Fabrication of MoS<sub>2</sub>-Graphene Heterostructures for Applications in High-Speed High-Responsivity Photodetectors
POSTER
Abstract
Juan Pablo Campbell Naranjo, James Xu, Benjarat Chumwong, Jie Goodrich, Daniel Castro, Benjamin Dechant, and Huizhong Xu
Department of Physics & Astronomy, San Francisco State University
1600 Holloway Avenue, San Francisco, CA 94132
Atomically thin 2D transition metal dichalcogenides such as MoS2 have shown promise for use in high-efficiency photodetectors (PDs) due to their tunable band gap, excellent switching ratio, and high responsivity [1]. For example, PDs based on CVD-grown monolayer MoS2 and bismuth electrode contacts have demonstrated photo-responsivities of up to 300 A/W at wavelengths around 400 nm [2]. However, applications for MoS2-based PDs are limited as their relatively low carrier mobility results in generally slow speeds. To overcome this limitation, PDs based on van der Waals heterostructures, in particular vertical MoS2-graphene heterostructures, have gained much attention in recent years [3,4]. In this study, we demonstrate the fabrication of MoS2-graphene vertical heterostructure photodetectors based on mechanically exfoliated MoS2 of varying thicknesses. By exploiting the combined advantages of the high photosensitivity of MoS2, the small Schottky barrier between MoS2 and graphene [5], and the short carrier transit time of graphene, we aim to greatly reduce the photocurrent response time while maintaining high photosensitivity.
[1] Y. Li et al., ACS Omega 7, 13615-13621 (2022).
[2] H.-L. Sinn et al., Adv. Photonics Res. 4, 2300029 (2023).
[3] N. Flöry et al., Nat. Nanotechnol. 15, 118-124 (2020).
[4] B. Hyot et al., Nanotechnology 35, 165503 (2024).
[5] J.Y. Kwak et al., Nano Lett. 14, 4511 (2014).
Department of Physics & Astronomy, San Francisco State University
1600 Holloway Avenue, San Francisco, CA 94132
Atomically thin 2D transition metal dichalcogenides such as MoS2 have shown promise for use in high-efficiency photodetectors (PDs) due to their tunable band gap, excellent switching ratio, and high responsivity [1]. For example, PDs based on CVD-grown monolayer MoS2 and bismuth electrode contacts have demonstrated photo-responsivities of up to 300 A/W at wavelengths around 400 nm [2]. However, applications for MoS2-based PDs are limited as their relatively low carrier mobility results in generally slow speeds. To overcome this limitation, PDs based on van der Waals heterostructures, in particular vertical MoS2-graphene heterostructures, have gained much attention in recent years [3,4]. In this study, we demonstrate the fabrication of MoS2-graphene vertical heterostructure photodetectors based on mechanically exfoliated MoS2 of varying thicknesses. By exploiting the combined advantages of the high photosensitivity of MoS2, the small Schottky barrier between MoS2 and graphene [5], and the short carrier transit time of graphene, we aim to greatly reduce the photocurrent response time while maintaining high photosensitivity.
[1] Y. Li et al., ACS Omega 7, 13615-13621 (2022).
[2] H.-L. Sinn et al., Adv. Photonics Res. 4, 2300029 (2023).
[3] N. Flöry et al., Nat. Nanotechnol. 15, 118-124 (2020).
[4] B. Hyot et al., Nanotechnology 35, 165503 (2024).
[5] J.Y. Kwak et al., Nano Lett. 14, 4511 (2014).
*We would like to acknowledge the support from the NSF (Award #ECCS-2151971 and Award #ECCS-2235474), and the DoD Army Research Office through the HBCU/MI program (grant #W911NF-21-1-0241).
Presenters
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Juan P Campbell Naranjo
- San Francisco State University