喷墨打印制备的SnO_2薄膜的气敏特性

简介了喷墨打印制备薄膜技术的优势与特点,配制了SnO2前驱溶液墨水,并利用该技术在金叉指氧化铝基片上喷镀SnO2前驱溶液墨水,而制得了SnO2气敏薄膜元件。利用XRD分析了SnO2薄膜的晶体结构。通过控制喷打墨水的次数,方便地控制了最终薄膜的厚度。并初步探讨了喷墨打印次数对最终薄膜元件性能的影响。当薄膜只喷打一次时,具有极高的电阻值,而且灵敏度比较低。而随着喷打次数的增加,即薄膜厚度的提高,薄膜电阻也随之降低,并对乙醇具有较好的气敏性能。     

多层薄膜高性能乙醇传感器

采用PECVD方法，分别注积了SnO2-Fe2O3、SnO2-TiO2-Fe2O3等双层和三层气敏薄膜材料，制成了旁热式传感器。实验结果表明，这种多层结构的元件对乙醇有很高的灵敏度与选择性。     

溅射Au对SnO_2/Fe_2O_3薄膜气敏特性的影响

通过直流溅射Au对PCVD方法制备的SnO2/Fe2O3双层薄膜的SnO2表面进行了修饰,并对修饰后的Au SnO2/Fe2O3薄膜的气敏特性进行了观测。结果表明,Au的催化作用使Au SnO2/Fe2O3薄膜气敏器件对CO,H2,C2H5OH等气体的灵敏度增大2～3倍,相应于最大灵敏度的工作温度均降低约60℃。这显示直流溅射Au是改善SnO2/Fe2O3双层薄膜气敏性能的一种有效手段。     

射频磁控溅射SnO2/MWCNTs 薄膜材料的气敏性能研究

采用射频反应磁控溅射方法制备掺杂多壁碳纳米管(MWCNTs)的snO2薄膜材料,并在此基础之上制作了N02气敏传感器,使用扫描电子显微镜(SEM)和X射线衍射仪(XRD)研究了SnO2/MWCNTs薄膜材料的表面形貌、物质组份材料特性,采用气敏元件测试系统来分析优越感的气敏效应,包括灵敏度、选择性、响应-恢复等特性,实验结果表明该气敏传感器对超低浓度(10ppb)NO2气体有很好的灵敏度,对干扰气体不敏感,提出了气敏机理解释实验现象.     

SnO2基半导体气敏元件低温特性研究

通过对某厂生产的SnO2基烧结型旁热式半导体气敏元件在-10～-40℃时气敏性能进行的实验研究,得到了其低温时的一些特性.实验结果拓展了其在低温情况下的应用,为进一步开发利用SnO2基气敏元件提供了条件.     

SnO2-La2O3复合膜/玻璃光波导气敏元件与性能研究

研制了掺有不同质量分数La2 O3的SnO2复合薄膜,并测定了该薄膜和各种挥发性有机物饱和蒸气接触前后的的吸光度变化,其中含有3.0%La2O3的SnO2薄膜在氯苯蒸气气氛中的吸光度变化较大.选用3.0%La2O3的SnO2复合薄膜作为敏感试剂固定在Sn掺杂玻璃光波导表面,研制出一种光波导气敏元件,并对氯苯蒸气进行了检测.室温下该敏感元件对于体积分数为4×10-6的氯苯蒸气有很明显响应.     

TiO2-SnO2复合氧化物介孔薄膜的气敏特性研究

采用蒸发诱导自组装工艺制备了TiO2-SnO2介孔金属氧化物薄膜。采用静态配气法,研究了不同掺杂量SnO2对TiO2元件气敏性的影响,并通过测定电化学阻抗谱,分析了介孔金属氧化物的气敏机理。结果表明:随着SnO2掺杂量的增加,TiO2元件对乙醇气体灵敏度也随之提高,而初始响应温度则随之降低。在250℃时,20%-TiO2和SnO2元件对体积分数为500×10-6乙醇的灵敏度分别为13.24和14.26。阻抗分析表明:复合氧化物对还原性气体敏感过程具有明显容抗特征。     

