Unprecedented Hole Concentration of NiSe<sub>2</sub> Electrodes Leading to Hole Degeneration of Entire WSe<sub>2</sub> Channels
Semimetal electrodes for 2D semiconductors have been extensively studied; however, research on p-type semimetals has been limited due to the scarcity of materials that satisfy both high work functions and low resistances. In response, we investigated the behavior of NiSe<sub>2</sub> as an electrode. Utilizing a novel co-evaporation method that suppresses oxidation and contamination, we synthesized NiSe<sub>2</sub> demonstrating a high work function of 5.53 eV, a low resistance of 5.81 × 10<sup>-5</sup> Ω cm, and a record hole concentration exceeding 10<sup>23</sup> cm<sup>-3</sup>. We confirmed that when WSe<sub>2</sub> comes into contact with NiSe<sub>2</sub>, the Fermi level of WSe<sub>2</sub> falls below the work function of NiSe<sub>2</sub>, leading to complete hole degeneration of the channel. This unusual Fermi level alignment correlates with the high hole concentration in NiSe<sub>2</sub> and the maximum energy level of its hole pockets. Our research provides new insights into how an electrode's hole concentration affects channel behavior.
Authors
- Soheil Ghods (ORCID: https://orcid.org/0000-0002-4374-2579)
- Hak Ki Yu (ORCID: https://orcid.org/0000-0003-4970-7018)
- Seung‐Il Kim (ORCID: https://orcid.org/0000-0002-3658-6221)
- Hyeon Ho Cho
- Ji Kwon Bae (ORCID: https://orcid.org/0009-0000-3840-3321)
- Jae‐Hyun Lee (ORCID: https://orcid.org/0000-0001-5117-8923)
- Hochan Jang (ORCID: https://orcid.org/0000-0002-1911-4847)
Institutions
- Pohang University of Science and Technology (KR)
- Ajou University (KR)
- Jeonbuk National University (KR)
Publication Details
- Journal
- Nano Letters
- Published
- 2024-10-08
- DOI
- https://doi.org/10.1021/acs.nanolett.4c03983
- Citations
- 5
- Primary Topic
- 2D Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.59
Funders
- Ministry of Science and ICT, South Korea