An azobenzene liquid crystalline mesogen, 6-(4-((4-methoxyphenyl)diazenyl)phenoxy)hexyl methacrylate (MMAZO) was incorporated into a block copolymer with regioregular poly(3-hexylthiophene) (P3HT). The synthesis was performed by a combination of Grignard metathesis (GRIM) and atom transfer radical polymerization (ATRP) techniques. The composition of synthesized copolymers was determined from (HNMR)-H-1 analysis. The P3HT block/random copolymers containing thermotropic liquid crystalline segments were expected to bring unique self-assembly and opto-electronic properties. The field-effect mobility of the P3HT copolymers was measured in organic thin film transistors (OTFT). The surface morphology of the P3HT copolymer films upon annealing was investigated by tapping mode atomic force microscopy (TMAFM). Finally, the transition of liquid crystalline mesophase in response to the temperature in the P3HT copolymers was investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). (C) 2015 Elsevier Ltd. All rights reserved.