Projects per year
Abstract
The light–matter interaction in materials is of remarkable interest for various photonic and optoelectronic applications, which is intrinsically determined by the bandgap of the materials involved. To extend the applications beyond the bandgap limit, it is of great significance to study the light–matter interaction below the material bandgap. Here, we report the ultrafast transient absorption of monolayer molybdenum disulfide in its sub-bandgap region from ~0.86 µm to 1.4 µm. Even though this spectral range is below the bandgap, we observe a significant absorbance enhancement up to ~4.2% in the monolayer molybdenum disulfide (comparable to its absorption within the bandgap region) due to pump-induced absorption by the excited carrier states. The different rise times of the transient absorption at different wavelengths indicate the various contributions of the different carrier states (i.e., real carrier states in the short-wavelength region of ~<1 µm, and exciton states in the long wavelength region of ~>1 µm). Our results elucidate the fundamental understanding regarding the optical properties, excited carrier states, and carrier dynamics in the technologically important near-infrared region, which potentially leads to various photonic and optoelectronic applications (e.g., excited-state-based photodetectors and modulators) of two-dimensional materials and their heterostructures beyond their intrinsic bandgap limitations.
Original language | English |
---|---|
Article number | 27 |
Number of pages | 9 |
Journal | Light-Science & Applications |
Volume | 10 |
Issue number | 1 |
DOIs | |
Publication status | Published - 29 Jan 2021 |
MoE publication type | A1 Journal article-refereed |
Fingerprint
Dive into the research topics of 'Ultrafast transient sub-bandgap absorption of monolayer MoS2'. Together they form a unique fingerprint.-
-: Atomically-engineered nonlinear photonics with two-dimensional layered superlattices.
Sun, Z. (Principal investigator), Varjamo, S.-T. (Project Member), Wang, Y. (Project Member), Pelgrin, V. (Project Member), Wang, Y. (Project Member), Yoon, H. H. (Project Member), Das, S. (Project Member), Huang, Y. (Project Member), Liapis, A. (Project Member), Dai, Y. (Project Member), Mohsen, A. (Project Member), Nigmatulin, F. (Project Member), Uddin, M. (Project Member), Du, M. (Project Member), Zhang, Y. (Project Member), Arias, J. C. (Project Member), Lin, Y. (Project Member), Pajunpää, T. (Project Member), Turunen, M. (Project Member), Cui, X. (Project Member), Xing, J. (Project Member), Cheng, X. (Project Member), Kaaripuro, H. (Project Member) & Edwards, C. (Project Member)
01/09/2019 → 31/08/2025
Project: EU: ERC grants
-
FAST: Ultrafast Data Production with Broadband Photodetectors for Active Hyperspectral Space Imaging
Sun, Z. (Principal investigator), Varjamo, S.-T. (Project Member), Pajunpää, T. (Project Member), Cui, L. (Project Member), Nigmatulin, F. (Project Member) & Das, S. (Project Member)
01/01/2021 → 31/12/2023
Project: Academy of Finland: Other research funding
-
NOIMO: Novel optical isolators to continue Moore's law in photonics integration
Kaaripuro, H. (Project Member), Varjamo, S.-T. (Project Member), Dai, Y. (Project Member), Das, S. (Principal investigator) & Liapis, A. (Project Member)
01/09/2020 → 31/08/2024
Project: Academy of Finland: Other research funding