共查询到19条相似文献,搜索用时 390 毫秒
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<正> 氢气是还原性很强的气体,广泛地用于石油化工、金属工艺、玻璃加工及半导体工业。氢气主要来源于水;氢燃烧时又还原为水,符合自然循环规律。现代工业中氢气已被越来越广泛地用于能源材料,很可能成为火箭、飞机、汽车的动力燃料。廉价制造、贮藏及高效率地利用已成为科技界研究的重要课题。但是,氢气的分子极小,极容易发生泄漏,一旦与空气混合又极容易发生爆炸。因此研制高灵敏度的、使用安全可靠的氢气敏感传感器是一项极其迫切的任务。近年来研制的半导体型的接触燃烧式敏感器件有以下缺点:一是选择性较差,如遇酒精(乙醇)气味的干扰就会发生误报,另外这类敏感器件工作于高温加热状态,消耗一定的能量,需要设置特殊的防爆结构,安全可靠性也比较差。 相似文献
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气体传感器从其材料与结构来说是多种多样的,但简单而又实用的气敏元件多采用金属氧化物半导体作为原料,其中ZnO、SnO_2和γ—Fe_2O_3是常用的检测还原性气体的敏感材料。这三种金属氧化物是一种N型半导体,当其表面吸附了电子给予性气体分子(例如H_2、CO等气体)时,由于半导体与气体分子之间费米能级的差异,会使电子从吸附于表面的气体分子向半导体方向运动,因此N型半导体的载流子密度加大,导电率增 相似文献
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针对传统的气体传感器检测的缺点,开发了一套基于虚拟仪器的检测氢气的光纤氢气传感器;它采用NI公司的图形化开发平台LabVIEW,将传统的电路分析和处理,以及传统仪器的功能集成于一台计算机中,用户可以修改虚拟仪器的软件模块中的参数来这到修改气体传感器检测的特性;该氢气传感器检测系统通过计算机进行各类采集有关数据的处理、数据存储和分析;同时,详细介绍了系统的硬件连接、基于LabVIEW的软件设计和检测系统的稳定性和可靠性. 相似文献
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《Sensors and actuators. B, Chemical》2006,113(1):419-427
The potential of Pd/porous-GaAs Schottky contacts for hydrogen detection at room temperature is presented. The Pd/porous-GaAs contacts were developed using an electrochemical system in our laboratory. Using both forward- and reverse current–voltage (I–V) characteristics we have found that the Pd/porous-GaAs Schottky diode sensor exhibited very high sensitivity towards hydrogen gas. The Pd/porous-GaAs diode sensor submitted to 500 ppm hydrogen gas at room temperature revealed a considerable increase in sensitivity of more than three times higher than that of the Pd/GaAs sample. The significant changes observed here have been found to be due to the results of a decrease in effective barrier height of the Schottky contact. This is due to a lowering of metal work function and eventually the creation of a dipole layer on the semiconductor surface induced by dissociation of hydrogen atoms on the Pd contact, followed by diffusion to the Pd/porous-GaAs interface. A comparative study has been conducted to show the differences between Pd/GaAs and the Pd/porous-GaAs Schottky contacts fabricated at different conditions and subjected to hydrogen gas at various operating temperatures. Scanning electron microscopy (SEM) was used to examine the porosity of the GaAs surfaces. SEM pictures showed highly porous structures of the Pd/porous-GaAs Schottky contacts provided for penetration of hydrogen gas molecules. 相似文献
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气-气复合型高选择性氢气敏感元件 总被引:1,自引:0,他引:1
根据半导体气敏元件电路工作原理,设计了一种新型的气- 气复合型的半导体H2 敏感元件,推导出了其灵敏度、选择性及热稳定性的关系式,指出了构成高选择性及好的热稳定性的复合气敏元件需满足的条件,并在实验中得到验证。 相似文献
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A new MEMS-based density and binary gas concentration sensor is discussed. The micromachined sensor is made using a resonating silicon tube. Gas density and concentration test data over pressure for air, hydrogen, nitrogen, argon, methane, carbon dioxide, sulfur hexafluoride and gas mixtures are presented. The measurement of the density low pressure (101-400 kPa) hydrogen is demonstrated. Coupling binary gas concentration and density measurements of low pressure, light gases like hydrogen and methane opens up new sensing applications like fuel cells, energy management, chemical and semiconductor processing. 相似文献
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在SnO_2主体材料中添加某种硝酸盐溶液浸泡过的α-Al_2O_3,可制成对乙醇蒸汽灵敏度高,对H_2,CO,CH_4和汽油蒸汽灵敏度很低,即选择性好的酒敏元件。采用金属-n~+-n半导体结构来实现金属电极和SnO_2半导体陶瓷之间的欧姆接触,能有效地抑制元件的金-半接触所引起的不良影响,对于提高元件性能的一致性和成品率有重要作用。本文研究了硝酸盐溶液浓度和元件灵敏度、选择性、最佳工作温度的关系。研究了不同结构的金属电极-SnO_2半导体陶瓷接触对元件性能的影响。 相似文献
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Yannick Schellander Marius Winter Maurice Schamber Fabian Munkes Patrick Schalberger Harald Kuebler Tilman Pfau Norbert Fruehauf 《Journal of the Society for Information Display》2023,31(5):363-372
In this work, real-time ultraviolet photodetectors are realized through metal–semiconductor–metal (MSM) structures. Amorphous indium gallium zinc oxide (a-IGZO) is used as semiconductor material and gold as metal electrodes. The readout of an individual sensor is implemented by a transimpedance amplifier (TIA) consisting of an all-enhancement a-IGZO thin-film transistor (TFT) operational amplifier and a switched capacitor (SC) as feedback resistance. The photosensor and the transimpedance amplifier are both manufactured on glass substrates. The measured photosensor possesses a high responsivity R , a low response time t R E S , and a good noise equivalent power value NEP . 相似文献
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一种提高陶瓷湿敏元件稳定性的表面修饰技术 总被引:1,自引:0,他引:1
介绍了化学沉淀法制备TiO2粉体的方法,通过掺入高价金属离子变成半导体陶瓷,制成湿敏元件.运用表面修饰技术,对元件进行改性,提高湿敏元件的稳定性. 相似文献