For a couple of decades, there is a tremendous growth in industries and technology in the global level. Unfortunately, emerging new industries became a main reason for rising air pollution in the earth’s environment. Hence, the health issues associated with air pollution are on a high scale that alarm us to monitor the quality of the air that we breathe, and demand development of efficient gas sensor devices. Recently, the groups of binary and ternary metal oxide semiconductors are regarded as reliable materials for gas sensing applications. Chemical spray pyrolysis, one of the efficient techniques to fabricate thin films with high reproducibility is triggering recent research on fabricating films for gas sensor applications. Here, the focus is on spray-deposited binary and ternary metal oxide thin films for gas sensing applications. The working mechanism of metal oxide sensors have been discussed comprehensively on the basis of redox reaction processes that caused band bending and variation of electrical conductivity of devices in the presence of target gases. This review also points out the shortcomings of existing technology and the possible ways to overcome them, and eventually future evolution in the field of gas sensor are also hypothesized.

几十年来，全球范围内的工业和技术取得了巨大的发展。不幸的是，新兴产业成为地球环境空气污染加剧的主要原因。因此，与空气污染相关的健康问题规模很大，提醒我们监测呼吸的空气质量，并需要开发高效的气体传感器设备。最近，二元和三元金属氧化物半导体组被认为是气体传感应用的可靠材料。化学喷雾热解是制造具有高重复性的薄膜的有效技术之一，正在引发有关制造气体传感器应用薄膜的最新研究。这里的重点是用于气体传感应用的喷涂沉积二元和三元金属氧化物薄膜。基于目标气体存在下引起能带弯曲和器件电导率变化的氧化还原反应过程，全面讨论了金属氧化物传感器的工作机理。这篇综述还指出了现有技术的缺点以及克服这些缺点的可能方法，并最终还假设了气体传感器领域的未来发展。