|About this Abstract
||Materials Science & Technology 2020
||Advances in Synthesis and Integration Methods for Enhanced Properties, and Applications in Emerging Nanomaterials
||Integration of Synthesis and Computation to Investigate Two-dimensional Transition Metal Chalcogenides: Strain, Defect, and Moiré Engineering
||Yanfu Lu, Fu Zhang, Wenkai Zheng, Daniel Schulman, Lavish Pabbi, Kazunori Fujisawa, Ana Laura Elias, Anna R Binion, Tomotaroh Granzier-Nakajima, Tianyi Zhang, Yu Lei, Zhong Lin, Eric W Hudson, Saptarshi Das, Luis Balicas, Mauricio Terrones, Susan B. Sinnott
|On-Site Speaker (Planned)
||Susan B. Sinnott
Density functional theory (DFT) calculations predict carbon doping of transition metal dichalcogenides (TMDs) tunes their electronic structure and optical properties. We synthesized these C-doped WS<sub>2</sub> monolayers by a plasma-assisted strategy to “gently” incorporate carbon as a substitutional anion dopant within the TMD lattice. Electrical characterization indicates that carbon may be an acceptor in WS<sub>2</sub>, thus effectively tuning its work function and making it ambipolar. We also investigated the sulfurization of thin (<50 nm) Mo<sub>2</sub>C systems using gaseous H<sub>2</sub>S. The controlled incorporation of sulfur can form metastable ternary solid solutions based on molybdenum-carbon-chalcogen whereas the presence of excessive chalcogen atoms results in phase segregation of stable carbides and sulfides. Lastly, DFT calculations predict that the majority of 2D TMDs can accommodate ±10% strain without breaking their crystal symmetry. ReSe<sub>2</sub> and Au<sub>2</sub>Se<sub>2</sub> at +5% epitaxial strain are predicted to possess extreme d<sub>11</sub> coefficients at -120 pm/V and 326 pm/V, respectively.