Electrical instability of polymer thin-film transistors using contact film transfer methods

The effects of molecular packing on electrical instability in poly(3-hexylthiophene) thin-film transistors were investigated by comparing two devices prepared using the same polymer solution and dielectric layer but by different processes. One device, which was prepared by a contact film transfer method by Wei et al. [ACS Appl. Mater. Interfaces 1, 2660 (2009)], utilized the structure formed at the air/solution interface and exhibited high performance, the absence of hysteresis and excellent electrical stability under prolonged continuous bias stress, in contrast to the other device prepared by conventional spin coating, which utilized structures formed at the solution/dielectric interface. Neither thermal nor solvent annealing was applied to control the molecular packing, and thus these results indicate that the highly ordered molecular packing formed at the air/solution interface can simultaneously contribute to enhanced electrical stability. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3454242]