【摘要】 以三氧化二铝(Al2O3)为衬底,二氧化钛(TiO2)为厚膜氧敏材料,研究衬底表面杂质对厚膜高温氧敏特性的影响。用X射线光电子能谱监测常用Al2O3基体在制备及表面抛光过程中引入的钙(Ca)、硅(Si)、钠(Na)、氮(N)等杂质及含量。X射线衍射分析表明:衬底杂质使厚膜主体物相仍保持金红石结构,但随着Si离子摩尔分数(下同)的提高,厚膜的金红石结构中出现低度的Si,Ti有序化。扫描电子显微镜分析表明:Ca,Na离子含量较高的样品,晶粒表层包覆使厚膜粒度呈现增大的迹象。伏安法的厚膜氧敏特性测试表明:衬底表面存留的Ca离子含量越高,引入深能级空穴浓度越高,高温(600℃以上)氧气响应特性变差。缺位分析认为,衬底表面存留Ca,Si,Na离子产生的Ti金属缺位是影响敏感膜高温富氧响应特性和响应时间的主要因素。更多还原

【Abstract】 Using aluminum oxide (Al2O3) as substrate and titania (TiO2) as sensitive material, the influence of substrate surface impurity on the oxygen response characteristics of TiO2 thick film was investigated. X-ray photoelectron spectroscopy was used to inspect the impurity type (Ca, Si, Na, or N) and concentration of substrate during preparation and polishing. X-ray diffraction indicate that TiO2 thick film retaine the rutile phase with an appropriate substrate impurity. However, as the content in mole of Si was increases, there was a small area where Si and Ti ordering of the TiO2 thick film appear. Scanning electron microscope shows that the higher the concentration of Ca and Na, the larger the grain of the material became under a surface cladding. The voltammetric testing shows that the higher the Ca concentration, the more holes appeared in the deep level defects, and the oxygen characteristics at high temperature are worse. The results indicate that the vacancy of Ti created by Ca, Si and Na staying on the substrate is the main factor that influences the response characteristics and response time of TiO2 thick film at high temperature.更多还原