Enhanced Bias Stability of Solution-Processed Zinc-Tin-Oxide Thin Film Transistors Using Self-Assembled Monolayer as a Selective Channel Passivation

The enhanced positive bias stability of amorphous zinc-tin-oxide thin-film transistors (a-ZTO TFTs) were obtained by applying self-assembled monolayer (SAM) as a selective passivation layer on the metal-oxide back channel area. The a-ZTO TFTs with passivation layers such as poly(methyl methacylate) (PMMA), SAM, and SAM/PMMA were fabricated by simple solution methods. After deposition of the passivation layers, the electrical characteristics of a-ZTO TFTs have not been changed and the threshold voltage shift (Delta V-th) under gate-bias stress for around 10(4) seconds was improved. The Delta V-th of the devices with PMMA, SAM, and SAM/PMMA dual layer were 3.79 V, 3.2 V, and 2.17 V, respectively.