Huang Xingyong, Zhuo Zhiwen, Yan Luo, Wang You, Xu Nan, Song Hai-Zhi, Zhou Liujiang
Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou, Zhejiang 313001, China.
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, China.
J Phys Chem Lett. 2021 Aug 19;12(32):7726-7732. doi: 10.1021/acs.jpclett.1c01958. Epub 2021 Aug 6.
Recently, two-dimensional (2D) metal halides have brought out an intensive interest for their unique mechanical, electronic, magnetic, and topological properties. Here, we theoretically report the existence of the single-layer (SL) zirconium dihalide materials ZrX (X = Cl, Br, and I) using first-principles calculations. SL ZrX, which can be obtained from its bulk phase through simple mechanical exfoliation, shows the dynamic, thermodynamic, and mechanical stability. Halogen atoms can effectively tune the electronic structure, dipole moment transition, band alignment, and light absorption. Specifically, ZrX monolayers intrinsically exhibit a ferroelasticity with an abnormal 120° orientation rotation, possessing a moderate switching barrier of 24-39 meV/atom. Importantly, we observe superior anisotropic light absorption responses on SL ZrX in the visible region. Besides, a series of ZrX-based excitonic solar cells have been proposed, which hold a large power conversion efficiency limit of 12.4-18.7%.
最近，二维（2D）金属卤化物因其独特的机械、电子、磁性和拓扑性质而引起了广泛关注。在此，我们通过第一性原理计算从理论上报道了单层（SL）二卤化锆材料ZrX（X = Cl、Br和I）的存在。SL ZrX可以通过简单的机械剥离从其体相获得，具有动态、热力学和机械稳定性。卤素原子可以有效地调节电子结构、偶极矩跃迁、能带排列和光吸收。具体而言，ZrX单层本质上表现出具有异常120°取向旋转的铁弹性，具有24 - 39 meV/原子的适度开关势垒。重要的是，我们在可见光区域观察到SL ZrX具有优异的各向异性光吸收响应。此外，还提出了一系列基于ZrX的激子太阳能电池，其功率转换效率极限高达12.4 - 18.7%。
