Combining side chain engineering and controlled alignment of PBTTT is an effective strategy to produce oriented thin films with improved thermoelectric performances when doped sequentially with the acceptor molecule F 6 TCNNQ. The substitution of linear alkyl side-chains (n-C 12) with a chain of identical length including an ether function (n-C 7 OC 4) leads to a new class of slightly polar PBTTT polymers, preserving the ease of synthesis and air stability of alkylated PBTTTs. This sidechain modification improves the structural order of PBTTT backbones and the thermomechanical properties of the polymer. It then can be oriented by high temperature rubbing up to 240°C to reach very high dichroic ratios up to 20 thanks to enhanced cohesive forces within side-chain layers. The side chain polarity of n-C7OC4 helps to tune the polymer-dopant interactions. A multi-technique approach demonstrates that F6TCNNQ dopants are randomly oriented in the disordered side chain layers of n-C7OC4 with some evidence of dopant clustering. The combination of improved alignment and random orientation of intercalated F6TCNNQ dopants helps reach a very high charge conductivity o = 5.104 S/cm and a record power factors PF = 2.9 mWm-1K-2 in the polymer chain direction.