Fig. 2

Pump-probe kinetics and Debye–Waller responses at 400-nm photoexcitation. Pump-probe kinetic plots for six diffraction planes at a carrier density of (a) 1.2 ± 0.1 × 10¹⁴ cm⁻² and (b) 1.8 ± 0.1 × 10¹⁴ cm⁻² at 400 nm excitation for the MoSe₂ bilayer, and (c) Debye–Waller responses at four carrier densities. A large deviation between linear fit and experimental data occurs at the highest carrier density (red). At this density, the first five data points are used for the linear fit. The corresponding temperatures calculated from the slopes are presented in the context and Supplementary Information. Error bars represent 68% confidence interval and are calculated from the propagation of standard error of the mean from the fit of averaged multiple pump-probe scans. d Kinetic plots for {110} and {300} planes at carrier density at 1.8 ± 0.1 × 10¹⁴ cm⁻² (blue) and 2.1 ± 0.1 × 10¹⁴ cm⁻² (red), respectively, for comparison. A complex Bragg peak intensity decay occurs at the highest carrier density (red), which may suggest an energy redistribution between different phonons from a strong carrier-modified potential energy surface