Humidity sensing performance of aligned assembly tin-doped zinc oxide nanocomposited films via low temperature immersion method / Ahmad Syakirin Ismail @ Rosdi

In this study, resistive humidity sensors were fabricated using ZnO-based nanocomposite films on top of ZnO-seed-layer-coated glass substrates. This study introduced different novel configurations of humidity sensors that were prepared using sol-gel immersion and sputtering method. Several approaches, such as doping and constructing composite films, were applied to improve the ZnO-based humidity sensors. The structural, optical, and electrical properties of the synthesized films were characterized via field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, atomic force microscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, ultraviolet–visible–infrared spectrophotometry, and two-probe current-voltage measurement. The humidity sensing performances of the films were measured in a humidity chamber equipped with a measurement system. Results showed that the intrinsic ZnO nanorod arrays (NRAs) exhibited a humidity sensitivity of 1.53. The humidity sensing performance of the fabricated ZnO NRAs could be further enhanced to 3.7 by doping with 1 at.% of tin (Sn). A slight increment of humidity sensitivity of the Sn-doped ZnO (SZO) film was facilitated by the enlargement of surface area.