低功耗C_2H_5OH气敏元件

采用超细SnO2粉体，按照MQ—J1工艺制成低功耗C2H5OH气敏元件。该气敏元件将工作温度降低一半以上，而且选择性好，同时简化了常规C2H5OH气敏元件的生产工艺，是一种具有开发前途的气敏元件。     

超微粒SnO_2气敏材料研制现状

介绍了超微粒SnO2材料的几种主要制备方法及由相应材料制成的气敏元件性能特点，探讨了SnO2气敏特性与粉体粒度的关系。     

气敏薄膜表面吸附结合能的宏观测量方法

在采用溅射方法制备的ZnO、SnO2/CeO2纳米平面气敏薄膜实验基础上,总结了气敏薄膜响应时间和恢复时间τc的宏观测量的特征时间次方规律.显微物理化学特性对研究气敏薄膜是十分必要却难以由微观直接测量获得,我们通过上述实验结果与气敏表面反应和表面吸附理论相结合,间接测量了气敏表面吸附结合能Ea这一微观特性,从而表明可以用宏观测量方法研究气敏薄膜的一些微观特性.     

MB/PVP薄膜光波导传感元件对甲醛的气敏性研究

以亚甲基兰(MB)作为敏感试剂,利用旋转甩涂法将掺有成膜剂聚乙烯吡咯烷酮(PVP)的MB溶液固定在玻璃光波导表面.研制了MB/PVP薄膜光波导传感元件,并且检测出了低浓度的甲醛蒸汽.实验结果表明,当被测气体接触到MB/PVP薄膜时,薄膜将被还原成无色;当被测气体离开薄膜一段时间后,MB/PVP薄膜颜色恢复到原来的颜色.在常温下该元件对浓度为25～g/m3的甲醛蒸汽有很明显的响应,同时该元件具有响应快、灵敏度高、制作工艺简单等特点.     

掺杂三乙醇胺铜配合物的PVA复合薄膜/K+交换玻璃光波导器件检测SO2气体

三乙醇胺酮配合物气敏性研究发现,该配合物与二氧化硫气体作用时透光率发生变化。以此结果为依据在K 交换玻璃光波导表面固定三乙醇胺铜配合物掺杂的聚乙烯醇复合薄膜,研制出了二氧化硫气体传感元件,并在光波导传感检测系统中测定其传感特性。实验结果表明,本传感元件对低浓度(500×10-9～15×10-6)二氧化硫气体有良好的线性快速可逆响应,低浓度氯化氢、硫化氢、二氧化氮、氨气以及挥发性有机物蒸汽对二氧化硫气体的检测没有干扰,具有灵敏度和选择性高、可逆性好,结构简单和易制作等特点。     

The Properties Difference of the Composites Based on the Float-Glass with the Bilateral Sol-Gel Films Studies

It has been determined the influence of the substrate from the float-glass parties on the composites with the bilateral nano film main optical characteristics (the refractive index and the reflectivity coefficient) and the nano film thickness as the nano photonics element. The composites and the nano films these characteristics dependences on the parties of the float-glass substrate (gas and tin) on which one or double-layers film was drawn at the speed values of 3.8, 5.8 and 17.3 mm/s have been studied. These studies show that the composites properties and the nano films thickness were sensitive both to the film drawing speed and to the float-glass parties (gas or tin) on which these nano films were drawn. These properties of the composites with the nano films drawn from the nitrate and chloride sols are different from each other.     

