【作者】 王蕊；

【导师】 张彤；

【作者基本信息】 吉林大学 ， 微电子学与固体电子学， 2010， 博士

【摘要】 本文主要以几种介孔材料为基础,研究了基于这几种材料的电阻型湿度传感器的湿度敏感性能,将新型的介孔材料引入到化学传感领域。在绪论部分,简要介绍了湿度传感器的发展历程、应用领域及国内外研究、发展现状,并对近年来新兴发展的介孔材料做了简要的介绍;第二章中以传统的LiCl为湿度活性物质,将其分别组装到介孔二氧化硅SBA-15和SBA-16的孔道中,并制备了电阻型湿度传感器,研究该材料体系的湿度敏感性能。经测试表明:介孔复合材料湿敏性能优越,基于该材料体系的湿敏元件全湿度量程内均表现出良好的湿敏特性;在此基础上,第三章主要介绍了基于一步合成法制备的介孔SBA-15担载传统氧化物(MgO、ZnO)材料的湿度敏感性能。通过适当比例金属氧化物的担载,虽然介孔的有序度有所下降,但是大大改善了该材料所制备元件的湿敏性能(灵敏度)。提高了元件的响应恢复时间,减小了湿滞。在第四章中,在总结前面实验的基础上,作者利用硬模板法制备了介孔金属氧化物In2O3和WO3,通过使传统的金属氧化物半导体材料介孔化的方法,增加材料的表面积及内部缺陷,由于比表面积的增大,大大提高了传统材料的化学敏感活性。基于介孔金属氧化物In2O3和WO3所制备的湿度传感器不但响应恢复迅速,而且湿滞很小,稳定性好。通过对传统化学敏感材料的介孔化改进,获得了性能优良的新型湿度敏感元件。在第五章中,作者主要研究了有机高分子聚合物PPY材料,PPY与SBA-15复合材料及K掺杂LaCo0.3Fe0.7O3材料的湿度敏感性能。通过延长聚合时间的方法,改善了PPY的湿敏特性;通过有机聚合物PPY与介孔SBA-15的复合,提高了湿度敏感元件的灵敏度;通过对传统陶瓷LaCo0.3Fe0.7O3材料湿敏性能的研究,发现适量碱金属盐的掺杂可以提高元件的敏感性能。在本部分,作者还以LaCo0.3Fe0.7O3材料体系为例,利用瞬时极性直流反转测试、直流、交流复阻抗分析法及介电损耗法探究了湿敏元件的感知机理,获得了研究湿度感知(湿)机理的一般性方法。更多还原

【Abstract】 Humidity sensors have been used in an increasing number of applications in industrial processing and environmental control. According to the operation principle, humidity sensors can be divided into resistive-type or capacitive-type. In our experiments, we studied the humidity sensitive properties of resistive-type humidity sensor. Growing demands for controlling water vapor have led to considerable interest in the development of sensing materials. Many kinds of materials including inorganic ceramic, organic polymer and electrolyte have been selected in fabricating humidity sensors. Among these materials, ceramics have been extensively investigated at both room and elevated temperatures. But it may unstable when it absorbed acid atmosphere. Polymers can not work under high temperature and electrolyte may soluble in highly humidity environments. That means all of them exist some disadvantages.Since a family of novel mesoporous silica materials was synthesized by the scientists from Mobil Oil Corporation, mesoporous materials have been receiving wide attention from both the scientific and industry communities. In recent years, The development of material science accelerated the application in many fields. The large surface area created by mesoporous materials enables an improvement in the water adsorption properties of humidity sensor. In this paper, several functional mesoporous materials have been synthesized and their application property in humidity sensors has been studied.In chapterⅡ, the author uses the mesoporous silica SBA-15 and SBA-16 as humidity sensing material. Mesoporous silica SBA-15 and SBA-16 are selected as the host material and LiCl is selected as humidity functional material. After loading optimized amount of LiCl, The humidity-sensitive properties were improved a lot. Except traditional LiCl, what about metal oxide semiconductor? Therefore, in chapterⅢ, the author loaded metal oxide into the mesoporous SBA-15. We obtained MgO/SBA-15 and ZnO/SBA-15 composites by one-pot synthesizing method and fabricated resistive-type humidity sensor. After testing the humidity-sensitive response, the optimized mount of metal oxide was obtained. When the molar ratio of the metal oxide and SBA-15 was 1:1, the humidity sensors show best sensitivity. Test results show that the appropriate introduction of metal oxides improved the performance of the humidity-sensitive properties.Since we found that the humidity-sensitivity can be improved by introduction of metal-oxide semiconductor into mesoporous pore. We considered about that if traditional metal-oxide semiconductor can be provided with mesopore, the sensitivity will be improved a lot. In the fourth chapter, we use nanocasting method in preparing mesoporous In2O3 and WO3 mesoporous materials. Then, studied the humidity-sensitive property based on mesoporous In2O3 and WO3. The sensor fabricated by mesoporous In2O3 and WO3 show quite satisfactory results. Combined with the material structure analysis, we also studied the humidity-sensing mechanism based on mesoporous In2O3 and WO3.Chapter V studied the humidity-sensitivity of organic polymer materials PPY and a traditional ABO3-type ceramics oxide LaCO0.3Fe0.7O3 material. Conducting polymers have been extensively studied because of their remarkable mechanical and electrical properties. Compare with other conducting polymers, PPY has relative high conductivity and environmental stability. In the experiments, we synthesized PPY with different polymerization times, and studied the effect of polymerization time on the humidity-sensitive properties. At last, we found that the humidity-sensitive properties were improved greatly by extending the polymerization time to 96 hours. In order to improve the humidity-sensitive property further, we also encapsulated conducting polymer NiO-PPY into the channel of mesoporous silica SBA-15 to form host-guest material. After loading the PPY into the mesoporous material, the sensitivity of the humidity sensor was improved greatly. This method combined the advantage of conductive polymer and mesopore structure. In the same chapter, we also studied the humidity-sensitive property of traditional ABO3-type ceramics oxide LaCO0.3Fe0.7O3. ABO3-type ceramics oxide is one of the traditional humidity-sensitive materials. We provided nano-LaCO0.3Fe0.7O3 by sol-gel method. K+ was doped by adding to the precursor and the appropriate doping of K’ improved the sensitivity of material in the low relative humidity.The author has employed different method in study the humidity-sensitive mechanism. For example, the polarization theory, complex impedance plots, the Direct-current method and so on. Finally, the conductive carriers were confirmed though the mechanism analysis.更多还原