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Recent technology development of logic devices based on 2-D semiconductors such as MoS2, WS2, and WSe2 has triggered great excitement, paving the way to practical applications. Making low-resistance p-type contacts to 2-D semiconductors remains a critical challenge. The key to addressing this challenge is to find high-work function metallic materials which also introduce minimal metal-induced gap states (MIGSs) at the metal/semiconductor interface. In this work, we perform a systematic computational screening of novel metallic materials and their heterojunctions with monolayer WSe2 based on ab initio density functional theory and quantum device simulations. Two contact strategies, van der Waals (vdW) metallic contact and bulk semimetallic contact, are identified as promising solutions to achieving Schottky-barrier-free and low-contact-resistance p-type contacts for WSe2 p-type field-effect transistor (pFETs). Good candidates of p-type contact materials are found based on our screening criteria, including 1H-NbS2, 1H-TaS2, and 1T-TiS2 in the vdW metal category, as well as Co3Sn2S2 and TaP in the bulk semimetal category. Simulations of these new p-type contact materials suggest reduced MIGS, less Fermi-level pinning effect, negligible Schottky barrier height and small contact resistance (down to 20 Ωμm )
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This content will become publicly available on September 16, 2026
Local Interface Effects Modulate Global Charge Order and Optical Properties of 1 T –TaS 2 /1 H –WSe 2 Heterostructures
1T–TaS2 is a layered charge density wave (CDW) crystal exhibiting sharp phase transitions and associated resistance changes. These resistance steps could be exploited for information storage, underscoring the importance of controlling and tuning the CDW states. Given the importance of out-of-plane interactions in 1T–TaS2, modulating interlayer interactions by heterostructuring is a promising method for tailoring CDW phase transitions. In this work, we investigate the optical and electronic properties of heterostructures comprising 1T–TaS2 and monolayer 1H–WSe2. By systematically varying the thickness of 1T–TaS2 and its azimuthal alignment with 1H–WSe2, we find that intrinsic moiré strain and interfacial charge transfer introduce CDW disorder in 1T–TaS2 and modify the CDW ordering temperature. Furthermore, our studies reveal that the interlayer alignment impacts the exciton dynamics in 1H–WSe2, indicating that heterostructuring can concurrently tailor the electronic phases in 1T–TaS2 and the optical properties of 1H–WSe2. This work presents a promising approach for engineering the optoelectronic behavior of heterostructures that integrate CDW materials and semiconductors.
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- Award ID(s):
- 2238196
- PAR ID:
- 10674730
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- ACS Nano
- Volume:
- 19
- Issue:
- 36
- ISSN:
- 1936-0851
- Page Range / eLocation ID:
- 32218 to 32230
- Subject(s) / Keyword(s):
- charge density wave, heterostructure, moiré, transition metal dichalcogenide, charge transfer
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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