Shi Li, Zhou Qionghua, Zhao Yinghe, Ouyang Yixin, Ling Chongyi, Li Qiang, Wang Jinlan
School of Physics, Southeast University , Nanjing 211189, China.
Synergetic Innovation Center for Quantum Effects and Applications (SICQEA), Hunan Normal University , Changsha 410081, China.
J Phys Chem Lett. 2017 Sep 21;8(18):4368-4373. doi: 10.1021/acs.jpclett.7b02059. Epub 2017 Aug 30.
Ultrathin indium selenide (InSe), as a newly emerging two-dimensional material with high carrier mobility and a broad absorption spectrum, has been the focus of current research. However, the long-term environmental instability of atomically thin InSe seriously limits its practical applications. To develop an effective strategy to protect InSe, it is crucial to reveal the degradation mechanism at the atomic level. By employing density functional theory and ab initio molecular dynamics simulations, we provide an in-depth understanding of the oxidation mechanism of InSe. The defect-free InSe presents excellent stability against oxidation. Nevertheless, the Se vacancies on the surface can react with water and oxygen in air directly and activate the neighboring In-Se bonds on the basal plane for further oxidation, leading to complete degradation of InSe into oxidation products of InO and elemental Se. Furthermore, we propose an efficient strategy to repair the Se vacancies by thiol chemistry. In this way, the repaired surface can resist oxidation from oxygen and retain the original high electron mobility of pristine InSe simultaneously.
超薄硒化铟（InSe）作为一种新兴的二维材料，具有高载流子迁移率和宽吸收光谱，一直是当前研究的焦点。然而，原子级薄的InSe长期的环境不稳定性严重限制了其实际应用。为了开发一种有效的策略来保护InSe，在原子水平上揭示其降解机制至关重要。通过采用密度泛函理论和从头算分子动力学模拟，我们对InSe的氧化机制有了深入的了解。无缺陷的InSe对氧化具有出色的稳定性。然而，表面的硒空位会直接与空气中的水和氧气反应，并激活基面相邻的In-Se键以进一步氧化，导致InSe完全降解为InO和元素硒的氧化产物。此外，我们提出了一种通过硫醇化学修复硒空位的有效策略。通过这种方式，修复后的表面可以抵抗氧气的氧化，同时保留原始InSe的高电子迁移率。
