二维半导体氧化物界面能带工程与量子霍尔效应

The two-dimensional electron gas as well as quantum Hall effect, which formed at the semiconductor/oxide interface, have attracted scientists' attention due to their rich scientific connotation and potential application prospects. However, the exploration of the mechanism of the quantum behavior, functional regulation and research on interface electronics devices are still in need of a breakthrough. This project focuses on band engineering and quantum Hall effect study at two-dimensional semiconductor/oxide (Bi2O2Se/SrTiO3) interface. Through the Molecular Beam Epitaxial (MBE) growth of the atomic-flat high-mobility two-dimensional semiconductor/oxide heterostructure, novel two-dimensional electron gas can be formed at the interface firstly. Then, by using ab-initio calculations, combined with the layer number control of the two-dimensional Bi2O2Se epitaxial layer, we can achieve the band control of the heterostructures. Finally, through quantum transport measurements, electrical properties as well as novel physical properties such as quantum Hall effect would be well studied. This project aims at exploring exotic properties of the new two-dimensional semiconductor/oxide heterostructures and its quantum devices and holds great promise in new effects in fundamental science as well as significant applications.

半导体氧化物异质界面形成的二维电子气和量子霍尔效应因其丰富的科学内涵及潜在的应用前景而备受关注，而界面量子行为的机制探索、功能调控及其界面电子学器件研究仍亟待突破。本项目围绕二维半导体氧化物界面能带工程与量子霍尔效应开展系统研究，通过原子级平整的新型高迁移率二维半导体/氧化物（Bi2O2Se/SrTiO3）异质界面的精确外延生长，产生新奇的界面二维电子气，通过低温量子输运的手段加以证明；利用第一性原理计算，并结合高迁移率二维Bi2O2Se外延层的层数控制，实现异质结的能带调控；通过低温量子输运系统地研究异质结体系的电学性质，并探索潜在的量子霍尔效应等新奇物性。本项目旨在探索新型二维半导体氧化物界面的奇异物性及其量子器件，具有重要的基础科学意义和潜在应用价值。

半导体/氧化物异质界面因其丰富的科学内涵（如量子霍尔效应）及潜在的应用前景（高速电子器件）而备受关注。然而现阶段对界面量子行为的机制探索、功能调控及相关电子学器件研究仍需突破。国家自然科学基金委青年基金项目“二维半导体氧化物界面能带工程与量子霍尔效应”，立足于Bi2O2Se/氧化物异质结体系，以低温量子输运为手段对Bi2O2Se/氧化物异质结进行系统的测量。在为期一年的项目执行过程中，实现了超高迁移率（＞160 000 cm2V−1 s−1）二维半导体Bi2O2Se的精准合成、高性能器件的制备（开态电流＞1.3 mA μm−1）、量子震荡的研究以及量子霍尔效应的探索。与此同时也在大面积转移的超平整石墨烯/氮化硼异质结中观测到了分数量子霍尔效应。本项目合成了高品质二维半导体Bi2O2Se，探索了新型二维半导体氧化物界面的奇异物性及相关量子器件，本项目研究对高迁移率二维半导体能带结构的理解以及其未来应用具有很大帮助。