2020 Fiscal Year Annual Research Report
Synthesis of wafer-scale two-dimensional transition metal dichalcogenide single crystals for high-performance electronic devices
| Project/Area Number |
19K15399
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| Research Institution | National Institute for Materials Science |
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Principal Investigator |
李 世勝 国立研究開発法人物質・材料研究機構, 若手国際研究センター, ICYS研究員 (90812678)
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| Project Period (FY) |
2019-04-01 – 2021-03-31
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| Keywords | 二次元ナノ材料科学 / 化学気相成長 / 遷移金属カルコゲナイド / 電界効果トランジスタ / 電子デバイス |
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| Outline of Annual Research Achievements |
Tunable Doping of Rhenium and Vanadium into Transition Metal Dichalcogenides for Two-Dimensional Electronics: Two-dimensional (2D) transition metal dichalcogenides (TMDCs) with unique electrical properties are fascinating materials used for future electronics. However, the strong Fermi level pinning effect at the interface of TMDCs and metal electrodes always leads to high contact resistance, which seriously hinders their application in 2D electronics. One effective way to overcome this is to use metallic TMDCs or transferred metal electrodes as van der Waals (vdW) contacts. Alternatively, using highly conductive doped TMDCs will have a profound impact on the contact engineering of 2D electronics. In this project, a novel chemical vapor deposition using mixed molten salts is established for vapor-liquid-solid growth of high-quality rhenium (Re, electron donor) and vanadium (V, electron acceptor)-doped TMDC monolayers with high controllability and reproducibility. A tunable semiconductor to metal transition is observed in the Re- and V-doped TMDCs. Electrical conductivity increases up to a factor of 108 in the degenerate V-doped WS2 and WSe2. Using V-doped WSe2 as vdW contact, the on-state current and on/off ratio of WSe2-based field effect transistors (FETs) have been substantially improved (from ~10e-8 to 10e-5 A; ~10e4 to 10e8), compared to metal contacts. Future studies on lateral contacts and interconnects using doped TMDCs will pave the way for 2D integrated circuits and flexible electronics. This achievement was published in Advanced Science, 2021, 8(12), 2004438.
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Research Products
(15 results)
