金属氧化物半导体薄膜气敏机理研究进展

气体传感器的核心介质为气敏薄膜,而薄膜本身的特性有关键的影响,主要体现在薄膜微观结构如晶粒尺寸、膜厚、空隙率和有效表面积等方面。溶胶-凝胶法由于有方法简单及成膜温度低等优点,得到了广泛研究与应用。本文综述了溶胶-凝胶法制备的金属氧化物薄膜微纳结构与气敏机理进来的研究进展,结果表明最佳的晶粒尺寸约为10nm,最佳膜厚约为110 nm。在晶粒尺寸控制方面,通过控制煅烧温度与时间及在溶胶-凝胶过程中加入不同的添加剂,可有效优化晶粒尺寸提高灵敏度。最后,从能带结构角度总结了气敏传感器的电学特性及荷电传输机理,讨论了热电子发射理论和电子隧穿理论起主导作用时的薄膜微纳结构。

Research Development on Gas Sensing Mechanism of Metal Oxide Semiconducting Thin Films

One of the key components of gas sensing devices is their active thin film whose performance is largely affected by the fabrication method.This is usually due to the differences in the film microstructures such as grain size,thickness,void fraction and effective surface area etc.Sol-Gel method has been well developed and widely used owing to its unique processes and advantages(e.g.easy film fabrication and low growth temperature).In this article,the preparation of metal oxide sol-gel thin films is reviewed ...