电化学WO_3基乙醇气敏元件的研制

在WO3粉体材料中加入一定质量比的添加剂,于恒温600℃烧结1h制成旁热式厚膜乙醇气敏元件。采用静态电压测量法,研究了元件的加热电压与元件灵敏度β的关系以及添加剂对元件的响应与恢复时间的影响。实验结果表明:WO3基元件掺入质量分数为0.5%的PdC l2在加热功率为600mW下可制作成反应能力强、灵敏度高的乙醇气敏元件。     

Fabrication of an S-shaped microactuator

We have developed a new fabrication process for electrostatic actuators having an S-shaped film element, which we previously invented for such applications as gas valves. The developed process allows batch fabrication of the actuator whose S-shaped structure height, which is equal to the amount of vertical film displacement, is of the order of a few hundred micrometers. The microactuators are fabricated by stacking three wafers. The middle wafer contains the sputtered Ni film strip which is buckled into an S-shape during the stacking process. The length of film necessary for the S-bend profile has a folded structure which is stretched after stacking. The size of the fabricated chip was 5 mm×5 mm, and the vertical film displacement was 220 μm. The actuator was operated by electrostatic force when the applied voltage was more than 70 V     

用于油库安全监测的气体传感器研究与设计

研究并设计了一种用于油库安全监测的气体传感器.传感器中气体敏感元件是利用直流磁控溅射法制备的Al掺杂ZnO薄膜.此薄膜对汽油等有机蒸汽有较高的敏感性和较短的响应(恢复)时间.当油气浓度较大时(大于1%),输出信号的变化仍较大.本传感器采用MAX197芯片,可以同时采集多个气敏元件的模拟信号并进行12位高精度A/D转换,利用无线收发模块F05C、J04E进行数据的无线传输.传感器拥有ACM12864液晶显示模块,方便数据显示.     

Pt/Pd对WO_3燃气敏感元件的影响

在WO3粉体材料中加入Pt,PtO2,Pd,PdCl2,以恒温600℃烧结1h制成旁热式厚膜可燃性气敏元件。采用静态电压测量法,研究了元件的加热电压与元件灵敏度的关系。实验结果表明:WO3元件掺入质量分数为0.5%的Pt/Pd,在加热功率为600 mW时,能提高元件的灵敏度2~10倍。     

一种AlN基陶瓷微热板NO2气体传感器研究

针对传统硅基微热板半导体气体传感器存在的热稳定性差,工艺复杂等难点,采用良好热导特性的AlN陶瓷为衬底,利用柔性机械剥离工艺和半导体材料In2O3/Nb2O5/Pt厚膜工艺制备了NO2微热板气体传感器.传感器中间加热区周围采用热隔离结构设计,降低了加热区温度分布梯度,提高了温度效率.利用ANSYS有限元工具进行了热结构仿真分析和响应测试分析,验证了热隔离结构设计的合理性.气敏测试分析表明,传感器在不同加热功率条件下,对5×10-6~100×10-6的NO2气体都具有良好的气敏响应特性,经对比分析,在功率150 mW~200 mW时稳定性最佳,且响应速率小于60 s,恢复时间在100 s左右,可实现5×10-6~100×10-6浓度的NO2气体良好检测功能.     

Design and optimization of heating plate for metal oxide semiconductor gas sensor

A thin film was coated onto the top of the heating electrodes to reduce the power consumption and improve the uniformity of temperature distribution. Finite element simulation software COMSOL was used to simulate the effect of coating materials and dependence of thicknesses of the coating film on the power consumption of the heating plate. On the basis of simulation, the temperature distribution of different heating plates was measured using infrared thermography. Experiments have showed that the power consumption of the heating plate can be significantly reduced and the temperature uniformity is promoted with adding the coating film on the top of the heating electrodes. The response of the gas sensor based on PdO-WO₃ nanoparticles was characterized with analyte of acetone. It was found that the addition of the coating film could enhance the response to acetone. In addition, the response speed of sensors was investigated with coating films and the results indicated that with the coating film sensor response speed became faster.

     

Enhancement of trimethylamine sensitivity of MOCVD-SnO2 thin film gas sensor by thorium

A thin film SnO₂-based trimethylamine (TMA) gas sensor has been developed by using metallorganic chemical vapor deposition (MOCVD) technique. The effects of temperature and thorium dopant on the sensitivity of the sensor have been studied. The peak sensitivity of the sensor to TMA was found at 290°C. Thorium was an excellent sensitizer, which could increase the sensitivity to 300 ppm TMA from 5.9 to 142. The MOCVD-SnO₂ element was capable of detecting TMA gas in a level of 10 ppm with short response time (16 s) with little interference of NH₃.