Transition Metal Dichalcogenides TMDs MoX2 (X=S, Se, Te) are an emergent class of layered materials displaying exciting optoelectronic properties which can be modified by varying the number of layers, by intercalation, or by applying an external strain/compression. In particular, these semiconducting materials can get a band gap closure under pressure and enter in a metallic phase. Here, we investigate the optical properties of MoSe2 under high pressure by means of Raman spectroscopy over a wide pressure range (0-30 GPa). No anomaly has been observed in the pressure dependence of the frequencies of the vibrational modes A1g, E12g (Raman first order) and E1g - E22g (Raman second-order), in agreement with the absence previously reported of any pressure induced structural transition. Interestingly, our detailed line-shape analysis show a clear anomaly in the pressure behavior of the linewidth of the A1g and E12g phonons at the insurgent metallization process which was observed in previous infrared and transport experiments. Our results indicate that the linewidths of Raman phonons peaks can be sensitive to even subtle pressure-induced electronic rearrangements and can thus be used to monitor the insurgence of a pressure-induced semiconductor-metal transition.

Effect of pressure on optical properties of the transition metal dichalcogenide MoSe2 / Caramazza, Simone; F., Capitani; C., Marini; A., Mancini; L., Malavasi; Dore, Paolo; Postorino, Paolo. - In: JOURNAL OF PHYSICS. CONFERENCE SERIES. - ISSN 1742-6596. - STAMPA. - (2017). ((Intervento presentato al convegno Joint AIRAPT-25 & EHPRG-53 International Conference on High Pressure Science And Technology tenutosi a Madrid nel From August 30th to September 4th , 2015 [10.1088/1742-6596/950/4/042012].

Effect of pressure on optical properties of the transition metal dichalcogenide MoSe2

CARAMAZZA, SIMONE;DORE, Paolo;POSTORINO, Paolo
2017

Abstract

Transition Metal Dichalcogenides TMDs MoX2 (X=S, Se, Te) are an emergent class of layered materials displaying exciting optoelectronic properties which can be modified by varying the number of layers, by intercalation, or by applying an external strain/compression. In particular, these semiconducting materials can get a band gap closure under pressure and enter in a metallic phase. Here, we investigate the optical properties of MoSe2 under high pressure by means of Raman spectroscopy over a wide pressure range (0-30 GPa). No anomaly has been observed in the pressure dependence of the frequencies of the vibrational modes A1g, E12g (Raman first order) and E1g - E22g (Raman second-order), in agreement with the absence previously reported of any pressure induced structural transition. Interestingly, our detailed line-shape analysis show a clear anomaly in the pressure behavior of the linewidth of the A1g and E12g phonons at the insurgent metallization process which was observed in previous infrared and transport experiments. Our results indicate that the linewidths of Raman phonons peaks can be sensitive to even subtle pressure-induced electronic rearrangements and can thus be used to monitor the insurgence of a pressure-induced semiconductor-metal transition.
Joint AIRAPT-25 & EHPRG-53 International Conference on High Pressure Science And Technology
dichalcogenides, high pressure, Raman spectroscopy
04 Pubblicazione in atti di convegno::04c Atto di convegno in rivista
Effect of pressure on optical properties of the transition metal dichalcogenide MoSe2 / Caramazza, Simone; F., Capitani; C., Marini; A., Mancini; L., Malavasi; Dore, Paolo; Postorino, Paolo. - In: JOURNAL OF PHYSICS. CONFERENCE SERIES. - ISSN 1742-6596. - STAMPA. - (2017). ((Intervento presentato al convegno Joint AIRAPT-25 & EHPRG-53 International Conference on High Pressure Science And Technology tenutosi a Madrid nel From August 30th to September 4th , 2015 [10.1088/1742-6596/950/4/042012].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/872699
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