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 Te4d electrons to shift towards higher binding energies.
Photo-induced lattice distortion in 2H-MoTe2 probed by time-resolved core level photoemission
Costantini, Roberto;Cilento, Federico;Morgante, Alberto;
2022-01-01
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 Te4d electrons to shift towards higher binding energies.File | Dimensione | Formato | |
---|---|---|---|
2955998-2-14.pdf
Accesso chiuso
Tipologia:
Documento in Versione Editoriale
Licenza:
Copyright Editore
Dimensione
13.66 MB
Formato
Adobe PDF
|
13.66 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
2955998-2-14-Post_print.pdf
Open Access dal 04/03/2023
Tipologia:
Bozza finale post-referaggio (post-print)
Licenza:
Digital Rights Management non definito
Dimensione
12 MB
Formato
Adobe PDF
|
12 MB | Adobe PDF | Visualizza/Apri |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.