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A multiscale simulation approach is developed to simulate the contact transport properties between semimetal and a monolayer two-dimensional transition metal dichalcogenide (TMDC) semiconductor. The results elucidate the mechanisms for low contact resistance between semimetal and TMDC semiconductor contacts from a quantum transport perspective. The simulation results compare favorably with recent experiments. Furthermore, the results show that the contact resistance of a bismuth-MoS2contact can be further reduced by engineering the dielectric environment and doping the TMDC material to [Formula: see text]. The quantum transport simulation indicates the possibility to achieve an ultrashort contact transfer length of ∼1 nm, which can allow aggressive scaling of the contact size.
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Semimetal–Monolayer Transition Metal Dichalcogenides Photodetectors for Wafer‐Scale Broadband Photonics
Atomically thin 2D transition metal dichalcogenides (TMDs), such as MoS2, are promising candidates for nanoscale photonics because of strong light–matter interactions. However, Fermi‐level pinning due to metal‐induced gap states (MIGS) at the metal–monolayer (1L)‐MoS2interface limits the application of optoelectronic devices based on conventional metals due to high contact resistance. On the other hand, a semimetal–TMD–semimetal device can overcome this limitation, where the MIGS are sufficiently suppressed allowing ohmic contacts. Herein, the optoelectronic performance of a bismuth–1L‐MoS2–bismuth device with ohmic electrical contacts and extraordinary optoelectronic properties is demonstrated. To address the wafer‐scale production, full coverage 1L‐MoS2grown by chemical vapor deposition. High photoresponsivity of 300 A W−1at wavelength 400 nm measured at 77 K, which translates into an external quantum efficiency (EQE) ≈1000 or 105%, is measured. The 90% rise time of the devices at 77 K is 0.1 ms, suggesting they can operate at the speed of ≈10 kHz. High‐performance broadband photodetector with spectral coverage ranging from 380 to 1000 nm is demonstrated. The combination of large‐array device fabrication, high sensitivity, and high‐speed response offers great potential for applications in photonics, including integrated optoelectronic circuits.
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- Award ID(s):
- 2151971
- PAR ID:
- 10400098
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Photonics Research
- Volume:
- 4
- Issue:
- 4
- ISSN:
- 2699-9293
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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