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12 February 2020
Layer-dependent signatures for exciton dynamics in monolayer and multilayer WSe2 revealed by fluorescence lifetime imaging measurement
Dameng Liu1(
)
)
Keywords:
density functional theory (DFT), two-dimensional (2D) WSe2, exciton dynamics, fluorescence lifetime, fluorescence lifetime imaging microscopy (FLIM)
Topics:
Density functional theoryDynamics Fluorescence imagingMonolayersOptical propertiesOptoelectronic devicesTransition metals
Cite this article:
Liu Y, Li H, Qiu C, et al.
Layer-dependent signatures for exciton dynamics in monolayer and multilayer WSe2 revealed by fluorescence lifetime imaging measurement.
Nano Research,
2020, 13(3): 661-666.
https://doi.org/10.1007/s12274-020-2670-7
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Two-dimensional (2D) transition-metal dichalcogenide (TMD) materials have aroused noticeable interest due to their distinguished electronic and optical properties. However, little is known about their complex exciton properties together with the exciton dynamics process which have been expected to influence the performance of optoelectronic devices. The process of fluorescence can well reveal the process of exciton transition after excitation. In this work, the room-temperature layer-dependent exciton dynamics properties in layered WSe2 are investigated by the fluorescence lifetime imaging microscopy (FLIM) for the first time. This paper focuses on two mainly kinds of excitons including the direct transition neutral excitons and trions. Compared with the lifetime of neutral excitons (< 0.3 ns within four-layer), trions possess a longer lifetime (~ 6.6 ns within four-layer) which increases with the number of layers. We attribute the longer-lived lifetime to the increasing number of trions as well as the varieties of trion configurations in thicker WSe2. Besides, the whole average lifetime increases over 10% when WSe2 flakes added up from monolayer to four-layer. This paper provides a novel tuneable layer-dependent method to control the exciton dynamics process and finds a relatively longer transition lifetime of trions at room temperature, enabling to investigate in the charge transport in TMD-based optoelectronics devices in the future.
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Layer-dependent signatures for exciton dynamics in monolayer and multilayer WSe2 revealed by fluorescence lifetime imaging measurement
Dameng Liu1(
)
)
Abstract
Two-dimensional (2D) transition-metal dichalcogenide (TMD) materials have aroused noticeable interest due to their distinguished electronic and optical properties. However, little is known about their complex exciton properties together with the exciton dynamics process which have been expected to influence the performance of optoelectronic devices. The process of fluorescence can well reveal the process of exciton transition after excitation. In this work, the room-temperature layer-dependent exciton dynamics properties in layered WSe2 are investigated by the fluorescence lifetime imaging microscopy (FLIM) for the first time. This paper focuses on two mainly kinds of excitons including the direct transition neutral excitons and trions. Compared with the lifetime of neutral excitons (< 0.3 ns within four-layer), trions possess a longer lifetime (~ 6.6 ns within four-layer) which increases with the number of layers. We attribute the longer-lived lifetime to the increasing number of trions as well as the varieties of trion configurations in thicker WSe2. Besides, the whole average lifetime increases over 10% when WSe2 flakes added up from monolayer to four-layer. This paper provides a novel tuneable layer-dependent method to control the exciton dynamics process and finds a relatively longer transition lifetime of trions at room temperature, enabling to investigate in the charge transport in TMD-based optoelectronics devices in the future.
Keywords:
density functional theory (DFT), two-dimensional (2D) WSe2, exciton dynamics, fluorescence lifetime, fluorescence lifetime imaging microscopy (FLIM)
References(56)
[1]
Conley, H. J.; Wang, B.; Ziegler, J. I.; Haglund, R. F. Jr.; Pantelides, S. T.; Bolotin, K. I. Bandgap engineering of strained monolayer and bilayer MoS2. Nano Lett. 2013, 13, 3626-3630.
[2]
Mak, K. F.; Lee, C.; Hone, J.; Shan, J.; Heinz, T. F. Atomically thin MoS2: A new direct-gap semiconductor. Phys. Rev. Lett. 2010, 105, 136805.
