Solvent vapor assisted spin-coating: A simple method to directly achieve high mobility from P3HT based thin film transistors

The P3HT thin films were made by novel solvent vapor assisted spin-coating method that adds several opened bottles of solvent into spin-coater and seals it with a lid. Such thin films directly had broader absorption and higher crystallinity. The corresponding thin film transistor had higher mobility of 0.041 cm2 V−1 s−1contrasting to 0.007 cm2 V−1 s−1of device based on P3HT thin film made by normal spin-coating. Compared with the solvent vapor annealed P3HT thin film made by normal spin-coating, the thin film made by solvent vapor assisted spin-coating has similar absorption spectrum, X-ray diffraction and device performance, which demonstrates that such novel method is equivalent to the combination of normal spin-coating and solvent vapor annealing. However the fabrication is more simple and the process time is reduced from several hours to several tens of seconds, which is more beneficial for actual mass production.