Figure 5.

Time dependence of Raman loss for P3HT in the ground state, singlet exciton states, and positive polaron states in a P3HT:PCBM blend film. Energy density of the actinic pump pulse was 60 μJ cm⁻². Filled circles represent the amplitude of the transients obtained by the least-squares fitting analysis of the time-resolved inverse Raman spectra with linear combinations of the spectra of the transients. Solid traces are the best fitted curves obtained by the least-squares fitting analysis with an error function, an exponential function and an offset, two exponential functions for the ground state, the singlet exciton states, and the positive polaron states, respectively.