Fig. 4

Pump-probe kinetics and Debye–Waller responses at 800 nm photoexcitation. a Time-resolved kinetic plots of MoSe₂ bilayer for six diffraction families, as depicted in the parenthesis at a carrier density of 2.0 ± 0.2 × 10¹⁴ cm⁻² excited at 800 nm. The resultant subpicosecond time constants are consistent with measurements at 400 nm. b At the same carrier density and wavelength for the bilayer with the pump-probe scan up to 100 ps. A clear recovery of Bragg peak intensity is shown (~100 ps). This is due to the heat propagation from the bilayer MoSe₂ to the substrate. c Power-dependent Debye–Waller responses of a bilayer for three effective carrier densities at 800 nm photoexcitation. Error bars represent 68% confidence interval and are obtained from the propagation of standard error of the mean from the fit of averaged multiple pump-probe scans. The mean-square displacements obtained from the linear least-square fit of data are shown in Supplementary Table 3. Note that at the highest carrier density, the Debye–Waller response is still linear without a large deviation, as seen in Fig. 2c