Microphase separation-promoted crystallization in all-conjugated poly(3-alkylthiophene) diblock copolymers with high crystallinity and carrier mobilityElectronic supplementary information (ESI) available: GPC profiles, 1H NMR spectra, degrees of crystallization of P3BDDT and SCLC mobility of P3BDDT after the "one-step" thermal treatment. See DOI: 10.1039/c2jm33204c

The crystallinity of all-conjugated diblock copolymer, poly(3-butylthiophene)- b -poly(3-dodecylthiophene) (P3BDDT), with varied block ratios was significantly enhanced by a "two-step" thermal annealing treatment. The resulting P3BDDT exhibited an attractively high crystallinity of 35%, which is a 3-fold enhancement over those of its homopolymer counterparts. The space-charge limited current (SCLC) mobility measurement revealed that the carrier mobility of the highly crystalline P3BDDT film was increased to as high as 8.4 × 10 3 cm 2 V 1 s 1 , exceeding the highest SCLC mobility of poly(3-alkylthiophene) homopolymer films reported in previous work ( i.e. , 1.6 × 10 3 cm 2 V 1 s 1 ). DSC, XRD, AFM and SAXS characterizations demonstrated that the interplay of crystallization and microphase separation during the "two-step" thermal annealing treatment plays a key role in the improvement of P3BDDT crystallinity. The crystallinity of all-conjugated diblock copolymer, poly(3-butylthiophene)- b -poly(3-dodecylthiophene) (P3BDDT), with varied block ratios was significantly enhanced by a "two-step" thermal annealing treatment.