Figure 4.

In‐depth discussion of cascaded carrier transport. a) Calculated squared width change obtained from individual Drude–Smith and Lorentz terms, as well as their combination. b,c) Calculated evolutions of the squared width with long‐term diffusion and fast expansion modulated by increasing b) lattice thermal conductance k _l and c) Drude weight w, respectively. d) Carrier transport in WS₂ with various thicknesses probed at 2.06 eV. Dots are experimental results, and solid lines are guidelines. A zoom‐in of the first 2 ps is shown in the inset for monolayer WS₂. Both the early nonlinear process and long‐term linear exciton diffusion can be found at all thicknesses. The pump fluence is 80 µJ cm⁻² for (a)–(c) and marked in (d).