High-Performance Indium Oxide Thin-Film Transistors With Aluminum Oxide Passivation

In this letter, high-performance thin-film transistors (TFTs), with indium oxide (In ₂ O ₃ ) as front channel layer, high permittivity ZrO ₂ as dielectric layer, and aluminum oxide (Al ₂ O ₃ ) as passivation layers were integrated by a fully solution process. It is found that the incorporation of Al ₂ O ₃ passivation layer gives rise to a sharp decrease in the off current (I _off ) and a corresponding increase in the on/off current ratio (I _on /I _off ) of the TFTs, compared to that without Al ₂ O ₃ passivation. Furthermore, the thickness effect of the passivation layer on the performance of In ₂ O ₃ /ZrO ₂ TFTs has been investigated systematically. The In ₂ O ₃ /ZrO ₂ TFTs with optimized Al ₂ O ₃ passivation layers can be operated at 3 V with high performance, including a high field-effect mobility of 21.22 cm ² N s, a large I _on /I _off of 10 ⁷ and a negligible hysteresis (~0 V). This work demonstrates an effective strategy for the construction of high performance TFTs by incorporating the passivation layer.