共查询到19条相似文献,搜索用时 773 毫秒
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SnO2超微粒薄膜气敏元件的研制与测试 总被引:2,自引:0,他引:2
用射频磁控反应溅射法在Si基片上沉积SnO_2超微粒薄膜,溅射过程中适量掺Pd,用IC技术制成气敏元件.实验结果表明:该元件在90℃左右时对氢气有极高的灵敏度,是一种薄膜化、集成化、高选择性的气敏元件.本文介绍薄膜制备、微观结构分析、元件设计及气敏特性测试. 相似文献
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针对多孔硅气敏传感器在室温下对NO2气体灵敏度较低、选择性不强的问题,采用双槽电化学腐蚀法制备多孔硅,然后在多孔硅顶部溅射沉积金属钨薄膜并经高温热处理氧化形成WO3纳米线,制备出WO3纳米线修饰多孔硅结构及其气敏传感器,对WO3纳米线/多孔硅材料进行了SEM和XRD分析,测试了传感器室温下对NO2的气敏特性。结果表明,制备WO3纳米线的最佳热处理条件是700℃,此温度下增加金属钨膜溅射时间可提升WO3纳米线的生长密度? 所制备的传感器对NO2气体表现出反型气敏响应,特别是溅射1min金属钨的样品显示出优异的NO2室温探测能力与选择性,对4×10-6NO的气敏灵敏度是单纯多孔硅样品的 5.8倍。 相似文献
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在陶瓷管上用Ti O2溅射法研制纳米薄膜乙醇传感器,同时作了机理分析。利用X射线衍射技术分析确定,在利用溅射法制备Ti O2纳米薄膜时,随着退火温度的提高,所形成的Ti O2薄膜晶体结构由无定型结构,向锐钛矿结构转变,随后又随温度升高逐渐转向金红石结构。晶粒大小随着退火温度的升高而增大,分别为13nm(500℃)、16nm(700℃)、28nm(1100℃)。经500℃退火的样品为锐钛矿晶体结构,晶粒尺寸为13nm,其乙醇灵敏度特性最好。此时元件的最佳加热工作电压8.0V,对应的工作温度为370℃。利用红外光谱测定,反应的生成物中有H2O、CH3CHO、C2H4,分别对应1694cm-1、1756cm-1和1720cm-1的红外吸收峰。但在反应生成物中,没有发现有乙酸产生。 相似文献
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ITO薄膜的气敏特性 总被引:4,自引:0,他引:4
本文研究了胶体法制备的ITO薄膜的气敏特性;并同时研究了各种掺杂杂质对ITO薄膜的气敏特性的影响。通过实验发现ITO薄膜对乙醇气体具有最高的灵敏度,对二氧化氮等也有较好的敏感特性。一般催化剂型掺杂物如贵金属等掺杂杂对提高ITO薄膜的灵敏度没有多大帮助。ITO薄膜与SnO2薄膜相比具有更高的稳定性。ITO薄膜的气敏特性既具有表面控制型的特征,又权有体效应气敏材料的敏感特性。 相似文献
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采用MEMS工艺在硅衬底上制备了铂电阻薄膜温度传感器,在500℃、600℃、700℃和800℃四个温度点下对铂电阻样品进行了热处理,对样品在退火前后的电阻值进行了测试和对比分析,对800℃的退火样品的阻温特性进行了多次测量,其在零摄氏度的电阻温度系数可达3150×10-6/K。另外还对退火后的铂电阻样品阻温特性进行了多次升温降温测试,其升温曲线和降温曲线基本重合,表明退火处理可以明显的改善铂薄膜温度传感器的稳定性和重复性。 相似文献
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讨论一种对二氧化氮具有高灵敏性的WO3纳米薄膜的制备方法.当基片温度为室温,溅射混合气体(O2/Ar)的比例为1:1时,用直流反应磁控溅射法制备的薄膜,经过两步热处理(300℃/600℃),得到纳米结构WO3气敏元件.通过XRD、XPS和SEM对该薄膜的晶体结构和化学成分进行分析,用静态配气法测试NO2气敏特性.在Si3N4基片上制备的这种薄膜对空气中较低浓度的NO2(体积分数为0.1×10-5~3×10-5)具有优异的敏感特性和响应特性,最佳工作温度为150℃,在此温度下对其他一些气体(如CO,C2H5OH,NH3)的敏感性很差,显示出良好的选择性. 相似文献
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为研究金属离子对金属氧化物半导体的表面敏化作用,以均匀沉淀法制备了ZnO纳米颗粒,并通过金属离子表面微滴注以及二次退火的方法制备出金属离子表面修饰的平面型ZnO气体传感器阵列。并以乙醚蒸汽为目标气体,进行气敏性能测试。发现大部分传感器对乙醚响应性很好,并且经过表面修饰,ZnO的乙醚敏感性能大多得到提升。特别地,Mg2+表面修饰的ZnO膜层展现了最优的气敏性能。X射线光电子能谱和光致发光谱证实,经过Mg2+表面修饰之后,氧空位缺陷浓度明显增加,并且表面羟基基团的数量显著减少,二者的协同作用构成了Mg2+表面修饰ZnO的敏化机制。 相似文献
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Yu-Jin ChenAuthor Vitae Gang XiaoAuthor VitaeTie-Shi WangAuthor Vitae Fan ZhangAuthor VitaeYang MaAuthor Vitae Peng GaoAuthor Vitae Chun-Ling ZhuAuthor VitaeEndi ZhangAuthor Vitae Zhi XuAuthor VitaeQiu-hong LiAuthor Vitae 《Sensors and actuators. B, Chemical》2011,155(1):270-277
Crystalline α-MoO3/TiO2 core/shell nanorods are fabricated by a hydrothermal method and subsequent annealing processes under H2/Ar flow and in the ambient atmosphere. The shell layer is composed of crystalline TiO2 particles with a diameter of 2-6 nm, and its thickness can be easily controlled in the range of 15-45 nm. The core/shell nanorods show enhanced sensing properties to ethanol vapor compared to bare α-MoO3 nanorods. The sensing mechanism is different from that of other one-dimensional metal oxide core/shell nanostructures due to very weak response of TiO2 nanoparticles to ethanol. The enhanced sensing properties can be explained by the change of type II heterojunction barrier formed at the interface between α-MoO3 and TiO2 in the different gas atmosphere. The present results demonstrate a novel sensing mechanism available for gas sensors with high performance. 相似文献
