This paper reviews the fabrication of zinc oxide-tin oxide (ZnO-SnO₂) nanocomposite in humidity sensors. ZnO and SnO₂ each has a wide energy band gap, making them suitable for producing high-quality humidity sensors. Also, ZnO and SnO₂ are the ideal heterojunctions with high sensitivity and thermal stability. When combined, ZnO-SnO₂ nanocomposite is an n-type semiconductor with high versatility in many applications, such as gas sensors, lithium-ion batteries, and photocatalytic degradation. Besides, the nanostructure film of ZnO-SnO₂ is relatively easy to prepare and characterise while manipulating ZnO and SnO2 could enhance device performances. Thus, the nanostructure of ZnO-SnO₂ would likely measure the humidity sensing performance easily.
