Raman Spectra of ZrS2 and ZrSe2 from Bulk to Atomically Thin Layers

In the race towards two-dimensional electronic and optoelectronic devices, semiconducting transition metal dichalcogenides (TMDCs) from group VIB have been intensively studied in recent years due to the indirect to direct band-gap transition from bulk to the monolayer. However, new materials still need to be explored. For example, semiconducting TMDCs from group IVB have been predicted to have larger mobilities than their counterparts from group VIB in the monolayer limit. In this work we report the mechanical exfoliation of ZrX2 (X = S, Se) from bulk down to the monolayer and we study the dimensionality dependence of the Raman spectra in ambient conditions. We observe Raman signal from bulk to few layers and no shift in the peak positions is found when decreasing the dimensionality. While a Raman signal can be observed from bulk to a bilayer for ZrS2, we could only detect signal down to five layers for flakes of ZrSe2. These results show the possibility of obtaining atomically thin layers of ZrX2 by mechanical exfoliation and represent one of the first steps towards the investigation of the properties of these materials, still unexplored in the two-dimensional limit.

[1]  Y. Bando,et al.  Electrical Transport and High‐Performance Photoconductivity in Individual ZrS2 Nanobelts , 2010, Advanced materials.

[2]  Takuo Tanaka,et al.  Few-layer HfS2 transistors , 2016, Scientific Reports.

[3]  Characterization of collective ground states in single-layer NbSe 2 , 2015, 1506.08460.

[4]  A. Balchin,et al.  Non‐stoichiometry in ZrS2 and ZrSe2 , 1978 .

[5]  R. Frindt.  SUPERCONDUCTIVITY IN ULTRATHIN NbSe$sub 2$ LAYERS. , 1972 .

[6]  R. Friend,et al.  Transport and Raman studies of the group IV layered compounds and their lithium intercalates: LixTiS2, LixTiSe2, LixZrS2, LixZrSe2, LixHfS2 and LixHfSe2 , 1987 .

[7]  A. Neto,et al.  Controlling many-body states by the electric-field effect in a two-dimensional material , 2016, Nature.

[8]  Kai Xu,et al.  Ultrasensitive Phototransistors Based on Few‐Layered HfS2 , 2015, Advanced materials.

[9]  Yanrong Li,et al.  Two-dimensional semiconductors with possible high room temperature mobility , 2014, Nano Research.

[10]  Qing Hua Wang,et al.  Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. , 2012, Nature nanotechnology.

[11]  J. Cheon,et al.  Tandem intercalation strategy for single-layer nanosheets as an effective alternative to conventional exfoliation processes , 2015, Nature Communications.

[12]  T. Pandey,et al.  High temperature thermoelectric properties of Zr and Hf based transition metal dichalcogenides: A first principles study. , 2015, The Journal of chemical physics.

[13]  Carlone,et al.  Resonance Raman spectrum of HfS2 and ZrS2. , 1988, Physical review. B, Condensed matter.

[14]  Yan Li,et al.  Indirect-to-direct band gap transition of the ZrS2 monolayer by strain: first-principles calculations , 2014 .

[15]  S. Bending,et al.  Superconductivity in two-dimensional NbSe2 field effect transistors , 2013 .

[16]  J. Wilson,et al.  The transition metal dichalcogenides discussion and interpretation of the observed optical, electrical and structural properties , 1969 .

[17]  D. Basko,et al.  Raman spectroscopy as a versatile tool for studying the properties of graphene. , 2013, Nature nanotechnology.

[18]  Xu Du,et al.  Electronic properties of graphene: a perspective from scanning tunneling microscopy and magnetotransport , 2012, Reports on progress in physics. Physical Society.

[19]  F. Guinea,et al.  Enhanced superconductivity in atomically thin TaS2 , 2016, Nature Communications.

[20]  Fengnian Xia,et al.  Recent Advances in Two-Dimensional Materials beyond Graphene. , 2015, ACS nano.

[21]  Andre K. Geim,et al.  Electric Field Effect in Atomically Thin Carbon Films , 2004, Science.

[22]  Moon J. Kim,et al.  HfSe2 thin films: 2D transition metal dichalcogenides grown by molecular beam epitaxy. , 2015, ACS nano.

[23]  F. McTaggart,et al.  The sulphides, Selenides, and Tellurides of Titanium, Zirconium, Hafnium, and Thorium. III. Electrical properties , 1958 .

[24]  Tuning electronic and magnetic properties of early transition-metal dichalcogenides via tensile strain , 2014, 1403.3172.

[25]  Yiming Zhu,et al.  Composition-dependent Raman modes of Mo(1-x)W(x)S2 monolayer alloys. , 2014, Nanoscale.

[26]  Daniel Wolverson,et al.  Raman-scattering measurements and first-principles calculations of strain-induced phonon shifts in monolayer MoS2 , 2013 .

[27]  Young Hee Lee,et al.  Oxidation Effect in Octahedral Hafnium Disulfide Thin Film. , 2016, ACS nano.

[28]  D. Greenaway,et al.  Preparation and optical properties of group IV–VI2 chalcogenides having the CdI2 structure , 1965 .

[29]  P. Temple,et al.  Multiphonon Raman Spectrum of Silicon , 1973 .

[30]  K Watanabe,et al.  Quality Heterostructures from Two-Dimensional Crystals Unstable in Air by Their Assembly in Inert Atmosphere. , 2015, Nano letters.

[31]  K. Loh,et al.  Two-dimensional dichalcogenides for light-harvesting applications , 2015 .

[32]  B. Liang,et al.  Infrared Spectra and Density Functional Theory Calculations of Group 6 Transition Metal Sulfides in Solid Argon , 2002 .

[33]  Xinsheng Wang,et al.  Controlled Synthesis of ZrS2 Monolayer and Few Layers on Hexagonal Boron Nitride. , 2015, Journal of the American Chemical Society.

[34]  A. Dimoulas,et al.  Epitaxial ZrSe2/MoSe2 semiconductor v.d. Waals heterostructures on wide band gap AlN substrates , 2015 .

[35]  F. McTaggart,et al.  The sulphides, Selenides, and Tellurides of Titanium, Zirconium, Hafnium, and Thorium. IV. Lubrication properties of the graphitic chalcogenides , 1958 .

[36]  Dominique Baillargeat,et al.  From Bulk to Monolayer MoS2: Evolution of Raman Scattering , 2012 .

[37]  Raman Signatures of Polytypism in Molybdenum Disulfide. , 2016, ACS nano.

[38]  Eunji Sim,et al.  Ultrathin zirconium disulfide nanodiscs. , 2011, Journal of the American Chemical Society.

[39]  Cinzia Casiraghi,et al.  Probing the nature of defects in graphene by Raman spectroscopy. , 2012, Nano letters.

[40]  Yan Li,et al.  Large scale ZrS2 atomically thin layers , 2016 .