Gautam Chetna, Thakurta Baishali, Pal Monalisa, Ghosh Anup Kumar, Giri Anupam
Department of Physics, Institute of Science, Banaras Hindu University, Varanasi, UP - 221005, India.
Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, UP - 221005, India.
Nanoscale. 2024 Mar 21;16(12):5941-5959. doi: 10.1039/d3nr06678a.
Two-dimensional (2D) van der Waals (vdW) materials, including graphene, hexagonal boron nitride (hBN), and metal dichalcogenides (MCs), form the basis of modern electronics and optoelectronics due to their unique electronic structure, chemical activity, and mechanical strength. Despite many proof-of-concept demonstrations so far, to fully realize their large-scale practical applications, especially in devices, wafer-scale single crystal atomically thin highly uniform films are indispensable. In this minireview, we present an overview on the strategies and highlight recent significant advances toward the synthesis of wafer-scale single crystal graphene, hBN, and MC 2D thin films. Currently, there are five distinct routes to synthesize wafer-scale single crystal 2D vdW thin films: (i) nucleation-controlled growth by suppressing the nucleation density, (ii) unidirectional alignment of multiple epitaxial nuclei and their seamless coalescence, (iii) self-collimation of randomly oriented grains on a molten metal, (iv) surface diffusion and epitaxial self-planarization and (v) seed-mediated 2D vertical epitaxy. Finally, the challenges that need to be addressed in future studies have also been described.
二维（2D）范德华（vdW）材料，包括石墨烯、六方氮化硼（hBN）和金属二硫属化物（MCs），由于其独特的电子结构、化学活性和机械强度，构成了现代电子学和光电子学的基础。尽管到目前为止已有许多概念验证演示，但要全面实现其大规模实际应用，尤其是在器件中的应用，晶圆级单晶原子级薄高度均匀薄膜是必不可少的。在这篇综述中，我们概述了相关策略，并重点介绍了在合成晶圆级单晶石墨烯、hBN和MC二维薄膜方面的最新重大进展。目前，有五种不同的途径来合成晶圆级单晶二维vdW薄膜：（i）通过抑制成核密度进行成核控制生长；（ii）多个外延核的单向排列及其无缝合并；（iii）在熔融金属上随机取向晶粒的自准直；（iv）表面扩散和外延自平面化；以及（v）种子介导的二维垂直外延。最后，还描述了未来研究中需要解决的挑战。
