Printed in-plane electrolyte-gated transistor based on zinc oxide

Abstract Printed electronics is a reputable research area that aims at simple alternatives of manufacturing low-cost, eco-friendly, and biodegradable electronic devices. Among these devices, electrolyte-gated transistors (EGTs) stand out due to their simple manufacturing process and architecture. Here we report the study of printed EGTs with in-plane gate transistor (IPGT) architecture based on zinc oxide nanoparticles. The drain, source, and gate electrodes with two different W/L channel ratios were fabricated using a screen-printed carbon-based ink. We also produced a conventional top-gate transistor as a standard device, using the same structure of the IPGT described above with the addition of an indium tin oxide strip positioned over the electrolyte as the top-gate electrode. The IPGT with W/L = 5 presented a high mobility of 7.95 ± 0.55 cm² V⁻¹ s⁻¹, while the W/L = 2.5 device exhibited a mobility of 3.03 ± 0.52 cm² V⁻¹ s⁻¹. We found that the measured field-effect mobility of the device can be affected by the high contact resistance from the carbon electrodes. This effect could be observed when the device’s geometric parameters were changed. Furthermore, we also found that the IPGT with W/L = 5 exhibited higher values for mobility and transconductance than the top-gate transistor, showing that the IPGTs architecture is a good approach for cheap and printed transistors with performance comparable to standard top-gate EGTs.