Electrolyte-Gated, High Mobility Inorganic Oxide Transistors from Printed Metal Halides

Inkjet printed and low voltage (≤1 V) driven field-effect transistors (FETs) are prepared from precursor-made In₂O₃ as the transistor channel and a composite solid polymer electrolyte (CSPE) as the gate dielectric. Printed halide precursors are annealed at different temperatures (300–500 °C); however, the devices that are heated to 400 °C demonstrate the best electrical performance including field-effect mobility as high as 126 cm² V^–1 s^–1 and subthreshold slope (68 mV/dec) close to the theoretical limit. These outstanding device characteristics in combination with ease of fabrication, moderate annealing temperatures and low voltage operation comprise an attractive set of parameters for battery compatible and portable electronics

High-Performance All-Printed Amorphous Oxide FETs and Logics with Electronically Compatible Electrode/Channel Interface

Oxide semiconductors typically show superior device performance compared to amorphous silicon or organic counterparts, especially when they are physical vapor deposited. However, it is not easy to reproduce identical device characteristics when the oxide field-effect transistors (FETs) are solution-processed/printed; the level of complexity further intensifies with the need to print the passive elements as well. Here, we developed a protocol for designing the most electronically compatible electrode/channel interface based on the judicious material selection. Exploiting this newly developed fabrication schemes, we are now able to demonstrate high-performance all-printed FETs and logic circuits using amorphous indium–gallium–zinc oxide (a-IGZO) semiconductor, indium tin oxide (ITO) as electrodes, and composite solid polymer electrolyte as the gate insulator. Interestingly, all-printed FETs demonstrate an optimal electrical performance in terms of threshold voltages and device mobility and may very well be compared with devices fabricated using sputtered ITO electrodes. This observation originates from the selection of electrode/channel materials from the same transparent semiconductor oxide family, resulting in the formation of In–Sn–Zn–O (ITZO)-based-diffused a-IGZO–ITO interface that controls doping density while ensuring high electrical performance. Compressive spectroscopic studies reveal that Sn doping-mediated excellent band alignment of IGZO with ITO electrodes is responsible for the excellent device performance observed. All-printed n-MOS-based logic circuits have also been demonstrated toward new-generation portable electronics