Fig. 1. Pump power dependence of ultrafast differential transmission dynamics (DTD) of pristine monolayer CVD-grown graphene. The arrow points to the pump power increase.

Fig. 2. Excitation power-dependent ultrafast dynamics of oxidized graphene with different degrees of oxidation. Oxidized for (a) 4 min, (b) 6 min, (c) 8 min, and (d) 10 min.

Fig. 3. Oxidation time dependence of the ultrafast dynamics of six graphene samples under excitation power of (a) 28 mW and (b) 131 mW.

Fig. 4. Raman spectra of graphene with different amounts of oxidation time. The number over each spectrum denotes oxidation time. Each spectrum is shifted upward for clarity. The inset shows the shift of the G peak and Fermi level with oxidation time.

Fig. 5. Simulated ultrafast dynamics of graphene with different Fermi levels but the same other parameters.