Superior Thermoelectric Performance of Robust Column-Layer ITO Thin Films Tuning by Profuse Interfaces

Indium tin oxide (ITO) thin films suffer from poor chemical stability at high temperatures because of the instability of point defects and structural variations. An interface design strategy was proposed herein to improve this situation, where a robust ITO-based thin film with a column-layer structure was fabricated. Three types of column-layer ITO thin films were fabricated via magnetron sputtering. By tuning the interfaces, we controlled the effective mass and weighted mobility, enhancing the electrical conductivity (2.17 × 10⁶ S m^-1) and power factor (1138 μW m^-1 K^-2). The crack propagation path was prolonged because of the profuse interfaces between the columns and layers in the alternate thin films. Thus, enhanced nanohardness (16.5 GPa) was obtained. The structural evolution and performance of the column-layer ITO thin films annealed under different conditions were investigated. The atoms were restricted by the profuse interfaces, resulting in high-temperature stability. The results demonstrate that the interface design of ITO thin films can efficiently modify the stability of conductive ceramics over a wide temperature range, which has significant potential for applications in microdevices and aero engines.