High-performance bilayer metal-oxide thin film transistors using ultra-thin solution-processed ZrOx dielectric

TL;DR

This paper demonstrates a high-performance bilayer metal-oxide thin-film transistor with ultra-thin solution-processed ZrOx dielectric, achieving high mobility, low off-current, and stability at low voltage, suitable for low-power switching applications.

Contribution

The study introduces a novel bilayer In2O3/InZnO TFT with ultra-thin ZrOx dielectric, achieving significantly improved mobility and stability over single-layer devices.

Findings

High field-effect mobility of 37.9 cm2/V s

On/off current ratio of 10^9

Stable threshold voltage under bias stress

Abstract

We reported here a high-performance In2O3/InZnO bilayer metal-oxide (BMO) thin-film transistor (TFT) using ultra-thin solution-processed ZrOx dielectric. A thin layer of In2O3 offers a higher carrier concentration, thereby maximizing the charge accumulation and yielding high carrier mobility. A thick layer of InZnO controls the charge conductance resulting in low off-state current and suitable threshold voltage. As a consequence, the BMO TFT showed higher filed-effect mobility (37.9 cm2/V s) than single-layer InZnO TFT (7.6 cm2/V s). More importantly, an on/off current ratio of 109, a subthreshold swing voltage of 120 mV/decade, as well as a threshold voltage shift (less than 0.4 V) under bias stress for 2.5 hours were obtained simultaneously. These promising properties are obtained at a low operation voltage of 3 V. This work demonstrates that the BMO TFT has great potential applications as switching transistor and low-power devices.