Photoinduced interlayer dynamics in T-d-MoTe2: A broadband pump-probe study

We report on time-resolved broadband transient reflectivity (tr-bb-TR) measurements performed on a bulk single crystal of T-d-MoTe2 as a function of the incident pump fluence (F). Tr-bb-TR data unveil photoinduced electronic changes progressing on the sub-picosecond timescale as well as the dynamics of the coherent low-frequency (1)A(1) interlayer shear phonon. Our results indicate a gradual evolution of both the TR and the (1)A(1) Fourier intensity spectra as a function of F, ruling out the threshold-like change that has been associated with the ultrafast photoinduced T-d -> 1T' phase transition. We also observe a large redshift of the (1)A(1) Fourier spectral features, which implies that large renormalization effects are taking place on the interband transitions that are dielectrically susceptible to the (1)A(1) interlayer shear phonon displacement.& nbsp;& nbsp;Published under an exclusive license by AIP Publishing.