av of -conjugated polymers and small molecules as a function of their reported field-effect mobility (FET). Two groups of -conjugated polymers are classified in this work. Amorphous or short-range ordered materials (blue circles) include rra-P3HT 1), PFO 2), TQ1 3), PCDTBT 4), PFBT 5), PTB7-Th 6), IDT-BT 7) and TIF-BT 8). Semi-crystalline conjugated polymers (orange squares) are pBTTT-C141), P(NDI2OD-T2) 2), rr-P3HT (3 and 6, of two distinctMw), rr-P3BT 4) and rr-P3DDT 5). avin semi-crystalline PDPP4T (filled left triangle) and DPPDTT (filled right triangle) films was determined by frequency-domain thermoreflectance (FDTR), therefore excluded from the ulterior statistical analysis of molecular descriptors to keep the methodological consistency of the experimental dataset. FETvalues were extracted from the literature as detailed in the Supporting Information. The dotted lines correspond to linear fits (in logarithmic scale) performed through orthogonal distance regressions; the shaded areas define their 95% (i.e., 2) confidence intervals following the effective variance method to account for uncertainties in both axes. Benchmark values (green symbols) corresponding to amorphous silicon (a-Si:H) and the lower limits identified for in linear (DH6T) and non-planar (PC71BM) conjugated molecules are also included.
