Does a large response suffice?: Thermally stable and low noise Si-doped IZO thin-film transistor-type gas sensors

The need for highly sensitive and reliable gas sensors is critical for various applications. Metal oxide gas sensors are at the forefront of this technological demand. However, existing studies predominantly focus on enhancing the sensor response, often neglecting other crucial performance metrics such as thermal stability, leading to sensors with suboptimal overall performance. In this study, we investigate the effects of silicon doping on indium-zinc-oxide (IZO) thin-film transistor (TFT)-type gas sensors from a comprehensive perspective. We demonstrate that Si-doping effectively reduces oxygen vacancies in the IZO film, leading to improvements in structural integrity and stability. This enhancement is reflected in a significant reduction in 1/f noise, an increase in SNR, and thermal stability. Consequently, the limit of detection (LoD) for the Si-doped IZO TFT-type gas sensor is markedly improved, decreasing from 1.8 ppb to 0.29 ppb. Our findings underscore the importance of a holistic approach in the development of metal oxide gas sensors. By considering a broad set of performance factors, we achieve a more reliable and sensitive gas-sensing platform. This study provides valuable insights for the future design and optimization of advanced gas sensors, ensuring better performance across diverse operating conditions. •Effects of silicon-doping on indium-zinc oxide (IZO) thin-film transistors (TFT) gas sensors are demonstrated.•The reliability of the sensor, including thermal stability and low-frequency noise, is improved by silicon-doping.•The limit-of-detection of the sensor to NO2 is improved to 0.2 ppb via optimization of various sensing metrics.