Figure 10.

A) Wide angle X-ray scattering image of C₁₆IDT-BT. B,C) Comparison of polymer chain orientation from GIXD and NEXAFS. The average orientation of the conjugated plane calculated from GIXD () as a function of the conjugated plane tilt, i.e., the angle between the (010) reflection and the conjugated plane normal for C₁₆IDT-BT (B) and fast-dried, non-annealed P3HT (C). The upper and lower bounds of the pink areas in a denote the average orientation of the conjugated plane that is compatible with NEXAFS spectra () of top and buried interfaces, respectively. The light-blue areas highlight the conjugated plane tilt range between 20° and 30°: that is, the most probable conjugated plane tilt range for alkylated polythiophenes. For C₁₆IDT-BT, the overlap between and the range of possiblesuggests that the conjugated planes are oriented in similar ways irrespective of whether their environments are crystalline or non-crystalline, whereas for P3HT the absence of overlap between the and suggests that the orientation of the chains in non-crystalline environments is likely to be different from those in crystalline domains. Reproduced with permission.[81] Copyright 2013, Macmillan Publishers Ltd