Temperature-Dependent Nonlinear Phonon Shifts in a Supported MoS<sub>2</sub> Monolayer

Taube, Andrzej; Judek, Jarosław; Jastrzębski, Cezariusz; Dużyńska, Anna; Switkowski, Krzysztof; Zdrojek, Mariusz

doi:10.1021/am502359k

Cited by 89 publications

(105 citation statements)

References 29 publications

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“…In this respect, resonant Raman spectroscopy with varying photon energies provides a complementary tool to emission and absorption measurements to access the electronic structure in SCTMDs as well as to study fundamental aspects of the electron-phonon interaction [134,136,137] . Already nonresonant Raman spectroscopy, meaning that neither the exciting (incoming resonance) nor the scattered photon energy (outgoing resonance) meet an optically active interband transition of the electronic bands, provides access to the number of layers [81,[138][139][140][141][142] , phase transition 2H, 3R, 1T, 1T' MX2 crystals [137,143,144] , strain [69,145,146] , disorder and defects [147] , doping [74,148] and temperature as well as thermal conductivity [97,[149][150][151][152] . Amazingly, this information can already be extracted by investigating only two Raman active zone center phonon modes in the higher frequency range (ωph > 200 cm -1 ).…”

Section: First Order Phonon Modes As Unique Fingerprint For Materials mentioning

confidence: 99%

“…Raman measurements with a high spatial resolution can not only be utilized to measure the local temperature but also to investigate the thermal conductivity of a material. It has been shown that both optical phonon modes with E'/E 1 2g and A'1/A1g symmetry of SC-TMDs are lowered with increasing temperature [149][150][151][152] . The first order temperature coefficients T for MoS2 are reported to be linear for both phonon modes.…”

Section: Temperature Shift Of the Phonon Modesmentioning

confidence: 99%

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Light–matter interaction in transition metal dichalcogenides and their heterostructures

Wurstbauer¹,

Miller²,

Parzinger³

et al. 2017

J. Phys. D: Appl. Phys.

104

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Abstract:The investigation of two-dimensional van der Waals materials is a vibrant, fast moving and still growing interdisciplinary area of research. Two-dimensional van der Waals materials are truly two-dimensional crystals with strong covalent in-plane bonds and weak van der Waals interaction between the layers with a variety of different electronic, optical and mechanical properties. A very prominent class of twodimensional materials are transition metal dichalcogenides and amongst them particularly the semiconducting subclass. Their properties include bandgaps in the near-infrared to the visible range, decent charge carrier mobility together with high (photo-)catalytic and mechanical stability and exotic many body phenomena. These characteristics make the materials highly attractive for both fundamental research as well as innovative device applications. Furthermore, the materials exhibit a strong light matter interaction providing a high sun light absorbance of up to 15% in the monolayer limit, strong scattering cross section in Raman experiments and access to excitonic phenomena in van der Waals heterostructures. This review focuses on the light matter interaction in MoS2, WS2, MoSe2, and WSe2 that is dictated by the materials complex dielectric functions and on the multiplicity of studying the first order phonon modes by Raman spectroscopy to gain access to several material properties such as doping, strain, defects and temperature. Two-dimensional materials provide an interesting platform to stack them into van der Waals heterostructures without the limitation of lattice mismatch resulting in novel devices for application but also to study exotic many body interaction phenomena such as interlayer excitons. Future perspectives of semiconducting transition metal dichalcogenides and their heterostructures for applications in optoelectronic devices will be examined and routes to study emergent fundamental problems and manybody quantum phenomena under excitations with photons will be discussed.

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Section: First Order Phonon Modes As Unique Fingerprint For Materials mentioning

confidence: 99%

Section: Temperature Shift Of the Phonon Modesmentioning

confidence: 99%

Light–matter interaction in transition metal dichalcogenides and their heterostructures

Wurstbauer¹,

Miller²,

Parzinger³

et al. 2017

J. Phys. D: Appl. Phys.

104

View full text Add to dashboard Cite

show abstract

“…The Raman modes of monolayer MoS 2 affected by temperature have been investigated in the literature: Both ‫ܧ‬ ଶ ଵ and ‫ܣ‬ ଵ peaks red-shift when temperature increases. [42][43][44][45][46] From the red-shifts of the both peaks in our samples, the temperature of Ag/Ti covered monolayer MoS 2 increased significantly during the Raman measurement. This heating effect was also observed in the Raman spectrum of few-layer MoS 2 : the two peaks also red-shift simultaneously after Au/Ti film deposition ( Figure 5(d)).…”

