Robust ITO-Al₂O₃Composite Thin Film Sensors for Extreme High-Temperature Applications via Microstructural Stabilization

Thin film sensors developed by micro electromechanical system (MEMS) and 3D printing technologies have emerged as a promising solution for in-situ measurements in high-temperature applications. However, temperature-driven microstructural degradation significantly compromises the structural integrity of thin films, altering their electrical transport behavior, and leading to electrical instability. In this study, we propose a transformative strategy to overcome the structural degradation of indium tin oxide (ITO) thin films. Specifically, alumina (Al2O3) was atomically introduced into the ITO matrix to form a composite texture. The results demonstrate that the Al/In alternately distributed new texture is beneficial for inhibiting grain growth and maintaining the structural integrity of the ITO matrix. Consequently, thin film temperature and strain sensors based on the modified thin film exhibited excellent performance in a series of high-temperature tests, surpassing the state-of-the-art devices.