ZnO based field-effect transistors (FETs): solution-processable at low temperatures on flexible substrates

Abstract

A well-performing ZnO field-effect transistor (FET) on polyethylenenaphthalate (PEN) foil with solution-processed ZnO semiconductor and dielectric material is presented for the first time. In addition, we developed a route that allows preparation of the ZnO semiconductor layer simply from commercially available ZnO dissolved in aqueous ammonia in a single processing step. The material performance in FETs exceeds that of state of the art solution-processable ZnO materials at comparably low processing temperatures (≤150 °C). Polysilsesquioxanes are identified as physically and chemically suitable dielectric materials that also fulfill the criteria solution processability at low temperatures. Water and ethyllactate are used as “green” solvents.