Mobility Enhancement in Solution-Processed Transparent Conductive Oxide TFTs due to Electron Donation from Traps in High-k Gate Dielectrics

High‐mobility ZnO thin films are deposited onto solution‐processed ZrO2 dielectrics in order to investigate the large differences between experimental field‐effect mobility values obtained when transparent conductive oxide (TCO) materials are deposited onto high‐k dielectrics as opposed to thermally grown SiO2. Through detailed electrical characterization, the mobility enhancement in ZnO is correlated to the presence of electron traps in ZrO2 serving to provide an additional source of electrons to the ZnO. Furthermore, as a consequence of the general tendency for solution‐processed high‐k dielectrics to exhibit similar behavior, the broad applicability is suggested to other TCO/high‐k material combinations in agreement with experimental observations. Zinc oxide (ZnO) thin‐films are deposited onto solution‐processed zirconia dielectrics to investigate differences in mobility obtained when transparent conductive oxide semiconductors are deposited onto high‐k dielectrics as opposed to thermally‐grown silica. Through detailed electrical characterization, the mobility enhancement in ZnO is correlated with the presence of electron traps in zirconia—providing an additional source of electrons to the ZnO.