When the molecules are oriented in the direction of the transport of the mobile charge carriers the number of scattering boundaries between the molecules will be fewer and therefore the the mobile charges will have larger mobility.
Even more of the the intermolecular forces are strong the scattering barrier will be high but its width will be very small so that the charge carriers can easily tunnel between the molecules.
The principle is that the mobility increases with increased order of the materials such that the mobility in crystalline materials is much higher than that in the polycrystalline material and lowest in amorphous materials.
Typically you would want your polymer chains to be aligned along the charge transport direction. This is why you often see solution alignment techniques, such as solution shearing, lead to devices with enhanced field-effect mobilities. Since intramolecular charge transport is faster than intermolecular, this intuitively makes sense.
When the molecules are oriented in the direction of the transport of the mobile charge carriers the number of scattering boundaries between the molecules will be fewer and therefore the the mobile charges will have larger mobility.
Even more of the the intermolecular forces are strong the scattering barrier will be high but its width will be very small so that the charge carriers can easily tunnel between the molecules.
The principle is that the mobility increases with increased order of the materials such that the mobility in crystalline materials is much higher than that in the polycrystalline material and lowest in amorphous materials.