Cited 0 time in webofscience Cited 0 time in scopus

Transient SHG Imaging on Ultrafast Carrier Dynamics of MoS2 Nanosheets

Title
Transient SHG Imaging on Ultrafast Carrier Dynamics of MoS2 Nanosheets
Authors
Jang, H.Dhakal, K.P.Joo, K.-I.Yun, Won SeokShinde, S.M.Chen, X.Jeong, Soon MoonLee, S.W.Lee, Z.Lee, Jae DongAhn, J.-H.Kim, Hyun Min
DGIST Authors
Jeong, Soon MoonLee, Jae DongKim, Hyun Min
Issue Date
2018-04
Citation
Advanced Materials, 30(14), 1705190
Type
Article
Article Type
Article
Keywords
Electromagnetic wave emissionExcitonsNanosheetsNonlinear opticsOptical pumpingOptical waveguidesPhononsStereochemistrySulfur compoundsAcoustic phononsCollaborative behaviorLight-matter interactionsLow-dimensional materialsMolybdenum disulfideOut-of-plane directionSecond harmonic generation microscopies (SHG)Ultrafast carrier dynamicsHarmonic generation
ISSN
0935-9648
Abstract
Understanding the collaborative behaviors of the excitons and phonons that result from light-matter interactions is important for interpreting and optimizing the underlying fundamental physics at work in devices made from atomically thin materials. In this study, the generation of exciton-coupled phonon vibration from molybdenum disulfide (MoS2) nanosheets in a pre-excitonic resonance condition is reported. A strong rise-to-decay profile for the transient second-harmonic generation (TSHG) of the probe pulse is achieved by applying substantial (20%) beam polarization normal to the nanosheet plane, and tuning the wavelength of the pump beam to the absorption of the A-exciton. The time-dependent TSHG signals clearly exhibit acoustic phonon generation at vibration modes below 10 cm-1 (close to the Γ point) after the photoinduced energy is transferred from exciton to phonon in a nonradiative fashion. Interestingly, by observing the TSHG signal oscillation period from MoS2 samples of varying thicknesses, the speed of the supersonic waves generated in the out-of-plane direction (Mach 8.6) is generated. Additionally, TSHG microscopy reveals critical information about the phase and amplitude of the acoustic phonons from different edge chiralities (armchair and zigzag) of the MoS2 monolayers. This suggests that the technique could be used more broadly to study ultrafast physics and chemistry in low-dimensional materials and their hybrids with ultrahigh fidelity. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
URI
http://hdl.handle.net/20.500.11750/5911
DOI
10.1002/adma.201705190
Publisher
Wiley-VCH Verlag
Related Researcher
  • Author Lee, Jae Dong Light and Matter Theory Laboratory
  • Research Interests Theoretical Condensed Matter Physics; Ultrafast Dynamics and Optics; Nonequilibrium Phenomena
Files:
There are no files associated with this item.
Collection:
Smart Textile Convergence Research Group1. Journal Articles
Department of Emerging Materials ScienceLight and Matter Theory Laboratory1. Journal Articles
Companion Diagnostics and Medical Technology Research Group1. Journal Articles


qrcode mendeley

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE