Enhanced Electrical Properties of P3HT:WO3 Hybrid Thin Film Transistors

In recent decades, conjugated polymers have been widely studied in organic electronics to produce low-cost transistors. Additionally, these polymers are doped with inorganic materials in order to improve the transistor performance in terms of mobility, on/off current ratio, and threshold voltage as well as to ease processability. In this study, we use various doping concentrations (0-50% in weight) of tungsten oxide (WO3) in poly(3-hexylthiophene) (P3HT), a well-studied organic semiconductor, to optimize the transistor performance. We treat spin-coated film of the hybrid P3HT:WO3 solution on hexamethyl disilazane (HMDS) as channels of commercial test chips including 20 transistors with their gold electrodes. Compared to using pristine P3HT, the proposed hybrid P3HT:WO3 formula which significantly improves the transistor performance. Almost 105 times larger mobilities, almost 10 times larger on/off current ratios, and nearly 22 V decrease in threshold voltages were achieved. It was also observed that the excess amount of WO3 doping leads to worse mobilities and on/off current ratios.