紫外光驱动下半导体微纳结构薄膜的气敏特性研究

发布时间：2018-05-28 12:56

  本文选题：胶体晶体球 + 紫外光驱动　； 参考：《中国科学技术大学》2017年博士论文

【摘要】：紫外光驱动型气体传感器由于其结构简单、成本低廉、操作方便以及可实现室温工作等优点,备受国内外科研人员的广泛关注。然而,发展高灵敏度、快速响应/恢复、高稳定性及低检测下限的高性能光驱动型气体传感器目前仍然是人们所面临的挑战。本文从敏感材料及其薄膜的结构调控出发,研究材料微结构、薄膜形态及关联尺寸等对气敏特性的影响,发展高性能紫外光驱动型气体传感器的构筑方法,初步开展气体传感器的应用研究,取得的结果主要如下:(1)研究了微纳结构阵列薄膜的微结构参数对气敏性能的影响。通过改变阵列周期探索了阵列周期尺寸与气敏性能的关系,考察了优化气敏性能的最佳光驱动功率,基于气敏性能结构参数关联性解释了微纳结构阵列薄膜气敏增强特性的内在机制。通过改变合成微纳结构阵列薄膜前驱体溶液的浓度,制备了两种不同结构的微纳米有序多孔阵列薄膜:闭环结构和碗状结构。对两种结构薄膜进行气敏测试分析可知,实验发现闭环结构薄膜对NO2气敏性能有显著的增强效果。(2)构建了分析多孔薄膜厚度与灵敏度关系的理论模型。通过理论模型分析发现,当紫外光渗透多孔薄膜的深度(h)大于多孔薄膜的厚度(H)时,随着厚度的增加,薄膜的灵敏度增大;当h≤H时,进一步增大薄膜厚膜,灵敏度会渐渐减小。为了验证该理论模型,我们研究了三种不同结构和不同致密度薄膜的厚度对氧化性气体气敏性能的影响。分析显示,实验结果与理论模型结果相吻合。(3)提出了一种简单、普适的方法制备金属氧化物空心球阵列薄膜。通过硫化聚苯乙烯微球(PS)模板结合水热法可制备出金属氧化物、有机半导体空心球阵列薄膜,改变PS球直径和水热反应时间可分别调控空心球阵列薄膜的直径和壳层厚度;尤为重要的是通过这种方法可实现在任意衬底上合成空心球阵列薄膜,这对其在多个领域中的应用非常重要。基于这种方法,我们在气体传感器衬底上成功合成了氧化铁和氧化锌空心球阵列薄膜,并研究了其气敏性能。结果表明,在低温下氧化铁空心球阵列薄膜对硫化氢有很好的选择性和较高的灵敏度;紫外光照射下氧化锌多孔空心球阵列薄膜对NO2有超快的响应/恢复速度并有较高的灵敏度。本论文研究建立了紫外光驱动下微纳结构的形态参数与气敏性能的关联,发展了高性能气体传感器的构筑及优化方法,并初步实现了对二氧化氮等气体的高敏感特性,具有重要的应用价值。
[Abstract]:Because of its simple structure, low cost, convenient operation and the ability to work at room temperature, ultraviolet light driven gas sensor has attracted wide attention from researchers at home and abroad. However, the development of high sensitivity, fast response / recovery, high stability and low detection limit of high performance light driven gas sensors is still a challenge. In this paper, based on the structural control of sensitive materials and their films, the effects of microstructure, film morphology and correlation size on gas sensing characteristics are studied, and the construction methods of high performance ultraviolet light driven gas sensors are developed. The main results are as follows: (1) the effect of microstructural parameters on the gas sensing properties of nanoscale array films is studied. By changing the array period, the relationship between the array cycle size and the gas sensing performance is explored, and the optimal light driving power for optimizing the gas sensing performance is investigated. Based on the correlation of gas sensing structure parameters, the intrinsic mechanism of gas sensing enhancement of micro / nano structure array films is explained. By changing the concentration of the precursor solution, two kinds of micro-nano ordered porous array films with different structures were prepared: closed loop structure and bowl structure. The experimental results show that the closed-loop structure films have significant enhancement effect on the gas sensitivity of NO2. A theoretical model for analyzing the relationship between the thickness of porous films and the sensitivity is established. Through theoretical model analysis, it is found that the sensitivity of porous films increases with the increase of thickness when the depth of porous films under ultraviolet light is greater than that of porous films, and the thickness of films increases further when h 鈮，

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