In situ GID and XRR characterization of 2D GaN growth on liquid gallium alloys

Liquid metal catalysts (LMCats) are a promising platform for the synthesis and growth of large, defect-free and highly crystalline two-dimensional (2D) materials such as graphene and hexagonal boron nitride. More recently, a larger range of 2D materials have been produced this way, including GaN, which is of high interest for applications in nanoelectronics. With the proposed experiments, we aim at investigating the structure of 2D GaN crystals during their growth on liquid gallium alloys. The in-plane lattice constant, crystallite size and strains of the 2D GaN crystals will be tracked in situ using GID and their thickness, roughness and distance from the substrate using XRR. These experiments will enable to unravel the growth mechanism of 2D GaN on the surface of liquid metals and determine optimized conditions for their growth.

液态金属催化剂（Liquid metal catalysts，简称LMCats）是一类极具应用前景的催化平台，可用于合成与生长大型、无缺陷且高结晶度的二维（2D）材料，例如石墨烯与六方氮化硼。近年来，通过该方法已制备出更多种类的二维材料，其中氮化镓（GaN）在纳米电子学领域具备极高的应用价值，因此受到广泛关注。本研究拟通过相关实验，探究在液态镓合金表面生长过程中二维氮化镓晶体的微观结构。研究将采用掠入射衍射（GID）原位表征二维氮化镓晶体的面内晶格常数、晶粒尺寸与应变情况，并借助X射线反射率（XRR）测定其厚度、表面粗糙度以及与基底的间距。本系列实验将阐明液态金属表面二维氮化镓的生长机制，并确定其最优生长条件。