Fig. 4

Third-harmonic scattering of P3AT. a THS intensity (I_3ω at 433 nm) vs. amount of methanol added for a polymer concentration of 0.047 mg mL⁻¹. The inset is the THS intensity at the low methanol regime for a polymer concentration of 0.26 mg mL⁻¹ and longer acquisition time. All data were corrected for self-absorption and dilution. b Depolarization ratio for THS vs. percentage of methanol added. The red dots represent the depolarization ratio observed for a polymer concentration of 0.26 mg mL⁻¹, the black dots for a polymer concentration of 0.047 mg mL⁻¹. The average depolarization ratio is within the error for the overall process (error calculated from the CI of the THS intensities for vertical and horizontal polarization). For the low methanol regime, the error is large as the signal intensity is low