[3]
Lee, H. S.; Min, S. W.; Chang, Y. G.; Park, M. K.; Nam, T.; Kim, H.; Kim, J. H.; Ryu, S.; Im, S. MoS2 nanosheet phototransistors with thickness-modulated optical energy gap. Nano Lett. 2012, 12, 3695-3700.
[4]
Xiao, D.; Liu, G. B.; Feng, W. X.; Xu, X. D.; Yao, W. Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides. Phys. Rev. Lett. 2012, 108, 196802.
[5]
Zhang, X. X.; Cao, T.; Lu, Z. G.; Lin, Y. C.; Zhang, F.; Wang, Y.; Li, Z. Q.; Hone, J. C.; Robinson, J. A.; Smirnov, D. et al. Magnetic brightening and control of dark excitons in monolayer WSe2. Nat. Nanotechnol. 2017, 12, 883-888.
[6]
Mak, K. F.; He, K. L.; Lee, C.; Lee, G. H.; Hone, J.; Heinz, T. F.; Shan, J. Tightly bound trions in monolayer MoS2. Nat. Mater. 2013, 12, 207-211.
[7]
Jones, A. M.; Yu, H. Y.; Ghimire, N. J.; Wu, S. F.; Aivazian, G.; Ross, J. S.; Zhao, B.; Yan, J. Q.; Mandrus, D. G.; Xiao, D. et al. Optical generation of excitonic valley coherence in monolayer WSe2. Nat. Nanotechnol. 2013, 8, 634-638.
[8]
Jones, A. M.; Yu, H. Y.; Ross, J. S.; Klement, P.; Ghimire, N. J.; Yan, J. Q.; Mandrus, D. G.; Yao, W.; Xu, X. D. Spin-layer locking effects in optical orientation of exciton spin in bilayer WSe2. Nat. Phys. 2014, 10, 130-134.
[9]
Ross, J. S.; Wu, S. F.; Yu, H. Y.; Ghimire, N. J.; Jones, A. M.; Aivazian, G.; Yan, J. Q.; Mandrus, D. G.; Xiao, D.; Yao, W. et al. Electrical control of neutral and charged excitons in a monolayer semiconductor. Nat. Commun. 2013, 4, 1474.
[10]
Godde, T.; Schmidt, D.; Schmutzler, J.; ABmann, M.; Debus, J.; Withers, F.; Alexeev, E.; Del Pozo-Zamudio, O.; Skrypka, O.; Novoselov, K. Exciton and trion dynamics in atomically thin MoSe2 and WSe2: Effect of localization. Phys. Rev. B 2016, 94, 165301.
[11]
Vaclavkova, D.; Wyzula, J.; Nogajewski, K.; Bartos, M.; Slobodeniuk, A. O.; Faugeras, C.; Potemski, M.; Molas, M. R. Singlet and triplet trions in WS2 monolayer encapsulated in hexagonal boron nitride. Nanotechnology 2018, 29, 325705.
[12]
Hong, X. P.; Kim, J.; Shi, S. F.; Zhang, Y.; Jin, C. H.; Sun, Y. H.; Tongay, S.; Wu, J. Q.; Zhang, Y. F.; Wang, F. Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures. Nat. Nanotechnol. 2014, 9, 682-686.
[13]
Pei, J. J.; Yang, J.; Xu, R. J.; Zeng, Y. H.; Myint, Y. W.; Zhang, S.; Zheng, J. C.; Qin, Q. H.; Wang, X. B.; Jiang, W. G. et al. Exciton and trion dynamics in bilayer MoS2. Small 2015, 11, 6384-6390.
[14]
Splendiani, A.; Sun, L.; Zhang, Y. B.; Li, T. S.; Kim, J.; Chim, C. Y.; Galli, G.; Wang, F. Emerging photoluminescence in monolayer MoS2. Nano Lett. 2010, 10, 1271-1275.
[15]
Zhang, Y.; Chang, T. R.; Zhou, B.; Cui, Y. T.; Yan, H.; Liu, Z. K.; Schmitt, F.; Lee, J.; Moore, R.; Chen, Y. L. et al. Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2. Nat. Nanotechnol. 2014, 9, 111-115.
