Hybrid top-gate transistors based on ink-jet printed zinc tin oxide and different organic dielectrics

摘要

We report about hybrid top-gate transistors based on ink-jet printed zinc tin oxide (ZTO) and different spin-coated organic dielectrics. Transistors using the polar dielectric poly(methyl methacrylate) (PMMA) and the nonpolar polystyrene (PS) were evaluated. By applying PMMA, we were able to process field-effect transistors with a saturation mobility of up to 4.3 cm(2) V-1 s(-1). This is the highest reported mobility of an ink-jet printed ZTO top-gate transistor using a spin-coated PMMA dielectric. This transistor also exhibits a small threshold voltage of 1.7V and an on/off-current ratio exceeding 10(5). The usage of PS as another organic dielectric leads to functional devices with inferior performance, meaning a saturation mobility of 0.2 cm(2) V-1 s(-1) and a threshold voltage of 9.7 V. The more polar character of the PMMA compared to the PS dielectric leading to a better adhesion on the quite hydrophilic ZTO surface could explain the improved device performance of the ZTO top-gate transistor using PMMA. Published by AIP Publishing.