熔融液体辅助的二维过渡金属硫族化合物大尺寸单晶的生长

超薄二维半导体性过渡金属硫族化合物（TMDCs）是下一代数字电子和光电子器件理想候选者，获得电学和机械性能极度均一的高质量大尺寸单晶是其在集成电路中大规模应用的先决条件。但目前生长的2D TMDCs单晶尺寸仍普遍在微米、毫米级别，其主要原因是缺乏合适的单核诱导体系和多种子法中可避免孪晶行为的理想基底。为了获得厘米级及以上的2D TMDCs单晶，本项目拟在生长体系中引入熔融溶液作为晶体生长的中介、基底或缓冲层（1）熔融混合液可以为成核控制提供稳定的环境和准确的亚稳区范围，进而通过激光等技术实现单核诱导；（2）熔融液膜表面可以降低晶体与基底的相互作用，有利于晶畴形貌和取向的调整，实现无缝融合。本项目还将搭建具有原位显微光学观察功能的晶体生长平台，为探索成核条件和准确测量亚稳区范围提供有力工具。本项目充满挑战，但是每部分都具有高的可行性，项目预期目标的实现将使2D材料的器件应用迈进一大步。

Ultrathin two-dimensional semiconducting transition metal dichalcognides (TMDCs) are promising candidates for next-generation digital electronics and optoelectronics, achieving high quality large-size single crystals with ultimate uniform electrical and mechanical properties are a prerequisite for their massive applications in integrated circuits. However, at present, the size of prepared TMDCs single crystals is typically range from micrometer to millimeter level, which mainly because of the lack of a suitable growth system to induce a single nucleus or an ideal substrate to avoid the presentence of antiparallel domains and twinning behavior in multiple seeds method. To obtain centimeter scale even larger TMDCs single crystal, liquid will be used in the crystal growth system to serve as the growth media or the growth substrate or the buffer layer: (1) The molten mixture will provide stable environment and accurate metastable region for nucleation control, and make it feasible to induce the formation of a single nucleus by laser irradiation; (2) The liquid surface will reduce the interaction between the crystal and the substrate, which is conducive to the adjustment of the morphology and orientation, so as to achieve seamless stitching of adjacent domains. A crystal growth platform with in-situ optical microscopic observation will be developed for the investigation of nucleation conditions and measuring the metastable region. This project is highly challenging but each step is feasible. The fulfill of the project goal will make a big step to electronic applications for 2D materials.