Controllable surface contact resistance in solution-processed thin-film transistors due to dimension modification

Abstract

The solution-processed thin-film transistors (TFTs) have become the core requirement for the flexible and transparent electronics industry since they are fabricated using cost-effective techniques. However, the fabrication of low-dimensional TFTs by the solution-processing technique is still a challenge due to the surface contact resistance (ρ c). The current study introduces a controllable ρ c involving the effect of dimensions (channel width/length = W/L) on TFTs. The ρ c was measured to be 2.04 × 109 µm VA−1 when the channel length (L) of the TFT was 40 µm. A substantial drop in the surface contact resistance to 1.8 × 108 µm VA−1 was found with L = 5 µm. Thus, a 91% control on ρ c was obtained when L reduced to 40 µm from 5 µm. Such a controllable ρ c was observed with respect to different dimensions of the TFTs. Indeed, an extreme control was obtained in the drain saturation current from 8 µA to 0.8 µA with respect to variation in dimension (W/L) from 15 to 2.5.