Singlet Exciton Lifetimes in Conjugated Polymer Films for Organic Solar Cells

Table S1. Transient decays of the excited state absorption of the singlet excitons of the polymers studied. Multiple single wavelength decays are plotted to improve the quality of the data fitting and avoid complications from spectral inhomogeneity. The experimental data is included as scatter points. The solid lines represent exponential fits to the data. The kinetics of BTT-DPP, DPP-TT-T, SiIDT-2FBT, SiIDT-BT were well fitted to a single exponential function. The kinetics of SiIDT-TPD, TTP and APFO3 were well fitted to a bi-exponential function. Exciton lifetimes presented in the main text were calculated from the weighted average of the lifetimes received from the fits. Due to more complex spectral decay dynamics, the lifetime of the APFO-3 exciton decay was taken from the second time constant received from the bi-exponential fit. Transient absorption spectra of the films are presented in the graph. The positive signals are assigned to exciton absorption while negative signal correspond to ground state bleaching. Both the bleaching and exciton absorption signals follow the same decay dynamics.