Effective Reduction of Leakage Currents in Single-walled Carbon-nanotube-network Thin-film Transistors

We report on the dependence of the reduced metallic percolation paths of single-wall carbon-nanotube-network thin-films (SCNTFs) on the channel aspect ratio and the number of strips (N(strip)). A longer channel length (L(C)) and the existence of strips in the channel region limit the number of metallic percolation conducting paths existing between the source and the drain in SCNTF transistors. Increasing the channel aspect ratio threefold resulted in an increase in the on/off current ratio (I(on)/I(off)) by 246%. We also observed that introducing 15 strips into the channel increased I(on)/I(off) by 859%, which was attributed to a reduction in the number of metallic percolation paths formed between the source and the drain. The results show that with a higher aspect ratio and with strips introduced into the channels, the semiconducting behavior of solution-processed SCNTF transistors can be enhanced.