Ran Meng, Zhao Chao, Xu Xiang, Kong Xiao, Lee Younghee, Cui Wenjun, Hu Zhi-Yi, Roxas Alexander, Luo Zhengtang, Li Huiqiao, Ding Feng, Gan Lin, Zhai Tianyou
State Key Laboratory of Materials Processing and Die and Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Centre for Multidimensional Carbon Materials, Institute for Basic Science, School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
Fundam Res. 2021 Nov 26;2(3):456-461. doi: 10.1016/j.fmre.2021.11.020. eCollection 2022 May.
In-plane anisotropy (IPA) due to asymmetry in lattice structures provides an additional parameter for the precise tuning of characteristic polarization-dependent properties in two-dimensional (2D) materials, but the narrow range within which such method can modulate properties hinders significant development of related devices. Herein we present a novel periodic phase engineering strategy that can remarkably enhance the intrinsic IPA obtainable from minor variations in asymmetric structures. By introducing alternant monoclinic and rutile phases in 2D VO single crystals through the regulation of interfacial thermal strain, the IPA in electrical conductivity can be reversibly modulated in a range spanning two orders of magnitude, reaching an unprecedented IPA of 113. Such an intriguing local phase engineering in 2D materials can be well depicted and predicted by a theoretical model consisting of phase transformation, thermal expansion, and friction force at the interface, creating a framework applicable to other 2D materials. Ultimately, the considerable adjustability and reversibility of the presented strategy provide opportunities for future polarization-dependent photoelectric and optoelectronic devices.
由于晶格结构不对称而产生的面内各向异性（IPA）为二维（2D）材料中与偏振相关的特性的精确调控提供了一个额外参数，但是这种方法能够调制特性的范围较窄，阻碍了相关器件的重大发展。在此，我们提出了一种新颖的周期性相位工程策略，该策略能够显著增强由不对称结构中的微小变化所获得的本征IPA。通过界面热应变调控在二维VO单晶中引入交替的单斜相和金红石相，电导率中的IPA能够在跨越两个数量级的范围内被可逆地调制，达到了前所未有的113的IPA。二维材料中这种引人入胜的局部相位工程能够通过一个由相变、热膨胀和界面摩擦力组成的理论模型得到很好的描述和预测，从而创建了一个适用于其他二维材料的框架。最终，所提出策略的显著可调性和可逆性为未来与偏振相关的光电和光电器件提供了机会。
