Formaldehyde sensing characteristics of an aluminum-doped zinc oxide (AZO) thin-film-based sensor

An aluminum-doped zinc oxide (AZO) thin-film-based formaldehyde sensor prepared using radio-frequency sputtering (RF) is studied. The proposed device has a very high formaldehyde sensing response of 95.5 (@20 ppm HCHO/air, 350 °C), an extremely low detection limit (≤40 ppb HCHO/air), a relatively low operating temperature (≤350 °C), and a wide sensing range. Moreover, the device has a simple structure and is easily fabricated, low cost, and environmentally friendly. Therefore, the proposed AZO thin-film-based sensor is promising for high-performance formaldehyde sensing applications.