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Semiconductor oxides with high room-temperature conductivity and wide bandgap are of significant interest for transparent conductors, channel materials in oxide-based electronics and high-power electronic device applications. Motivated by applications in oxide electronics and heterostructures, rapid progress has been made with myriad growth approaches to obtain high quality thin films, although questions remain regarding electronic transport mechanisms and mobility optimization. Recently, use of electrolyte gating technique have proven to be effective in inducing large carrier densities (~1015 cm 2) due to the formation of nanoscale electric double layer transistors (EDLTs) at the electrolyte/oxide interface. A detailed study of epitaxial SrSnO3 electric double layer transistors based on ion gel electrolyte which resulted in a seven-fold increase in electron mobility at 150K, is discussed. Wide-range tuning of the electronic ground state in stannate based perovskite oxides with exceptional gate voltage operational window (approaching ±4V) at 270 K is presented. A similar approach is performed on β – Ga2O3 to achieve high room temperature mobility 200 cm2/V-s with exceptionally high induced carrier densities. The detailed temperature dependent electronic properties using two-channel conduction method reveal the importance of screening effects that help to achieve high electron mobilities. The true and robust nature of doping mechanisms i.e., electrolyte vs electrochemical in electrolyte gating technique is carefully analyzed in oxide-based electrolyte gated systems. The strong dependence of unwarranted redox reactions at oxide/electrolyte interface on pristine film stoichiometry helps to elucidate oxide-based electrolyte gated mechanisms. This study establishes the electrolyte gating as an effective and reversible method to dynamically tune electronic phase transitions and achieve high electron mobilities in semiconductor oxide films and heterostructures.
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