Figure 5

(a) Out-of-plane XRD pattens of the pristine PCBM film and the pSi/PCBM films with different surface modifier concentrations. All the films were spin-coated on silicon wafers. The pristine PCBM film was thermally annealed at 150 °C and the pSi/PCBM films were annealed at 130 °C. The patterns are shifted along the y-axis for clarity. Out-of-plane XRD patterns of (b) pSi/PCBM and (c) pure PCBM films on silicon wafers, which were thermally annealed at different temperatures. The bSi/PCBM film were prepared by spin-coating the mixed solution of bSi (0.88 g L⁻¹) and PCBM (10 g L⁻¹). The insets show magnified views. The patterns are shifted in the y-axis for clarity. (d) Si:C atomic ratio on the surfaces of the pSi/PCBM films measured by XPS plotted as a function of the thermal annealing temperature. The films with SSM were prepared by spin-coating the mixed solution of PCBM (10 g L⁻¹) and the surface modifiers. The concentration of pSi was 1.36 g L⁻¹.