Study of the source/drain contact resistance effect in Ni/P3HT/PVA/Al OFETs on flexible substrates

Top gate-bottom contacts transistors of Poly 3-hexylthiophene and cross-linked Poly Vinyl Alcohol with different channel lengths (10, 20 and 40 μm) were fabricated on top of polyethylene-naphthalate films using standard photolithography and plasma etching. The transistors presented good characteristics at low voltages and excellent environmental stability. Transmission line method (TLM), based on Shockley model was applied to characterize the transistors. The contact resistance has a higher impact on short channel transistors performance. The shorter the channel length and the higher the semiconductor conductivity, the higher is the impact of contact resistance. On these cases, the use of TLM for parameter extraction becomes essential.