Bilayer structure for hydrogen detection in a surface acoustic wave sensor system
Bilayer structure for hydrogen detection in a surface acoustic wave sensor system
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DOI：
10.1016/s0925-4005(01)01061-9
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发表时间：
2002-02-28
影响因子：
8.4
通讯作者：
Bodzenta, J
中科院分区：
文献类型：
--
作者：
Jakubik, WP;Urbanczyk, MW;Bodzenta, J
本文介绍了基于声表面波（SAW）双延迟线系统的双层结构氢传感器的研究结果。传感器材料由两层组成，在两种不同的气相沉积工艺中进行，第一层是720 nm的铜酞菁（CuPc）层，第二层是20 nm的薄钯（Pd）膜。该结构形成在LiNbO 3 Y切割Z传播衬底上的双延迟线系统中的一个中，而另一个用作参考，允许容易地检测出现的差分频率Δ f。取决于工作频率模式，该频率在200-400 kHz的范围内，而振荡器频率在43.6 MHz的范围内。波长为80 μ m。在这样的双层结构中，即使在室温下，我们也可以检测到中等浓度范围内的氢（在氮气中为0.5%至3%）。该传感器灵敏度高、稳定性好、完全可逆。定义为90%饱和度的响应和恢复时间非常好（从0.5%的100 s到1.5%的1000 s），从实用的角度来看，这是非常重要的。灵敏度依赖于温度，并随着相互作用温度的升高而降低。此外，氢化钯在30和43摄氏度下的相变是明显的，并且可重复地观察到“相互作用跃变”，这对于传感器来说是一个缺点。这种不希望的相变在较高温度下向较高氢浓度的方向转变，因此可以避免;例如，对于所研究的浓度范围（0.5-3%的氢在氮气中），在61 ℃下。(C)2002 Elsevier Science B. V.保留所有权利。
Presented here are the results concerning a hydrogen sensor based on a bilayer structure in a surface acoustic wave (SAW) dual delay line system. The sensor material consists of two layers performed in two different vapour deposition processes, The first one is a 720 nm copper phthalocyanine (CuPc) layer, the second is a 20 nm thin palladium (Pd) film. This structure was formed in one of the dual delay line systems on a LiNbO3 Y-cut Z-propagation substrate, while the other serves as a reference, permitting easy detection of the arising differential frequency Deltaf. This frequency, depending on the operating frequency modes, is in the range of 200-400 kHz, whereas the oscillator frequencies are in the range of 43.6 MHz. The wavelength is 80 mum. In such a bilayer structure we can detect hydrogen in a medium concentration range (from 0.5 to 3% in nitrogen), even at room temperature. The sensor is highly sensitive, very stable and is entirely reversible. The response and recovery times defined as 90% of the saturation level are quite good (from 100 s for 0.5% to 1000 s for 1.5%), which is very important from a practical point of view. The sensitivity depends on temperature, and decreases with the increase of the interaction temperature. In addition, the phase transition of the palladium hydride at 30 and 43 degreesC is distinct and repeatably visible as an "interaction jump", which is something of a disadvantage in respect of the sensor. This undesirable phase transition shifts in the direction of higher hydrogen concentrations at higher temperatures, and consequently can be avoided; for instance, at 61 degreesC for the investigated concentration range (0.5-3% of hydrogen in rnitrogen). (C) 2002 Elsevier Science B.V. All rights reserved.