Scalable fabrication of prototype sensor for selective and sub-ppm level ethanol sensing based on TiO2 nanotubes decorated porous silicon
Scalable fabrication of prototype sensor for selective and sub-ppm level ethanol sensing based on TiO2 nanotubes decorated porous silicon
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DOI：
10.1016/j.snb.2017.03.154
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发表时间：
2017-10
影响因子：
8.4
通讯作者：
Priyanka Dwivedi;N. Chauhan;P. Vivekanandan;Samaresh Das;D. Kumar;S. Dhanekar
中科院分区：
文献类型：
--
作者：
Priyanka Dwivedi;N. Chauhan;P. Vivekanandan;Samaresh Das;D. Kumar;S. Dhanekar
研制了一种基于tio2纳米管/多孔硅（PS）异质结的微型乙醇传感器原型，用于亚ppm范围内的乙醇选择性传感。利用射频溅射技术在PS表面沉积了厚度为~ 200 nm的钛（Ti）。将硅和钛依次阳极氧化形成PS和纳米管。采用升压法制作了电阻式传感器测试用电触点。该传感器被封装在一个12针的接头上，并在0.5至100ppm的浓度范围内测试不同VOCs的存在。在150℃左右的温度下，tio2纳米管/PS异质结的形成导致了乙醇的选择性感应。与纯PS和纯tio2传感器相比，该传感器的灵敏度提高了许多。讨论了异质结的形成，对乙醇的选择性响应，在较低工作温度下的亚ppm水平传感。该研究揭示了TiO2/PS异质结的集体性质，并展示了在亚ppm水平下测试晶圆级集成可重复乙醇传感器的潜力。
A miniaturized prototype sensor based on TiO2nanotubes/porous silicon (PS) heterojunction is developed for selective ethanol sensing in sub-ppm range. Titanium (Ti) of thickness ∼ 200 nm was deposited on PS using RF sputtering technique. Both silicon and Ti were sequentially anodized to form PS and nanotubes respectively. Electrical contacts for testing of resistive sensors were fabricated using lift off process. The sensor was packaged onto a 12-pin header and tested in presence of different VOCs with concentration ranging from 0.5 to 100 ppm. The selective ethanol sensing at around 150 °C stems from the formation of TiO2nanotubes/PS heterojunction. The sensitivity of such a sensor, improved manifold in comparison to the response of pure PS and pure TiO2based sensors. The formation of heterojunction, selective response to ethanol, sub-ppm level sensing at comparatively low operating temperature is discussed. The study unfolds the collective properties of TiO2/PS heterojunction and demonstrates the potential of wafer scale integrated repeatable ethanol sensor tested at sub-ppm level.