Figure 4.

(a) Typical in situ Raman spectroscopy data set showing the evolution of the carbon-related Raman bands as a function of stepwise increases in incident laser power (normalized Raman intensity false-colored surface map with x-axis showing Raman shift, y-axis showing time, and z-axis showing normalized Raman intensity; an additional false-colored surface projection of normalized Raman intensity is projected onto the xy-plane [top of graph]; the yz-plane shows the stepwise increased incident laser power as a function of time). (b) Time evolution of the normalized G peak intensity (extracted from (a)) as a function of the stepwise increases in incident laser power. (c) Time-averaged Raman spectra as a function of applied laser power. Averaging was performed over the time-resolved Raman spectra in (a) at constant incident laser power steps. Spectra are offset for clarity. (d) G peak width and I(D)/I(G) and I(2D)/I(G) intensity ratios as a function of applied laser power, extracted from the Raman spectra in (c). For a comment on temperature estimations, see the Supporting Information. Estimated uncertainty in temperature for the in situ Raman measurements is ±50 °C.