[16]
Jin, W. C.; Yeh, P. C.; Zaki, N.; Zhang, D. T.; Sadowski, J. T.; Al-Mahboob, A.; van Der Zande, A. M.; Chenet, D. A.; Dadap, J. I.; Herman, I. P. Direct measurement of the thickness-dependent electronic band structure of MoS2 using angle-resolved photoemission spectroscopy. Phys. Rev. Lett. 2013, 111, 106801.
[17]
Vasili, P.; Tersoff, J.; Phaedon, A. Scaling of excitons in carbon nanotubes. Phys. Rev. Lett. 2004, 92, 257402.
[18]
Berghäuser, G.; Malic, E. Analytical approach to excitonic properties of MoS2. Phys. Rev. B 2014, 89, 125309.
[19]
Eda, G.; Maier, S. A. Two-dimensional crystals: Managing light for optoelectronics. Acs Nano 2013, 7, 5660-5665.
[20]
Yang, J.; Xu, R. J.; Pei, J. J.; Myint, Y. W.; Wang, F.; Wang, Z.; Zhang, S.; Yu, Z. F.; Lu, Y. R. Optical tuning of exciton and trion emissions in monolayer phosphorene. Light: Sci. Appl. 2015, 4, e312.
[21]
Selig, M.; Berghäuser, G.; Raja, A.; Nagler, P.; Schüller, C.; Heinz, T. F.; Korn, T.; Chernikov, A.; Malic, E.; Knorr, A. Excitonic linewidth and coherence lifetime in monolayer transition metal dichalcogenides. Nat. Commun. 2016, 7, 13279.
[22]
Palummo, M.; Bernardi, M.; Grossman, J. C. Exciton radiative lifetimes in two-dimensional transition metal dichalcogenides. Nano Lett. 2015, 15, 2794-2800.
[23]
Rivera, P.; Schaibley, J. R.; Jones, A. M.; Ross, J. S.; Wu, S. F.; Aivazian, G.; Klement, P.; Seyler, K.; Clark, G.; Ghimire, N. J. et al. Observation of long-lived interlayer excitons in monolayer MoSe2- WSe2 heterostructures. Nat. Commun. 2014, 6, 6242.
[24]
Gao, S.; Gu, B. C.; Jiao, X. C.; Sun, Y. F.; Zu, X. L.; Yang, F.; Zhu, W. G.; Wang, C. M.; Feng, Z. M.; Ye, B. J. et al. Highly efficient and exceptionally durable CO2 photoreduction to methanol over freestanding defective single-unit-cell bismuth vanadate Layers. J. Am. Chem. Soc. 2017, 139, 3438-3445.
[25]
Patton, B.; Langbein, W.; Woggon, U. Trion, biexciton, and exciton dynamics in single self-assembled CdSe quantum dots. Phys. Rev. B 2003, 68, 125316.
[26]
Lui, C. H.; Frenzel, A. J.; Pilon, D. V.; Lee, Y. H.; Ling, X.; Akselrod, G. M.; Kong, J.; Gedik, N. Trion-induced negative photoconductivity in monolayer MoS2. Phys. Rev. Lett. 2014, 113, 166801.
[27]
Barker, S. E.; Wang, S. J.; Godiksen, R. H.; Castellanos, G. W.; Berghuis, M.; Raziman, T. V.; Curto, A. G.; Rivas, J. G. Preserving the emission lifetime and efficiency of a monolayer semiconductor upon transfer. Adv. Opt. Mater. 2019, 7, 1900351.
[28]
Urbaszek, B.; Marie, X.; Amand, T.; Krebs, O.; Voisin, P.; Maletinsky, P.; Högele, A.; Imamoglu, A. Nuclear spin physics in quantum dots: An optical investigation. Rev. Mod. Phys. 2013, 85, 79-133.
[29]
Wang, Q. H.; Kalantar-Zadeh, K.; Kis, A.; Coleman, J. N.; Strano, M. S. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nat. Nanotechnol. 2012, 7, 699-712.
