First- and second-order Raman scattering from MoTe2 single crystal★,★★
Physics Department, Sapienza University of Rome,
P.le Aldo Moro,
2 CNR-SPIN and Physics Department, Sapienza University of Rome, P.le Aldo Moro, 00185 Roma, Italy
3 CNR-IOM and Physics Department, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Roma, Italy
a e-mail: email@example.com
Received in final form: 27 September 2017
Published online: 12 February 2018
We report on Raman experiments performed on a MoTe2 single crystal. The system belongs to the wide family of transition metal dichalcogenides which includes several of the most interesting two-dimensional materials for both basic and applied physics. Measurements were performed in the standard basal plane configuration, by placing the ab plane of the crystal perpendicular to the wave vector ki of the incident beam to explore the in-plane vibrational modes, and in the edge plane configuration with ki perpendicular to the crystal c axis, thus mainly exciting out-of-plane modes. For both configurations we performed a polarization-dependent study of the first-order Raman components and detailed computation of the corresponding selection rules. We were thus able to provide a complete assignment of the observed first-order Raman peaks, in agreement with previous literature results. A thorough analysis of the second-order Raman bands, as observed in both basal and edge plane configurations, provides new information and allows a precise assignment of these spectral structures. In particular, we have observed and assigned Raman active modes of the M point of the Brillouin zone previously predicted by ab initio calculations but never previously measured.
Contribution to the Topical Issue “Shaping Nanocatalysts”, edited by Francesca Baletto, Roy L. Johnston, Jochen Blumberger and Alex Shluger.
Supplementary material in the form of one pdf file from the Journal web page at https://doi.org/10.1140/epjb/e2017-80399-5.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2018