Sivasakthya Mohan1,Yuqian Gu1,2,Martha Serna1,Jia Yu1,Shanmukh Kutagulla1,Keji Lai1,Kenneth Liechti1,Deji Akinwande1
The University of Texas at Austin1,Intel Corporation2
Sivasakthya Mohan1,Yuqian Gu1,2,Martha Serna1,Jia Yu1,Shanmukh Kutagulla1,Keji Lai1,Kenneth Liechti1,Deji Akinwande1
The University of Texas at Austin1,Intel Corporation2
Despite the widespread research in studying the synthesis and properties of two-dimensional (2D) materials for electronic devices, there are still some intrinsic challenges such as zero bandgap (for e.g., graphene), low carrier mobilities (e.g., Transition Metal Dichalcogenides or TMDs) which prevent their successful transition to real-world applications. 2D heterostructures present new prospects for advanced materials design for specific optoelectronic and transport applications. By combining the unique properties of different 2D materials, heterostructures can be tailored suitably to possess distinct functionalities. While the fabrication of vertical heterostructures is more common through exfoliation and transfer methods, contaminations and stacking orientations between the layers often restrict their device performance<sup>1</sup>. To this end, efforts have been made in the synthesis of lateral heterostructures where the different domains are covalently bonded and can enhance device performance.<br/>In this work, we synthesized wafer-scale lateral heterostructures of MoS<sub>2</sub> and WS<sub>2</sub> on sapphire, through e-beam lithographic patterning followed by one-step, low-temperature sulfurization<sup>2</sup> of the thin metal films of molybdenum and tungsten. The quality and number of layers of the sulfurized heterostructures have been evaluated using optical microscopy, large-area Raman maps, and cross-section TEM. The seamless transition between the 2D TMDs at the interface has been further evaluated using high-resolution characterization techniques such as XPS, ToFSIMS, and atomic force microscopy. A scanning microwave impedance microscope (MIM) was employed to obtain the spatial conductivity resolution of the heterojunctions. Enhanced photocurrent measurements obtained on the fabricated devices pointed to potential applications in photo-sensing devices.<br/><b>REFERENCES</b><br/>1. Chakraborty, S. K., Kundu, B., Nayak, B., Dash, S. P., & Sahoo, P. K. (2022). Challenges and opportunities in 2D heterostructures for electronic and optoelectronic devices. Iscience, 25(3), 103942.<br/>2. Gu, Yuqian, et al. "Sulfurization Engineering of One - Step Low - Temperature MoS2 and WS2 Thin Films for Memristor Device Applications." Advanced Electronic Materials 8.2 (2022): 2100515.