Band Alignment among CNTs with Varying Diameters and Schottky Barrier Fluctuations between CNTs and Metals: A First-Principles Study
In carbon nanotube thin film transistors (CNT-TFTs), the performance is significantly influenced by the fluctuation in the diameter of the CNTs in channel. In this work, first-principles calculations were employed to explore the fluctuations in the valence band maximum and conduction band minimum of CNTs with diameters ranging from 0.78 to 2.07 nm. Band alignment analysis reveals maximum offsets reach 0.54 eV for the valence band and 0.48 eV for the conduction band, with larger CNTs (diameters over 1.8 nm) exhibiting energy band fluctuations of less than 0.06 eV. Further analysis shows that the fluctuation in Schottky barrier height (SBH) is smaller between CNTs and Pd compared to CNTs and Ti. Atomistic simulations of Pd-CNT-Pd devices at −2 V demonstrate that the variation in on-state current between 1.49 and 2.04 nm CNTs is six times smaller than that between 1.02 and 1.49 nm CNTs. This indicates that inter-nanotube fluctuations in larger-diameter CNTs have a smaller impact on device current compared to fluctuations in smaller-diameter CNTs. These findings suggest that larger-diameter CNTs (greater than 1.8 nm) enhance the uniformity of electrical properties, presenting a promising approach to improving the reliability of CNT-based thin-film devices.
Authors
- Bo Li (ORCID: https://orcid.org/0000-0003-4905-2744)
- Fanyu Liu (ORCID: https://orcid.org/0000-0002-6154-4971)
- Yu‐Qing Zhao (ORCID: https://orcid.org/0000-0001-8073-5346)
- Maguang Zhu (ORCID: https://orcid.org/0000-0001-7037-0136)
- Yuanjun Tang (ORCID: https://orcid.org/0009-0008-2938-768X)
- Zhenping Wu (ORCID: https://orcid.org/0000-0003-2986-8068)
- Tao Zhang (ORCID: https://orcid.org/0000-0002-6261-9074)
- Fan Zhang (ORCID: https://orcid.org/0000-0002-3261-3536)
- Lei Wang (ORCID: https://orcid.org/0000-0002-0537-1105)
- Huiping Zhu (ORCID: https://orcid.org/0000-0003-1307-3631)
- Yang Zhang (ORCID: https://orcid.org/0000-0002-3588-4702)
Institutions
- Hunan University of Science and Technology (CN)
- Beijing University of Posts and Telecommunications (CN)
- Chinese Academy of Sciences (CN)
- Sensors (United States) (US)
- Photonics (United States) (US)
- Sensor Electronics (United States) (US)
- State Key Laboratory of Information Photonics and Optical Communications
- Nanjing University (CN)
Publication Details
- Journal
- ACS Applied Nano Materials
- Published
- 2025-04-14
- DOI
- https://doi.org/10.1021/acsanm.5c00541
- Citations
- 1
- Primary Topic
- Semiconductor materials and interfaces
- Type
- article
- Field-Weighted Citation Impact
- 1.25
Funders
- National Natural Science Foundation of China
- Youth Innovation Promotion Association of the Chinese Academy of Sciences
- National Key Research and Development Program of China
- Fundamental Research Funds for the Central Universities
- Bureau of Frontier Sciences and Education, Chinese Academy of Sciences