Figure 6. Summary of blend image characterization.

(a,b) EFSEM images subject to FFT band-pass filter and thresholded to emphasize the imaged domain structure. Red areas correlate to those deemed to be P3HT-rich, and blue to those deemed to be PCBM-rich. The mixed phase is preserved in these images. a shows the same area as Fig. 3a (20 nm scale bar), and b the same area as Fig. 3b (30 nm scale bar). c shows radially averaged autocorrelation functions applied to Fig. 3a,b. Clear peaks in both functions are observed at ∼16 and ∼28 nm. Other, smaller peaks are also identified at longer correlation lengths.