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Czech KJ, Thompson BJ, Kain S, Ding Q, Shearer MJ, Hamers RJ, Jin S, Wright JC. Measurement of Ultrafast Excitonic Dynamics of Few-Layer MoS2 Using State-Selective Coherent Multidimensional Spectroscopy. ACS NANO 2015; 9:12146-12157. [PMID: 26525496 DOI: 10.1021/acsnano.5b05198] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report the first coherent multidimensional spectroscopy study of a MoS2 film. A four-layer sample of MoS2 was synthesized on a silica substrate by a simplified sulfidation reaction and characterized by absorption and Raman spectroscopy, atomic force microscopy, and transmission electron microscopy. State-selective coherent multidimensional spectroscopy (CMDS) on the as-prepared MoS2 film resolved the dynamics of a series of diagonal and cross-peak features involving the spin-orbit split A and B excitonic states and continuum states. The spectra are characterized by striped features that are similar to those observed in CMDS studies of quantum wells where the continuum states contribute strongly to the initial excitation of both the diagonal and cross-peak features, while the A and B excitonic states contributed strongly to the final output signal. The strong contribution from the continuum states to the initial excitation shows that the continuum states are coupled to the A and B excitonic states and that fast intraband relaxation is occurring on a sub-70 fs time scale. A comparison of the CMDS excitation signal and the absorption spectrum shows that the relative importance of the continuum states is determined primarily by their absorption strength. Diagonal and cross-peak features decay with a 680 fs time constant characteristic of exciton recombination and/or trapping. The short time dynamics are complicated by coherent and partially coherent pathways that become important when the excitation pulses are temporally overlapped. In this region, the coherent dynamics create diagonal features involving both the excitonic states and continuum states, while the partially coherent pathways contribute to cross-peak features.
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Affiliation(s)
- Kyle J Czech
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Blaise J Thompson
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Schuyler Kain
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Qi Ding
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Melinda J Shearer
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Robert J Hamers
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Song Jin
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - John C Wright
- Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States
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Webber D, de Boer T, Yildirim M, March S, Mathew R, Gamouras A, Liu X, Dobrowolska M, Furdyna J, Hall K. Measurement of coherence decay in GaMnAs using femtosecond four-wave mixing. J Vis Exp 2013:51094. [PMID: 24326982 PMCID: PMC4028863 DOI: 10.3791/51094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The application of femtosecond four-wave mixing to the study of fundamental properties of diluted magnetic semiconductors ((s,p)-d hybridization, spin-flip scattering) is described, using experiments on GaMnAs as a prototype III-Mn-V system. Spectrally-resolved and time-resolved experimental configurations are described, including the use of zero-background autocorrelation techniques for pulse optimization. The etching process used to prepare GaMnAs samples for four-wave mixing experiments is also highlighted. The high temporal resolution of this technique, afforded by the use of short (20 fsec) optical pulses, permits the rapid spin-flip scattering process in this system to be studied directly in the time domain, providing new insight into the strong exchange coupling responsible for carrier-mediated ferromagnetism. We also show that spectral resolution of the four-wave mixing signal allows one to extract clear signatures of (s,p)-d hybridization in this system, unlike linear spectroscopy techniques. This increased sensitivity is due to the nonlinearity of the technique, which suppresses defect-related contributions to the optical response. This method may be used to measure the time scale for coherence decay (tied to the fastest scattering processes) in a wide variety of semiconductor systems of interest for next generation electronics and optoelectronics.
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Affiliation(s)
- Daniel Webber
- Department of Physics and Atmospheric Science, Dalhousie University
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Davis JA, Hall CR, Dao LV, Nugent KA, Quiney HM, Tan HH, Jagadish C. Three-dimensional electronic spectroscopy of excitons in asymmetric double quantum wells. J Chem Phys 2011; 135:044510. [DOI: 10.1063/1.3613679] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- J. A. Davis
- ARC Centre of Excellence for Coherent X-Ray Science, Australia
- Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Victoria 3122, Australia
| | - C. R. Hall
- ARC Centre of Excellence for Coherent X-Ray Science, Australia
- Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Victoria 3122, Australia
| | - L. V. Dao
- ARC Centre of Excellence for Coherent X-Ray Science, Australia
- Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Victoria 3122, Australia
| | - K. A. Nugent
- ARC Centre of Excellence for Coherent X-Ray Science, Australia
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - H. M. Quiney
- ARC Centre of Excellence for Coherent X-Ray Science, Australia
- School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - H. H. Tan
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra 0200, Australia
| | - C. Jagadish
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra 0200, Australia
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Yang L, Zhang T, Bristow AD, Cundiff ST, Mukamel S. Isolating excitonic Raman coherence in semiconductors using two-dimensional correlation spectroscopy. J Chem Phys 2009; 129:234711. [PMID: 19102556 DOI: 10.1063/1.3037217] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present the experimental and simulation results of two-dimensional optical coherent correlation spectroscopy signals along the phase-matching direction k(I) = -k(1) + k(2) + k(3) projected on the two-dimensional (2D) (Omega(3),Omega(2)) plane corresponding to the second and third delay periods. Overlapping Raman coherences in the conventional (Omega(3),Omega(1)) 2D projection may now be clearly resolved. The linewidths of the heavy-hole (HH) and light-hole (LH) excitonic Raman coherence peaks are obtained. Further insights on the higher-order (beyond time-dependent Hartree-Fock) correlation effects among mixed (HH and LH) two excitons can be gained by using a cocircular pulse polarization configuration.
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Affiliation(s)
- Lijun Yang
- Department of Chemistry, University of California, Irvine, California 62697-2025, USA
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Borca CN, Zhang T, Li X, Cundiff ST. Optical two-dimensional Fourier transform spectroscopy of semiconductors. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.09.090] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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