[30]
Cai, M. Z.; Thorpe, D.; Adamson, D. H.; Schniepp, H. C. Methods of graphite exfoliation. J. Mater. Chem. 2012, 22, 24992-25002.
[31]
Li, H.; Lu, G.; Wang, Y. L.; Yin, Z. Y.; Cong, C. X.; He, Q. Y.; Wang, L.; Ding, F.; Yu, T.; Zhang, H. Mechanical exfoliation and characterization of single-and few-layer nanosheets of WSe2, TaS2, and TaSe2. Small 2013, 9, 1974-1981.
[32]
Ferrari, A. C.; Meyer, J. C.; Scardaci, V.; Casiraghi, C.; Lazzeri, M.; Mauri, F.; Piscanec, S.; Jiang, D.; Novoselov, K. S.; Roth, S. et al. Raman spectrum of graphene and graphene layers. Phys. Rev. Lett. 2006, 97, 187401.
[33]
Lin, Y. X.; Ling, X.; Yu, L. L.; Huang, S. X.; Hsu, A. L.; Lee, Y. H.; Kong, J.; Dresselhaus, M. S.; Palacios, T. Dielectric screening of excitons and trions in single-layer MoS2. Nano Lett. 2014, 14, 5569-5576.
[34]
Li, L. K.; Kim, J.; Jin, C. H.; Ye, G. J.; Qiu, D. Y.; da Jornada, F. H.; Shi, Z. W.; Chen, L.; Zhang, Z. C.; Yang, F. Y. et al. Direct observation of the layer-dependent electronic structure in phosphorene. Nat. Nanotechnol. 2017, 12, 21-25.
[35]
Becker, W.; Su, B.; Holub, O.; Weisshart, K. FLIM and FCS detection in laser-scanning microscopes: Increased efficiency by GaAsP hybrid detectors. Microsc. Res. Tech. 2011, 74, 804-811.
[36]
Setyawan, W.; Curtarolo, S. High-throughput electronic band structure calculations: Challenges and tools. Comput. Mater. Sci. 2010, 49, 299-312.
[37]
Grimme, S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction. J. Comput. Chem. 2006, 27, 1787-1799.
[38]
Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865.
[39]
del Corro, E.; Terrones, H.; Elias, A.; Fantini, C.; Feng, S. M.; Nguyen, M. A.; Mallouk, T. E.; Terrones, M.; Pimenta, M. A. Excited excitonic states in 1L, 2L, 3L, and bulk WSe2 observed by resonant Raman spectroscopy. Acs Nano 2014, 8, 9629-9635.
[40]
Zhao, W. J.; Ghorannevis, Z.; Amara, K. K.; Pang, J. R.; Toh, M.; Zhang, X.; Kloc, C.; Tan, P. H.; Eda, G. Lattice dynamics in mono-and few-layer sheets of WS2 and WSe2. Nanoscale 2013, 5, 9677-9683.
[41]
He, K. L.; Kumar, N.; Zhao, L.; Wang, Z. F.; Mak, K. F.; Zhao, H.; Shan, J. Tightly bound excitons in monolayer WSe2. Phys. Rev. Lett. 2014, 113, 026803.
[42]
Tonndorf, P.; Schmidt, R.; Böttger, P.; Zhang, X.; Börner, J.; Liebig, A.; Albrecht, M.; Kloc, C.; Gordan, O.; Zahn, D. R. T. et al. Photoluminescence emission and Raman response of monolayer MoS2, MoSe2, and WSe2. Opt. Express 2013, 21, 4908-4916.
[43]
Plechinger, G.; Nagler, P.; Arora, A.; Schmidt, R.; Chernikov, A.; Del Águila, A. G.; Christianen, P. C. M.; Bratschitsch, R.; Schüller, C.; Korn, T. Trion fine structure and coupled spin-valley dynamics in monolayer tungsten disulfide. Nat. Commun. 2016, 7, 12715.
[44]
Zhu, W. Q.; Esteban, R.; Borisov, A. G.; Baumberg, J. J.; Nordlander, P.; Lezec, H. J.; Aizpurua, J.; Crozier, K. B. Quantum mechanical effects in plasmonic structures with subnanometre gaps. Nat. Commun. 2016, 7, 11495.
