| Autor: |
Kim, In Soo, Sangwan, Vinod K., Jariwala, Deep, Wood, Joshua D., Park, Spencer, Chen, Kan-Sheng, Shi, Fengyuan, Ruiz-Zepeda, Francisco, Ponce, Arturo, Jose-Yacaman, Miguel, Dravid, Vinayak P., Marks, Tobin J., Hersam, Mark C., Lauhon, Lincoln J. |
| Rok vydání: |
2014 |
| Předmět: |
|
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1021/nn503988x |
| Popis: |
Ultrathin transition metal dichalcogenides (TMDCs) of Mo and W show great potential for digital electronics and optoelectronic applications. Whereas early studies were limited to mechanically exfoliated flakes, the large-area synthesis of 2D TMDCs has now been realized by chemical vapor deposition (CVD) based on a sulfurization reaction. Since then, the optoelectronic properties of CVD grown monolayer MoS$_{2}$ have been heavily investigated, but the influence of stoichiometry on the electrical and optical properties has been largely overlooked. Here we systematically vary the stoichiometry of monolayer MoS$_{2}$ during CVD via controlled sulfurization and investigate the associated changes in photoluminescence and electrical properties. X-ray photoelectron spectroscopy is employed to measure relative variations in stoichiometry and the persistence of MoO$_{x}$ species. As MoS$_{2-{\delta}}$ is reduced (increasing {\delta}), the field-effect mobility of monolayer transistors increases while the photoluminescence yield becomes non-uniform. Devices fabricated from monolayers with the lowest sulfur content have negligible hysteresis and a threshold voltage of ~0 V. We conclude that the electrical and optical properties of monolayer MoS$_{2}$ crystals can be tuned via stoichiometry engineering to meet the requirements of various applications. |
| Databáze: |
arXiv |
| Externí odkaz: |
|
