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.