Fig. 1

Absorption profiles and optical simulations. a Chemical structure of active layer components and solvents. b Absorption profiles for PBTA-Si:PTzBI-Si:N2200 (1.3:0.7:1) blend films with different active layer thickness, determined by reflection (double-pass) mode. c Number of absorbed photons versus wavelength for 1.3:0.7:1-cells with active layer thickness of 130 nm and 320 nm, simulated by transfer matrix formalism. d Simulated J_SC versus active layer thickness based on constant IQE, with the red stars represent J_SC calculated from experimental IQE; the dashed line and patterned areas are guides to the eyes