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罗丹明6G/PMMA(R6G/PMMA)荧光复合材料在室温附近表现出良好的温度传感特性.通过在20℃~60℃温度范围内测试不同配比的R6G/PMMA复合材料的荧光发射光谱,对荧光光强It、谱峰位置λp以及新型荧光特征参数"谱带重心"λB等材料荧光特性的分析表明:①对于不同组分配比的材料,荧光强度均随温度升高而猝灭,光强的温度敏感规律呈线性;②以质量比R6G:PMMA=1:5的复合材料为代表,实验系统作温度传感应用,以谱带重心波长为传感信号的温度传感方程为λB=581.9+0.065T,拟合优度(R2)为0.98,系统的分辨力为1 ℃,以30 ℃测试数据作参考的相对灵敏度为3.3%/℃,精度远远优于谱峰位置作温度传感信号;③荧光复合材料的R6G:PMMA质量比变化基本不影响谱带重心为温度传感信号的灵敏度.本文分析了实验观察到的温敏荧光现象的成因,对基于R6G/PMMA荧光复合材料的新型温度传感器在电磁干扰环境、生物体温监测、大气环境温度监测等方面的应用作出了明确预期. 相似文献
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Gas sensing properties of a composite composed of electrospun poly(methyl methacrylate) nanofibers and in situ polymerized polyaniline 总被引:1,自引:1,他引:0
Poly(methyl methacrylate) (PMMA) nanofibers with different diameters were fabricated by electrospinning and their composites with polyaniline (PANI) were formed by virtue of in situ solution polymerization. The coaxial composite nanofibers so prepared were then transferred to the surface of a gold interdigitated electrode to construct a gas sensor. The structure and morphology of the PANI/PMMA composite fibers were characterized by UV–vis spectroscopy and scanning electron microscopy, which indicated that the coaxial nanofibres of PANI emeraldine salt and PMMA were successfully prepared. The electrical responses of the gas sensor based on the composite nanofibres towards triethylamine (TEA) vapors were investigated at room temperature. It was revealed that the sensor showed a sensing magnitude as high as 77 towards TEA vapor of 500 ppm. In addition, the responses were linear, reversible and reproducible towards TEA vapors ranging from 20 to 500 ppm. The diameters of the electrospun PMMA fibers had an effect on the sensing magnitude of the gas sensor, which is proposed to relate to the difference in the surface-to-volume ratio of the fibers. Furthermore, it was found that the concentration of doping acids only led to changes in resistance of the sensor, but could not affect its sensing characteristics. In contrast, the nature of the doping acids was determinative for the sensing magnitude of the sensor. The gas sensor with toluene sulfonic acid as the doping acid exhibited the highest sensing magnitude, which is explained by taking into account of the sensing mechanism and the interactions of doping acids with TEA vapor. 相似文献
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Ehsan DaneshAuthor VitaeSeyed Reza GhaffarianAuthor Vitae Payam Molla-AbbasiAuthor Vitae 《Sensors and actuators. B, Chemical》2011,155(2):562-567
The fabrication of novel porous conductive composite vapor sensors characterized by different porosities and specific surface areas is described in this study. These samples were obtained by the dry-cast non-solvent induced phase separation (NIPS) method. Porous composite structures have been studied by the SEM, BET and water evaporation methods. Testing different concentrations of several organic vapors, the porous sensors showed improved sensitivities and response times as compared to their dense counterpart. Improved characteristics of the sensor response were correlated to better sorption and diffusion properties of sensing film due to increased porosity and specific surface area obtained by this method of film fabrication. A competition theory was proposed that describes the optimum porosity and thickness of sensing films in which the highest sensitivities were observed. 相似文献