Section: Raman Spectroscopy Of Mos 2 Covered With Metalmentioning

confidence: 99%

Influence of Metal–MoS₂Interface on MoS₂Transistor Performance: Comparison of Ag and Ti Contacts

Yuan

Cheng

You

et al. 2015

ACS Appl. Mater. Interfaces

102

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In this work, we compare the electrical characteristics of MoS2 field-effect transistors (FETs) with Ag source/drain contacts with those with Ti and demonstrate that the metal-MoS2 interface is crucial to the device performance. MoS2 FETs with Ag contacts show more than 60 times higher ON-state current than those with Ti contacts. In order to better understand the mechanism of the better performance with Ag contacts, 5 nm Au/5 nm Ag (contact layer) or 5 nm Au/5 nm Ti film was deposited onto MoS2 monolayers and few layers, and the topography of metal films was characterized using scanning electron microscopy and atomic force microscopy. The surface morphology shows that, while there exist pinholes in Au/Ti film on MoS2, Au/Ag forms a smoother and denser film. Raman spectroscopy was carried out to investigate the metal-MoS2 interface. The Raman spectra from MoS2 covered with Au/Ag or Au/Ti film reveal that Ag or Ti is in direct contact with MoS2. Our findings show that the smoother and denser Au/Ag contacts lead to higher carrier transport efficiency.

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“…In nanoelectronic device application, it is very important to understand the effect of phonons because the self-heating of the device can significantly affect the performance. The temperature dependence of Raman shift of monolayer and few layer MoS 2 has been extensively studied over a heating process1314, a cooling process15, and a wide temperature range from 77 K to 623 K16. Thermal conductivity of MoS 2 was given out based the temperature dependence of Raman shifts1617.…”

mentioning

confidence: 99%

Quantitative Analysis of Temperature Dependence of Raman shift of monolayer WS2

Huang

Gao

Yang

et al. 2016

Sci Rep

101

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We report the temperature-dependent evolution of Raman spectra of monolayer WS2 directly CVD-grown on a gold foil and then transferred onto quartz substrates over a wide temperature range from 84 to 543 K. The nonlinear temperature dependence of Raman shifts for both and A1g modes has been observed. The first-order temperature coefficients of Raman shifts are obtained to be −0.0093 (cm−1/K) and −0.0122 (cm−1/K) for and A1g peaks, respectively. A physical model, including thermal expansion and three- and four-phonon anharmonic effects, is used quantitatively to analyze the observed nonlinear temperature dependence. Thermal expansion coefficient (TEC) of monolayer WS2 is extracted from the experimental data for the first time. It is found that thermal expansion coefficient of out-plane mode is larger than one of in-plane mode, and TECs of and A1g modes are temperature-dependent weakly and strongly, respectively. It is also found that the nonlinear temperature dependence of Raman shift of mode mainly originates from the anharmonic effect of three-phonon process, whereas one of A1g mode is mainly contributed by thermal expansion effect in high temperature region, revealing that thermal expansion effect cannot be ignored.

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Temperature-Dependent Nonlinear Phonon Shifts in a Supported MoS₂ Monolayer

Cited by 89 publications

References 29 publications

Light–matter interaction in transition metal dichalcogenides and their heterostructures

Light–matter interaction in transition metal dichalcogenides and their heterostructures

Influence of Metal–MoS₂Interface on MoS₂Transistor Performance: Comparison of Ag and Ti Contacts

Quantitative Analysis of Temperature Dependence of Raman shift of monolayer WS2

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Temperature-Dependent Nonlinear Phonon Shifts in a Supported MoS2 Monolayer

Cited by 89 publications

References 29 publications

Light–matter interaction in transition metal dichalcogenides and their heterostructures

Light–matter interaction in transition metal dichalcogenides and their heterostructures

Influence of Metal–MoS2Interface on MoS2Transistor Performance: Comparison of Ag and Ti Contacts

Quantitative Analysis of Temperature Dependence of Raman shift of monolayer WS2

Contact Info

Product

Resources

About

Temperature-Dependent Nonlinear Phonon Shifts in a Supported MoS₂ Monolayer

Influence of Metal–MoS₂Interface on MoS₂Transistor Performance: Comparison of Ag and Ti Contacts