Supporting Information

The supplementary material contains additional experimental information supporting the micro-area TA measurements, including: (1) the setup used to regulate the anti-solvent (DCM) evaporation rate (Fig. S1); (2) Gaussian beam profiles of the pump and probe beams used to determine the ~1.9 µm excitation spot size (Fig. S2); (3) optical imaging confirming the spatial confinement of the beam spot on the sample surface (Fig. S3); and (4) TA spectra and PB2 dynamics obtained from an independently prepared sample to demonstrate measurement reproducibility (Fig. S4).