Yang Wei, Guan Zhizi, Wang Hongfa, Chen Yongchao, Wang Hailong, Li Junwen
CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, CAS Center for Excellence in Complex System Mechanics, University of Science and Technology of China Hefei Anhui 230027 China
DFTWorks LLC Oakton VA 22124 USA
RSC Adv. 2022 Sep 22;12(41):26994-27001. doi: 10.1039/d2ra04782a. eCollection 2022 Sep 16.
The experimental fabrication of novel two-dimensional ZnSb inspires us to explore the tunability of its fundamental physical properties. In this work, we present the density functional theory simulations on the mechanical, electronic and transport properties of the two-dimensional ZnSb monolayers functionalized with halogen atoms. It is found that the halogen atoms prefer to form ionic bonds with Sb atoms and these ZnSbX (X = Cl, Br and I) monolayers are very flexible with Young's moduli ranging from 24.02 N m to 30.16 N m along the armchair and zigzag directions. The pristine ZnSb monolayer sheet exhibits metallic phase while the functionalization can lead to a metal-to-semiconductor transition with band gaps as large as 0.55 eV. The transport study reveals a large tunability with the hole mobility reaching 43.44 × 10 cm V s along the armchair direction and the electron mobility as high as 36.99 × 10 cm V s along the zigzag direction. In contrast, the electron mobility along the armchair direction and the hole mobility along the zigzag direction are of relatively small magnitude. The ultrahigh carrier mobility together with the directional anisotropy can boost the separation of photo-excited electron-hole pairs. The finite band gaps and exceptional transport property of ZnSbX monolayers render them new materials with promising applications in flexible optoelectronic and nanoelectronic devices.
新型二维ZnSb的实验制备激发了我们探索其基本物理性质可调性的兴趣。在这项工作中，我们展示了对用卤素原子功能化的二维ZnSb单层的力学、电子和输运性质的密度泛函理论模拟。研究发现，卤素原子倾向于与Sb原子形成离子键，并且这些ZnSbX（X = Cl、Br和I）单层非常柔韧，沿扶手椅方向和锯齿方向的杨氏模量范围为24.02 N/m至30.16 N/m。原始的ZnSb单层片表现出金属相，而功能化可导致金属到半导体的转变，带隙高达0.55 eV。输运研究表明其具有很大的可调性，空穴迁移率沿扶手椅方向达到43.44×10 cm²/V·s，电子迁移率沿锯齿方向高达36.99×10 cm²/V·s。相比之下，沿扶手椅方向的电子迁移率和沿锯齿方向的空穴迁移率幅度相对较小。超高的载流子迁移率以及方向各向异性能够促进光激发电子 - 空穴对的分离。ZnSbX单层的有限带隙和优异的输运性质使其成为在柔性光电器件和纳米电子器件中具有广阔应用前景的新材料。
