Gate dielectric based steady state & transient analysis of channel characteristics for organic thin-film transistors

Gate dielectric materials play a crucial role in the design of organic thin-film transistors. The effects of the low-k and high-k gate dielectric materials, both organic and inorganic, on the bottom gate Pentacene/a-IGZO thin-film transistors (TFT) are studied and simulated using 2D numerical device simulation. The effect on the electrical characteristics of different gate dielectrics namely Air, SiO2 (Silicon Oxide), Si3N4 (Silicon Nitride), Al2O3 (Aluminum Oxide), Sapphire, Y2O3 (Yttrium Trioxide), HfO2 (Hafnium Oxide), Ta2O5 (Tantalum Oxide), La2O3 (Lanthanum Oxide), Nb2O5 (Niobium Oxide) and TiO2 (Titanium Oxide) have been studied and compared using current-voltage (I-V) transfer characteristics in the linear and saturation regime for both n-type and p-type transistors. In addition, the analysis was also carried out for organic gate dielectrics such as PMMA (poly methyl methacrylate), silk fibroin, PVA (polyvinyl alcohol) and CEP (Cyanoethyl pullulan). From the extracted results, it is found that the device shows better performance for TiO2 which shows a high ON current of - 1.36 mu A and 13.4 mu A for p-and n-type transistors respectively. Furthermore, the low threshold voltage (VTH), high ON/OFF ratio, high gate oxide capacitance (C ' OX), and low subthreshold slope (SS) ensure a low operating voltage, thus enabling the realization of low power devices and low gate leakage (IGS), which also suppresses the excess heat generated in the device. Finally, the tuning of the high-k gate dielectric thickness can be extended further for future work and analysis.