Fig. 1
From: Developing design criteria for organic solar cells using well-absorbing non-fullerene acceptors
Comparison between the experimental and simulated absorption coefficients of organic molecules for OPV. (a) Absorption coefficients of the non-fullerene acceptors FBR27 (red) and IDTBR28 (cyan), the donor polymer PTB7-Th29,30 (blue), and their blends (ratio 1:2) (light blue, purple) determined from UV–Vis measurements. (b) Exemplary curves of simulated absorption coefficients α1(E) and α2(E) representing the organic donor and acceptor material. The coefficient αmax and the full-width half-max (FWHM) describe the strength and shape of the absorption peak. In addition, the energies Eip,1 and Eip,2 indicate the inflection points of the corresponding absorption edges whose variation causes a shift in peak position. The effective absorption coefficient αeff(E) of the blend material, used in our simulations, results from the superposition of the respective absorption coefficients α1(E) and α2(E). The corresponding parameters of the simulation are listed in Supplementary Table 1, and Eip,1 = 1.7 eV and Eip,2 = 2 eV
