Park Younghee, Ahn Chaehyeon, Ahn Jong-Guk, Kim Jee Hyeon, Jung Jaehoon, Oh Juseung, Ryu Sunmin, Kim Soyoung, Kim Seung Cheol, Kim Taewoong, Lim Hyunseob
Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju61005, Republic of Korea.
Department of Chemistry, University of Ulsan, Ulsan44776, Republic of Korea.
ACS Nano. 2023 Jan 12. doi: 10.1021/acsnano.2c08983.
A highly reproducible route for the epitaxial growth of single-crystalline monolayer MoS on a C-plane sapphire substrate was developed using vapor-pressure-controllable inorganic molecular precursors MoOCl and HS. Microscopic, crystallographic, and spectroscopic analyses indicated that the epitaxial MoS film possessed outstanding electrical and optical properties, excellent homogeneity, and orientation selectivity. The systematic investigation of the effect of growth temperature on the crystallographic orientations of MoS revealed that the surface termination of the sapphire substrate with respect to the growth temperature determines the crystallographic orientation selectivity of MoS. Our results suggest that controlling the surface to form a half-Al-terminated surface is a prerequisite for the epitaxial growth of MoS on a C-plane sapphire substrate. The insights on the growth mechanism, especially the significance of substrate surface termination, obtained through this study will aid in designing efficient epitaxial growth routes for developing single-crystalline monolayer transition metal dichalcogenides.
利用蒸气压可控的无机分子前驱体MoOCl和HS，开发了一种在C面蓝宝石衬底上外延生长单晶单层MoS的高度可重复的方法。微观、晶体学和光谱分析表明，外延MoS薄膜具有优异的电学和光学性能、出色的均匀性和取向选择性。对生长温度对MoS晶体取向影响的系统研究表明，蓝宝石衬底相对于生长温度的表面终止决定了MoS的晶体取向选择性。我们的结果表明，控制表面形成半Al终止表面是在C面蓝宝石衬底上外延生长MoS的先决条件。通过本研究获得的关于生长机制的见解，特别是衬底表面终止的重要性，将有助于设计高效的外延生长路线，以开发单晶单层过渡金属二硫属化物。
