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Published on: November 28, 2017
Screening Crystallographic Planes on Sapphire for Single-Crystal MoS2 Epitaxy
Xilu Zou1,2, Lei Liu2, Ruikang Dong2
1National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Researchers explored sapphire crystallographic planes for deterministic molybdenum disulfide (MoS2) epitaxy. This work identifies optimal planes and a universal principle for wafer-scale single-crystal growth, advancing beyond-silicon electronics.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Wafer-scale single-crystal two-dimensional transition metal dichalcogenides (TMDs) are crucial for next-generation electronics.
- Sapphire's c-plane is the conventional substrate, but other crystallographic planes offer unexplored potential for van der Waals epitaxy.
Purpose of the Study:
- To develop a theoretical framework for exploring diverse sapphire crystallographic planes for deterministic molybdenum disulfide (MoS2) epitaxy.
- To identify optimal substrate planes and understand the governing principles for high-quality TMD growth.
Main Methods:
- A theoretical framework was developed to evaluate interfacial strain and surface energy across 33 sapphire crystallographic planes.
- Computational analysis identified key descriptors for predicting successful epitaxial growth.
Main Results:
- Five optimal sapphire crystallographic planes (A(112̅0), C(0001), P(112̅3), R(11̅02), and S(11̅01)) were identified for deterministic MoS2 epitaxy.
- Unidirectional alignment is achieved by reducing substrate surface symmetry, either intrinsically or through engineered step-edges.
Conclusions:
- A universal principle for controlling TMD epitaxy based on substrate surface symmetry was established.
- This principle enables the successful wafer-scale, single-crystal MoS2 growth on the five predicted sapphire planes, paving the way for advanced electronic applications.
