Figure 3: MPA of organic D–A blend.

(a) PA spectra of a ~100-nm thick film of rrP3HT/PCBM (1.2:1) blend at B=0 (black line) and B=150 mT (red line). E₁ and E₂ polaron PA bands are assigned. The difference, ΔPA (enlarged by a factor of 50) is also plotted (blue line). (b) The MPA(B) response obtained at E₁=0.35 eV.