Fast highly-sensitive room-temperature semiconductor gas sensor based on the nanoscale Pt-TiO2-Pt sandwich

SENSORS AND ACTUATORS B-CHEMICAL

卷:207

Article

Plecenik, T.¹  Mosko, M.^1,2  Haidry, A. A.¹  Durina, P.¹  Truchly, M.¹  Grancic, B.¹  Gregor, M.¹  Roch, T.¹  Satrapinskyy, L.¹  Moskova, A.²  Mikula, M.¹  Kus, P.¹  Plecenik, A.¹ 

[1] Comenius Univ, Fac Math Phys & Informat, Dept Expt Phys, Bratislava 84248, Slovakia

[2] Slovak Acad Sci, Inst Elect Engn, Bratislava 84104, Slovakia

关键词: Hydrogen;    Gas sensor;    Nanoscale;    Sandwich;    Room temperature;    TiO2;   

DOI  :  10.1016/j.snb.2014.10.003

来源: Elsevier

【 摘 要 】

Development of fast highly-sensitive semiconductor gas sensors operating at room temperature, which would be compatible with semiconductor technology, remains a challenge for researchers. Here we present such sensor based on a nanoscale Pt-TiO2-Pt sandwich. The sensor consists of a thin (similar to 30 nm) nanocrystalline TiO2 layer with similar to 10 nm grains, placed between the bottom Pt electrode layer and top Pt electrode shaped as a long narrow (width w down to 80 nm) stripe. If we decrease w to similar to 100 nm and below, the sensor exposed to air with 1% H-2 exhibits the increase of response (R-air/R-H2) up to similar to 10(7) and decrease of the reaction time to only a few seconds even at room temperature. The sensitivity increase is due to a nontrivial non-ohmic effect, a sudden decrease (by three orders of magnitude) of the electrical resistance with decreasing w for w similar to 100 nm. This non-ohmic effect is explained as a consequence of two nano scale-related effects: the hydrogen- diffusion-controlled spatially-inhomogeneous resistivity of the TiO2 layer, combined with onset of the hot-electron-temperature instability when the tiny grains are subjected to high electric field. (C) 2014 The Authors. Published by Elsevier B.V.

【 授权许可】

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