The large‐area synthesis of high‐quality MoS2plays an important role in realizing industrial applications of optoelectronics, nanoelectronics, and flexible devices. However, current techniques for chemical vapor deposition (CVD)‐grown MoS2require a high synthetic temperature and a transfer process, which limits its utilization in device fabrications. Here, the direct synthesis of high‐quality monolayer MoS2with the domain size up to 120 µm by metal‐organic CVD (MOCVD) at a temperature of 320 °C is reported. Owing to the low‐substrate temperature, the MOCVD‐grown MoS2exhibits low impurity doping and nearly unstrained properties on the growth substrate, demonstrating enhanced electronic performance with high electron mobility of 68.3 cm2V−1s−1at room temperature. In addition, by tuning the precursor ratio, a better understanding of the MoS2growth process via a geometric model of the MoS2flake shape, is developed, which can provide further guidance for the synthesis of 2D materials.
The 2D van der Waals crystals have shown great promise as potential future electronic materials due to their atomically thin and smooth nature, highly tailorable electronic structure, and mass production compatibility through chemical synthesis. Electronic devices, such as field effect transistors (FETs), from these materials require patterning and fabrication into desired structures. Specifically, the scale up and future development of “2D”-based electronics will inevitably require large numbers of fabrication steps in the patterning of 2D semiconductors, such as transition metal dichalcogenides (TMDs). This is currently carried out via multiple steps of lithography, etching, and transfer. As 2D devices become more complex (e.g., numerous 2D materials, more layers, specific shapes, etc.), the patterning steps can become economically costly and time consuming. Here, we developed a method to directly synthesize a 2D semiconductor, monolayer molybdenum disulfide (MoS2), in arbitrary patterns on insulating SiO2/Si via seed-promoted chemical vapor deposition (CVD) and substrate engineering. This method shows the potential of using the prepatterned substrates as a master template for the repeated growth of monolayer MoS2patterns. Our technique currently produces arbitrary monolayer MoS2patterns at a spatial resolution of 2 μm with excellent homogeneity and transistor performance (room temperature electron mobility of 30 cm2V−1s−1and on–off current ratio of 107). Extending this patterning method to other 2D materials can provide a facile method for the repeatable direct synthesis of 2D materials for future electronics and optoelectronics.
more » « less- NSF-PAR ID:
- 10085774
- Publisher / Repository:
- Proceedings of the National Academy of Sciences
- Date Published:
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 116
- Issue:
- 9
- ISSN:
- 0027-8424
- Page Range / eLocation ID:
- p. 3437-3442
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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