Sub-Nm Kinetically Controlled Liquid Metal Printing of Ternary Antimony Indium Oxide Transistors

Abstract

Two-dimensional (2D) metal oxide semiconductors offer a superlative combination of high electron mobility and visible range transparency uniquely suitable for flexible transparent electronics. Synthesis of these ultrathin (< 3 nm) semiconductors by Cabrera Mott oxidation of liquid metals could enable emerging device applications but requires precise design of their electrostatics at the nanoscale. This study demonstrates sub-nanometer-level control over the thickness of semiconducting 2D antimony-doped indium oxide (AIO) by manipulating the kinetics of Cabrera Mott oxidation through variable-speed liquid metal printing at plastic-compatible temperatures (175 °C). By modulating both the growth kinetics and doping, we engineer the conductivity and crystallinity of AIO for integration in ultrathin channel transistors exhibiting exceptional steep turn on, on-off ratios > 106, and an outstanding average mobility of 34.7 ± 12.9 cm2/Vs. This result shows the potential for kinetically controlling 2D oxide synthesis for various high-performance optoelectronic device applications.

Keywords: 2D oxides, transparent transistor, printed electronics, liquid metals, thin film transistors