Toward Phonon-Limited Transport in Two-Dimensional Transition Metal Dichalcogenides by Oxygen-Free Fabrication

Toward Phonon-Limited Transport in Two-Dimensional Transition Metal Dichalcogenides by Oxygen-Free Fabrication

ACS Nano

10.1021/acsnano.5c00995

https://doi.org/10.1021/acsnano.5c00995

Subhrajit Mukherjee, Shuhua Wang, Dasari Venkatakrishnarao, Yaoju Tarn, Teymour Talha-Dean, Rainer Lee, Ivan A. Verzhbitskiy, Ding Huang, Abhishek Mishra, John Wellington John, Sarthak Das, Fabio Bussolotti, Thathsara Deshani Maddumapatabandi, Yee Wen Teh, Yee Sin Ang, Kuan Eng Johnson Goh, Chit Siong Lau

25 February 2025

Mukherjee, S., Wang, S., Venkatakrishnarao, D., Tarn, Y., Talha-Dean, T., Lee, R., Verzhbitskiy, I. A., Huang, D., Mishra, A., John, J. W., Das, S., Bussolotti, F., Maddumapatabandi, T. D., Teh, Y. W., Ang, Y. S., Johnson Goh, K. E., & Lau, C. S. (2025). Toward Phonon-Limited Transport in Two-Dimensional Transition Metal Dichalcogenides by Oxygen-Free Fabrication. ACS Nano, 19(9), 9327–9339. https://doi.org/10.1021/acsnano.5c00995

Developing future electronics will require aggressive scaling of the channel material thickness while maintaining device performance. Two-dimensional (2D) semiconductors are promising candidates to sustain further device scaling, but despite more than two decades of intense research, experimental performance continues to lag theoretical expectations. Here, we develop an oxygen-free approach to fabricate 2D field-effect transistors and push the electrical transport toward the theoretical phonon-limited intrinsic mobility. This approach achieves record carrier mobilities of 91 and 132 cm2 V–1 s–1 for mono- and bilayer MoS2 transistors on silicon oxide substrates. Statistical analysis of over 60 MoS2 and WS2 devices confirms that oxygen-free fabrication enhances device performance by more than an order of magnitude across key figures of merit. While previous studies suggest that 2D transition metal dichalcogenides such as MoS2 and WS2 are relatively stable in air, we show that even short-term ambient exposure can degrade their performance. We identify oxygen as a crucial factor in limiting transistor performance through irreversible chemisorption. This study emphasizes the criticality of avoiding oxygen exposure and offers guidance for device manufacturing that impacts fundamental research and practical applications of 2D materials.

Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

This research / project is supported by the Agency for Science, Technology and Research - NA
Grant Reference no. : #21709

This research / project is supported by the Agency for Science, Technology and Research - NA
Grant Reference no. : C230917006

This research / project is supported by the Agency for Science, Technology and Research - NA
Grant Reference no. : C230917007, C222812022

This research / project is supported by the Agency for Science, Technology and Research - Manufacturing, Trade, and Connectivity Individual Research Grants
Grant Reference no. : M23M6c0103

This research / project is supported by the Agency for Science, Technology and Research - Manufacturing, Trade, and Connectivity Young Individual Research Grants
Grant Reference no. : M21K3c0124

This research / project is supported by the National Research Foundation - Competitive Research Programme
Grant Reference no. : CRP21-2018-0001

This research / project is supported by the Agency for Science, Technology and Research - Manufacturing, Trade, and Connectivity Young Individual Research Grants
Grant Reference no. : M22K3c0105

This research / project is supported by the Ministry of Education - Academic Research Fund Tier 2
Grant Reference no. : MOE-T2EP50221-0019

This research / project is supported by the Singapore University of Technology and Design - SUTD-ZJU IDEA Thematic Research Grant
Grant Reference no. : SUTD-ZJU (TR) 202203

https://oar.a-star.edu.sg/communities-collections/articles/21822

1936-0851
1936-086X

Science and Engineering Research Council