Performance Modulation of Printed Two-Dimensional GaO_x Film Transistor Upon Annealing Treatment

Gallium oxide (Ga2O3), an emerging ultrabroadband semiconductor, is a crucial material for developing next-generation high-efficiency, high-power electronic devices. In this work, we prepared 2D GaOx films for lap thin-film transistors (TFTs) using tumbling to peel off the oxide layer on the surface of the liquid gallium metal. By treating the 2D GaOx films with different annealing temperatures and changing their internal defect concentrations, we realized the tuning of the films in terms of optical properties, electrical properties, and the performance of GaOx-based TFT devices with channel layer thicknesses of less than 10 nm. After annealing, the films were transformed from amorphous GaOx to β-Ga2O3, the visible transmittance was kept above 98%, the oxygen vacancy concentration decreased from 69 to 9.1%, the figure of merit increased monotonically from 3.9 to 4.2 eV, and the electrical characteristics gradually transitioned from a conductor to a semi-insulator. The Ioff of GaOx-based TFTs is below 1 nA, and the Ion/Ioff can reach 104, showing excellent potential in electrical devices.