The technological interest in MoTe2 as a phase engineered material is related to the possibility of triggering the 2H-1T ' phase transition by optical excitation, potentially allowing for an accurate patterning of metallic areas into a semiconducting canvas via laser irradiation. In this paper, we investigate the photo-induced modifications of a bulk 2H-MoTe2 crystal by means of time-resolved X-ray photoemission spectroscopy. We observe that in the microsecond timescale, the core levels shift to higher kinetic energies due to surface photovoltage fields, while in the sub-nanosecond range, the photoemission peaks shift in the opposite direction. With the support of DFT calculations, we ascribe the latter effect to the deformation of the lattice in the out-of-plane direction, which is along the pathway for the 2H-1T ' phase transition. Our data indicate an intermediate lattice excitation state with a measured lifetime in the order of 600 ps, in which the displacement of Mo and Te atoms causes the Te 4d electrons to shift towards higher binding energies.

Costantini, R., Cilento, F., Salvador, F., Morgante, A., Giorgi, G., Palummo, M., et al. (2022). Photo-induced lattice distortion in 2H-MoTe2 probed by time-resolved core level photoemission. FARADAY DISCUSSIONS, 236, 429-441 [10.1039/d1fd00105a].

Photo-induced lattice distortion in 2H-MoTe2 probed by time-resolved core level photoemission

M. Palummo;
2022

Abstract

The technological interest in MoTe2 as a phase engineered material is related to the possibility of triggering the 2H-1T ' phase transition by optical excitation, potentially allowing for an accurate patterning of metallic areas into a semiconducting canvas via laser irradiation. In this paper, we investigate the photo-induced modifications of a bulk 2H-MoTe2 crystal by means of time-resolved X-ray photoemission spectroscopy. We observe that in the microsecond timescale, the core levels shift to higher kinetic energies due to surface photovoltage fields, while in the sub-nanosecond range, the photoemission peaks shift in the opposite direction. With the support of DFT calculations, we ascribe the latter effect to the deformation of the lattice in the out-of-plane direction, which is along the pathway for the 2H-1T ' phase transition. Our data indicate an intermediate lattice excitation state with a measured lifetime in the order of 600 ps, in which the displacement of Mo and Te atoms causes the Te 4d electrons to shift towards higher binding energies.
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore FIS/03
English
Costantini, R., Cilento, F., Salvador, F., Morgante, A., Giorgi, G., Palummo, M., et al. (2022). Photo-induced lattice distortion in 2H-MoTe2 probed by time-resolved core level photoemission. FARADAY DISCUSSIONS, 236, 429-441 [10.1039/d1fd00105a].
Costantini, R; Cilento, F; Salvador, F; Morgante, A; Giorgi, G; Palummo, M; Dell'Angela, M
Articolo su rivista
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/307996
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 0
  • ???jsp.display-item.citation.isi??? 0
social impact