Revisiting the Epitaxial Growth Mechanism of 2D TMDC Single Crystals
Epitaxial growth of 2D transition metal dichalcogenides (TMDCs) on sapphire substrates has been recognized as a pivotal method for producing wafer-scale single-crystal films. Both step-edges and symmetry of substrate surfaces have been proposed as controlling factors. However, the underlying fundamental still remains elusive. In this work, through the molybdenum disulfide (MoS<sub>2</sub>) growth on C/M sapphire, it is demonstrated that controlling the sulfur evaporation rate is crucial for dictating the switch between atomic-edge guided epitaxy and van der Waals epitaxy. Low-concentration sulfur condition preserves O/Al-terminated step edges, fostering atomic-edge epitaxy, while high-concentration sulfur leads to S-terminated edges, preferring van der Waals epitaxy. These experiments reveal that on a 2 in. wafer, the van der Waals epitaxy mechanism achieves better control in MoS<sub>2</sub> alignment (≈99%) compared to the step edge mechanism (<85%). These findings shed light on the nuanced role of atomic-level thermodynamics in controlling nucleation modes of TMDCs, thereby providing a pathway for the precise fabrication of single-crystal 2D materials on a wafer scale.
Authors
- Areej Aljarb (ORCID: https://orcid.org/0000-0002-8716-4600)
- Yi Wan (ORCID: https://orcid.org/0000-0002-6202-4193)
- Kaimin Shih (ORCID: https://orcid.org/0000-0002-6461-3207)
- Fangyuan Zheng (ORCID: https://orcid.org/0000-0001-9939-8087)
- Yu‐Ming Chang (ORCID: https://orcid.org/0000-0002-8078-9181)
- Lain‐Jong Li (ORCID: https://orcid.org/0000-0002-4059-7783)
- Jiacheng Min
- Qinze Yu (ORCID: https://orcid.org/0009-0000-5116-2833)
- Pengfei Yang (ORCID: https://orcid.org/0000-0002-4753-3109)
- Yuxiang Zhang (ORCID: https://orcid.org/0000-0002-1109-6197)
- Chenyang Li (ORCID: https://orcid.org/0000-0002-5155-4631)
- Jing‐Kai Huang (ORCID: https://orcid.org/0000-0002-7187-2653)
- Zhengtang Luo
- Yang Ni (ORCID: https://orcid.org/0000-0002-9678-6997)
- Haomin Liu (ORCID: https://orcid.org/0000-0001-9511-2416)
- Yu Li
Institutions
- City University of Hong Kong (HK)
- Chinese University of Hong Kong (HK)
- King Abdulaziz University (SA)
- Hong Kong University of Science and Technology (HK)
- HKUST Shenzhen Research Institute (CN)
- King Abdullah University of Science and Technology (SA)
- University of Hong Kong (HK)
Publication Details
- Journal
- Advanced Materials
- Published
- 2024-08-16
- DOI
- https://doi.org/10.1002/adma.202404923
- Citations
- 29
- Primary Topic
- 2D Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 3.40
Funders
- University Grants Committee
- Natural Science Foundation of Guangdong Province
- University of Hong Kong
- Hong Kong Polytechnic University
- University Research Committee, University of Hong Kong
- Key Technologies Research and Development Program