties and potential electronic and optoelectronic applications. However, the scalable synthesis methods for ultrathin layered hafnium-based semiconductor laterally epitaxy growth and its heterostructure are still restricted, also for the understanding of its formation mechanism. Herein, we report the stable sublimation of alkali halide vapor assisted synthesis strategy for high-quality 2D HfSe₂ nanosheets via chemical vapor deposition. Single-crystalline ultrathin 2D HfSe₂ nanosheets were systematically grown by tuning the growth parameters, reaching the lateral size of 6–40 µm and the thickness down to 4.5 nm. The scalable amorphous HfO₂ and HfSe₂ heterostructures were achieved by the controllable oxidation, which benefited from the approximate zero Gibbs free energy of unstable 2D HfSe₂ templates. The crystal structure, elemental, and time dependent Raman characterization were carried out to understand surface precipitated Se atoms and the formation of amorphous Hf–O bonds, confirming the slow surface oxidation and lattice incorporation of oxygen atoms. The relatively smooth surface roughness and electrical potential change of HfO₂–HfSe₂ heterostructures indicate the excellent interface quality, which helps obtain the high performance memristor with high on/off ratio of 10⁵ and long retention period over 9000 s. Our work introduces a new vapor catalysts strategy for the synthesis of lateral 2D HfSe₂ nanosheets, also providing the scalable oxidation of the Hf-based heterostructures for 2D electronic devices.

二维铪基半导体及其具有天然氧化物的异质结构已显示出独特的物理特性和潜在的电子和光电应用。然而，超薄层状铪基半导体横向外延生长及其异质结构的可扩展合成方法仍然受到限制，对其形成机制的理解也受到限制。在此，我们报告了通过化学气相沉积碱卤化物蒸气辅助合成高质量二维 HfSe ₂ 纳米片的稳定升华策略。通过调整生长参数，系统地生长了单晶超薄二维 HfSe ₂ 纳米片，横向尺寸达到 6–40 µm，厚度降至 4.5 nm。通过可控氧化实现了可扩展的非晶态 HfO ₂ 和 HfSe ₂ 异质结构，这得益于不稳定的二维 HfSe ₂ 模板的近似为零的吉布斯自由能。进行了晶体结构、元素和时间相关的拉曼表征，以了解表面沉淀的 Se 原子和无定形 Hf-O 键的形成，证实了缓慢的表面氧化和氧原子的晶格结合。 HfO ₂ –HfSe ₂ 异质结构相对光滑的表面粗糙度和电位变化表明其具有优异的界面质量，有助于获得高开/关比为10 <的高性能忆阻器。 b7> 且保留时间超过 9000 秒。我们的工作引入了一种新的蒸汽催化剂策略，用于合成横向 2D HfSe ₂ 纳米片，还为 2D 电子器件提供了基于 Hf 的异质结构的可扩展氧化。