[45]
Özden, A.; Şar, H.; Yeltik, A.; Madenoğlu, B.; Sevik, C. Ay, F.; Perkgöz, N. K. CVD grown 2D MoS2 layers: A photoluminescence and fluorescence lifetime imaging study. Phys. Status Solidi RRL 2016, 10, 792-796.
[46]
Hegarty, J.; Goldner, L.; Sturge, M. D. Localized and delocalized two-dimensional excitons in GaAs-AlGaAs multiple-quantum-well structures. Phys. Rev. B 1984, 30, 7346(R).
[47]
Yang, J.; Xu, R. J.; Pei, J. J.; Myint, Y. W.; Wang, F.; Wang, Z.; Zhang, S.; Yu, Z. F.; Lu, Y. R. Optical tuning of exciton and trion emissions in monolayer phosphorene. Light: Sci. Appl. 2015, 4, e312.
[48]
Wang, H. N.; Zhang, C. J.; Chan, W. M.; Manolatou, C.; Tiwari, S.; Rana, F. Radiative lifetimes of excitons and trions in monolayers of the metal dichalcogenide MoS2. Phys. Rev. B 2016, 93, 045407.
[49]
Singh, A.; Tran, K.; Kolarczik, M.; Seifert, J.; Wang, Y. P.; Hao, K.; Pleskot, D.; Gabor, N. M.; Helmrich, S.; Owschimikow, N. et al. Long-lived valley polarization of intravalley trions in monolayer WSe2. Phys. Rev. Lett. 2016, 117, 257402.
[50]
Tripathi, L. N.; Iff, O.; Betzold, S.; Dusanowski, Ł.; Emmerling, M.; Moon, K.; Lee, Y. J.; Kwon, S. H.; Höfling, S.; Schneider, C. Spontaneous emission enhancement in strain-induced WSe2 monolayer-based quantum light sources on metallic surfaces. ACS Photonics 2018, 5, 1919-1926.
[51]
Chernikov, A.; Berkelbach, T. C.; Hill, H. M.; Rigosi, A.; Li, Y. L.; Aslan, O. B.; Reichman, D. R.; Hybertsen, M. S.; Heinz, T. F. Exciton binding energy and nonhydrogenic Rydberg series in monolayer WS2. Phys. Rev. Lett. 2014, 113, 076802.
[52]
Yuan, L.; Huang, L. B. Exciton dynamics and annihilation in WS2 2D semiconductors. Nanoscale 2015, 7, 7402-7408.
[53]
Danon, J.; Nazarov, Y. V. Pauli spin blockade in the presence of strong spin-orbit coupling. Phys. Rev. B 2009, 80, 041301.
[54]
Patton, B.; Langbein, W.; Woggon, U. Trion, biexciton, and exciton dynamics in single self-assembled CdSe quantum dots. Phys. Rev. B 2003, 68, 125316.
[55]
Molas, M. R.; Nogajewski, K.; Slobodeniuk, A. O.; Binder, J.; Bartos, M.; Potemski, M. The optical response of monolayer, few-layer and bulk tungsten disulfide. Nanoscale 2017, 9, 13128-13141.
[56]
Zhou, Y.; Scuri, G.; Wild, D. S.; High, A. A.; Dibos, A.; Jauregui, L. A.; Shu, C.; De Greve, K.; Pistunova, K.; Joe, A. Y. et al. Probing dark excitons in atomically thin semiconductors via near-field coupling to surface plasmon polaritons. Nat. Nanotechnol. 2017, 12, 856-860.
Publication history
Copyright
Acknowledgements
Publication history
Received: 24 October 2019
Revised: 19 January 2020
Accepted: 23 January 2020
Published:
12 February 2020
Issue date: March 2020
Copyright
© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2020
Acknowledgements
This work is supported by the National Natural Science Foundation of China (Nos. 51527901, 51575298, 51705285, and 11890672). And we are grateful to Tsinghua-Nikon Imaging Core Facility for providing technical support and to Yanli Zhang for assistance with confocal microscopy and image processing.
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