Naphthyl end-capped bithiophene film on plant-based polyamide-4,10

We report on a vacuum deposited 5,5’-bis(naphth-2-yl)-2,2’-bithiophene (NaT2) film on bio-based polyamide-4,10 (PA410) substrate. The substrate is moderately hydrophobic with dominant dispersive interactions. Nominally 25 nm thick NaT2 films on PA410 adopt lying-down (face-on) crystals that follow island type growth mode. They show charge carrier mobilities 3⋅10 cm/Vs as well as the area normalized photoresponsitivities up to 20 μA/W at 100 V and a light intensity of 78 W/m. Full coverage is achieved for 50 nm film thickness. This performance matches that of identically prepared films on polyester substrates that are commonly employed in organic electronics. This study shows how photosensitive bithiophenes can be grown on low carbon footprint polyamides, ultimately lowering the carbon footprint of the entire device.