Ion-gating analysis on conduction mechanisms in oxide semiconductors

Abstract

• Self-gated field-effect by ion adsorption at the solid–liquid interface (ion-gating). • Resistive factors of indium tin oxide controlled depending on sputtering conditions. • A fundamental correlation between the ion-gating effect and the resistive factors. • Ion-gating analysis on the resistance-dependent behavior of electrons in the electrode. • Identification of conduction mechanisms in amorphous oxide semiconductors. The electric field-effect is one of the common methods to tune the conductivity of materials in semiconductor devices because it can control the accumulation or depletion of charge carriers. However, to efficaciously dominate the electrical properties of the semiconductor in such a way, the application of an external voltage through the gate is an inevitable condition. Here, we propose an ion-dynamics-driven (ionovoltaic) transducer focusing on a self-gated field-effect by ion adsorption at the solid–liquid interface (an ion-gating effect without applied electric field). Considering an effective resistance derived from the generated signal, we establish an equivalent circuit of the ion-gating field-effect transducer to specifically analyze the conduction behavior of traveling electrons in an amorphous indium tin oxide film. As a result, using water droplet flow, we provide a convenient method to identify inherent conduction mechanisms of amorphous oxide semiconductors. This analysis has great potential as a tool to leap forward into a new interdisciplinary approach covering interface science and solid-state physics from a peculiar concept based on the ion-gating effect.