Ko Hayoung, Choi Soo Ho, Park Yunjae, Lee Seungjin, Oh Chang Seok, Kim Sung Youb, Lee Young Hee, Kim Soo Min, Ding Feng, Kim Ki Kang
Department of Energy Science, Sungkyunkwan University (SKKU), Suwon, 16419, South Korea.
Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University (SKKU), Suwon, 16419, South Korea.
Nat Commun. 2024 Jul 11;15(1):5848. doi: 10.1038/s41467-024-50184-5.
Atomic sawtooth surfaces have emerged as a versatile platform for growth of single-crystal van der Waals layered materials. However, the mechanism governing the formation of single-crystal atomic sawtooth metal (copper or gold) films on hard substrates (tungsten or molybdenum) remains a puzzle. In this study, we aim to elucidate the formation mechanism of atomic sawtooth metal films during melting-solidification process. Utilizing molecular dynamics, we unveil that the solidification of the liquid copper initiates at a high-index tungsten facet with higher interfacial energy. Subsequent tungsten facets follow energetically favourable pathways of forming single-crystal atomic sawtooth copper film during the solidification process near melting temperature. Formation of atomic sawtooth copper film is guaranteed with a film thickness exceeding the grain size of polycrystalline tungsten substrate. We further demonstrate the successful growth of centimeter-scale single-crystal monolayer hexagonal boron nitride films on atomic sawtooth copper films and explore their potential as efficient oxygen barrier.
原子锯齿状表面已成为生长单晶范德华层状材料的通用平台。然而，在硬质衬底（钨或钼）上形成单晶原子锯齿状金属（铜或金）薄膜的机制仍然是个谜。在本研究中，我们旨在阐明原子锯齿状金属薄膜在熔化-凝固过程中的形成机制。利用分子动力学，我们揭示了液态铜的凝固起始于具有较高界面能的高指数钨晶面。随后的钨晶面在接近熔点的凝固过程中遵循形成单晶原子锯齿状铜薄膜的能量有利路径。当薄膜厚度超过多晶钨衬底的晶粒尺寸时，原子锯齿状铜薄膜的形成得以保证。我们进一步证明了在原子锯齿状铜薄膜上成功生长厘米级单晶单层六方氮化硼薄膜，并探索了它们作为高效氧阻隔层的潜力。
